Aspergers (also called Asperger's Syndrome, Asperger's Disorder, Asperger's or AS) is the Autism Spectrum Disorder (ASD) in which there is no general delay in language or cognitive development. Like the more severe Autism Spectrum Disorders, it is characterized by difficulties in social interaction and restricted, stereotyped patterns of behavior and interests. Although not mentioned in standard diagnostic criteria for Aspergers, physical clumsiness and atypical use of language are frequently reported.
Aspergers is named after Austrian pediatrician Hans Asperger who, in 1944, described kids in his practice who lacked nonverbal communication skills, demonstrated limited empathy with their peers, and were physically clumsy. Fifty years later, Aspergers was standardized as a diagnosis, but questions about many aspects of Aspergers remain. For example, there is lingering doubt about the distinction between Aspergers and High-Functioning Autism (HFA); partly due to this, the prevalence of Aspergers is not firmly established. The exact cause of Aspergers is unknown, although research supports the likelihood of a genetic basis; brain imaging techniques have not identified a clear common pathology.
There is no single management for Aspergers, 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 people with Aspergers can learn to cope with their differences, but may continue to need moral support and encouragement to maintain an independent life. Researchers and people with Aspergers have advocated a shift in attitudes toward the view that Aspergers is a difference, rather than a disability that must be treated or cured.
Classification—
Aspergers is one of the Autism Spectrum Disorders (ASD) or Pervasive Developmental Disorders (PDD), which are a 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, Autism Spectrum Disorder 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. Autism Spectrum Disorder, in turn, is a subset of the broader autism phenotype (BAP), which describes people who may not have Autism Spectrum Disorder but do have autistic-like traits, such as social deficits. Of the other four Autism Spectrum Disorder forms, autism is the most similar to Aspergers 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 pervasive developmental disorder not otherwise specified (PDD-NOS) is diagnosed when the criteria for a more specific disorder are unmet. The extent of the overlap between Aspergers and high-functioning autism (HFA—autism unaccompanied by mental retardation) is unclear. The current Autism Spectrum Disorder classification may not reflect the true nature of the conditions.
Characteristics—
A pervasive developmental disorder, Aspergers 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. Intense preoccupation with a narrow subject, one-sided verbosity, restricted prosody, and physical clumsiness are typical of the condition, but are not required for diagnosis.
Social Interaction—
The lack of demonstrated empathy is possibly the most dysfunctional aspect of Aspergers. People with Aspergers 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 behaviors in areas such as eye contact, facial expression, posture, and gesture.
Unlike those with autism, people with Aspergers 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. This social awkwardness has been called "active but odd". This failure to react appropriately to social interaction may appear as disregard for other people's feelings, and may come across as insensitive. The cognitive ability of kids with Aspergers often lets them articulate social norms in a laboratory context, 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. People with Aspergers 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 naive. Childhood desires for companionship can be numbed through a history of failed social encounters.
The hypothesis that people with Aspergers are predisposed to violent or criminal behavior has been investigated but is not supported by data. More evidence suggests kids with Aspergers are victims rather than victimizers.
Restricted and Repetitive Interests and Behavior—
People with Aspergers often display intense interests, such as this boy's fascination with molecular structure.
People with Aspergers often display behavior, interests, and activities that are restricted and repetitive and are sometimes abnormally intense or focused. They may stick to inflexible routines, move in stereotyped and repetitive ways, or preoccupy themselves with parts of objects.
Pursuit of specific and narrow areas of interest is one of the most striking features of Aspergers. People with Aspergers may collect volumes of detailed information on a relatively narrow topic such as dinosaurs or deep fat fryers, without necessarily having genuine understanding of the broader topic. For example, a youngster might memorize camera model numbers while caring little about photography. This behavior is usually apparent by grade school, typically age 5 or 6 in the United States. 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 kids, this symptom may go unrecognized.
Stereotyped and repetitive motor behaviors are a core part of the diagnosis of Aspergers and other Autism Spectrum Disorders. They include hand movements such as flapping or twisting, and complex whole-body movements. These are typically repeated in longer bursts and look more voluntary or ritualistic than tics, which are usually faster, less rhythmical and less often symmetrical.
Speech and Language—
Although people with Aspergers acquire language skills without significant general delay and their speech typically lacks significant abnormalities, language acquisition and use is often atypical. Abnormalities include verbosity; abrupt transitions; literal interpretations and miscomprehension of nuance; use of metaphor meaningful only to the speaker; auditory perception deficits; unusually pedantic, formal or idiosyncratic speech; and oddities in loudness, pitch, intonation, prosody, and rhythm.
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 Aspergers 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. People with Aspergers 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.
Kids with Aspergers 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. Kids with Aspergers appear to have particular weaknesses in areas of nonliteral language that include humor, irony, and teasing. Although people with Aspergers usually understand the cognitive basis of humor they seem to lack understanding of the intent of humor to share enjoyment with others. Despite strong evidence of impaired humor appreciation, there are anecdotal reports of humor in people with Aspergers, which challenge theories of humor in Aspergers.
Other—
People with Aspergers 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.
People with Aspergers often have excellent auditory and visual perception. Kids with Autism Spectrum Disorder 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. Conversely, compared to people with HFA, people with Aspergers have deficits in some tasks involving visual-spatial perception, auditory perception, or visual memory. Many accounts of people with Aspergers and Autism Spectrum Disorder 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; these sensory responses are found in other developmental disorders and are not specific to Aspergers or to Autism Spectrum Disorder. 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.
Hans Asperger’s initial accounts and other diagnostic schemes include descriptions of physical clumsiness. Kids with Aspergers 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. 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 Aspergers from other high-functioning Autism Spectrum Disorders.
Kids with Aspergers are more likely to have sleep problems, including difficulty in falling asleep, frequent nocturnal awakenings, and early morning awakenings. Aspergers is also associated with high levels of alexithymia, which is difficulty in identifying and describing one's emotions. Although Aspergers, lower sleep quality, and alexithymia are associated, their causative relationship is unclear.
Causes—
Hans Asperger described common symptoms among his clients' family members, especially fathers, and research supports this observation and suggests a genetic contribution to Aspergers. Although no specific gene has yet been identified, multiple factors are believed to play a role in the expression of autism, given the phenotypic variability seen in this group of kids. Evidence for a genetic link is the tendency for Aspergers to run in families and an observed higher incidence of family members who have behavioral symptoms similar to Aspergers but in a more limited form (for example, slight difficulties with social interaction, language, or reading). Most research suggests that all Autism Spectrum Disorders have shared genetic mechanisms, but Aspergers may have a stronger genetic component than autism. There is probably a common group of genes where particular alleles render an individual vulnerable to developing Aspergers; if this is the case, the particular combination of alleles would determine the severity and symptoms for each individual with Aspergers.
A few Autism Spectrum Disorder cases have been linked to exposure to teratogens (agents that cause birth defects) during the first eight weeks from conception. Although this does not exclude the possibility that Autism Spectrum Disorder can be initiated or affected later, it is strong evidence that it arises very early in development. Many environmental factors have been hypothesized to act after birth, but none has been confirmed by scientific investigation.
Mechanism—
Aspergers appears to result from developmental factors that affect many or all functional brain systems, as opposed to localized effects. Although the specific underpinnings of Aspergers or factors that distinguish it from other Autism Spectrum Disorders are unknown, and no clear pathology common to people with Aspergers has emerged, it is still possible that Aspergers mechanism is separate from other Autism Spectrum Disorder. Neuroanatomical studies and the associations with teratogens strongly suggest that the mechanism includes alteration of brain development soon after conception. 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. Several theories of mechanism are available; none are likely to provide complete explanations.
The underconnectivity theory hypothesizes underfunctioning high-level neural connections and synchronization, along with an excess of low-level processes. 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 Autism Spectrum Disorder. A related theory—enhanced perceptual functioning—focuses more on the superiority of locally oriented and perceptual operations in autistic people.
The 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. For example, one study found that activation is delayed in the core circuit for imitation in people with Aspergers. 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, or hyper-systemizing, which hypothesizes that autistic people can systematize internal operation to handle internal events but are less effective at empathizing by handling events generated by other agents.
Other possible mechanisms include serotonin dysfunction and cerebellar dysfunction.
Screening—
Moms & dads of kids with Aspergers can typically trace differences in their kids' development to as early as 30 months of age. Developmental screening during a routine check-up by a general practitioner or pediatrician may identify signs that warrant further investigation. The diagnosis of Aspergers is complicated by the use of several different screening instruments, including the Aspergers Diagnostic Scale, Autism Spectrum Screening Questionnaire (ASSQ), Childhood Aspergers Test (CAST), Gilliam Asperger’s Disorder Scale (GADS), Krug Asperger’s Disorder Index (KADI), and the Autism Spectrum Quotient (AQ). None have been shown to reliably differentiate between Aspergers and other Autism Spectrum Disorders.
Diagnosis—
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, U.S. criteria also require significant impairment in day-to-day functioning. Other sets of diagnostic criteria have been proposed by Szatmari et al. and by Gillberg and Gillberg.
Diagnosis is most commonly made between the ages of four and eleven. A comprehensive assessment involves a multidisciplinary team that observes across multiple settings, 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. The current "gold standard" in diagnosing Autism Spectrum Disorders 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 youngster. Delayed or mistaken diagnosis can be traumatic for people and families; for example, misdiagnosis can lead to drugs that worsen behavior. Many kids with Aspergers are initially misdiagnosed with attention-deficit hyperactivity disorder (ADHD). Diagnosing adults is more challenging, as standard diagnostic criteria are designed for kids and the expression of Aspergers changes with age. Conditions that must be considered in a differential diagnosis include other Autism Spectrum Disorders, the schizophrenia spectrum, ADHD, obsessive compulsive disorder, depression, semantic pragmatic disorder, nonverbal learning disorder, Tourette syndrome, stereotypic movement disorder and bipolar disorder.
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 management options and the expansion of benefits have motivated providers to overdiagnose Autism Spectrum Disorder. There are indications Aspergers has been diagnosed more frequently in recent years, partly as a residual diagnosis for kids of normal intelligence who do not have autism but have social difficulties. There are questions about the external validity of the Aspergers diagnosis, that is, it is unclear whether there is a practical benefit in distinguishing Aspergers from HFA and from PDD-NOS; the same youngster can receive different diagnoses depending on the screening tool.
Management—
Aspergers management attempts to manage distressing symptoms and to teach age-appropriate social, communication and vocational skills that are not naturally acquired during development, with intervention tailored to the needs of the individual youngster, based on multidisciplinary assessment. Although progress has been made, data supporting the efficacy of particular interventions are limited.
The ideal management for Aspergers 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 management package. Aspergers management resembles that of other high-functioning Autism Spectrum Disorders except that it takes into account the linguistic capabilities, verbal strengths, and nonverbal vulnerabilities of people with Aspergers. A typical program generally includes:
- cognitive behavioral therapy to improve stress management relating to anxiety or explosive emotions, and to cut back on obsessive interests and repetitive routines
- drug therapy, for coexisting conditions such as depression and anxiety
- occupational or physical therapy to assist with poor sensory integration and motor coordination
- social communication intervention, which is specialized speech therapy to help with the pragmatics of the give and take of normal conversation
- the training and support of moms & dads, particularly in behavioral techniques to use in the home
- the training of social skills for more effective interpersonal interactions
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, stereotypies, or spontaneous language; unintended side effects are largely ignored. Despite the popularity of social skills training, its effectiveness is not firmly established. A randomized controlled study of a model for training moms & dads in problem behaviors in their kids with Aspergers showed that moms & dads attending a one-day workshop or six individual lessons reported fewer behavioral problems, while moms & dads receiving the individual lessons reported less intense behavioral problems in their Aspergers kids. Vocational training is important to teach job interview etiquette and workplace behavior to older kids and adults with Aspergers, and organization software and personal data assistants to improve the work and life management of people with Aspergers are useful.
No drugs directly treat the core symptoms of Aspergers. Although research into the efficacy of pharmaceutical intervention for Aspergers is limited, it is essential to diagnose and treat comorbid conditions. Deficits in self-identifying emotions or in observing effects of one's behavior on others can make it difficult for people with Aspergers to see why drug therapy may be appropriate. Drug therapy can be effective in combination with behavioral interventions and environmental accommodations in treating comorbid symptoms such as anxiety, depression, inattention and aggression. The atypical neuroleptic drugs risperidone and olanzapine have been shown to reduce the associated symptoms of Aspergers; 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 inhibitors (SSRIs) fluoxetine, fluvoxamine and sertraline have been effective in treating restricted and repetitive interests and behaviors.
Care must be taken with drugs; abnormalities in metabolism, cardiac conduction times, and an increased risk of type 2 diabetes have been raised as concerns with these drugs, along with serious long-term neurological side effects. SSRIs can lead to manifestations of behavioral activation such as increased impulsivity, aggression and sleep disturbance. 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 and increased serum prolactin levels. Sedation and weight gain are more common with olanzapine, which has also been linked with diabetes. Sedative side-effects in school-age kids have ramifications for classroom learning. People with Aspergers 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.
Prognosis—
There is some evidence that as many as 20% of kids with Aspergers "grow out" of it, and fail to meet the diagnostic criteria as adults. As of 2006, no studies addressing the long-term outcome of people with Aspergers are available and there are no systematic long-term follow-up studies of kids with Aspergers. People with Aspergers appear to have normal life expectancy but have an increased prevalence of comorbid psychiatric conditions such as depression and anxiety that may significantly affect prognosis. Although social impairment is lifelong, outcome is generally more positive than with people with lower functioning Autism Spectrum Disorders; for example, Autism Spectrum Disorder symptoms are more likely to diminish with time in kids with Aspergers or HFA. 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 and Aspergers has not prevented some adults from major accomplishments such as winning the Nobel Prize.
Kids with Aspergers may require special education services because of their social and behavioral difficulties although many attend regular education classes. Adolescents with Aspergers 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. The "different-ness" adolescents experience can be traumatic. 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 concern with failing in social encounters; the resulting stress may manifest as inattention, withdrawal, reliance on obsessions, hyperactivity, or aggressive or oppositional behavior. Depression is often the result of chronic frustration from repeated failure to engage others socially, and mood disorders requiring management may develop.
Education of families is critical in developing strategies for understanding strengths and weaknesses; helping the family to cope improves outcome in kids. Prognosis may be improved by diagnosis at a younger age that allows for early interventions, while interventions in adulthood are valuable but less beneficial. There are legal implications for people with Aspergers as they run the risk of exploitation by others and may be unable to comprehend the societal implications of their actions.
Epidemiology—
Prevalence estimates vary enormously. A 2003 review of epidemiological studies of kids found prevalence rates ranging from 0.03 to 4.84 per 1,000, with the ratio of autism to Aspergers ranging from 1.5:1 to 16:1; 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 Aspergers might be around 0.26 per 1,000. Part of the variance in estimates arises from differences in diagnostic criteria. For example, a relatively small 2007 study of 5,484 eight-year-old kids in Finland found 2.9 kids per 1,000 met the ICD-10 criteria for an Aspergers 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 more likely to have Aspergers than girls; estimates of the sex ratio range from 1.6:1 to 4:1, using the Gillberg and Gillberg criteria.
Anxiety and depression are the most common other conditions seen at the same time; comorbidity of these in persons with Aspergers is estimated at 65%. Depression is common in adolescents and adults; kids are likely to present with ADHD. Reports have associated Aspergers 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 Aspergers across studies. One study of males with Aspergers found an increased rate of epilepsy and a high rate (51%) of nonverbal learning disorder. Aspergers is associated with tics, Tourette syndrome, and bipolar disorder, and the repetitive behaviors of Aspergers have many similarities with the symptoms of obsessive-compulsive disorder and obsessive-compulsive personality disorder. 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.
History—
Named after the Austrian pediatrician Hans Asperger (1906–80), Aspergers is a relatively new diagnosis in the field of autism. In 1944, Asperger described four kids in his practice who had difficulty in integrating themselves socially. The kids 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. Unlike today's Aspergers, autistic psychopathy could be found in people of all levels of intelligence, including those with mental retardation. He called his young clients "little professors", and believed some would be capable of exceptional achievement and original thought later in life. His paper was published during wartime and in German, so it was not widely read elsewhere.
Lorna Wing popularized the term Aspergers in the English-speaking medical community in her 1981 publication of a series of case studies of kids showing similar symptoms, and Uta Frith translated Asperger's paper to English in 1991. Sets of diagnostic criteria were outlined by Gillberg and Gillberg in 1989 and by Szatmari et al. in the same year. Aspergers 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).
Hundreds of books, articles and websites now describe Aspergers, and prevalence estimates have increased dramatically for Autism Spectrum Disorder, with Aspergers recognized as an important subgroup. Whether it should be seen as distinct from high-functioning autism is a fundamental issue requiring further study. 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.
Cultural Aspects—
People with Aspergers may refer to themselves in casual conversation as Aspies, coined by Liane Holliday Willey in 1999. 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. The Internet has allowed people with Aspergers to communicate and celebrate with each other in a way that was not previously possible due to their rarity and geographic dispersal. A subculture of Aspies has formed. Internet sites like Wrong Planet have made it easier for people to connect.
Autistic people have contributed to a shift in perception of Autism Spectrum Disorders as complex syndromes 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 pathological; they promote tolerance for what they call neurodiversity. These views are the basis for the autistic rights and autistic pride movements.
Simon Baron-Cohen has argued that Aspergers 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 youngster 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." 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."