INTRODUCTION: Despite being crucial in ensuring the best treatment outcomes, adherence status is frequently overlooked in comprehensive chronic care. Thus, the present study critically evaluates, integrates, and summarizes psychotropic medication non-adherence and its determinants among patients with mental disorders in a resource limited life trajectories to inform policy and future research.

METHOD: Systematic review and meta-analysis following the Cochrane handbook for systematic reviews of interventions and Preferred Reporting Items for Systematic review and Meta-analysis (PRISMA) statement was conducted. PubMed (Medline), CINAHL, PsychINFO, EMBASE, and Google Scholar databases were comprehensively searched to retrieve published and grey literature from index inception to October 2024. Observational original studies focused on the magnitude of psychotropic treatment non-adherence and its predictors were eligible for inclusion. Risk-of-bias was assessed using Joanna Briggs Institute (JBI) criteria. Protocol was pre-registered at PROSPERO with a reference number of CRD42024578766.

RESULTS: Twenty-three studies (n = 23, 359) were included, 22 of them in the quantitative analysis. The pooled prevalence of non-adherence was 46% (95% CI: 40%-52%, I = 96.95%). Subgroup analysis revealed that non-adherence was higher among patients with major depressive disorder (40.43%, I = 98.87%). Sociodemographic factors (aOR = 1.58, I = 87.13%), patient-related factors (aOR = 1.47, I = 25.62%), lack of insight (aOR = 1.24, I = 72.12%), negative attitude towards the treatment (aOR = 1.78, I = 0.00%), poor social support (aOR = 1.49, I = 82.55%), self-stigma (aOR = 1.97, I = 30.70%), and drug-related factors (aOR = 1.42, I = 64.16%) were the predictors. Substance use was identified as a protective factor for adherence (aOR = 0.84, I = 99.97%).

CONCLUSION: Altogether, we discovered that psychotropic treatment non-adherence among patients with psychiatric disorders was quite common. This analysis may serve as a high-grade ore for policymakers, though it must be interpreted with caution due to significant heterogeneity. Notwithstanding stringent methodology, depending on cross-sectional studies limits its clinical guidance.

...Substance use: Eleven studies found the association of substance abuse risk behaviour with drug non-adherence among psychiatric patients [16, 23, 49, 50, 52, 56, 58, 60, 63, 64, 66]. Individuals who abuse substances, such as alcohol use, khat chewing, cannabis use, and cigarette smoking, were 16% less likely to be non-adherent than those who did not use substance [aOR = 0.84 95% CI: (0.71–0.97)]. High levels of heterogeneity were noted, and the stability of the overall estimate was confirmed by leave-one-out sensitivity analysis (S8 Table). Furthermore, no small study effect was found....