Autism: Introduction

  1. Characteristics of autism
  2. Diagnoses: the autistic spectrum
  3. Associated problems
  4. Prevalence
  5. Treatments
  6. Outcome

Autism is a pervasive developmental disorder, appearing prior to the age of three years. It is characterized by impairment in communication, social interaction, and behavior. Autistic symptoms, and the severity of impairment caused by autism, vary from individual to individual. Individuals with autism range from non-verbal and severely mentally retarded to more independent, although still affected by difficulty with social skills. The latter group is relatively small.

1. Characteristics of Autism

Individuals with an autistic disorder tend to three share common factors: impairment in social interaction, language delays and impairments, and a restricted repertoire of activities and interests. There are also a number of less common factors.

a. Impairment in social interaction
Infants with autism often refuse to cuddle or engage in eye-to-eye gaze, and as children, rarely engage in spontaneous play (Koegel, Valdez-Menchaca, & Koegel, 1994). Children also may avoid others of their own age; as adolescents and adults, they may want to make friends, but have a great deal of difficulty doing so due to lack of social skills (Howlin, 1997). They are also impaired in both the recognition and production of emotional expression, making it very difficult for them to read others’ reactions accurately (Loveland, Tunali-Kotoski, Pearson, Brelsford et al., 1995).

b. Language delays and impairments
The second common factor is language delays and impairments, possibly as a result of impaired social functioning (Koegel et al., 1994). Even those who do develop language still have difficulty communicating in a way that would be considered "normal" by others; for example, children with Asperger’s Disorder (a variant of autism or a similar disorder as discussed below) have unimpaired verbal skills but often engage in long monologues without spaces for others to communicate or respond.

c. Restricted repertoire of activities and interests
The third common factor is a restricted repertoire of activities and interests. Individuals with autism often engage in self-stimulatory behavior, "repetitive behavior that appears to serve no observable social function" (Koegel et al., 1994), such as lining up small objects, flicking their fingers in front of their face, and rocking back and forth. These behaviors are also known as stereotypies. In milder form, they may manifest as particular hobbies, such as an intense interest in train schedules, constellations, math, music, and so forth.

d. Other common features
Some other common features of autism include extreme difficulty in dealing with change (Cohen, 1998) and difficulty in regulating sensory input (Ornitz, 1992). At the same time, children with autism often have good visuospatial skills and good rote memory (Prior & Ozonoff, 1998), and a small subgroup of children with autism display splinter skills, impressive but isolated skills such as the ability to name what day of the week any day in history falls on or the ability to play a piece of music perfectly the first time it is heard.

2. Diagnoses: the autistic spectrum

Autism, termed Autistic Disorder under the DSM-IV, is considered to be one of the Pervasive Developmental Disorders (PDDs). The other PDDs are Asperger’s Disorder, Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS), Childhood Disintegrative Disorder (CDD), and Rett’s Disorder (DSM-IV).

The diagnosis of Asperger’s Disorder is given to children who display autistic symptoms but have no language delay. The diagnosis of PDD-NOS is given to those who display some autistic symptoms but not enough for a diagnosis of Autistic Disorder, Asperger’s Disorder, or CDD (Cohen, 1998). The diagnosis of CDD is given to those who have a period of documented normal development prior to the emergence of autistic symptoms (DSM-IV). Some diagnosticians believe these three disorders to be points along an autistic spectrum ranging from severely impaired (Autistic Disorder, CDD) to less impaired (PDD-NOS, Asperger’s Disorder), but some believe them to be separate disorders. Rett’s Disorder, which is rare and occurs only in girls, is not generally considered part of such a spectrum.

In this chapter, unless otherwise specified, "autism" is used to refer to these disorders collectively, with the most emphasis on Autistic Disorder followed by Asperger’s Disorder.

3. Associated problems

Individuals with autism often have other medical problems as well. Seventy percent are mentally retarded; twenty-five percent suffer from epilepsy; and smaller numbers suffer from attentional deficits, and aggressive and impulsive disorders (Teeter & Semrud-Clikeman, 1997), as well as fragile-X syndrome and an increased rate of minor physical anomalies (Koegel, Valdez-Menchaca, & Koegel, 1994).

4. Prevalence

Autism occurs in 5 of every 10,000 people (Fombonne, 1998); estimates of Asperger’s Disorder are similar (Volkmar & Klin, 2000). Autism is highly genetic: rates are very high for identical twins with estimates as high as 98% (Szatmari & Jones, 2000). The rates for fraternal twins and non-twin siblings of affected individuals are considerably higher than in the general population, although lower than that for identical twins (Volkmar & Klin, 2000). One estimate of the genetics of autism, based on statistical modeling of the prevalence of autism among families, suggests that there are two to five genes which predispose the bearer to develop autism (Cook, 2000).

5. Treatments

Although there is no cure for autism, behavioral and pharmacological treatments are effective in reducing some of the symptoms. Behavioral treatment focuses on teaching new skills, particularly social skills, and attempts to decrease maladaptive behavior (Harris, 1998). Early intervention with behavioral therapy can be helpful. Drugs can reduce symptoms of autism such as anxiety, aggression, and compulsive behavior.

In addition, unproven and frequently ineffective treatments for autism abound. Many of these are supported with at best poorly done research studies and at worst only anecdotal information. Parents are often attracted to these because they want the best for their child, and conventional treatments seem to offer little in comparison with impressive claims of healing. Unfortunately, these treatments are often expensive and result in little in the way of improvement. Unproven treatments, and other controversial issues related to autism, are more fully discussed in the links.

6. Outcome

Most individuals with autism need complete supervision all their lives, some achieve independence, and many are somewhere in between (Howlin & Goode, 1998); they may hold a job, but still live at home. Those who do achieve some degree of independence often remain socially isolated; many have difficulty with achieving close friendships and some do not desire to do so. Individuals with better outcomes tend to be those with higher verbal ability, intelligence, and education; success depends on both the severity of autism as well as environmental factors. Girls tend to be more severely affected by autism and do less well in adult life than do boys.