Abstract
Background: Affective temperaments predispose to life adaptation and affective disorders. The relationship between temperaments and sleep quality is rarely investigated in community-based studies. We hypothesized that cyclothymic-related temperaments relate to worse sleep quality, whereas the hyperthymic temperament favours sleep quality.
Method: We investigated 3701 18 to 65 years old adults from the population-based CHRIS study in Italy. Participants were 54 % females, mean age 38.5 years. The Pittsburgh Sleep Quality Index (PSQI) was the primary outcome score. Five affective temperaments split into quartiles for direct comparison from the TEMPS-M questionnaire were the exposures of interest. Additional covariates comprised sex, age, trait anxiety, and sleep quality-related lifestyles assessed via interviews, self-administered questionnaires or instrumental measurements.
Results: The hyperthymic temperament showed a negative association (better sleep quality) with the global PSQI, whereas the cyclothymic-related temperaments had all associations in opposite direction. While inclusion of trait anxiety appeared to mediate some results, the anxious and other cyclothymic related temperaments were still directly associated with multiple dimensions of poor sleep quality.
Limitations: The cross-sectional design, possible selection into the study by temperamental background or sleep disorders, and no clinically validated self-assessed psychiatric constructs represent possible weaknesses.
Conclusions: Our findings support the hypothesis of a biological binary diathesis of affective temperaments, with hyperthymic and cyclothymic-related temperaments predisposing sleep quality in an antithetical way.