Prevalence of depression and depressive symptoms at high altitudes: A systematic review and meta-analysis

Background: The aim of the present study was to determine the prevalence of depression or depressive symptoms in people residing in high-altitude regions. Methods: Eleven databases were searched for studies on depression and depressive symptoms: PubMed, ISI Web of Science, CINAHL, Embase, Scopus, PsycINFO, Psychology and Behavioral Sciences Collection, Psychology Database, Academic Search Ultimate, SciELO and LILACS. Systematic review and meta-analysis were performed based on the inclusion of these articles measuring the prevalence of depressive symptoms in people living at high altitude (>= 1500 m above sea level [masl]). The protocol was registered in PROSPERO (CRD42021271069). Results: Eight articles with >40,000 participants from 4 different countries were included. Among the samples treated, the combined prevalence of depressive symptoms was 17.9 % (I-2: 99 %) and the only estimate by subpopulation at the country level was possible for China, with >36,000 participants, being 28.7 % (I-2: 4 %). Limitations: Considerable heterogeneity was reported in the estimation of overall prevalence due to the quality of the studies and the instruments used to screen for depressive symptoms. Conclusion: Almost two out of every 10 people living at high-altitude regions suffer from depressive symptoms. Therefore, it is necessary to adapt interventions to this condition and further research in the field is required.