Social demographic characteristics (N = 261).

Opioid use disorder is a major global health concern. While methadone treatment is effective in treating opioid use disorder, individuals often experience severe mental health issues, particularly depression. This study aimed to assess the prevalence of depression and its associated factors among clients attending a methadone clinic in the Pwani Region, Tanzania. A cross-sectional study was conducted at Tumbi Hospital to assess the prevalence of depression and its associated factors among 261 clients at the methadone treatment clinic. Participants were recruited through simple random sampling. Depression-related data were collected using the Patient Health Questionnaire-9 (PHQ-9). Descriptive statistics were used to analyze the socio-demographic and clinical data and prevalence of depression. Furthermore, bivariate and multivariate logistic regression were used to determine the factors associated with depression. A P-value of less than 0.05 with a 95% confidence interval was used to identify the statistically significant association. The mean age of respondents was 40.28 years (SD ± 8.29), and 98.1% were male. The prevalence of depression was 73.9%, with 47.9% of respondents experiencing minimal depression. Females had a 15 times higher risk of depression (adOR = 15.126; P = 0.021) compared to their counterparts. Clients with a history of incarceration were at twice the higher risk of depression (adOR = 2.371; P = 0.012), while not using tramadol for pain management had a reduced risk of depression (adOR = 0.853; P