These Personality Traits Are Strong Predictors of Insomnia Severity

Personality traits such as neuroticism and openness to experience can predispose to or potentially perpetuate insomnia, according to the findings of a study published in the Journal of Sleep Research.

Researchers conducted a cross-sectional study to assess the interaction between personality traits and insomnia. Participants aged between 18 and 59 years with and without insomnia were recruited in 2021 and 2022 from the University Hospital of the University of São Paulo Medical School in Brazil. Insomnia was defined using criteria from the Diagnostic and Statistical Manual of Mental Disorders (DSM-5); and participants in the insomnia group underwent medical and neuropsychiatric assessment prior to study initiation.

Enrolled participants answered self-administered questionnaires such as the revised Neuroticism-Extroversion-Openness Five-Factor Inventory (NEO-FFI-R), Insomnia Severity Index (ISI), and the Hospital Anxiety and Depression Scale (HADS). Multivariate linear regression models and mediation analyses were employed for statistical analysis.

A total of 595 participants were enrolled, including 242 individuals without insomnia (mean age, 36.9 years; women, 86%) and 353 individuals with insomnia (mean age, 40.0 years; women, 78%). The neuroticism score was higher in individuals with insomnia compared with those without insomnia; those with insomnia also had lower scores on openness, agreeableness, conscientiousness, and extraversion.

Strong and significant correlations (r >0.5) were observed between anxiety and depression, insomnia severity and anxiety, neuroticism and anxiety, and neuroticism and depression. A moderate, positive correlation was observed between insomnia severity and neuroticism (r >0.3).

Linear regression showed that age, educational level, and financial instability were significant predictors of insomnia. After controlling for personality traits and accounting for anxiety and depression, significant predictors for insomnia included age, sex, openness, anxiety, and depression. The association between insomnia and neuroticism was shown to be mediated by symptoms of anxiety.

Depression was not a significant mediator between neuroticism and insomnia; however, depression score did moderate the relationship between neuroticism and severity of insomnia. An increase in depression scores was found to weaken the positive relationship between neuroticism and insomnia severity.

Study limitations included a cross-sectional design and self-reported sleep measures and variables.

“The present study demonstrated that neuroticism and openness to experience personality traits are significant predictors of insomnia severity. In the case of neuroticism, the association is fully mediated by anxiety symptoms and moderated by depression symptoms,” the researchers concluded.