Tuberculosis - Depression syndemic: A public health challenge.

Introduction: Depression is common in Tuberculosis (TB) and associated with adverse outcomes through pathogenic mechanisms and impaired self-care behaviours including reduced treatment adherence. Undiagnosed depression can threaten the robustness of DOTS model despite large public health investment. The Depression-Tuberculosis Syndemic requires collaborative partnership with mental health professionals.

Aim: To study the evidence base for Depression-Tuberculosis Syndemic.

Methodology: A Pubmed and Google Scholar search was conducted using the key words "Depression", "Tuberculosis" and "Syndemic" and abstracts screened for appropriateness and relevance.

Result: Depression-TB Syndemic is common with a bidirectional relationship. Depression is associated with higher hazard ratio and increased prevalence of TB. Depression is independently associated with higher morbidity, mortality, drug resistance, risk of TB reactivation and community TB transmission. The underlying biopsychosocial mechanism of Depression- Tuberculosis Syndemic includes biological factors like inflammatory cascade, HPA axis dysregulation and psychosocial factors like perceived stigma and treatment non-adherence.

Discussion: Depression is a poor prognostic factor in TB. The National Mental Health Programme (NMHP) and National Strategic Plan (NSP) for Tuberculosis Elimination (2017-2025) work in independent verticals with no integration at policy or at ground level. This results in lack of identification and appropriate management of depression in patients with Tuberculosis despite repeated contact with health care personnel in DOTS centres. A collaborative approach for early diagnosis and management of depression in patients with Tuberculosis (Secondary Prevention) can help decrease the burden of disease and improve outcomes.

Conclusion: Depression-TB Syndemic requires collaborative approaches at the program level and at the point of service delivery.