Algorithm Guided Treatment Versus Treatment as Usual (TAU) for Patients With Treatment Resistant Depression

The trial utilizes a pragmatic, randomized, open label design with two parallel arms. Participants aged 18-65 with a diagnosis of unipolar depressive disorder and without stable remission in the past 12 months are randomized 1:1 to receive either algorithm guided treatment (AGT) or treatment as usual (TAU). The AGT approach incorporates pre-defined treatment steps, critical decision points, and "if-then" rules based on symptom response. It leverages prior treatment history, current symptomatology, and tolerability profiles to personalize the therapeutic sequence and reduce treatment inertia. In contrast, TAU reflects standard clinical practice, where treatment decisions are left to clinician discretion without algorithmic structure. The primary objective of the study is to determine whether AGT leads to a greater reduction in depressive symptoms over a 12-week treatment period, as measured by the 6-item Hamilton Depression Rating Scale (HAMD-6). Secondary objectives include evaluating cognitive and psychosocial functioning, suicide risk, treatment adherence, tolerability, number of medication changes, and long-term outcomes at a 24-week follow-up, providing insights into the longer-term trajectory of TRD management.