AUTISM

Diagnosis

DSM-IV describes autistic disorder as consisting of twelve possible symptom areas in three areas of development. These include social—marked impairment in nonverbal behaviors, failure at peer relations, impaired sharing of pleasure and lack of socioemotional reciprocity; communication—delay in communication without gesture compensation, impairment in conversational ability, stereotyped and repetitive language, and lack of imaginative play; atypical activities and interests—restricted interests, nonfunctional routines and rituals, and preoccupation with parts of objects. To be diagnosed with autistic disorder, an individual must exhibit at least six out of the twelve symptoms, with at least two being in the social domain, along with one each in the communicative domain and the domain of atypical activities and interests. Individuals with at least one symptom each in the social and communicative domains, but fewer than six symptoms overall, are classified as PDD-NOS as are individuals without symptoms in the domain of atypical activities and interests. The criteria for Asperger's disorder uses the same social criteria as autistic disorder, but requires at least one symptom in the area of atypical activities and interests, as well as normal age of onset for language.

Prevalence of Autism

There is much controversy concerning the prevalence of autism. DSM-IV notes a prevalence rate of 4 to 5 cases per 10,000 in the United States, though these data are based on diagnostic criteria from the third edition of theDSM, criteria that have been shown to be diagnostically more restrictive. Many investigators have suggested a prevalence rate for PDD of around 1 in 800 cases in the United States, but no definitive prevalence data exist for DSM-IV criteria. It is clear, however, that more cases are being diagnosed. Several possible influences include earlier detection, diagnosis of more mildly affected individuals, the use of autism rather than mental retardation as the primary diagnosis in cases of more severe mental retardation, and the preference for this diagnosis in geographic regions where it is associated with higher intensity delivery of services. According toDSM-IV, approximately 70 percent of individuals diagnosed with autism have also been diagnosed with mild to severe mental retardation.

Causes of the Disorder

The causes of autism remain incompletely understood, although 40 percent to 60 percent of cases are believed to have a genetic component traced to multiple genes predisposing development of different aspects of autism. Concordance in monozygotic (identical) twins is around 95 percent; in dizygotic (fraternal) twins, around 9 percent; and in siblings, 3 percent. About 15 percent to 25 percent of siblings of individuals with autism have mild to severe language difficulties.

Autism's Clinical Course

Autism is usually detected in the third or fourth year of life. Early hallmarks include a failure to begin pointing, an apparent lack of interest in peers, a disinterest in playing with toys (or a disinterest in playing with them the same way that others of the same age do), and a delay in the development of speech for communicative purposes. Children with autism have a difficult time coordinating verbal and nonverbal forms of communication and therefore often do not mark acknowledgement of being spoken to with a gaze, do not mark their own communicative speech with eye contact directed at the listener, and do not coordinate body gesture with gaze and vocalization in such communicative efforts. Some children with autism develop single words slowly, but then lose these words, seldom use them, or seemingly plateau in language development. Others develop language for the first time around the third or fourth year of life or after initiation of speech therapy. Early language for a child with autism is marked by an instrumental quality with utterances mainly focused on getting needs and wants addressed. There is typically little conversational use of language.

Autism has sometimes been characterized as a primary disorder of failing to develop a theory of mind. Autistic children, especially in the early years, show a fairly universal disability at assuming the perspective of others, engaging in planned deception, or showing empathy or sympathy. The range of emotional recognition and expression is more limited than normal and social-emotional responses are usually severely lacking. When language does develop, it may be characterized by use of immediate or delayed echolalia in the form of repeating what has just been heard (in the case of the former) or repeating something from past experience in its entirety (in the case of the latter). Echolalia often, though not always, serves some abbreviated communicative function resulting in a characteristically stilted manner of discourse.

In addition to social and language deficits, autism is often marked by odd ways of relating to the environment, which may include adherence to unreasonable routines, ritualized ways of carrying out everyday activities, and a general resistance to change. Autistic children may exhibit overly repetitive tendencies in speech and play, and for many, novelty is generally eschewed and exploratory activity is greatly reduced compared to peers. There may be fixations or avoidance of specific sensory stimuli, such as covering the ears to certain kinds of sounds, visually fixating on objects with a strong vertical or horizontal axis, peripheral gazing at objects, sniffing objects not usually smelled, and physical hypersensitivities—a strong aversion to solid foods or certain types of food, or the avoidance of certain types of clothing.

Treatment for Autism

Treatment for autism is mostly based on methods of changing maladaptive behavior and developing learning skills. Behavior modification approaches, educationally based approaches, speech therapy, parent skill training, and adaptive skill training are generally part of an individualized multimodal treatment plan. The prescribing of drugs is used as an adjunct to treat specific symptoms, but there is no medication that treats autism as a whole. In the latter part of the 1990s, comparative reviews of model programs have shown that multiple methods are effective and that there is no one behavioral approach that is of singular value. Intensity of treatment, age of initiation of treatment, parent training, high teacher to student ratios, and use of structured intervention procedures all contribute to positive outcomes. Proven treatments include the use of behavior analysis procedures using discrete trial training methods tailored for areas of common autistic cognitive and motivational deficit, and the Treatment and Education for Autistic and Communication Handicapped Children (TEACCH) curriculum for structure with its emphasis on visually based guidance. Other treatment approaches target specific symptom areas such as the Picture Exchange Communication System (PECS), which targets communication. Most treatment programs are eclectic and integrate features of a number of approaches.

The field of autism treatment, both behavioral and medical, has been subject to many treatment fads, all claiming high levels of success that are either invalidated or simply not supported by subsequent controlled studies. On the behavioral side, such putative cures include facilitated communication, holding therapy, auditory integration therapy, and sensory-integration therapy. Putative cures on the medical side include treatment with megavitamins, B vitamins, dimethylglycene, secretin, and elimination diets for gluten and casein. Most families, at least initially, undertake multiple treatments including trials of some unproven treatments, which over time, tend to be tailored by perceived or measurable positive responses.

See also: FACILITATED COMMUNICATION; SOCIAL DEVELOPMENT

Bibliography

American Psychiatric Association. The Diagnostic and Statistical Manual of Mental Disorders: DSM-IV. Washington, DC: American Psychiatric Association, 1994.

Bryson, S. E. "Epidemiology of Autism: Overview and Issues Understanding." In Donald J. Cohen and Fred R. Volkmar eds., Handbook of Autism and Pervasive Developmental Disorders, 2nd edition. New York: Wiley, 1997.

Green, Gina. "Evaluating Claims about Treatment for Autism." InCatherine Maurice, Gina Green, and Stephen Luce eds., Behavioral Intervention for Young Children with Autism: A Manual for Parents and Professionals. Austin, TX: Pro Ed, 1996.

Harris, Sandra, and Jan Handleman, eds. Preschool Education Programs for Children with Autism. Austin, TX: Pro Ed, 1994.

Bryna Siegel