# Circadian preference and quality of life in adults with autism spectrum disorder: a Brazilian cross-sectional self-reported survey

## TL;DR

Adults with autism who prefer evening activity report lower quality of life, suggesting that sleep patterns may impact well-being in this group.

## Contribution

This study is the first to show that evening chronotype independently predicts lower quality of life in adults with autism.

## Key findings

- Evening chronotype was associated with significantly lower overall and physical health quality of life scores.
- Unemployment, low income, tobacco use, and physical inactivity were also independently linked to lower quality of life.
- Intermediate chronotype was the most common among participants, followed by evening and morning types.

## Abstract

Adults with Autism Spectrum Disorder (ASD) often experience significant challenges that affect their quality of life (QoL), including mental health issues, socioeconomic strain, and circadian rhythm disruptions. Chronotype, or an individual’s biological preference for sleep-wake patterns, has been associated with well-being in neurotypical populations but remains underexplored in adults with ASD. This study aimed to investigate the association between chronotype and perceived QoL in Brazilian adults with ASD.

We conducted a cross-sectional, web-based survey as part of the SOLACE-ASD Brasil project. A total of 439 adults (≥ 18 years) with a self-reported diagnosis of ASD completed standardized questionnaires assessing chronotype (Morningness-Eveningness Questionnaire) and QoL (EUROHIS-QOL 8). Sociodemographic, behavioral, and clinical variables were also collected. Associations were examined using multiple linear regression and ANCOVA, adjusting for potential confounders.

Intermediate chronotype was the most prevalent (40.1%), followed by evening (38.7%) and morning (21.2%) chronotypes. Overall, 60.4% of participants reported low QoL. Evening-type individuals had significantly lower overall and physical health QoL scores than morning and intermediate types. In multivariate analysis, evening chronotype, unemployment, low income, tobacco use, and physical inactivity were independently associated with lower QoL.

Chronotype is an independent predictor of QoL in adults with ASD, with evening preference linked to worse outcomes. These findings highlight the importance of considering circadian biology in public health strategies and suggest that chronotype-targeted interventions could improve QoL in this population.

The online version contains supplementary material available at 10.1007/s11136-026-04176-1.

Adults with autism spectrum disorder (ASD) often face challenges that affect their daily lives, including mental health struggles, sleep problems, and limited access to work or social support. This study explored whether a person’s natural sleep pattern, called chronotype, is related to how they feel about their quality of life. Chronotype refers to whether someone tends to be more active in the morning, in the evening, or somewhere in between. The study included 439 adults with ASD in Brazil who answered online surveys about their daily habits, health, and well-being. Most participants reported low quality of life, especially those who preferred staying up late (evening chronotype). These individuals also had more physical health complaints. The main finding is that having an evening chronotype is linked to lower quality of life in adults with ASD, even when other factors like income, employment, and physical activity are considered. This means that sleep-wake patterns may play an important role in how adults with ASD experience daily life. These results suggest that helping adults with ASD create better sleep routines, or adjusting work and school schedules to fit their natural rhythms, might improve their well-being.

The online version contains supplementary material available at 10.1007/s11136-026-04176-1.