Cognitive emotion regulation difficulties increase affective reactivity to daily-life stress in autistic adolescents and young adults.

 = 55, age = 18.1) adolescents and young adults. We used the ecological momentary assessment, a technique that allows to assess individuals repeatedly in their daily life using their smartphone. Moreover, participants filled a questionnaire to evaluate the strategies they use to regulate emotions when faced with difficulties. Finally, a clinical interview and a parent-report questionnaire were used to assess mental health symptoms. Autistic youth reported higher levels of perceived daily stress compared with non-autistic peers. Moreover, they showed increased affective reactivity to stress related to their daily activities. Autistic participants reported more emotion regulation difficulties (e.g. more repetitive thinking of difficulties) compared with non-autistic participants. Difficulties in emotion regulation increased negative emotions in relation to stress and might contribute to the severity of mental health symptoms. We conclude that adolescents and young adults with autism report high perceived stress in their daily lives. To minimize the negative impact of stress and the development of mental health symptoms, people supporting autistic young people could focus on stress management skills and the strategies that the youth use to manage emotions.