Asperger's disorder, which is also called Asperger's syndrome (AS) or autistic psychopathy, belongs to a group of childhood disorders known as pervasive developmental disorders (PDDs) or autistic spectrum disorders. The essential features of Asperger's disorder are severe social interaction impairment and restricted, repetitive patterns of behavior and activities. It is similar to autism , but children with Asperger's do not have the same difficulties in acquiring language that children with autism have.
In the mental health professional's diagnostic hand book, the Diagnostic and Statistical Manual of Mental Disorders fourth edition text revised, or DSM-IV-TR , Asperger's disorder is classified as a developmental disorder of childhood.
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 DSM-IV (published in 1994) there was no officially agreed-upon definition of AS. In the words of ICD-10, the European equivalent of the DSM-IV, Asperger's is "a disorder of uncertain nosological validity." (Nosological refers to the classification of diseases.) There are three major reasons for this lack of clarity: differences between the diagnostic criteria used in Europe and those used in the United States; the fact that some of the diagnostic criteria depend on the observer's interpretation rather than objective measurements; and the fact that the clinical picture of Asperger's changes as the child grows older.
Asperger's disorder is one of the milder pervasive developmental disorders. 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 feed or dress themselves and take care of their other daily needs. The distinguishing features of AS are problems with social interaction, particularly reciprocating and empathizing with the feelings of others; difficulties with nonverbal communication (such as 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 (for example, the parts of a clock or small machine, 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).
Causes and symptoms
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 2002.
In addition, about 50% of AS patients have a history of oxygen deprivation during the birth process, which has led to the hypothesis that the disorder 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.
In young children, the symptoms of AS typically include problems picking up social cues and understanding the basics of interacting with other children. The child may want friendships but find him- or herself unable to make friends.
Most children with Asperger's are diagnosed during the elementary school years because the symptoms of the disorder become more apparent at this point. They include:
- Poor pragmatic language skills. This phrase means that the child does not use the right tone or volume of voice for a specific context, and does not understand that using humorous or slang expressions also depends on social context.
- Problems with hand-eye coordination and other visual skills.
- Problems making eye contact with others.
- Learning difficulties, which may range from mild to severe.
- Tendency to become absorbed in a particular topic and not know when others are bored with conversation about it. At this stage in their education, children with AS are likely to be labeled as "nerds."
- Repetitive behaviors. These include such behaviors as counting a group of coins or marbles over and over; reciting the same song or poem several times; buttoning and unbuttoning a jacket repeatedly; etc.
Adolescence is one of the most painful periods of life for young people with Asperger's, because social interactions are more complex in this age group and require more subtle social skills. Some boys with AS become frustrated trying to relate to their peers and may become aggressive. Both boys and girls with the disorder are often quite naive for their age and easily manipulated by "street-wise" classmates. They are also more vulnerable than most youngsters to peer pressure.
Little research has been done regarding adults with AS. Some have serious difficulties with social and occupational functioning, but others are able to finish their schooling, join the workforce, and marry and have families.
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, and nothing is known about the incidence of the disorder in different racial or ethnic groups.
With regard to gender differences, AS appears to be much more common in boys. Dr. Asperger's first patients were all boys, but girls have been diagnosed with AS since the 1980s. One Swedish study found the male/female ratio to be 4:1; however, the World Health Organization's ICD-10 classification gives the male to female ratio as 8 to 1.
As of early 2002, 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 may overlap 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 higher than 70) autism" or HFA, and "schizoid personality disorder of childhood." Unlike schizoid personality disorder of childhood, AS is not an unchanging set of personality traits— AS 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 (scores on verbal sections of standardized intelligence tests ) is usually higher than performance IQ (how well the child performs in school). The reverse is usually true for 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-TR criteria for Asperger's disorder
The DSM-IV-TR specifies the following 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 (facial expressions, for example); lack of age-appropriate peer relationships; failure to share enjoyment, interests, or accomplishment with others; lack of reciprocity (turn-taking) 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.
To establish the diagnosis, the child psychiatrist or psychologist would observe the child, and would interview parents, possibly teachers, and the affected child (depending on the child's age), and would gather a comprehensive medical and social history.
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's Syndrome, a detailed multi-item questionnaire developed in 1996.
Brain imaging findings
As of 2002, 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 structure composed of portions of three adjoining brain lobes), and damage to the left temporal lobe (a part of the brain containing a sensory area associated with hearing). The first single photon emission tomography (SPECT) study of an AS patient found a lower-than-normal supply of blood to the left parietal area of the brain, an area associated with bodily sensations. Brain imaging studies on a larger sample of AS patients is the next stage of research.
As of 2002, there is no cure for AS and no prescribed treatment regimen for all AS patients. Specific treatments are based on the individual's symptom pattern.
Many children with AS do not require any medication. For those who do, the drugs that are recommended most often include psychostimulants ( methylphenidate , pemoline ), clonidine , or one of the tricyclic antidepressants (TCAs) for hyperactivity or inattention; beta blockers , neuroleptics (antipsychotic medications), or lithium ( lithium carbonate ) for anger or aggression; selective serotonin reuptake inhibitors (SSRIs) or TCAs for rituals (repetitive behaviors) and preoccupations; and SSRIs or TCAs for anxiety symptoms. One alternative herbal remedy that has been tried with AS patients is St. John's wort .
AS patients often benefit from individual psychotherapy , particularly during adolescence, in order to cope with depression and other painful feelings related to their social difficulties. Many children with AS are also helped by group therapy , which brings them together with others facing the same challenges. There are therapy groups for parents as well.
Therapists who are experienced in treating children with Asperger's disorder have found that the child should be allowed to proceed slowly in forming an emotional bond with the therapist. Too much emotional intensity at the beginning may be more than the child can handle. Behavioral approaches seem to work best with these children. Play therapy can be helpful in teaching the child to recognize social cues as well as lowering the level of emotional tension.
Adults with AS are most likely to benefit from individual therapy using a cognitive-behavioral approach, although many also attend group therapy. Some adults have been helped by working with speech therapists on their pragmatic language skills. A relatively new approach called behavioral coaching has been used to help adults with Asperger's learn to organize and set priorities for their daily activities.
Most AS patients 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 AS children are dyslexic; others have difficulty with writing or mathematics. In some cases, AS children have been mistakenly put in special programs either for children with much lower levels of functioning, or for children with conduct disorders. AS children do best in structured learning situations in which they learn problem-solving and social 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. One approach that has been found helpful at the high-school level is to pair the adolescent with AS with a slightly older teenager who can serve as a mentor. The mentor can "clue in" the younger adolescent about the slang, dress code, cliques, and other "facts of life" at the local high school.
Adults with AS are productively employed in a wide variety of fields, including the learned professions. They do best, however, in jobs with regular routines or occupations that allow them to work in isolation. In large companies, employers or supervisors and workplace colleagues may need some information about AS in order to understand the new employee's "eccentricities."
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 2002 are equipped to meet the special social needs of this group of children. Adults with AS appear to be at greater risk of depression than the general population. In addition, some researchers believe that people with AS have an increased risk of a psychotic episode (a period of time during which the affected person loses touch with reality) in adolescence or adult life.
Effective prevention of Asperger's disorder awaits further genetic mapping together with ongoing research in the structures and functioning of the brain. The only practical preventive strategy as of 2002 is better protection of the fetus against oxygen deprivation during childbirth.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th edition, text revised. Washington, DC: American Psychiatric Association, 2000.
"Psychiatric Conditions in Childhood and Adolescence." Section 19, Chapter 274. In The Merck Manual of Diagnosis and Therapy , edited by Mark H. Beers, M.D., and Robert Berkow, M.D. Whitehouse Station, NJ: Merck Research Laboratories, 1999.
Thoene, Jess G., ed. Physicians' Guide to Rare Diseases. Montvale, NJ: Dowden Publishing Company, 1995.
World Health Organization (WHO). The ICD-10 Classification of Mental and Behavioural Disorders. Geneva: WHO, 1992.
Bishop, D. V. M. "Autism, Asperger's Syndrome & Semantic-Pragmatic Disorder: Where Are the Boundaries?" British Journal of Disorders of Communication 24 (1989): 107-121.
Gillberg, C. "The Neurobiology of Infantile Autism." Journal of Child Psychology and Psychiatry 29 (1988): 257-266.
Autism Research Institute. 4182 Adams Avenue, San Diego, CA 92116.
Families of Adults Afflicted with Asperger's Syndrome (FAAAS). P.O. Box 514, Centerville, MA 02632. <www.faaas.org> .
National Association of Rare Disorders (NORD). P.O. Box 8923, New Fairfield, CT 06812-8923. (800) 999-NORD or (203) 746-6518.
Yale-LDA Social Learning Disabilities Project. Yale Child Study Center, New Haven, CT. The Project is looking for study subjects with PDDs between the ages of 8 and 24, including AS patients. Contact person: Sanno Zack at (203) 785-3488 or Sanno.Zack@yale.edu. <www.info.med.Yale.edu/chldstdy/autism> .
American Academy of Child & Adolescent Psychiatry (AACAP). "Asperger's Disorder." AACAP Facts For Families Pamphlet #69. Washington, DC: American Academy of Child & Adolescent Psychiatry, 1999.
Rebecca J. Frey, Ph.D.