Impact of Mental Health and Substance Use on TB Preventive Therapy Adherence in HIV

Overview

In a prospective cohort of 224 people with HIV initiating tuberculosis preventive therapy (TPT) in South Africa, depression symptoms were common and significantly associated with lower TPT adherence and completion. Other mental health symptoms and substance use were prevalent but did not independently predict adherence outcomes.

Background

Tuberculosis remains the leading cause of death among people with HIV (PWHIV), despite advances in antiretroviral therapy (ART) and TB preventive therapy (TPT). Combining ART with TPT reduces TB incidence and mortality, yet TPT uptake and completion remain suboptimal. Mental health disorders and substance use are common comorbidities in PWHIV and have been linked to poorer HIV outcomes, but their impact on TPT adherence is less well understood. South Africa, with a high burden of HIV and TB, has implemented a 3-month weekly isoniazid–rifapentine regimen (3HP) to improve TPT delivery.

Data Highlights

Key Findings

• Half (50%) of PWHIV initiating TPT completed the therapy.
• Depression symptoms were present in 36% of participants and were independently associated with 9% fewer TPT doses taken and lower odds of completion (OR 0.48).
• Anxiety symptoms, unhealthy alcohol use, and tobacco use were common but not independently linked to TPT adherence or completion after adjustment.
• Qualitative interviews highlighted that mental health challenges negatively influenced adherence and underscored the need for integrated social and psychological support.
• Referral to mental health services was provided for participants with moderate to severe symptoms or suicidality.

Clinical Implications

Screening for depression among PWHIV initiating TPT is critical, as depressive symptoms significantly reduce adherence and completion rates. Integrating mental health support and counseling into TPT programs may improve treatment outcomes. Addressing mental health comorbidities should be a priority to enhance the effectiveness of TB prevention strategies in high-burden settings.

Conclusion

Depression is a prevalent and impactful barrier to successful TPT adherence and completion among PWHIV. Targeted mental health interventions are essential to optimize TB preventive efforts in this vulnerable population.

References

1. World Health Organization End TB Strategy
2. South African National HIV and TB Guidelines 2023
3. Patient Health Questionnaire-9 (PHQ-9) Validation Studies
4. Generalized Anxiety Disorder 7-item (GAD-7) Scale
5. Alcohol Use Disorders Identification Test–Consumption (AUDIT-C)