Guoliang Li1, Xuezhi Li2,Debiao Liu,1  Li Li 3, Ying Li 4, Yan Liu*2

1 School of Mental Health, Jining Medical University, Jining, 272067, China
2 Shandong Key Laboratory of Behavioral Medicine, School of Mental Health, Jining Medical University, Jining, 272067, China
3 Jining Taibaihu New District Construction Bureau, Jining, 272067, China
Library of Jining Medical University, Jining 272067, China

Backgrounds:  Major depressive disorder (MDD) is a potentially debilitating psychiatric disorder affecting more than 300 million people worldwide.1 According to statistics, unipolar depression occurs in 7% of the general older population and it accounts for 5.7% of YLDs among those over 60 years old.2 Depression in old age is often not treated effectively because it is considered a normal part of aging in older people and a natural response to chronic diseases, deaths and negative life events.3 The aim of this study is to conduct a systematic review and meta-analysis of predictive factors for major depressive disorder (MDD) in the elder population.

Methods: Four English databases (Web of science, Embase, Pubmed, psyINFO) and three Chinese databases (Weipu, CNKI, Wanfang) were searched for cohort or longitudinal studies. Random effect models were used based on significant heterogeneity. Funnel plots and Begg’s test were both conducted to investigate the potential publication biases. Stata version 14.0 was used for all statistical analyses.

Results: A total of 89 studies were included in this systematic review. Based on quality assessment with the Newcastle-Ottawa Scale, 39 studies which were more than 5 scores, covering 226,248 elderly participants, were included for meta-analysis. The strongest five predictors were as follows: physical function limitation (RR=2.08, 95% CI: 1.37-2.79), sleep disturbance (RR=2.07, 95% CI: 1.16-2.97), cognitive function limitation (RR=1.97, 95% CI: 1.31-2.64), obesity (RR=1.12, 95% CI: 1.03-1.20) and physical activity (RR=0.88, 95% CI: 0.76-0.99).  The range of followed-up period of all 39 studies was 1-21 years and the median was 4 years.

Conclusion: It is crucial to summary a theoretical prevention framework according these risk factors of MDD among the elderly. It provided clues for the policy-makers to prevent late-life MDD and to facilitate MDD remission among the elderly.