Mild sleep disturbance as a vulnerability factor for inflammation-induced depressed mood in women: An experimental study

Abstract

Sleep disturbance and depression are major public health burdens, particularly in women, and sleep disturbance is a well-known risk factor for depression. Systemic inflammation has been suggested as a potential mechanism of this association. This study examined whether self-reported sleep disturbance acted as a vulnerability factor for inflammation-induced depression among healthy women. Healthy women aged 18–50 (N = 67) were randomly assigned to receive either placebo or low-dose endotoxin (0.8 ng/kg). Self-reported depressed mood was repeatedly assessed over 6 h. Participants exposed to endotoxin, compared with placebo, showed greater increases in depressed mood over time according to mixed-effects model regression (X2 = 28.35, df = 6, p = 0.0001). To examine whether sleep disturbance enhances depressive responses to endotoxin, moderation was tested for sleep disturbance assessed using the Pittsburgh Sleep Quality Index (PSQI) as a binary variable using median split (PSQI global score ≥3 vs.