Eyes wide open: A systematic review of the association between insomnia and aggression in forensic contexts

Sleep quality has been highlighted as a significant predictor of violent behavior through lifespan and across pathologies and a causal link has also been suggested. Despite the high prevalence of insomnia and its potential impact as a modifiable risk factor for aggressive behavior, a comprehensive synthesis of the literature is lacking. We aimed to systematically review the published works exploring the role of sleep in aggressive behaviors, especially focusing on forensic contexts. We performed a systematic review searching the electronic databases PubMed and Scopus through December 2020 and selected articles that compared sleep of offenders and controls and articles that studied the association between sleep and aggression. Ten articles were selected: 2 compared sleep in offenders and controls and 8 studied the association between sleep and aggression. Offenders showed worse sleep features than control both objectively and subjectively measured. Sleep quality was associated with aggression, but sleep quantity was less studied. Sleep seems to have a prominent role in aggressive behaviors but studies concerning this topic are few; samples and methods were highly heterogeneous and most studies were cross-sectional. Future studies are needed to clarify the association between sleep disturbances and aggression, adopting a more systematized approach. Sleep assessment and treatment and might be particularly useful, especially in high-risk populations.