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| '''For patient information click [[Asperger syndrome (patient information)|here]]''' | | '''For patient information click [[Asperger syndrome (patient information)|here]]''' |
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| {{CMG}} | | {{CMG}} {{AE}}{{SHA}} ''' Christeen Henen, M.D. |
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| {{SK}} Asperger's syndrome; Asperger's disorder; Asperger's; AS | | {{SK}} Asperger's syndrome; Asperger's disorder; Asperger's; AS |
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| ==Overview== | | ==[[Asperger syndrome overview|Overview]]== |
| '''Asperger syndrome''' is the [[autism spectrum disorder]] (ASD) in which there is no general [[language delay|delay in language]] or [[cognitive development]]. As in other ASDs, people with AS have difficulties in [[social interaction]] and restricted, <!-- This does NOT mean "stereotype" as in prejudice; please follow the link and see -->[[Stereotypy|stereotyped]] patterns of behavior, interests and activities. Although not mentioned in standard diagnostic criteria for AS, physical clumsiness and atypical use of language are frequently reported.<ref name="McPartland"/><ref name="Baskin"/>
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| Asperger's syndrome is named after Austrian pediatrician [[Hans Asperger]] who, in 1944, described children in his practice who lacked [[nonverbal communication]] skills, demonstrated limited [[empathy]] with their peers, and were physically clumsy.<ref name=ha/> Fifty years later, AS was standardized as a diagnosis, but questions about many aspects of AS remain.<ref name=Woodbury-Smith/> For example, there is lingering doubt about the distinction between AS and [[high-functioning autism]] (HFA);<ref name="Klin"/> partly due to this, the [[prevalence]] of AS is not firmly established. The exact [[etiology|cause]] of AS is unknown, although research supports the likelihood of a [[genetics|genetic]] basis; [[neuroimaging|brain imaging]] techniques have not identified a clear common pathology.<ref name=McPartland/>
| | ==[[Asperger syndrome historical perspective|Historical Perspective]]== |
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| There is no single treatment for Asperger's syndrome, and the effectiveness of particular interventions is supported by only limited data. Intervention is aimed at improving symptoms and function. The mainstay of management is behavioral therapy, focusing on specific deficits to address poor communication skills, obsessive or repetitive routines, and physical clumsiness. Most individuals with AS can learn to cope with their differences, but may continue to need moral support and encouragement to maintain an independent life.<ref name=NINDS>{{cite web |author= National Institute of Neurological Disorders and Stroke (NINDS) |date=2007-07-31 |url=http://www.ninds.nih.gov/disorders/asperger/detail_asperger.htm |accessdate=2007-08-24 |title= Asperger syndrome fact sheet}} NIH Publication No. 05-5624.</ref> Researchers and people with AS have advocated a shift in attitudes toward the view that AS is a difference, rather than a disability that must be treated or cured.<ref name=Baron-Cohen2000/>
| | ==[[Asperger syndrome classification|Classification]]== |
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| ==Classification== | | ==[[Asperger syndrome pathophysiology|Pathophysiology]]== |
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| Asperger's syndrome is one of the [[autism spectrum disorder]]s (ASD) or [[pervasive developmental disorder]]s (PDD), which are a [[spectrum disorder|spectrum of psychological conditions]] that are characterized by abnormalities of [[social interaction]] and communication that pervade the individual's functioning, and by restricted and repetitive interests and behavior. Like other psychological development disorders, ASD begins in infancy or childhood, has a steady course without remission or relapse, and has impairments that result from maturation-related changes in various systems of the brain.<ref name=ICD-10-F84.0>{{cite book |chapterurl=http://www.who.int/classifications/apps/icd/icd10online/?gf80.htm+f840 |date=2006 |accessdate=2007-06-25 |title= International Statistical Classification of Diseases and Related Health Problems |edition= 10th ed. ([[ICD-10]]) |author= [[World Health Organization]] |chapter= F84. Pervasive developmental disorders}}</ref> ASD, in turn, is a subset of the broader autism [[phenotype]] (BAP), which describes individuals who may not have ASD but do have autistic-like [[Trait (biology)|traits]], such as social deficits.<ref>{{cite journal |author= Piven J, Palmer P, Jacobi D, Childress D, Arndt S |title= Broader autism phenotype: evidence from a family history study of multiple-incidence autism families |journal= Am J Psychiatry |date=1997 |volume=154 |issue=2 |pages=185–90 |pmid=9016266 |url=http://ajp.psychiatryonline.org/cgi/reprint/154/2/185.pdf |format=PDF}}</ref> Of the other four ASD forms, [[autism]] is the most similar to AS in signs and likely causes but its diagnosis requires impaired communication and allows delay in [[cognitive development]]; [[Rett syndrome]] and [[childhood disintegrative disorder]] share several signs with autism, but may have unrelated causes; and [[PDD not otherwise specified|pervasive developmental disorder not otherwise specified (PDD-NOS)]] is diagnosed when the criteria for a more specific disorder are unmet.<ref>{{cite journal |author= Lord C, Cook EH, Leventhal BL, [[David Amaral|Amaral DG]] |title= Autism spectrum disorders |journal=Neuron |volume=28 |issue=2 |date=2000 |pages=355–63 |doi=10.1016/S0896-6273(00)00115-X |pmid=11144346}}</ref> The extent of the [[Diagnosis of Asperger syndrome#Differences from high-functioning autism|overlap between AS and high-functioning autism]] ([[High-functioning autism|HFA]]—autism unaccompanied by mental retardation) is unclear.<ref name=Klin/><ref>
| | ==[[Asperger syndrome causes|Causes]]== |
| {{cite journal |journal= J Autism Dev Disord |date=2008 |title= Examining the validity of autism spectrum disorder subtypes |author= Witwer AN, Lecavalier L |doi=10.1007/s10803-008-0541-2 |pmid=18327636}}
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| </ref><ref name=Kasari>{{cite journal |author= Kasari C, Rotheram-Fuller E |title= Current trends in psychological research on children with high-functioning autism and Asperger disorder |journal= Curr Opin Psychiatry |volume=18 |issue=5 |pages=497–501 |year=2005 |pmid=16639107 |doi= <!-- 10.1097/01.yco.0000179486.47144.61 says Diberri; but this incorrectly points to PMID 7473944 -->}}</ref> The current ASD classification may not reflect the true nature of the conditions.<ref>{{cite journal |author= [[Peter Szatmari|Szatmari P]] |year=2000 |title= The classification of autism, Asperger's syndrome, and pervasive developmental disorder |journal= Can J Psychiatry |volume=45 |issue=8 |pages=731–38 |pmid=11086556 |url=http://ww1.cpa-apc.org:8080/Publications/Archives/CJP/2000/Oct/Classification.asp}}</ref>
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| ==Characteristics== | | ==[[Asperger syndrome differential diagnosis|Differentiating Asperger Syndrome from other Disorders]]== |
| A [[pervasive developmental disorder]], Asperger's syndrome is distinguished by a pattern of symptoms rather than a single symptom. It is characterized by qualitative impairment in social interaction, by stereotyped and restricted patterns of behavior, activities and interests, and by no clinically significant delay in cognitive development or general delay in language.<ref name=BehaveNet>{{cite book |title= Diagnostic and Statistical Manual of Mental Disorders |edition= 4th ed., text revision ([[DSM-IV-TR]]) |author= [[American Psychiatric Association]] |date=2000 |isbn=0-89042-025-4 |chapter= Diagnostic criteria for 299.80 Asperger's Disorder (AD) |chapterurl=http://www.behavenet.com/capsules/disorders/asperger.htm |accessdate=2007-06-28}}</ref> Intense preoccupation with a narrow subject, one-sided verbosity, restricted [[Prosody (linguistics)|prosody]], and physical clumsiness are typical of the condition, but are not required for diagnosis.<ref name=Klin>{{cite journal |journal= Rev Bras Psiquiatr |year=2006 |volume=28 |issue= suppl 1 |pages=S3–S11 |title= Autism and Asperger syndrome: an overview |author= Klin A |doi=10.1590/S1516-44462006000500002 |pmid=16791390 |url=http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-44462006000500002&lng=en&nrm=iso&tlng=en}}</ref>
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| ===Social interaction=== | | ==[[Asperger syndrome epidemiology and demographics|Epidemiology and Demographics]]== |
| {{further|[[Sociological and cultural aspects of autism#Asperger syndrome and interpersonal relationships|Asperger syndrome and interpersonal relationships]]}}
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| The lack of demonstrated empathy is possibly the most dysfunctional aspect of Asperger syndrome.<ref name=Baskin/> Individuals with Asperger's syndrome experience difficulties in basic elements of social interaction, which may include a failure to develop friendships or to seek shared enjoyments or achievements with others (for example, showing others objects of interest); a lack of social or emotional reciprocity; and impaired [[Nonverbal communication|nonverbal behaviors]] in areas such as eye contact, facial expression, posture, and gesture.<ref name=McPartland>{{cite journal |author= McPartland J, Klin A |title= Asperger's syndrome |journal= Adolesc Med Clin |volume=17 |issue=3 |pages=771–88 |year=2006 |pmid=17030291 |doi=10.1016/j.admecli.2006.06.010 |doi_brokendate=2008-06-25}}</ref>
| | ==[[Asperger syndrome risk factors|Risk Factors]]== |
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| Unlike those with autism, people with AS are not usually withdrawn around others; they approach others, even if awkwardly, for example by engaging in a one-sided, long-winded speech about a favorite topic while being oblivious to the listener's feelings or reactions, such as signs of boredom or haste to leave.<ref name=Klin/> This social awkwardness has been called "active but odd".<ref name=Klin/> This failure to react appropriately to social interaction may appear as disregard for other people's feelings, and may come across as insensitive.<ref name=Klin/> The cognitive ability of children with AS often lets them articulate social norms in a laboratory context,<ref name=McPartland/> where they may be able to show a theoretical understanding of other people’s emotions; they typically have difficulty acting on this knowledge in fluid, real-life situations, however.<ref name=Klin/> People with AS may analyze and distill their observation of social interaction into rigid behavioral guidelines and apply these rules in awkward ways—such as forced eye contact—resulting in demeanor that appears rigid or socially naïve. Childhood desires for companionship can be numbed through a history of failed social encounters.<ref name=McPartland/>
| | ==[[Asperger syndrome screening|Screening]]== |
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| The [[hypothesis]] that individuals with AS are predisposed to violent or criminal behavior has been investigated but is not supported by data.<ref name="McPartland"/><ref>{{cite journal |journal= J Autism Dev Disord |year=2008 |title= Offending behaviour in adults with Asperger syndrome |author= Allen D, Evans C, Hider A, Hawkins S, Peckett H, Morgan H |pmid=17805955 |doi=10.1007/s10803-007-0442-9 |volume=38 |issue=4 |pages=748–58}}</ref> More evidence suggests children with AS are victims rather than victimizers.<ref name=Tsatsanis>{{cite journal |journal= Child Adolesc Psychiatr Clin N Am |year=2003 |volume=12 |issue=1 |pages=47–63 |title= Outcome research in Asperger syndrome and autism |author= Tsatsanis KD |pmid=12512398 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000561/fulltext |doi=10.1016/S1056-4993(02)00056-1}}</ref>
| | ==[[Asperger syndrome natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
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| === Restricted and repetitive interests and behavior ===
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| [[Image:Riboflavin penicillinamide.jpg|left|thumb|Those with AS often display intense interests, such as this boy's fascination with molecular structure.]]
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| People with Asperger syndrome display behavior, interests, and activities that are restricted and repetitive and are sometimes abnormally intense or focused. They may stick to inflexible routines or rituals, move in stereotyped and repetitive ways, or preoccupy themselves with parts of objects.<ref name=BehaveNet/>
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| Pursuit of specific and narrow areas of interest is one of the most striking features of AS.<ref name=McPartland/> Individuals with AS may collect volumes of detailed information on a relatively narrow topic such as dinosaurs or deep fat fryers,<!--This is cited text, it is not a joke, please do not remove--> without necessarily having genuine understanding of the broader topic.<ref name=McPartland/><ref name=Klin/> For example, a child might memorize camera model numbers while caring little about photography.<ref name=McPartland/> This behavior is usually apparent by grade school, typically age 5 or 6 in the United States.<ref name=McPartland/> Although these special interests may change from time to time, they typically become more unusual and narrowly focused, and often dominate social interaction so much that the entire family may become immersed. Because topics such as dinosaurs often capture the interest of children, this symptom may go unrecognized.<ref name=Klin/>
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| [[Stereotypy|Stereotyped]] and repetitive motor behaviors are a core part of the diagnosis of AS and other ASDs.<ref>{{cite journal |journal= J Autism Dev Disord |year=2005 |volume=35 |issue=2 |pages=145–58 |title= Repetitive behavior profiles in Asperger syndrome and high-functioning autism |author= South M, Ozonoff S, McMahon WM |doi=10.1007/s10803-004-1992-8 |pmid=15909401}}</ref> They include hand movements such as flapping or twisting, and complex whole-body movements.<ref name=BehaveNet/> These are typically repeated in longer bursts and look more voluntary or ritualistic than [[tic]]s, which are usually faster, less rhythmical and less often symmetrical.<ref name=RapinTS>{{cite journal |author= Rapin I |title= Autism spectrum disorders: relevance to Tourette syndrome |journal= Adv Neurol |volume=85 |pages=89–101 |year=2001 |pmid=11530449}}</ref>
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| ===Speech and language===
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| Although individuals with Asperger syndrome acquire language skills without significant general delay and their speech typically lacks significant abnormalities, language acquisition and use is often atypical.<ref name=Klin/> Abnormalities include verbosity; abrupt transitions; literal interpretations and miscomprehension of nuance; use of [[metaphor]] meaningful only to the speaker; [[Auditory processing disorder|auditory perception deficits]]; unusually [[pedant]]ic, [[Register (linguistics)|formal]] or [[Idiosyncrasy#Psychiatry|idiosyncratic]] speech; and oddities in [[loudness]], [[Tone (linguistics)|pitch]], [[Intonation (linguistics)|intonation]], [[Prosody (linguistics)|prosody]], and [[rhythm]].<ref name=McPartland/>
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| Three aspects of communication patterns are of clinical interest: poor prosody, tangential and circumstantial speech, and marked verbosity. Although [[inflection]] and intonation may be less rigid or monotonic than in autism, people with AS often have a limited range of intonation; speech may be unusually fast, jerky or loud. Speech may convey a sense of incoherence; the conversational style often includes monologues about topics that bore the listener, fails to provide context for comments, or fails to suppress internal thoughts. Individuals with AS may fail to monitor whether the listener is interested or engaged in the conversation. The speaker's conclusion or point may never be made, and attempts by the listener to elaborate on the speech's content or logic, or to shift to related topics, are often unsuccessful.<ref name=Klin/>
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| Children with AS may have an unusually sophisticated vocabulary at a young age and have been colloquially called "little professors", but have difficulty understanding [[figurative language]] and tend to use language literally.<ref name=McPartland/> Children with AS appear to have particular weaknesses in areas of nonliteral language that include humor, irony, and teasing. Although individuals with AS usually understand the cognitive basis of [[humor]] they seem to lack understanding of the intent of humor to share enjoyment with others.<ref name=Kasari/> Despite strong evidence of impaired humor appreciation, there are anecdotal reports of humor in individuals with AS, which challenge theories of humor in AS.<ref>{{cite journal |author= Lyons V, Fitzgerald M |title= Humor in autism and Asperger syndrome |journal= J Autism Dev Disord |volume=34 |issue=5 |pages=521–31 |year=2004 |pmid=15628606 |doi=10.1007/s10803-004-2547-8}}</ref>
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| ===Other===
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| Individuals with Asperger syndrome may have signs or symptoms that are independent of the diagnosis, but can affect the individual or the family. These include differences in perception and problems with motor skills, sleep, and emotions.
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| Individuals with AS often have excellent auditory and visual perception.<ref>{{cite journal |journal= J Child Psychol Psychiatry |date=2004 |volume=45 |issue=4 |pages=672–86 |title= Emanuel Miller lecture: confusions and controversies about Asperger syndrome |author= Frith U |doi=10.1111/j.1469-7610.2004.00262.x |pmid=15056300}}</ref> Children with ASD often demonstrate enhanced perception of small changes in patterns such as arrangements of objects or well-known images; typically this is domain-specific and involves processing of fine-grained features.<ref>{{cite book |chapter= Psychological factors in autism |author= Prior M, Ozonoff S |pages=69–128 |title= Autism and Pervasive Developmental Disorders |edition= 2nd ed |editor= Volkmar FR |publisher= Cambridge University Press |year=2007 |isbn=0-521-54957-4}}</ref> Conversely, compared to individuals with HFA, individuals with AS have deficits in some tasks involving visual-spatial perception, auditory perception, or visual memory.<ref name=McPartland/> Many accounts of individuals with AS and ASD report other unusual sensory and perceptual skills and experiences. They may be unusually sensitive or insensitive to sound, light, touch, texture, taste, smell, pain, temperature, and other stimuli, and they may exhibit [[synesthesia]];<ref>{{cite book |author= Bogdashina O |title= Sensory Perceptional Issues in Autism and Asperger Syndrome: Different Sensory Experiences, Different Perceptual Worlds |publisher= Jessica Kingsley |year=2003 |isbn=1-843101-66-1}}</ref> these sensory responses are found in other developmental disorders and are not specific to AS or to ASD. There is little support for increased [[fight-or-flight response]] or failure of [[habituation]] in autism; there is more evidence of decreased responsiveness to sensory stimuli, although several studies show no differences.<ref>{{cite journal |author= Rogers SJ, Ozonoff S |title= Annotation: what do we know about sensory dysfunction in autism? A critical review of the empirical evidence |journal= J Child Psychol Psychiatry |volume=46 |issue=12 |pages=1255–68 |year=2005 |pmid=16313426 |doi=10.1111/j.1469-7610.2005.01431.x}}</ref>
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| Hans Asperger’s initial accounts<ref name="McPartland"/> and other diagnostic schemes<ref name="EhlGill">{{cite journal |author= Ehlers S, Gillberg C |title= The epidemiology of Asperger's syndrome. A total population study |journal= J Child Psychol Psychiat |year=1993 |volume=34 |issue=8 |pages=1327–50 |doi=10.1111/j.1469-7610.1993.tb02094.x |pmid=8294522}}</ref> include descriptions of physical clumsiness. Children with AS may be delayed in acquiring skills requiring motor dexterity, such as riding a bicycle or opening a jar, and may seem to move awkwardly or feel "uncomfortable in their own skin". They may be poorly coordinated, or have an odd or bouncy gait or posture, poor handwriting, or problems with visual-motor integration.<ref name="McPartland"/><ref name="Klin"/> They may show problems with [[proprioception]] (sensation of body position) on measures of [[apraxia]] (motor planning disorder), balance, [[tandem gait]], and finger-thumb apposition. There is no evidence that these motor skills problems differentiate AS from other high-functioning ASDs.<ref name= "McPartland"/>
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| Children with AS are more likely to have sleep problems, including difficulty in falling asleep, frequent nocturnal [[Wakefulness|awakenings]], and early morning awakenings.<ref>{{cite journal |journal= J Intellect Disabil Res |year=2005 |volume=49 |issue=4 |pages=260–8 |title= A survey of sleep problems in autism, Asperger's disorder and typically developing children |author= Polimeni MA, Richdale AL, Francis AJ |doi=10.1111/j.1365-2788.2005.00642.x |pmid=15816813}}</ref><ref name=Tani/> AS is also associated with high levels of [[alexithymia]], which is difficulty in identifying and describing one's emotions.<ref>Alexithymia and AS:
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| *{{cite journal |author= Fitzgerald M, Bellgrove MA |title= The overlap between alexithymia and Asperger's syndrome |journal= J Autism Dev Disord |volume=36 |issue=4 |pages=573–6 |year=2006 |pmid=16755385 |doi=10.1007/s10803-006-0096-z}}
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| *{{cite journal |author= Hill E, Berthoz S |year=2006 |title= Response |journal= J Autism Dev Disord |volume=36 |issue=8 |pages=1143–5 |doi=10.1007/s10803-006-0287-7 |pmid=17080269}}
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| *{{cite journal |journal= PLoS ONE |year=2007 |volume=2 |issue=9 |pages=e883 |title= Self-referential cognition and empathy in autism |author= Lombardo MV, Barnes JL, Wheelwright SJ, Baron-Cohen S |doi=10.1371/journal.pone.0000883 |pmid=17849012 |url=http://www.plosone.org/article/fetchArticle.action?articleURI=info:doi/10.1371/journal.pone.0000883}}</ref> Although AS, lower sleep quality, and alexithymia are associated, their causative relationship is unclear.<ref name=Tani>{{cite journal |author= Tani P, Lindberg N, Joukamaa M ''et al.'' |title= Asperger syndrome, alexithymia and perception of sleep |journal= Neuropsychobiology |volume=49 |issue=2 |pages=64–70 |year=2004 |pmid=14981336 |doi=10.1159/000076412}}</ref>
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| ==Causes==
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| {{see|Causes of autism}}
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| Hans Asperger described common symptoms among his patients' family members, especially fathers, and research supports this observation and suggests a genetic contribution to Asperger syndrome. Although no specific gene has yet been identified, multiple factors are believed to play a role in the [[Expressivity|expression]] of autism, given the [[phenotype|phenotypic]] variability seen in this group of children.<ref name=McPartland/><ref name="Foster"/> Evidence for a genetic link is the tendency for AS to run in families and an observed higher [[Incidence (epidemiology)|incidence]] of family members who have behavioral symptoms similar to AS but in a more limited form (for example, slight difficulties with social interaction, language, or reading).<ref name=NINDS/> Most research suggests that all autism spectrum disorders have shared genetic mechanisms, but AS may have a stronger genetic component than autism.<ref name="McPartland"/> There is probably a common group of genes where particular [[allele]]s render an individual vulnerable to developing AS; if this is the case, the particular combination of alleles would determine the severity and symptoms for each individual with AS.<ref name=NINDS/>
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| A few ASD cases have been linked to exposure to [[teratogen]]s (agents that cause [[birth defect]]s) during the first eight weeks from [[Human fertilization|conception]]. Although this does not exclude the possibility that ASD can be initiated or affected later, it is strong evidence that it arises very early in development.<ref name=Arndt>{{cite journal |journal= Int J Dev Neurosci |date=2005 |volume=23 |issue=2–3 |pages=189–99 |title= The teratology of autism |author= Arndt TL, Stodgell CJ, Rodier PM |doi=10.1016/j.ijdevneu.2004.11.001 |pmid=15749245}}</ref> Many environmental factors have been hypothesized to act after birth, but none has been confirmed by scientific investigation.<ref>{{cite journal |author= [[Michael Rutter|Rutter M]] |title= Incidence of autism spectrum disorders: changes over time and their meaning |journal= Acta Paediatr |volume=94 |issue=1 |date=2005 |pages=2–15 |pmid=15858952 |doi= 10.1080/08035250410023124}}</ref>
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| ==Mechanism==
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| {{further|[[Autism#Mechanism|Mechanism of autism]]}}
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| Asperger syndrome appears to result from developmental factors that affect many or all functional brain systems, as opposed to localized effects.<ref name=Mueller>{{cite journal |journal= Ment Retard Dev Disabil Res Rev |date=2007 |volume=13 |issue=1 |pages=85–95 |title= The study of autism as a distributed disorder |author= Müller RA |doi=10.1002/mrdd.20141 |pmid=17326118}}</ref> Although the specific underpinnings of AS or factors that distinguish it from other ASDs are unknown, and no clear pathology common to individuals with AS has emerged,<ref name=McPartland/> it is still possible that AS's mechanism is separate from other ASD.<ref>{{cite journal |journal= Aust N Z J Psychiatry |year=2002 |volume=36 |issue=6 |pages=762–70 |title= A clinical and neurobehavioural review of high-functioning autism and Asperger's disorder |author= Rinehart NJ, Bradshaw JL, Brereton AV, Tonge BJ |pmid=12406118 |doi=10.1046/j.1440-1614.2002.01097.x}}</ref> [[Neuroanatomy|Neuroanatomical]] studies and the associations with [[Teratology|teratogens]] strongly suggest that the mechanism includes alteration of brain development soon after conception.<ref name=Arndt/> Abnormal migration of embryonic cells during fetal development may affect the final structure and connectivity of the brain, resulting in alterations in the neural circuits that control thought and behavior.<ref>{{cite journal |author= Berthier ML, Starkstein SE, Leiguarda R |title= Developmental cortical anomalies in Asperger's syndrome: neuroradiological findings in two patients |journal= J Neuropsychiatry Clin Neurosci |volume=2 |issue=2 |pages=197–201 |year=1990 |pmid=2136076}}</ref> Several theories of mechanism are available; none are likely to be complete explanations.<ref>{{cite journal |author= Happé F, Ronald A, Plomin R |title= Time to give up on a single explanation for autism |journal= Nat Neurosci |date=2006 |volume=9 |issue=10 |pages=1218–20 |pmid=17001340 |doi=10.1038/nn1770}}</ref>
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| [[Image:FMRI.jpg|thumb|[[Functional magnetic resonance imaging]] provides some evidence for both underconnectivity and mirror neuron theories.<ref name=Just/><ref name=Iacoboni/>]]
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| The underconnectivity theory hypothesizes underfunctioning high-level neural connections and synchronization, along with an excess of low-level processes.<ref name=Just>{{cite journal |journal= Cereb Cortex |year=2007 |volume=17 |issue=4 |pages=951–61 |title= Functional and anatomical cortical underconnectivity in autism: evidence from an FMRI study of an executive function task and corpus callosum morphometry |author= Just MA, Cherkassky VL, Keller TA, Kana RK, Minshew NJ |doi=10.1093/cercor/bhl006 |pmid=16772313 |url=http://cercor.oxfordjournals.org/cgi/content/full/17/4/951}}</ref> It maps well to general-processing theories such as [[weak central coherence theory]], which hypothesizes that a limited ability to see the big picture underlies the central disturbance in ASD.<ref>{{cite journal |author= Happé F, [[Uta Frith|Frith U]] |title= The weak coherence account: detail-focused cognitive style in autism spectrum disorders |journal= J Autism Dev Disord |date=2006 |volume=36 |issue=1 |pages=5–25 |doi=10.1007/s10803-005-0039-0 |pmid=16450045}}</ref> A related theory—enhanced perceptual functioning—focuses more on the superiority of locally oriented and [[perceptual]] operations in autistic individuals.<ref>{{cite journal |journal= J Autism Dev Disord |date=2006 |volume=36 |issue=1 |pages=27–43 |title= Enhanced perceptual functioning in autism: an update, and eight principles of autistic perception |author= Mottron L, [[Michelle Dawson|Dawson M]], Soulières I, Hubert B, Burack J |doi=10.1007/s10803-005-0040-7 |pmid=16453071}}</ref>
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| The [[Mirror neuron|mirror neuron system]] (MNS) theory hypothesizes that alterations to the development of the MNS interfere with imitation and lead to Asperger's core feature of social impairment.<ref name=Iacoboni>{{cite journal |journal= Nat Rev Neurosci |date=2006 |volume=7 |issue=12 |pages=942–51 |title= The mirror neuron system and the consequences of its dysfunction |author= Iacoboni M, Dapretto M |doi=10.1038/nrn2024 |pmid=17115076}}</ref><ref>{{cite journal |journal= Sci Am |year=2006 |volume=295 |issue=5 |pages=62–9 |title= Broken mirrors: a theory of autism |author= [[Vilayanur S. Ramachandran|Ramachandran VS]], Oberman LM |pmid=17076085 |url=http://psy.ucsd.edu/chip/pdf/brokenmirrors_asd.pdf |format=PDF |accessdate=2008-04-17}}</ref> For example, one study found that activation is delayed in the core circuit for imitation in individuals with AS.<ref>{{cite journal |journal= Ann Neurol |year=2004 |volume=55 |issue=4 |pages=558–62 |title= Abnormal imitation-related cortical activation sequences in Asperger's syndrome |author= Nishitani N, Avikainen S, Hari R |doi=10.1002/ana.20031 |pmid=15048895}}</ref> This theory maps well to social cognition theories like the [[theory of mind]], which hypothesizes that autistic behavior arises from impairments in ascribing mental states to oneself and others,<ref>{{cite journal |author= Baron-Cohen S, Leslie AM, Frith U |title= Does the autistic child have a 'theory of mind'? |journal=Cognition |volume=21 |issue=1 |pages=37–46 |year=1985 |doi=10.1016/0010-0277(85)90022-8 |pmid=2934210 |url=http://ruccs.rutgers.edu/~aleslie/Baron-Cohen%20Leslie%20&%20Frith%201985.pdf |format=PDF |accessdate=2007-06-28}}</ref> or [[EQ SQ theory|hyper-systemizing]], which hypothesizes that autistic individuals can systematize internal operation to handle internal events but are less effective at [[Empathy|empathizing]] by handling events generated by other agents.<ref>{{cite journal |author= [[Simon Baron-Cohen|Baron-Cohen S]] |title= The hyper-systemizing, assortative mating theory of autism |journal= Prog Neuropsychopharmacol Biol Psychiatry |date=2006 |volume=30 |issue=5 |pages=865–72 |doi=10.1016/j.pnpbp.2006.01.010 |pmid=16519981}}</ref>
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| Other possible mechanisms include [[serotonin]] dysfunction<ref>{{cite journal |journal= Am J Psychiatry |year=2006 |volume=163 |issue=5 |pages=934–6 |title= Cortical serotonin 5-HT<sub>2A</sub> receptor binding and social communication in adults with Asperger's syndrome: an in vivo SPECT study |author= Murphy DG, Daly E, Schmitz N ''et al.'' |doi=10.1176/appi.ajp.163.5.934 |pmid=16648340}}</ref> and [[cerebellar]] dysfunction.<ref>{{cite journal |journal=Cerebellum |year=2005 |volume=4 |issue=4 |pages=279–89 |title= Behavioural aspects of cerebellar function in adults with Asperger syndrome |author= Gowen E, Miall RC |doi=10.1080/14734220500355332 |pmid=16321884}}</ref>
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| ==Screening==
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| Parents of children with Asperger syndrome can typically trace differences in their children's development to as early as 30 months of age.<ref name=Foster/> Developmental screening during a routine check-up by a general practitioner or pediatrician may identify signs that warrant further investigation.<ref name=McPartland/><ref name=NINDS/> The diagnosis of AS is complicated by the use of several different screening instruments,<ref name=NINDS/><ref name=EhlGill/> including the Asperger Syndrome Diagnostic Scale (ASDS), Autism Spectrum Screening Questionnaire (ASSQ), Childhood Asperger Syndrome Test (CAST), Gilliam Asperger’s Disorder Scale (GADS), Krug Asperger’s Disorder Index (KADI),<ref>{{cite journal |journal= J Autism Dev Disord |date=2005 |volume=35 |issue=1 |pages=25–35 |title= Diagnostic assessment of Asperger's disorder: a review of five third-party rating scales |author= Campbell JM |doi=10.1007/s10803-004-1028-4 |pmid=15796119}}</ref> and the [[Autism Spectrum Quotient]] (AQ).<ref>{{cite journal |journal= J Autism Dev Disord |date=2005 |volume=35 |issue=3 |pages=331–5 |title= Screening adults for Asperger Syndrome using the AQ: a preliminary study of its diagnostic validity in clinical practice |author= Woodbury-Smith MR, Robinson J, Wheelwright S, Baron-Cohen S |doi=10.1007/s10803-005-3300-7 |pmid=16119474 |url=http://autismresearchcentre.com/docs/papers/2005_Woodbury-Smith_etal_ScreeningAdultsForAS.pdf|format=PDF}}</ref> None have been shown to reliably differentiate between AS and other ASDs.<ref name=McPartland/>
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| ==Diagnosis== | | ==Diagnosis== |
| {{main|Diagnosis of Asperger syndrome}}
| | [[Diagnostic Criteria]] | [[Asperger syndrome history and symptoms|History and Symptoms]] | [[Asperger syndrome physical examination|Physical Examination]] | [[Asperger syndrome laboratory findings|Laboratory Findings]] | [[Asperger syndrome other diagnostic studies|Other Diagnostic Studies]] |
| Standard diagnostic criteria require impairment in social interaction, and repetitive and stereotyped patterns of behavior, activities and interests, without significant delay in language or cognitive development. Unlike the international standard,<ref name=ICD-10-F84.0/> U.S. criteria also require significant impairment in day-to-day functioning.<ref name=BehaveNet/> Other sets of diagnostic criteria have been proposed by [[Peter Szatmari#Diagnostic criteria for Asperger syndrome|Szatmari ''et al.'']]<ref>{{cite journal |journal= Can J Psychiatry |year=1989 |volume=34 |issue=6 |pages=554–60 |title= Asperger's syndrome: a review of clinical features |author= Szatmari P, Bremner R, Nagy J |pmid=2766209}}</ref> and by [[Christopher Gillberg#Gillberg's criteria for Asperger's syndrome|Gillberg and Gillberg]].<ref name=Gill>{{cite journal |journal= J Child Psychol Psychiatry |year=1989 |volume=30 |issue=4 |pages=631–8 |title= Asperger syndrome—some epidemiological considerations: a research note |author= Gillberg IC, Gillberg C |doi=10.1111/j.1469-7610.1989.tb00275.x |pmid=2670981}}</ref>
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| Diagnosis is most commonly made between the ages of four and eleven.<ref name="McPartland"/> A comprehensive assessment involves a multidisciplinary team<ref name="Baskin"/><ref name=NINDS/><ref name=Fitzgerald/> that observes across multiple settings,<ref name=McPartland/> and includes neurological and genetic assessment as well as tests for cognition, psychomotor function, verbal and nonverbal strengths and weaknesses, style of learning, and skills for independent living.<ref name=NINDS/> The current "gold standard" in diagnosing ASDs combines clinical judgment with the [[Autism Diagnostic Interview-Revised]] (ADI-R)—a semistructured parent interview—and the [[Autism Diagnostic Observation Schedule]] (ADOS)—a conversation and play-based interview with the child.<ref name=Woodbury-Smith>{{cite journal |journal= Eur Child Adolesc Psychiatry |date=2008 |title= Asperger syndrome |author= Woodbury-Smith MR, Volkmar FR |doi=10.1007/s00787-008-0701-0 |pmid=18563474}}</ref> Delayed or mistaken diagnosis can be traumatic for individuals and families; for example, misdiagnosis can lead to medications that worsen behavior.<ref name=Fitzgerald/> Many children with AS are initially misdiagnosed with [[attention-deficit hyperactivity disorder]] (ADHD).<ref name="McPartland"/> Diagnosing adults is more challenging, as standard diagnostic criteria are designed for children and the expression of AS changes with age.<ref>{{cite journal |author= Tantam D |title= The challenge of adolescents and adults with Asperger syndrome |journal= Child Adolesc Psychiatr Clin N Am |volume=12 |issue=1 |pages=143–63 |year=2003 |pmid=12512403 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000536/fulltext |doi=10.1016/S1056-4993(02)00053-6}}</ref> Conditions that must be considered in a [[differential diagnosis]] include other ASDs, the [[schizophrenia]] spectrum, ADHD, [[obsessive compulsive disorder]], [[clinical depression|depression]], [[semantic pragmatic disorder]], [[nonverbal learning disorder]],<ref name=Fitzgerald>{{cite journal |author= Fitzgerald M, Corvin A |date=2001 |doi=10.1192/apt.7.4.310 |url=http://apt.rcpsych.org/cgi/content/full/7/4/310 |title= Diagnosis and differential diagnosis of Asperger syndrome |journal= Adv Psychiatric Treat |volume=7 |issue=4 |pages=310–8}}</ref> [[Tourette syndrome]],<ref name=RapinTS/> [[stereotypic movement disorder]] and [[bipolar disorder]].<ref name=Foster>{{cite journal |journal= Curr Opin Pediatr |year=2003 |volume=15 |issue=5 |pages=491–4 |title= Asperger syndrome: to be or not to be? |author= Foster B, King BH |pmid=14508298 |doi=10.1097/00008480-200310000-00008}}</ref>
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| Underdiagnosis and overdiagnosis are problems in marginal cases. The cost of screening and diagnosis and the challenge of obtaining payment can inhibit or delay diagnosis. Conversely, the increasing popularity of drug treatment options and the expansion of benefits has motivated providers to overdiagnose ASD.<ref>{{cite journal |author= Shattuck PT, Grosse SD |title= Issues related to the diagnosis and treatment of autism spectrum disorders |journal= Ment Retard Dev Disabil Res Rev |date=2007 |volume=13 |issue=2 |pages=129–35 |doi=10.1002/mrdd.20143 |pmid=17563895}}</ref> There are indications AS has been diagnosed more frequently in recent years, partly as a residual diagnosis for children of normal intelligence who do not have autism but have social difficulties. There are questions about the external validity of the AS diagnosis, that is, it is unclear whether there is a practical benefit in distinguishing AS from HFA and from PDD-NOS;<ref>{{cite journal |journal= Child Adolesc Psychiatr Clin N Am |year=2003 |volume=12 |issue=1 |pages=1–13 |title= Asperger syndrome: diagnosis and external validity |author= Klin A, Volkmar FR |pmid=12512395 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000524/fulltext |doi=10.1016/S1056-4993(02)00052-4}}</ref> the same child can receive different diagnoses depending on the screening tool.<ref name="NINDS"/>
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| ==Management==
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| {{see|Autism therapies}}
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| Asperger syndrome treatment attempts to manage distressing symptoms and to teach age-appropriate social, communication and vocational skills that are not naturally acquired during development,<ref name="McPartland"/> with intervention tailored to the needs of the individual child, based on multidisciplinary assessment.<ref>{{cite journal |journal= Compr Psychiatry |year=2004 |volume=45 |issue=3 |pages=184–91 |title= Asperger's disorder: a review of its diagnosis and treatment |author= Khouzam HR, El-Gabalawi F, Pirwani N, Priest F |doi=10.1016/j.comppsych.2004.02.004 |pmid=15124148}}</ref> Although progress has been made, data supporting the efficacy of particular interventions are limited.<ref name="McPartland"/><ref>{{cite journal |author= Attwood T |title= Frameworks for behavioral interventions |journal= Child Child Adolesc Psychiatr Clin N Am |volume=12 |issue=1 |pages=65–86 |year=2003 |pmid=12512399 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000548/fulltext |doi= 10.1016/S1056-4993(02)00054-8}}</ref>
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| The ideal treatment for AS coordinates therapies that address core symptoms of the disorder, including poor communication skills and obsessive or repetitive routines. While most professionals agree that the earlier the intervention, the better, there is no single best treatment package.<ref name=NINDS/> AS treatment resembles that of other high-functioning ASDs, except that it takes into account the linguistic capabilities, verbal strengths, and nonverbal vulnerabilities of individuals with AS.<ref name=McPartland/> A typical program generally includes:<ref name=NINDS/>
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| * the training of [[social skills]] for more effective interpersonal interactions;<ref>{{cite journal |author= Krasny L, Williams BJ, Provencal S, Ozonoff S |title= Social skills interventions for the autism spectrum: essential ingredients and a model curriculum |journal= Child Adolesc Psychiatr Clin N Am |volume=12 |issue=1 |pages=107–22 |year=2003 |pmid=12512401 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000512/fulltext |doi=10.1016/S1056-4993(02)00051-2}}</ref>
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| * [[cognitive behavioral therapy]] to improve stress management relating to anxiety or explosive emotions,<ref name=Myles>{{cite journal |author= Myles BS |title= Behavioral forms of stress management for individuals with Asperger syndrome |journal= Child Adolesc Psychiatr Clin N Am |volume=12 |issue=1 |pages=123–41 |year=2003 |pmid=12512402 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000482/fulltext |doi=10.1016/S1056-4993(02)00048-2}}</ref> and to cut back on obsessive interests and repetitive routines;
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| * [[medication]], for coexisting conditions such as depression and anxiety;<ref name=Towbin/>
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| * [[Occupational therapy|occupational]] or [[physical therapy]] to assist with poor [[Sensory Integration Dysfunction|sensory integration]] and [[motor coordination]];
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| * social communication intervention, which is specialized [[speech therapy]] to help with the [[pragmatics]] of the give and take of normal conversation;<ref>{{cite journal |author= Paul R |title= Promoting social communication in high functioning individuals with autistic spectrum disorders |journal= Child Adolesc Psychiatr Clin N Am |volume=12 |issue=1 |pages=87–106 |year=2003 |pmid=12512400 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000470/fulltext |doi=10.1016/S1056-4993(02)00047-0}}</ref>
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| * the training and support of parents, particularly in behavioral techniques to use in the home.
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| Of the many studies on behavior-based early intervention programs, most are case studies of up to five participants, and typically examine a few problem behaviors such as [[self-injury]], [[aggression]], noncompliance, [[Stereotypy|stereotypies<!--NOT "stereotypes"-->]], or spontaneous language; unintended [[Adverse effect (medicine)|side effects]] are largely ignored.<ref name=interrev>{{cite journal |author= Matson JL |title= Determining treatment outcome in early intervention programs for autism spectrum disorders: a critical analysis of measurement issues in learning based interventions |journal= Res Dev Disabil |volume=28 |issue=2 |pages=207–18 |year=2007 |pmid=16682171 |doi=10.1016/j.ridd.2005.07.006}}</ref> Despite the popularity of social skills training, its effectiveness is not firmly established.<ref>{{cite journal |journal= J Autism Dev Disord |date=2008 |title= Social skills interventions for children with Asperger's syndrome or high-functioning autism: a review and recommendations |author= Rao PA, Beidel DC, Murray MJ |doi=10.1007/s10803-007-0402-4 |pmid=17641962 |volume=38 |issue=2 |pages=353–61}}</ref> A randomized controlled study of a model for training parents in problem behaviors in their children with AS showed that parents attending a one-day workshop or six individual lessons reported fewer behavioral problems, while parents receiving the individual lessons reported less intense behavioral problems in their AS children.<ref>{{cite journal |author= Sofronoff K, Leslie A, Brown W |title= Parent management training and Asperger syndrome: a randomized controlled trial to evaluate a parent based intervention |journal=Autism |volume=8 |issue=3 |pages=301–17 |year=2004 |pmid=15358872 |doi=10.1177/1362361304045215}}</ref> Vocational training is important to teach job interview etiquette and workplace behavior to older children and adults with AS, and organization software and personal data assistants to improve the work and life management of people with AS are useful.<ref name="McPartland"/>
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| No medications directly treat the core symptoms of AS.<ref name=Towbin>{{cite journal |author= Towbin KE |title= Strategies for pharmacologic treatment of high functioning autism and Asperger syndrome |journal= Child Adolesc Psychiatr Clin N Am |volume=12 |issue=1 |pages=23–45 |year=2003 |pmid=12512397 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000494/fulltext |doi=10.1016/S1056-4993(02)00049-4}}</ref> Although research into the efficacy of pharmaceutical intervention for AS is limited,<ref name="McPartland"/> it is essential to diagnose and treat [[Comorbidity|comorbid]] conditions.<ref name="Baskin"/> Deficits in self-identifying emotions or in observing effects of one's behavior on others can make it difficult for individuals with AS to see why medication may be appropriate.<ref name=Towbin/> Medication can be effective in combination with behavioral interventions and environmental accommodations in treating comorbid symptoms such as [[anxiety]], [[clinical depression|depression]], inattention and aggression.<ref name="McPartland"/> The [[Atypical antipsychotic|atypical neuroleptic]] medications [[risperidone]] and [[olanzapine]] have been shown to reduce the associated symptoms of AS;<ref name="McPartland"/> risperidone can reduce repetitive and self-injurious behaviors, aggressive outbursts and impulsivity, and improve stereotypical patterns of behavior and social relatedness. The [[selective serotonin reuptake inhibitor]]s (SSRIs) [[fluoxetine]], [[fluvoxamine]] and [[sertraline]] have been effective in treating restricted and repetitive interests and behaviors.<ref name="McPartland"/><ref name="Baskin"/><ref name="Foster"/>
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| Care must be taken with medications; abnormalities in [[metabolism]], [[Electrical conduction system of the heart|cardiac conduction]] times, and an increased risk of [[Diabetes mellitus type 2|type 2 diabetes]] have been raised as concerns with these medications,<ref name="Newcomer">{{cite journal |author= Newcomer JW |title= Antipsychotic medications: metabolic and cardiovascular risk |journal= J Clin Psychiatry |volume=68 |issue= suppl 4 |pages=8–13 |year=2007 |pmid=17539694}}</ref><ref name="Chavez">{{cite journal |author= Chavez B, Chavez-Brown M, Sopko MA, Rey JA |title= Atypical antipsychotics in children with pervasive developmental disorders |journal= Pediatr Drugs |volume=9 |issue=4 |pages=249–66 |year=2007 |pmid=17705564 |doi= 10.2165/00148581-200709040-00006}} </ref> along with serious long-term neurological side effects.<ref name=interrev/> SSRIs can lead to manifestations of behavioral activation such as increased impulsivity, aggression and sleep disturbance.<ref name="Foster"/> Weight gain and fatigue are commonly reported side effects of risperidone, which may also lead to increased risk for [[extrapyramidal]] symptoms such as restlessness and [[dystonia]]<ref name="Foster"/> and increased serum [[prolactin]] levels.<ref>{{cite journal |author= Staller J |title= The effect of long-term antipsychotic treatment on prolactin |journal= J Child Adolesc Psychopharmacol |volume=16 |issue=3 |pages=317–26 |year=2006 |pmid=16768639 |doi=10.1089/cap.2006.16.317}}</ref> Sedation and weight gain are more common with olanzapine,<ref name="Chavez"/> which has also been linked with diabetes.<ref name="Newcomer"/> Sedative side-effects in school-age children<ref>{{cite journal |journal= Ann Pharmacother |year=2007 |volume=41 |issue=4 |pages=626–34 |title= Use of atypical antipsychotics in the treatment of autistic disorder |author= Stachnik JM, Nunn-Thompson C |doi=10.1345/aph.1H527 |pmid=17389666}}</ref> have ramifications for classroom learning. Individuals with AS may be unable to identify and communicate their internal moods and emotions or to tolerate side effects that for most people would not be problematic.<ref>{{cite journal |title= Asperger syndrome and high functioning autism: research concerns and emerging foci |journal= Curr Opin Psychiatry |volume=16 |issue=5 |pages=535–542 |date=2003 |author= Blacher J, Kraemer B, Schalow M |doi=10.1097/01.yco.0000087260.35258.64 |doi_brokendate= 2008-06-25}}</ref>
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| ==Prognosis==
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| There is some evidence that as many as 20% of children with AS "grow out" of it, and fail to meet the diagnostic criteria as adults.<ref name=Woodbury-Smith/>
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| As of 2006, no studies addressing the long-term outcome of individuals with Asperger syndrome are available and there are no systematic long-term follow-up studies of children with AS.<ref name="Klin"/> Individuals with AS appear to have normal [[life expectancy]] but have an increased [[prevalence]] of [[comorbid]] [[psychiatry|psychiatric]] conditions such as [[Clinical depression|depression]] and [[anxiety disorder|anxiety]] that may significantly affect [[prognosis]]. Although social impairment is lifelong, outcome is generally more positive than with individuals with lower functioning autism spectrum disorders;<ref name="McPartland"/> for example, ASD symptoms are more likely to diminish with time in children with AS or HFA.<ref>{{cite journal |journal=Pediatrics |year=2005 |volume=116 |issue=1 |pages=117–22 |title= Modeling clinical outcome of children with autistic spectrum disorders |author= Coplan J, Jawad AF |doi=10.1542/peds.2004-1118 |pmid=15995041 |url=http://pediatrics.aappublications.org/cgi/content/full/116/1/117 |laysummary=http://stokes.chop.edu/publications/press/?ID=181 |laysource=press release |laydate=2005-07-05}}</ref> Although most students with AS/HFA have average mathematical ability and test slightly worse in mathematics than in general intelligence, some are gifted in mathematics<ref>{{cite journal |journal=Autism |date=2007 |volume=11 |issue=6 |pages=547–56 |title= Mathematical ability of students with Asperger syndrome and high-functioning autism |author= Chiang HM, Lin YH |doi=10.1177/1362361307083259 |pmid=17947290}}</ref> and AS has not prevented some adults from major accomplishments such as winning the [[Nobel Prize]].<ref>{{cite news |author= Herera S |title= Mild autism has 'selective advantages' |url=http://www.msnbc.msn.com/id/7030731/ |date=2005-02-25 |accessdate=2007-11-14 |publisher=CNBC}}</ref>
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| Children with AS may require [[special education]] services because of their social and behavioral difficulties although many attend regular education classes.<ref name="Klin"/> Adolescents with AS may exhibit ongoing difficulty with self-care, organization and disturbances in social and romantic relationships; despite high cognitive potential, most remain at home, although some do marry and work independently.<ref name="McPartland"/> The "different-ness" adolescents experience can be traumatic.<ref name="Moran">{{cite journal |author= Moran M |url=http://pn.psychiatryonline.org/cgi/content/full/41/19/21 |title= Asperger's may be answer to diagnostic mysteries |journal= Psychiatr News |year=2006 |volume=41 |issue=19 |pages=21}}</ref> Anxiety may stem from preoccupation over possible violations of routines and rituals, from being placed in a situation without a clear schedule or expectations, or from [[Social anxiety|concern with failing in social encounters]];<ref name=McPartland/> the resulting stress may manifest as inattention, withdrawal, reliance on obsessions, hyperactivity, or aggressive or oppositional behavior.<ref name=Myles/> Depression is often the result of chronic frustration from repeated failure to engage others socially, and mood disorders requiring treatment may develop.<ref name="McPartland"/>
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| Education of families is critical in developing strategies for understanding strengths and weaknesses;<ref name="Baskin"/> helping the family to cope improves outcome in children.<ref name=Tsatsanis/> Prognosis may be improved by diagnosis at a younger age that allows for early interventions, while interventions in adulthood are valuable but less beneficial.<ref name="Baskin"/> There are legal implications for individuals with AS as they run the risk of exploitation by others and may be unable to comprehend the societal implications of their actions.<ref name="Baskin"/>
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| ==Epidemiology==
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| {{see|Conditions comorbid to autism spectrum disorders}}
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|
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| [[Prevalence]] estimates vary enormously. A 2003 review of [[Epidemiological study|epidemiological]] studies of children found [[prevalence]] rates ranging from 0.03 to 4.84 per 1,000, with the ratio of autism to Asperger syndrome ranging from 1.5:1 to 16:1;<ref>{{cite journal |journal= Child Adolesc Psychiatr Clin N Am |year=2003 |volume=12 |issue=1 |pages=15–21 |title= Epidemiologic data on Asperger disorder |author= Fombonne E, Tidmarsh L |pmid=12512396 |url=http://www.childpsych.theclinics.com/article/PIIS1056499302000500/fulltext |doi=10.1016/S1056-4993(02)00050-0}}</ref> combining the average ratio of 5:1 with a conservative prevalence estimate for autism of 1.3 per 1,000 suggests indirectly that the prevalence of AS might be around 0.26 per 1,000.<ref>{{cite book |chapter= Epidemiological surveys of pervasive developmental disorders |author= [[Eric Fombonne|Fombonne E]] |pages=33–68 |title= Autism and Pervasive Developmental Disorders |edition= 2nd ed |editor= Volkmar FR |publisher= Cambridge University Press |year=2007 |isbn=0-521-54957-4}}</ref> Part of the variance in estimates arises from [[Diagnosis of Asperger syndrome#Multiple sets of diagnostic criteria|differences in diagnostic criteria]]. For example, a relatively small 2007 study of 5,484 eight-year-old children in Finland found 2.9 children per 1,000 met the ICD-10 criteria for an AS diagnosis, 2.7 per 1,000 for Gillberg and Gillberg criteria, 2.5 for DSM-IV, 1.6 for Szatmari ''et al.'', and 4.3 per 1,000 for the union of the four criteria. Boys seem to be at higher risk for AS than girls; estimates of the sex ratio range from 1.6:1 to 4:1, using the Gillberg and Gillberg criteria.<ref name=Mattila/>
| | ==Treatment== |
|
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| [[Anxiety]] and [[Clinical depression|depression]] are the most common other conditions seen at the same time; [[comorbidity]] of these in persons with AS is estimated at 65%.<ref name=McPartland/> Depression is common in adolescents and adults; children are likely to present with [[Attention-deficit hyperactivity disorder|ADHD]].<ref name=Ghaziuddin><!-- This article is not available online, even though all the other articles in that journal issue are online. What gives? Perhaps we can find a better source? -->{{cite journal |author= Ghaziuddin M, Weidmer-Mikhail E, Ghaziuddin N |title= Comorbidity of Asperger syndrome: a preliminary report |journal= J Intellect Disabil Res |volume=42 |issue=4 |pages=279–83 |year=1998 |pmid=9786442 |doi= <!-- This comment prevents the DOI bot from inserting an incorrect DOI, as it did on 2008-07-27 15:42:46 UTC. -->}}</ref> Reports have associated AS with medical conditions such as [[aminoaciduria]] and [[ligamentous laxity]], but these have been case reports or small studies and no factors have been associated with AS across studies.<ref name="McPartland"/> One study of males with AS found an increased rate of [[epilepsy]] and a high rate (51%) of [[nonverbal learning disorder]].<ref>{{cite journal |author= Cederlund M, Gillberg C |title= One hundred males with Asperger syndrome: a clinical study of background and associated factors |journal= Dev Med Child Neurol |volume=46 |issue=10 |pages=652–60 |year=2004 |doi=10.1111/j.1469-8749.2004.tb00977.x |pmid=15473168 |doi_brokendate= 2008-06-25}}</ref> AS is associated with [[tic]]s, [[Tourette syndrome]], and [[bipolar disorder]], and the repetitive behaviors of AS have many similarities with the symptoms of [[obsessive-compulsive disorder]] and [[obsessive-compulsive personality disorder]].<ref>{{cite journal |author= Gillberg C, Billstedt E |title= Autism and Asperger syndrome: coexistence with other clinical disorders |journal= Acta Psychiatr Scand |volume=102 |issue=5 |pages=321–30 |year=2000 |doi=10.1034/j.1600-0447.2000.102005321.x |pmid=11098802}}</ref> Although many of these studies are based on psychiatric clinic samples without using standardized measures, it seems reasonable to conclude that comorbid conditions are relatively common.<ref name=Woodbury-Smith/> | | [[Asperger syndrome medical therapy|Medical Therapy]] | [[Asperger syndrome behavioral therapy|Behavioral Therapy]] | [[Asperger syndrome cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Asperger syndrome future or investigational therapies|Future or Investigational Therapies]] |
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| ==History==
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| {{main|History of Asperger syndrome}}
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| Named after the Austrian pediatrician [[Hans Asperger]] (1906–80), Asperger syndrome is a relatively new diagnosis in the field of autism.<ref name="What'sSpecial">{{cite journal |author= Baron-Cohen S, Klin A |title= What's so special about Asperger Syndrome? |journal= Brain Cogn |volume=61 |issue=1 |pages=1–4 |year=2006 |pmid=16563588 |doi=10.1016/j.bandc.2006.02.002 |url=http://www.elsevier.com/authored_subject_sections/S05/S05_360/pdf/klin.pdf |format=PDF}}</ref>
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| In 1944, Asperger described four children in his practice<ref name=Baskin>{{cite journal |author= Baskin JH, Sperber M, Price BH |title= Asperger syndrome revisited |journal= Rev Neurol Dis |volume=3 |issue=1 |pages=1–7 |year=2006 |pmid=16596080}}</ref> who had difficulty in integrating themselves socially. The children lacked nonverbal communication skills, failed to demonstrate empathy with their peers, and were physically clumsy. Asperger called the condition "autistic psychopathy" and described it as primarily marked by [[social isolation]].<ref name=NINDS/> Unlike today's AS, autistic psychopathy could be found in people of all levels of intelligence, including those with mental retardation.<ref>{{cite book |author= Wing L |chapter= The relationship between Asperger's syndrome and Kanner's autism |editor= Frith U |title= Autism and Asperger syndrome |date=1991 |publisher= Cambridge University Press |isbn=0-521-38608-X |pages=93–121}}</ref> He called his young patients "little professors",<ref name=ha>{{cite book |author= [[Hans Asperger|Asperger H]]; tr. and annot. Frith U |origdate=1944 |chapter= 'Autistic psychopathy' in childhood |editor= Frith U |title= Autism and Asperger syndrome |date=1991 |publisher= Cambridge University Press |isbn=0-521-38608-X |pages=37–92}}</ref> and believed some would be capable of exceptional achievement and original thought later in life.<ref name="Baskin"/> His paper was published during wartime and in German, so it was not widely read elsewhere.
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| [[Lorna Wing]] popularized the term ''Asperger syndrome'' in the English-speaking medical community in her 1981 publication<ref>{{cite journal |author= [[Lorna Wing|Wing L]] |title= Asperger's syndrome: a clinical account |journal= Psychol Med |volume=11 |issue=1 |pages=115–29 |year=1981 |pmid=7208735 |url=http://www.mugsy.org/wing2.htm |accessdate=2007-08-15}}</ref> of a series of case studies of children showing similar symptoms,<ref name="What'sSpecial"/> and [[Uta Frith]] translated Asperger's paper to English in 1991.<ref name=ha/> Sets of diagnostic criteria were outlined by Gillberg and Gillberg in 1989 and by Szatmari ''et al.'' in the same year.<ref name="Mattila">{{cite journal |author= Mattila ML, Kielinen M, Jussila K ''et al.'' |title= An epidemiological and diagnostic study of Asperger syndrome according to four sets of diagnostic criteria |journal= J Am Acad Child Adolesc Psychiatry |volume=46 |issue=5 |pages=636–46 |year=2007 |pmid=17450055 |doi=10.1097/chi.0b013e318033ff42}}</ref> AS became a standard diagnosis in 1992, when it was included in the tenth edition of the [[World Health Organization]]’s diagnostic manual, ''International Classification of Diseases'' ([[ICD-10]]); in 1994, it was added to the fourth edition of the [[American Psychiatric Association]]'s diagnostic reference, ''Diagnostic and Statistical Manual of Mental Disorders'' ([[DSM-IV]]).<ref name=NINDS/>
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| Hundreds of books, articles and websites now describe AS, and prevalence estimates have increased dramatically for ASD, with AS recognized as an important subgroup.<ref name="What'sSpecial"/> Whether it should be seen as distinct from high-functioning autism is a fundamental issue requiring further study.<ref name="Baskin"/> There is little consensus among clinical researchers about the use of the terms ''Asperger's syndrome'' or ''Asperger's disorder'', and there are questions about the empirical validation of the DSM-IV and ICD-10 criteria.<ref name="Klin"/>
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| ==Cultural aspects==
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| {{see|Sociological and cultural aspects of autism}}
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| People with Asperger syndrome may refer to themselves in casual conversation as ''aspies'', coined by [[Liane Holliday Willey]] in 1999.<ref>{{cite book |author= Willey LH |title= Pretending to be Normal: Living with Asperger's Syndrome |publisher= Jessica Kingsley |year=1999 |isbn=1-85302-749-9}}</ref> The word ''[[neurotypical]]'' (abbreviated ''NT'') describes a person whose neurological development and state are typical, and is often used to refer to non-autistic people.
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| The [[Internet]] has allowed individuals with AS to communicate and [[Autistic Pride Day|celebrate]] with each other in a way that was not previously possible due to their rarity and geographic dispersal. A [[Sociological and cultural aspects of autism|subculture of aspies]] has formed. Internet sites like [[Wrong Planet]] have made it easier for individuals to connect.<ref>{{cite journal |journal= Disabil Soc |date=2007 |volume=22 |issue=7 |pages=761–76 |title= 'Surplus suffering': differences between organizational understandings of Asperger's syndrome and those people who claim the 'disorder' |author= Clarke J, van Amerom G |doi=10.1080/09687590701659618}}</ref>
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| Autistic people have contributed to a shift in perception of autism spectrum disorders as complex [[syndrome]]s rather than diseases that must be cured. Proponents of this view reject the notion that there is an "ideal" brain configuration and that any deviation from the norm is [[Anatomical pathology|pathological]]; they promote tolerance for what they call [[neurodiversity]].<ref>{{cite book |author= Williams CC |chapter= In search of an Asperger |editor= Stoddart KP |title= Children, Youth and Adults with Asperger Syndrome: Integrating Multiple Perspectives |year=2005 |publisher= Jessica Kingsley |isbn=1-84310-319-2 |pages=242–52 |quote= The life prospects of people with AS would change if we shifted from viewing AS as a set of dysfunctions, to viewing it as a set of differences that have merit.}}</ref> These views are the basis for the [[Autism rights movement|autistic rights]] and [[Sociological and cultural aspects of autism#Autistic pride|autistic pride]] movements.<ref>{{cite book |author= Dakin CJ |chapter= Life on the outside: A personal perspective of Asperger syndrome |editor= Stoddart KP |title= Children, Youth and Adults with Asperger Syndrome: Integrating Multiple Perspectives |year=2005 |publisher= Jessica Kingsley |isbn=1-84310-319-2 |pages=352–61}}</ref>
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| [[Simon Baron-Cohen]] has argued that AS and high-functioning autism are different cognitive styles, not disabilities, and that a diagnosis of AS/HFA should not be received as a family tragedy, but as interesting information, such as learning that a child is left-handed. According to Baron-Cohen, "people with AS/HFA might not necessarily be disabled in an environment in which an exact mind, attracted to detecting small details, is an advantage."<ref name=Baron-Cohen2000>{{cite journal |journal= Dev Psychopathol |year=2000 |volume=12 |issue=3 |pages=489–500 |title= Is Asperger syndrome/high-functioning autism necessarily a disability? |author= Baron-Cohen S |pmid=11014749 |doi=10.1017/S0954579400003126}}</ref> [[Tony Attwood]] argues, "the unusual profile of abilities that we define as Asperger's syndrome has probably been an important and valuable characteristic of our species throughout evolution."<ref>{{cite book |author= [[Tony Attwood|Attwood T]] |year=2006 |title= The Complete Guide to Asperger's Syndrome |publisher= Jessica Kingsley |isbn=1-84310-495-4 |pages= p. 12}}</ref>
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| ==References==
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| {{reflist|2}}
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| {{Pervasive developmental disorders}} | | {{Pervasive developmental disorders}} |
| {{Mental and behavioural disorders}} | | {{Mental and behavioural disorders}} |
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| [[de:Autismus#Asperger-Syndrom]] | | [[de:Asperger syndromeus#Asperger-Syndrom]] |
| [[et:Aspergeri sündroom]] | | [[et:Aspergeri sündroom]] |
| [[es:Síndrome de Asperger]] | | [[es:Síndrome de Asperger]] |
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