ASD-Related and Psychiatric Symptomatology Across the Adult Lifespan
Although autism spectrum disorder (ASD) is considered a lifelong neurodevelopmental disorder, knowledge on the condition in middle and late adulthood is still limited. A steadily increasing number of studies suggest that some behavioral symptoms might abate over time, even though outcome is rather poor and the diagnosis is rarely waived. Psychopathology frequently co-occurs with ASD, but whether psychiatric symptoms and disorders, representing an important target for treatment, also diminish across the adult lifespan remains largely unknown.
The aim of this cross-sectional study is to investigate the relationship between age and ASD symptomatology (including social-emotional reciprocity and sensory sensitivity), and psychiatric symptoms and disorders.
We administered self- and proxy-reported questionnaires (Autism-spectrum Quotient, Interpersonal Reactivity Index, Sensory Sensitivity Questionnaire, Symptom Checklist-90) and a neuropsychiatric interview (Mini International Neuropsychiatric Interview) to 435 adults with and without ASD (age range 19-79 years, IQ>80).
Self-report was poorly concordant to proxy-report, suggesting that both measures reveal different aspects of ASD symptomatology. Moreover, although age-related differences in social-emotional reciprocity were not observed, general and sensory symptoms increased in middle adulthood and decreased in late adulthood. High levels of depression, anxiety, and psychological distress characterized individuals with ASD across adulthood. More specifically, 79% experienced a psychiatric disorder at least once in their lives, and depression and anxiety disorders were most common. Nevertheless, older adults with ASD less often met criteria for any psychiatric diagnosis and, specifically, for social phobia.
The high number of self-reported ASD symptoms and the persistence of these symptoms across the adult lifespan, underline the lifelong nature of this neuropsychiatric condition. However, despite consistently high levels of psychological distress, lifetime diagnoses for any psychiatric disorder occurred less often in older adults than in younger adults, suggesting reduced psychopathology in late adulthood.