Sleep quality among adults with attention deficit hyperactivity disorder or autism spectrum disorder: which is the role of gender and chronotype?

Both Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) present increased prevalence rates of sleep difficulties, which persist into adulthood. However, it is still unclear whether in adults these disorders show specific sleep patterns and which role is played by comorbidities, circadian preferences and gender. This study aimed to describe and compare subjective measures of sleep in adults with ADHD and high-functioning ASD, in relation to the levels of anxiety and depression, chronotype and gender. In a sample of 136 adults (43 ADHD, 43 high-functioning ASD, 50 controls) subjective sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI), and clinical scales were used to assess chronotype and the levels of anxiety and depression. The three groups showed a significant difference in the distribution of chronotypes, with greater prevalence of an Evening chronotype among ASD compared to controls. The MANCOVA using PSQI subscale scores as dependent variables and MEQ-SA score and depression range as covariates showed that the three groups significantly differ in quality, latency, efficiency, and dysfunction scores with a significant differences between ASD and ADHD in efficiency and dysfunction. Compared to men, women showed higher scores on PSQI total and quality subscale across the three groups and higher duration scores only within ASD group. Our results indicate that both ADHD and ASD adults show unique sleep disturbances and suggest that ASD patients, especially women, may display more pronounced disordered sleep.