What this Trial Is About

The goal of this psychotherapy clinical trial is to evaluate whether a algorithm-based personalized modular psychotherapy is more effective than usual individual psychotherapy in treating major depressive disorder complicated by personality dysfunction and/or complex trauma in adults aged 18 to 65 receiving care in the Chilean public mental health system. The main questions it aims to answer are: * Does algorithm-based modular psychotherapy lead to greater clinically significant reduction and remission of depressive symptoms compared to usual psychotherapy? * Does algorithm-based modular psychotherapy lead to greater improvement in emotional regulation, interpersonal functioning, and self-related functioning, including changes observed in daily life? Researchers will compare algorithm-based modular psychotherapy to usual individual psychotherapy provided in public community mental health centers to see if the modular, personalized approach results in better clinical outcomes, stronger therapeutic alliance, and higher treatment satisfaction. Participants will: * Be randomly assigned to receive either algorithm-based modular psychotherapy or usual individual psychotherapy * Attend weekly individual psychotherapy sessions * Complete structured diagnostic interviews and self-report questionnaires before, during, and after treatment * Provide brief daily reports on mood, emotions, and interpersonal experiences using a smartphone before and after treatment

Modular Intervention for Depression Study