MADISON, Wis. -- Symptoms of autism, including maladaptive behaviors and impaired social interactions, appear to lessen over time in a significant percentage of patients studied over nearly five years.
MADISON, Wis., Sept. 27 -- Symptoms of autism, including maladaptive behaviors and impaired social interactions, appear to lessen over time in a significant percentage of patients.
In a study of 241 adolescents and adults here and in Massachusetts with autism spectrum disorders, who were followed for nearly five years, many had stable symptoms, but a greater percentage had declines in their levels of autistic symptoms, reported Paul T. Shattuck, Ph.D., M.S.S.W., now at Washington University in St. Louis.
But even with improvement, most of the patients in their sample remained seriously impaired, pointing to a need for continued intervention, the investigators wrote in the October issue of the Journal of Autism and Developmental Disorders.
"On average, people are getting better," said Dr. Shattuck. "It is a hopeful finding, but the fact remains that those with severe autism will depend on others for their everyday needs and care for the rest of their lives."
The investigators conducted a study to get a better grasp on the prevalence of autism symptoms and maladaptive behaviors among teens and adults with autism spectrum disorders from, and to determine predictors of change over time.
The patients in the community sample were 10 or older at enrollment, had received a diagnosis of autism spectrum disorder (autistic disorder, Asperger disorder, or pervasive developmental disorder not otherwise specified), and to have had a researcher-administered Autism Diagnostic Interview-Revised (ADI-R).
Data were collected every 18 months via two- to three-hour interviews with family members. The 241 patients were followed from baseline through fourth follow-up, at 4.5 years.
The patients ranged from 10 to 52 years at baseline (mean 22, + 9.7); two-thirds of the patients ranged from 10 to 21. Three-fourths of the patients were male. About two-thirds of the patients (68.5%) also had a diagnosis of mental retardation.
The authors saw decreases over time in the broad domains of communication, social reciprocity, and repetitive behaviors and stereotyped interests. They looked at 32 specific symptoms within those domains.
They also evaluated broader maladaptive behaviors not specific to autism, such as aggression and self-injury.
They found that "for all major symptoms, the percentage of people who improved was always greater than the percentage who worsened," Dr. Shattuck said. "If there was significant symptom change over time, it was always in the direction of improvement, though there was always a group in the middle that showed no change. The mean never went down."
In terms of percentages, the largest changes were decreases in repetitive behaviors and stereotyped interests. For example, there was an 18.3% decrease in mean scale scores for circumscribed interests, a 15.8% decline in unusual preoccupations, and a 15.8% decline in unusual sensory interests.
Other areas of change included decreased deficits in reciprocal conversations, inappropriate questions or statements, direct gaze, and smiling in social situations.
Nonverbal communication impairments improved in 26.1% of all patients in the sample, stayed the same in 54.4%, and worsened in 19.5%.
Verbal communication impairments in the 179 patients who were verbal at baseline improved in 51.4%, remained unchanged in 22.9%, and deteriorated in 25.7%.
Impairments in social reciprocity among all 241 patients improved in 32.0%, were unchanged in 53.5%, and got worse in 14.5%.
Repetitive behaviors and stereotyped interests, again in all 241 patients, improved in 58.5%., stayed the same in 24.1%, and worsened in 17.4%.
They also found that for seven of eight maladaptive behaviors there was significant decrease over time. The seven behaviors were unusual or repetitive habits, withdrawal or inattentive behavior, hurtful to self, hurtful to others, destructive to property, socially offensive behaviors, and uncooperative behavior. For the eighth - disruptive behavior - there was a trend toward decrease, but this was not significant.
"Whereas the overall trend across measures was one of improvement, approximately half of the sample remained stable between [baseline] and [most recent follow-up] with respect to nonverbal communication impairments, impairments in social reciprocity, and all measures of maladaptive behaviors," the authors wrote. "Although worsening of symptoms was observed in only a small minority of sample members, identification of factors differentiating those whose symptoms and maladaptive behaviors worsened is warranted in future research."
The authors noted that autism treatment services are more widely available for children than for teens and adults, but the analysis indicates that both symptoms and behaviors can improve among older patients with autism spectrum disorders as well.
"Over time, patterns of improvement represent the product of interactions among the autism spectrum disorder genotype, the autism spectrum disorder behavioral phenotype, and the environment, including the family environment, treatments, and interventions," they wrote.
They also cautioned against reduction or withdrawal of services from older patients with autism spectrum disorder "under the false assumption that this population's impairments will spontaneously remit to a point where assistance and supervision is not required."
The authors acknowledged that the study was limited by its relatively short follow-up and by the use of parent-guardian reports rather than direct observation.