Community-Based Trauma Mental Health Task-Sharing Counsellor Caseload Size and Post-Traumatic Stress Disorder Symptom Remission in Ugandan Villages: A Multilevel Analysis of Workforce Saturation Thresholds

Task-sharing models that deploy lay counsellors to deliver trauma-focused mental health care in low-resource settings assume that counsellor caseloads can expand without diminishing clinical effectiveness, yet the threshold at which caseload growth begins to erode post-traumatic stress disorder (PTSD) symptom remission remains unquantified. The framework specifies how village-level clustering of trauma exposure, counsellor-level burnout and fidelity decay, and client-level symptom severity interact to produce non-linear remission returns to caseload expansion. Using a formal derivation of the saturation threshold and a replication-based illustration calibrated to plausible Ugandan task-sharing parameters, the analysis identifies the conditions under which marginal caseload increases yield negative remission returns. The contribution is a testable threshold model that reframes caseload policy from a linear scaling problem to a saturation problem, with implications for supervision ratios, caseload caps and the design of cluster-randomised evaluations of task-sharing programmes.