This work may not be copied, distributed, displayed, published, reproduced, transmitted, modified, posted, sold, licensed, or used for commercial purposes. By downloading this file, you are agreeing to the publisher’s Terms & Conditions.

Original Research

Insomnia as a Risk for Depression: A Longitudinal Epidemiologic Study on a Japanese Rural Cohort

Isa Okajima, PhD; Yoko Komada, PhD; Takashi Nomura, MD, PhD; Kenji Nakashima, MD, PhD; and Yuichi Inoue, MD, PhD

Published: October 4, 2011

Article Abstract

Objectives: To determine (1) whether insomnia is a factor related to the presence or persistence of depression for 2 years in the Japanese population and (2) which component of insomnia is associated with the presence of depression for 2 years in a rural cohort.

Method: This is a community-based longitudinal study. Two thousand eight hundred twenty-five people aged 20 years or older were evaluated at baseline, and of those participants, 1,577 (56%) were reevaluated after 2 years. During both surveys, the participants were asked to describe demographic variables and to fill out self-rating scales of insomnia (Pittsburgh Sleep Quality Index [PSQI]) and depressive symptoms (Center for Epidemiologic Studies Depression Scale).

Results: The results of a multiple logistic regression analysis showed that depression (OR = 6.0; 95% CI, 4.4-8.0) and insomnia (OR = 2.1; 95% CI, 1.5-2.8) at baseline were significantly associated with the presence of depression at the follow-up. Most of the PSQI subscales, except for sleep duration and habitual sleep efficiency, were significantly associated (P < .01) with the presence of depression at the follow-up. In addition, the new appearance and repeated existence of depression at the follow-up were related to persistent insomnia (adjusted ORs = 7.0 and 3.3 [P < .001], respectively). A result of the receiver operating characteristic curve showed that persons with insomnia whose PSQI scores exceeded 8 points at the baseline were most likely to still have insomnia at the follow-up (cutoff point = 7.5).

Conclusions: On the basis of our results in a Japanese population, insomnia with high severity level could be a risk factor for the presence/persistence of depression in the long-term prognosis.

J Clin Psychiatry 2012; 73(3):377-383

Volume: 72

Quick Links:

Continue Reading…

Subscribe to read the entire article


Buy this Article as a PDF