Asperger syndrome (AS), which is also called Asperger disorder or autistic psychopathy, belongs to a group of childhood disorders known as pervasive developmental disorders (PDDs) or autistic spectrum disorders. AS was first described by Hans Asperger, an Austrian psychiatrist, in 1944. Asperger's work was unavailable in English before the mid-1970s; as a result, AS was often unrecognized in English-speaking countries until the late 1980s. Before the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV 1994), there was no official definition of AS.
Children with AS learn to talk at the usual age and often have above-average verbal skills. They have normal or above-normal intelligence and the ability to take care of themselves. The distinguishing features of AS are problems with social interaction, particularly reciprocating and empathizing with the feelings of others; difficulties with nonverbal communication (e.g., facial expressions); peculiar speech habits that include repeated words or phrases and a flat, emotionless vocal tone; an apparent lack of "common sense"; a fascination with obscure or limited subjects (e.g., doorknobs, railroad schedules, astronomical data, etc.) often to the exclusion of other interests; clumsy and awkward physical movements; and odd or eccentric behaviors (hand wringing or finger flapping; swaying or other repetitious whole-body movements; watching spinning objects for long periods of time).
There is some indication that AS runs in families, particularly in families with histories of depression and bipolar disorder. Asperger noted that his initial group of patients had fathers with AS symptoms. Knowledge of the genetic profile of the disorder, however, is quite limited as of 2001.
Although the incidence of AS has been variously estimated between 0.024% and 0.36% of the general population in North America and northern Europe, further research is required to determine its true rate of occurrence—especially because the diagnostic criteria have been defined so recently. In addition, no research regarding the incidence of AS has been done on the populations of developing countries.
AS appears to be much more common in boys. One Swedish study found the male/female ratio to be 4:1. Dr. Asperger's first patients were all boys, but girls have been diagnosed with AS since the 1980s.
Signs and symptoms
About 50% of patients with Asperger syndrome have a history of oxygen deprivation during the birth process, which has led to the hypothesis that the syndrome is caused by damage to brain tissue before or during childbirth. Another cause that has been suggested is an organic defect in the functioning of the brain. Behavioral symptoms that are considered diagnostically significant are described in the next section.
As of 2001, there are no blood tests or brain scans that can be used to diagnose AS. Until DSM-IV (1994), there was no "official" list of symptoms for the disorder, which made its diagnosis both difficult and inexact. Although most children with AS are diagnosed between five and nine years of age, many are not diagnosed until adulthood. Misdiagnoses are common; AS has been confused with such other neurological disorders as Tourette's syndrome, or with Attention-Deficit Disorder (ADD), Oppositional Defiant Disorder (ODD), or Obsessive-Compulsive Disorder (OCD). Some researchers think that AS overlaps with some types of learning disability, such as the Nonverbal Learning Disability (NLD) syndrome identified in 1989.
The inclusion of AS as a separate diagnostic category in DSM-IV was justified on the basis of a large international field trial of over a thousand children and adolescents. Nevertheless, the diagnosis of AS is also complicated by confusion with such other diagnostic categories as "high-functioning (IQ >70) autism," or HFA, and "schizoid personality disorder of childhood." With regard to the latter, AS is not an unchanging set of personality traits but has a developmental dimension. AS is distinguished from HFA by the following characteristics:
- Later onset of symptoms (usually around three years of age)
- Early development of grammatical speech; the AS child's verbal IQ is usually higher than performance IQ (the reverse being the case in autistic children)
- Less severe deficiencies in social and communication skills
- Presence of intense interest in one or two topics
- Physical clumsiness and lack of coordination
- Family is more likely to have a history of the disorder
- Lower frequency of neurological disorders
- More positive outcome in later life.
DSM-IV criteria for Asperger syndrome
DSM-IV specifies six diagnostic criteria for AS:
- The child's social interactions are impaired in at least two of the following ways: markedly limited use of nonverbal communication; lack of age-appropriate peer relationships; failure to share enjoyment, interests, or accomplishment with others; lack of reciprocity in social interactions.
- The child's behavior, interests, and activities are characterized by repetitive or rigid patterns, such as an abnormal preoccupation with one or two topics, or with parts of objects; repetitive physical movements; or rigid insistence on certain routines and rituals.
- The patient's social, occupational, or educational functioning is significantly impaired.
- The child has normal age-appropriate language skills.
- The child has normal age-appropriate cognitive skills, self-help abilities, and curiosity about the environment.
- The child does not meet criteria for another specific PDD or schizophrenia.
Other diagnostic scales and checklists
Other instruments that have been used to identify children with AS include Gillberg's criteria, a six-item list compiled by a Swedish researcher that specifies problems in social interaction, a preoccupying narrow interest, forcing routines and interests on the self or others, speech and language problems, nonverbal communication problems, and physical clumsiness; and the Australian Scale for Asperger Syndrome, a detailed multi-item questionnaire developed in 1996.
Brain imaging findings
As of 2001, only a few structural abnormalities of the brain have been linked to AS. Findings include abnormally large folds in the brain tissue in the left frontal region, abnormally small folds in the operculum (a lid-like
Treatment and management
As of 2001, there is no cure for AS and no prescribed regimen for all affected patients. Specific treatments are based on the individual's symptom pattern.
The drugs that are recommended most often for children with AS include psychostimulants (methylphenidate, pemoline), clonidine, or one of the tricyclic antidepressants (TCAs) for hyperactivity or inattention; beta blockers, neuroleptics, or lithium for anger or aggression; selective serotonin reuptake inhibitors (SSRIs) or TCAs for rituals and preoccupations; and SSRIs or TCAs for anxiety symptoms. One alternative herbal remedy that has been tried with some patients is St. John's wort.
Most patients with AS have normal or above-normal intelligence, and are able to complete their education up through the graduate or professional school level. Many are unusually skilled in music or good in subjects requiring rote memorization. On the other hand, the verbal skills of children with AS frequently cause difficulties with teachers, who may not understand why these "bright" children have social and communication problems. Some children are dyslexic; others have difficulty with writing or mathematics. In some cases, children with AS have been mistakenly put in special programs either for children with much lower levels of functioning, or for children with conduct disorders. Children with AS do best in structured learning situations in which they learn problem-solving and life skills as well as academic subjects. They frequently need protection from the teasing and bullying of other children, and often become hypersensitive to criticism by their teenage years.
Adults with AS are productively employed in a wide variety of fields. They do best, however, in jobs with regular routines or jobs that allow them to work in isolation. Employers and colleagues may need some information about Asperger syndrome in order to understand the employee's behavior.
AS is a lifelong but stable condition. The prognosis for children with AS is generally good as far as intellectual development is concerned, although few school districts as of 2001 are equipped to meet their special social needs. In addition, some researchers think that people with AS have an increased risk of becoming psychotic in adolscence or adult life.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 4th edition. Washington, DC: American Psychiatric Association, 1994.
Thoene, Jess G., editor. Physicians' Guide to Rare Diseases. Montvale, NJ: Dowden Publishing Company, 1995.
Autism Research Institute. 4182 Adams Ave., San Diego, 92116. Fax: (619) 563-6840.
Families of Adults Afflicted with Asperger's Syndrome (FAAAS). PO Box 514, Centerville, MA 02632. <http://www.faaas.org>.
National Organization for Rare Disorders (NORD). PO Box 8923, New Fairfield, CT 06812-8923. (203) 746-6518 or (800) 999-6673. Fax: (203) 746-6481. <http://www.rarediseases.org>.
Yale-LDA Social Learning Disabilities Project. Yale Child Study Center, 230 South Frontage Road, New Haven, CT 06520-7900. (203) 785-3488. <http://info.med.Yale.edu/chldstdy/autism>.
Asperger's Disorder Home Page, maintained by Kaan Ozbayrak, MD. <http://www.ummed.edu/pub/o/ozbayrak/autasp>.
Center for the Study of Autism Home Page, maintained by Stephen Edelson, PhD. <http://www.autism.org/asperger.html>.
O.A.S.I.S. (Online Asperger Syndrome Information and Support). <http://www.udel.edu/bkirby/asperger/>.
Rebecca J. Frey, PhD
Table Of Contents
- Genetic profile
- Signs and symptoms
- DSM-IV criteria for Asperger syndrome
- Other diagnostic scales and checklists
- Brain imaging findings
- Treatment and management
- Educational considerations