Click here to view next page of this article

 

Autism and Autistic Disorder

Autistic disorder is characterized by sustained impairments in reciprocal social interactions, communication deviance, and restricted, stereotypical behavioral patterns. According to DSM-IV, abnormal functioning in the above areas must be present by age 3 years. More than two thirds of autistic persons function on a secretin

EPIDEMIOLOGY

Prevalence

Most of the epidemiological surveys have found rates of 4 to 5 out of 10,000. However, recent studies have found higher rates, which may be attributed to more thorough case ascertainment, more uniform (or perhaps broader) diagnostic criteria, and, in some studies, earlier age at onset.

Sex ratio

The higher incidence of autism in boys than in girls has been well documented, with ratios of 2.6 to 1 common and ratios up to 4 to 1 found in some studies. Girls are often more severely affected.

ETIOLOGY

Biological theories

Early clues to the biological basis of autism included the high rate of associated mental retardation, the 4 to 1 male-female ratio, the increased incidence of seizure disorders, and the recognition that medical and genetic conditions such as congenital rubella and untreated phenylketonuria could be associated.

DIAGNOSIS AND CLINICAL FEATURES

The diagnosis of autistic disorder requires that a certain number of criteria in three symptom areas of social interaction, verbal and nonverbal communication and play, and repertoire of activities and interests be met. However, children meeting criteria for autistic disorder may appear very different from one another owing to differences in intellectual and language ability: Both the mute, aloof child and the one who asks grammatically perfect but inappropriately personal questions of strangers.

Age at onset

Onset characteristically occurs before age 3 years and is marked by failure to develop language and failure to develop relatedness to parents--the most frequent reasons parents of autistic children.

Qualitative impairment in social interaction

The social impairment in autistic disorder was viewed by Kanner as the core deficit in a...

The nature of the social impairment in autism varies with the child's developmental level, and its severity often decreases as the child gets..

Qualitative impairment in verbal and nonverbal communication and play

Delays and abnormalities in language and speech are frequent presenting complaints of parents, and up to 50 percent of autistic children remain without spoken language. Babbling, which precedes words, may be absent. Autistic children often do not comprehend language spoken to them or have a selective disinterest...

Autistic children often repeat words immediately heard (immediate echolalia) or heard in the past (delayed echolalia) without intent to communicate. When asked a question, they may repeat the question asked so...

Children with autism who do have communicative speech have difficulty having a conversation as they do not know how to take turns, maintain a topic, or look at their conversational partner. They may repeat questions over and over again even though they know the answer, or they may engage in...

Markedly restricted repertoire of activities and interests

Autistic children resist change in their environment and new routines. For example, the child may exhibit distress if the usual route to the supermarket is not taken or the bowl he or she is accustomed to eating

Associated features
COGNITIVE IMPAIRMENT

Approximately 75 to 80 percent are mentally retarded, with the majority functioning in the moderate range of retardation. The retardation is not a consequence of social isolation, lack of motivation, or negativity

ABNORMALITIES OF MOTOR BEHAVIOR

Most autistic children display stereotypies, such as hand flapping and rocking, with the most severe stereotypies occurring in the most intellectually impaired. Motor mannerisms may be seen, such as odd

ABNORMAL RESPONSES TO SENSORY STIMULI

Some children exhibit hypersensitivity to sound (hyperacusis) and cover their ears when they hear loud noises such as firecrackers exploding, dogs barking, or police sirens wailing. Other children may appear

SLEEPING AND EATING DISTURBANCES

Sleep disturbances, such as reversal of sleep pattern and recurrent awakening at night, and

MOOD AND AFFECT DISTURBANCES

Some autistic individuals show sudden mood changes and may laugh or cry for no apparent reason. It is not uncommon to see autistic children giggling to themselves. Some children are emotionally fragile.

SELF-INJURIOUS BEHAVIOR AND AGGRESSION AGAINST OTHERS

Autistic children may bite their hands or fingers, which may lead to bleeding and callous formation. Head banging may result in welts and frontal bossing. They may pick their skin, pull their hair, bang on their

SEIZURE DISORDERS

Epileptic seizures occur in approximately 10 to 25 percent of autistic persons. The development of a seizure disorder is highly correlated with the severity of mental retardation and the level of ...

COURSE AND PROGNOSIS

Although most autistic children show improvement in social relatedness and language ability with increasing age, autistic disorder remains a lifelong disability, with the majority of persons so affected

TREATMENT

Behavior therapy

Behavior therapy, which uses specific behavior modification procedures, may be helpful in establishing desired behaviors and eliminating problem behaviors in autistic children. After a behavioral analysis is performed, techniques such as shaping or prompting are used to develop desired responses, which are then reinforced by increasingly mature rewards. However, autistic children may fail to generalize.

Psychotherapy

With the recognition of the biological basis of autism came the realization that psychodynamic psychotherapy in young autistic children, including unstructured play therapy, was not appropriate.

Psychopharmacological treatment

In a subgroup of autistic children with target symptoms, such as temper tantrums, aggressiveness, self-injury, hyperactivity, and stereotypies, appropriate psychoactive agents may be an important part of a comprehensive treatment program. Clinical and laboratory monitoring is recommended throughout

ANTIPSYCHOTICS

It was hypothesized that the stereotypies and hyperactivity seen in many autistic children were a function of increased dopaminergic activity. That was the rationale for the use of antipsychotics, which block dopamine receptors, in autistic children. In individually regulated doses of 0.25 to 4.0 mg a day, or from 0.016 to 0.217 mg/kg a day, the high-potency antipsychotic haloperidol proved...

FENFLURAMINE

The finding of hyperserotonemia in one third of autistic children led to the hypothesis that autistic symptoms may be due to increased brain serotonin levels. That hypothesis in turn led to the study of

NALTREXONE

Similarities between the behaviors of autistic children and the behaviors of opiate addicts while intoxicated and during withdrawal led to the theory of opioid dysregulation in autism. Case reports and open trials

SYMPATHOMIMETICS

The efficacy of amphetamines was investigated in autistic children because hyperactivity and inattention, frequently seen in such children, are ameliorated by amphetamines in nonautistic children with

CLOMIPRAMINE

Clomipramine (Anafranil), an antidepressant, inhibits the reuptake of serotonin, which has been implicated in the pathogenesis of autistic disorder. A recent double-blind, placebo-controlled crossover study found clomipramine to be superior to both desipramine (Norpramin) and placebo in decreasing

CLONIDINE

The possibility that some symptoms of autism reflect hyperarousal and dysregulation of the adrenergic system led to the study of clonidine (Catapres), an alpha2 -adrenergic agonist that reduces noradrenergic

The efficacy of various other psychopharmacological agents, including buspirone (BuSpar), propranolol (Inderal), and fluoxetine, in a few autistic persons.

More