RESUMEN
Disruption in routine may be related to experiencing negative emotional states and to aggressive behaviors in individuals with Autism Spectrum Disorder (ASD). The lockdown because of COVID-19 contributed to the disruption of individuals' routines, including the sleep−wake cycle. The current study tested a relationship between the adherence to the sleep−wake routine and aggressive behaviors via the mediation role of negative emotional states (i.e., anxiety and anger). Forty-three parents of adults with ASD completed a web-based questionnaire about their life condition during the first lockdown (April−May 2020). Preliminary analyses showed a worsening in the adults' aggressive behaviors during the lockdown in comparison to before it (Z = −3.130; p = 0.002). In the mediation models, the relationship between the adherence to the sleep−wake routines and aggressive behaviors was significant. The models showed the hypothesized mediated relationships among the adherence to the sleep−wake routines, negative emotional states, and aggressive behaviors (Model 1: F (1, 41) = 10.478, p < 0.001; Model 2: F(1, 41) = 9.826, p = 0.003). The findings confirmed the potential protective role of the adherence to the sleep−wake routines for the emotional and behavioral adjustment of adults with autism. Theoretical and practical contributions of the study were discussed; indeed, our results may inform parent-coaching as well as intervention programs for individuals with ASD given that adequate sleep hygiene may contribute to improvements in internalizing/externalizing behaviors.