Depression and anxiety among incarcerated people who use drugs in Malaysia: substance-specific and syndemic correlates in a prison-based study

Background: Incarcerated people who use drugs (PWUD) face a disproportionate burden of mental health disorders due to the convergence of substance dependence, criminalisation, social marginalisation, and limited access to mental health care. Prisons in Southeast Asia are increasingly recognised as critical settings for addressing mental health inequities; however, empirical evidence on depression and anxiety among incarcerated PWUD remains scarce. This study examined the prevalence of depressive and anxiety symptoms among incarcerated PWUD in Malaysia and explored their associations with substance use patterns and comorbid infectious diseases using a syndemic framework.

Methods: We conducted a cross-sectional prison-based study among 547 incarcerated adults with a history of drug use in Malaysia. Depressive symptoms were assessed using the Centre for Epidemiologic Studies Depression Scale (CES-D), and anxiety symptoms using the Generalised Anxiety Disorder-7 (GAD-7), and opioid dependence using the RODS. Sociodemographic characteristics, lifetime and recent substance use patterns, and clinical conditions including HIV, hepatitis C virus (HCV), and tuberculosis were collected. Multivariable logistic regression models were used to identify factors associated with depression and anxiety, with interaction analyses examining effect modification by HCV status.

Results: Among 547 people in prison, the mean age was 39.9 (10.524) years, 19.9% completed only primary school, 46.7% had OUD, and 26.3% tested positive for Hep C. Overall, 11.8% of participants screened positive for depressive symptoms and 6.8% for anxiety, with substantial overlap between the two conditions. Depression and anxiety were strongly and bidirectionally associated, reflecting marked mental health comorbidity within the prison setting. After adjustment, cocaine use (AOR 2.6 (95%CI 1.1-6.7) and inhalant use (AOR 2.9 (95%CI 1.1-7.2) remained independently associated with depressive symptoms. HCV infection was significantly (AOR 2.04 (95%CI 1.04-4.03) associated with depression in models excluding anxiety, and interaction analyses suggested that HCV amplified the association between cocaine use and depression.

Conclusion: Depression and anxiety among incarcerated PWUD in Malaysia are closely interconnected and shaped by substance-specific and clinical factors, consistent with a syndemic pattern of vulnerability in prison settings. These findings highlight the urgent need to integrate routine mental health screening and care into prison health services and existing substance use and infectious disease programmes. Strengthening prison-based mental health interventions may play a critical role in improving health outcomes during incarceration and supporting continuity of care post-release.

To be updated shortly..