Correlations among insomnia symptoms, sleep medication use and depressive symptoms

Aim: To elucidate the factors associated with insomnia symptoms and the use of sleep medication, and the correlations among insomnia symptoms, sleep medication use and depressive symptoms in the general population. Methods: This survey was conducted in a rural community of Japan. Questionnaires consisted of basic information, the Pittsburgh Sleep Quality Index, and a 12-item version of the Center for Epidemiological Studies Depression scale, and were administered to all community members aged 20 years or over. A total of 2822 respondents with valid answers were subjected to analysis. Results: Occurrence of insomnia symptoms appeared to be associated with advancing age and existence of depressive symptoms. The extent of sleep medication use in the entire sample was 9%, and the value in the subjects with insomnia symptoms was 26%. Sleep medication use in insomniacs was associated with female sex and advancing age as well as higher scores in subcomponents of both poor subjective sleep quality and prolonged delay of sleep onset. Depressive symptoms were worst in the group with insomnia symptoms using sleep medication, and were significantly lower in the group without insomnia symptoms using sleep medication. Conclusions: Our study revealed that female sex, advancing age, depressive symptoms, poor sleep quality, and prolonged delay of sleep onset appeared as risk factors for sleep medication use. Insomnia symptoms were suspected to act as an exacerbating factor for depressive symptoms. However, our findings suggested that appropriate use of sleep medication could reduce depressive symptoms in the subjects with insomnia symptoms.