BACKGROUND: Comorbid mental disorders in patients with TB may exacerbate TB treatment outcomes. We systematically reviewed current evidence on the association between mental disorders and TB outcomes.METHODS: We searched eight databases for studies published from 1990 to 2018 that compared TB treatment outcomes among patients with and without mental disorders. We excluded studies that did not systematically assess mental disorders and studies limited to substance use. We extracted study and patient characteristics and effect measures and performed a meta-analysis using random-effects models to calculate summary odds ratios (ORs) with 95% confidence intervals (CIs).RESULTS: Of 7687 studies identified, 10 were included in the systematic review and nine in the meta-analysis. Measurement of mental disorders and TB outcomes were heterogeneous across studies. The pooled association between mental disorders and any poor outcome, loss to follow-up, and non-adherence were OR 2.13 (95%CI 0.85-5.37), 1.90 (95%CI 0.33-10.91), and 1.60 (95%CI 0.81-3.02), respectively. High statistical heterogeneity was present.CONCLUSION: Our review suggests that mental disorders in TB patients increase the risk of poor TB outcomes, but pooled estimates were imprecise due to small number of eligible studies. Integration of psychological and TB services might improve TB outcomes and progress towards TB elimination.