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

The aim of the present study was to determine the prevalence of depression or depressive symptoms in people residing in high-altitude regions.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).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 % (I2: 99 %) and the only estimate by subpopulation at the country level was possible for China, with >36,000 participants, being 28.7 % (I2: 4 %).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.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.