Melatonin moderates the relationship between insomnia and Major Depressive Disorder

Sleep dysfunction is one of the cardinal symptoms of Major Depressive Disorder (MDD). The aim of this study was to investigate if improvements in sleep from use of melatonin would improve depressive symptoms in study participants. We hypothesized that participants who took melatonin would score lower on the Center for Epidemiological Studies Depression scale (CESD) and on the Pittsburgh Sleep Quality Index (PSQI). Participants recruited from Amazon’s MTurk and from American University’s human research participant pool (HRPP) answered a survey assessing depressive symptoms, sleep disturbances, melatonin use, and sleep hygiene. At a critical p value of .05, results showed that melatonin moderated the relationship between depression and insomnia, that depression and sleep hygiene were positively correlated, and that there was a relationship between sleep hygiene and melatonin use. There was no direct relationship between melatonin use and depression or insomnia symptoms. Future research in this area could examine the relationship between sleep hygiene and depression or between sleep hygiene and use of sleep medication.