Personality traits and insomnia: direct and anxiety-mediated associations.

Insomnia is the one of the most prevalent sleep disorders in the adult population. Studies have shown that personality traits, particularly neuroticism, act as factors that predispose to and potentially perpetuate insomnia; however, there is still no consensus in the literature regarding these relationships considering their mechanisms. A total of 595 participants answered the Insomnia Severity Index, Revised Neuroticism-Extroversion-Openness (NEO) Five-Factor Inventory, Hospital Anxiety and Depression Scale, questions of the Diagnostic and Statistical Manual of Mental Disorders (fifth edition), and a sociodemographic questionnaire. Descriptive analysis, correlations and stepwise linear regression were used to assess the associations between the five personality traits and insomnia severity. Mediation and moderation analyses were performed to evaluate the mechanisms underlying the association between insomnia severity and neuroticism. There was a direct negative association between insomnia severity and openness to experience and an indirect positive association between insomnia severity and neuroticism. Anxiety was identified as a mediator and depression as a moderator of the association between insomnia severity and neuroticism. The neuroticism and openness to experience personality traits are significant predictors of insomnia severity. Openness to experience appears to be a protective factor against insomnia. Longitudinal studies are needed to confirm our findings. These results may contribute to the development of new psychological and behavioural protocols for the treatment of insomnia.