Collaborative Stepped-care Intervention for Adults With Subthreshold Depressive Symptoms in the Primary Care Setting

"After initial clinical assessment, participants will be offered interventions based on their depressive symptom severity (Patient Health Questionnaire-9-item \[PHQ-9\]).~Mild symptoms (PHQ-9=5-9) without major risks (\*see above): 4 weekly CBT-informed intervention sessions led by trained Emotional Support Assistants (Peer Supporters with 80hrs mental health training + 15hrs intensive clinical training).~Mild symptoms (PHQ-9=5-9) with major risk factors or moderate-to-moderately severe symptoms (PHQ-9=10-19): 6 weekly CBT-based intervention sessions led by trained clinical social workers, with 2 booster sessions as necessary. Individual CBT-based intervention will be provided to those unsuitable for group interventions.~In cases of non-remission (PHQ-9≥5): a second intervention trial will be provided. Those needing additional support will be referred to a partnered General Practitioner (if PHQ-9=10-19) or referred to more intensive psychological or psychiatric services as needed."

Following an initial interview session with research assessments, participants continue with their usual care at their primary care setting.