Community-Based Trauma Rehabilitation Financing Gaps and Mental Health Relapse in Post-Conflict Burundi: A Difference-in-Differences Analysis of Health Insurance Enrollment Timing

Mutuelle de Santé enrollment timing is hypothesised to condition whether community-based trauma rehabilitation in post-conflict Burundi protects against mental health relapse, yet the causal structure of that conditioning has not been formally specified. The framework distinguishes three enrollment states—pre-rehabilitation enrollment, enrollment concurrent with rehabilitation, and post-rehabilitation enrollment—and derives the parallel-trends assumption each state requires. A formal treatment of the two-way fixed-effects estimator shows that staggered enrollment generates negative weighting of already-treated units, biasing the standard estimator toward the null when rehabilitation effects are dynamic. The paper then situates the framework against the empirical record on community health financing in Burundi and comparable post-conflict settings, and against the broader literature on mental health relapse in low-income and conflict-affected populations. The contribution is a specification of the enrollment-timing mechanism, a set of testable predictions, and a design protocol for a trial that has not yet been executed. No primary data are analysed; the paper is a methodological and conceptual contribution to the design of financing-mental health research in post-conflict settings.