Higher sleep reactivity and insomnia mutually aggravate depressive symptoms: a cross-sectional epidemiological study in Japan

Objective Sleep reactivity assessed using the Ford Insomnia Response to Stress Test (FIRST) is associated with depression. This study clarified stress reactivity and insomnia effects on depressive symptoms. Methods A cross-sectional questionnaire survey was administered to 2645 participating government employees (35.4% female, mean age 42.8 years) during health checks conducted at Tottori prefecture, Japan, in June 2012. Questionnaire items included: demographic information; the FIRST; the Pittsburgh Sleep Quality Index (PSQI); and a 12-item version of the Center for Epidemiological Studies Depression scale (CES-D). The study defined CES-D scores of ≥12 points as positive for depression, PSQI scores of ≥5.5 points as positive for insomnia symptoms, and FIRST scores of ≥19 points as indicating higher sleep reactivity. Results Multivariate logistic regression analysis revealed insomnia (adjusted OR = 3.40), higher sleep reactivity (adjusted OR = 1.78), presence of disease currently being treated (adjusted OR = 1.84), and being female (adjusted OR = 1.53) as independently associated with depression. Participants with insomnia and a high FIRST score showed higher CES-D scores than those with insomnia alone and those with high FIRST without insomnia (all p < 0.01). Conclusions Sleep reactivity might be associated with depression, independent of insomnia. Elevated sleep reactivity and insomnia symptoms are thought to aggravate depressive symptoms.