Autism

Happiness

Clinical psychology

Psychiatry

Developmental psychology

Cognition

Psychosocial

Psychology

Intelligence quotient

Autism spectrum disorder

Autism Diagnostic Observation Schedule

Neurodevelopmental disorder

Intellectual disability

Social psychology

Wechsler Adult Intelligence Scale

Longitudinal data on the functioning of adults referred for possible autism as children are sparse and possibly different from datasets consisting of adult clinical referrals. A total of 123 young adults, mean age of 26, referred for neurodevelopmental disorders in early childhood were categorized into three outcome groups: autism spectrum disorder (ASD) diagnosis at some point and current intelligence quotient (IQ) ⩾ 70 (Ever ASD-Higher IQ), ever ASD and current IQ &lt; 70 (Ever ASD-Lower IQ), and individuals who never received an ASD diagnosis (Never ASD). Independence and well-being were assessed through direct testing, questionnaires, and interviews. Verbal IQ, beyond intellectual disability status, accounted for group differences in employment; autistic features (Autism Diagnostic Observation Schedule Calibrated Severity Score) were uniquely related to adaptive skills and friendships. In many ways, the Never ASD group had similar outcomes compared to the ASD groups. However, lower well-being and fewer positive emotions were related to ASD diagnosis across IQ. The Ever ASD-Lower IQ group had the highest levels of irritability, hyperactivity, and medications. Families played a major role in supporting adults with and without ASD at all intellectual levels. Realistic ways of increasing independence should be developed through working with adults and their families, while acknowledging the contribution of individual differences in mental health, intelligence, and autism symptoms across neurodevelopmental disorders. Lay abstract It is important to better understand how adults with autism are functioning in adulthood. Studies that have tracked individuals across the lifespan can help identify developmental factors influence differences in adult outcomes. The present study examines the independence, well-being, and functioning of 123 adults that have been closely followed since early childhood. Autism diagnosis and cognitive assessments were given frequently throughout childhood and during adulthood. We examined differences between adults who had received an autism diagnosis at some point with higher cognitive abilities (Ever ASD-High IQ) and lower cognitive abilities (Ever ASD-Low IQ), as well as adults who never received a diagnosis of autism in the course of the study (Never ASD). We found that autistic features specifically related to adaptive skills and friendships, and verbal intelligence related to work outcomes. In many ways, the Never ASD group had similar outcomes compared to the ASD groups. However, adults with ASD tended to have lower well-being and fewer positive emotions. Families played a major role in supporting adults with and without ASD at all intellectual levels. The findings suggest that realistic ways of increasing independence need to be developed by working with adults and their families, while acknowledging the contribution of individual differences in mental health, intelligence and autism symptoms across neurodevelopmental disorders.

Work, living, and the pursuit of happiness: Vocational and psychosocial outcomes for young adults with autism