Mental health effects of unemployment and re-employment: a systematic review and meta-analysis of longitudinal studies.

This systematic review examined the impact of unemployment and re-employment on mental health problems (depression, anxiety and psychological distress) among working-age adults. We searched MEDLINE, Embase, APA PsycINFO and Web of Science (January 2012-March 2024) and included studies from a prior meta-analysis (1990-2012). Risk of bias was assessed using the Newcastle-Ottawa Scale. We conducted random-effects meta-analyses and narrative synthesis and evaluated the certainty of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Of 9328 search records, 38 prospective longitudinal studies met the inclusion criteria (27 from 2012-2024 and 11 from 1990-2012). A pooled standardised mean difference (SMD, Cohen's d) of 0.19 (95% CI 0.08 to 0.30, I²=88.7%) indicated increased symptom levels among the unemployed compared with those regularly employed. Similarly, pooled effect estimates indicated reduced symptoms after re-employment, with a stronger effect observed in between-group difference-in-difference analyses (SMD=-0.27, 95% CI -0.35 to -0.20, I²=40.1%) than within-group analyses (SMD=-0.19, 95% CI -0.29 to -0.10, I²=84.3%). The certainty of evidence for all outcomes based on our GRADE evaluation was low. Our systematic review and meta-analysis suggest that unemployment increases the risk of mental health problems, while re-employment may reduce this risk. However, due to the lack of high-certainty evidence, further longitudinal studies with multiple follow-ups are needed to strengthen causal inferences and better clarify mental health trajectories before and after re-employment.