Unintended consequences: college students' melatonin usage, sleep disturbance, and depressive symptoms.

With such high rates of undergraduate sleep problems, students have chosen to take melatonin, an over-the-counter supplement that can facilitate sleep. Questions remain as to the effectiveness of melatonin for sleep problems, and questions have emerged about its impact on mental health. Accordingly, the current study examined how ongoing melatonin usage might impact relative changes in college students' sleep disturbance and ultimately their depressive symptoms. The two-wave (baseline and 2-month follow-up), online sample consisted of 331 undergraduates (86% female; M age  = 21.3, SD  = 2.4), who reported on melatonin usage, sleep disturbance, and depressive symptoms. Controlling for sleep hygiene, socio-economic status, and gender, our model demonstrated a significant indirect effect from ongoing melatonin usage to depressive symptoms. Specifically, melatonin consumption predicted relative increases in sleep disturbance, which, in turn, predicted corresponding increases in students' depressive symptoms. Given the increasing prevalence of melatonin usage, the potential for unforeseen consequences remains high. Results suggest that the negative consequences of melatonin use can include both college students' mental health and their sleep. Given the efficacy of addressing sleep problems with cognitive or behavioral strategies, it is essential that student support services highlight alternatives to melatonin and the potential problems associated with its use.