Trauma-Focused Therapy Dose Compression and Mental Health Relapse in Zambian District Clinics: A Regression Discontinuity Analysis of Caseload Ceiling Thresholds

District clinics in Zambia operate under fixed caseload ceilings that determine how many trauma-focused therapy sessions each patient can receive. When enrolment exceeds these ceilings, session frequency and total dose are compressed, yet the relationship between dose compression and relapse remains poorly characterised. The design uses the caseload ceiling as the running variable, with clinics just above the threshold delivering compressed doses and clinics just below delivering full doses. The analysis specifies relapse within six months of treatment completion as the primary outcome, measured through routine clinic records. The proposed framework addresses selection bias by restricting comparison to clinics in a narrow bandwidth around the threshold, where assignment to compressed versus full dose is plausibly as-good-as-random. The paper derives the identifying assumptions, specifies the estimation equation, and discusses the conditions under which the design yields credible estimates. It also examines the ethical and practical constraints of implementing such a design in low-resource clinical settings. The contribution is methodological: it provides a template for evaluating dose compression effects using existing administrative data, without requiring randomised assignment. The framework has implications for how district clinics allocate scarce therapy resources and for how mental health systems in low- and middle-income countries monitor treatment fidelity under caseload pressure.