Cost-Benefit Analysis of Interpersonal Therapy and Fluoxetine for Treating Depression and PTSD in Primary Care Settings in Kenya

Background Kenya faces a significant mental health crisis, with 1.9 million reported cases of depression and 10.6% prevalence of post-traumatic stress disorder (PTSD). The economic burden of mental health conditions was 62.2 billion Kenyan shillings in 2021, accounting for 0.6% of GDP. This study performed a cost-benefit analysis (CBA) of Interpersonal Psychotherapy (IPT) and fluoxetine (FLX) for treating depression and PTSD in a primary care setting. Methods The SMART-DAPPER project in western Kenya (Kisumu County Referral Hospital) employed a Sequential, Multiple Assignment Randomized Trial design to train non-specialist providers in administering IPT and FLX for adult depression and PTSD. A cost-benefit analysis (CBA) compared intervention costs with income gains from increased productivity, using micro-costing for treatment expenses and the World Bank’s Living Standards Measurement Study to assess productivity. The benefit-cost ratio was calculated over one and ten years with annual relapse rates of 10%, 25%, and 50%). This study adhered to CONSORT guidelines. Results The study enrolled 1,918 participants: 986 received IPT and 932 received FLX. Remission was achieved after the first round of therapy by 782 and 798, respectively. IPT averaged 11.5 sessions of 60 minutes, costing in total 5,050 KES ($42.79); FLX averaged 5.3 sessions of 20 minutes, costing 2,511 KES ($21.28), including the medication. Both treatments increased income, with IPT participants gaining 16,242 KES and FLX participants 13,239 KES in the first year. Benefit-cost ratios were 3.2:1 for IPT and 5.3:1 for FLX. Over ten years, FLX showed higher CBA ratios (10 to 31:1) than IPT (6 to 18:1). Conclusion This study found productivity gains greater than primary care-based treatment costs for IPT and FLX for depression and PTSD in Kenya. FLX demonstrated a more favorable benefit-to-cost ratio. Future research should address the capacity of government health care to sustain delivery of psychological and pharmacological therapy. Ethics registration: The study was approved by the UCSF Institutional Review Board (IRB), the Kenyatta National Hospital-University of Nairobi Ethics and Research Committee, and the Kenya Pharmacy and Poison’s Board. It was registered on ClinicalTrials.gov (NCT03466346), registration date 2018-03-15, https://clinicaltrials.gov and conducted by Human Subjects Protections (HSP) and Good Clinical Practice (GCP). The trial was monitored by the United States National Institutes for Health (NIH) through PPD.