Collaborative care — principles to multimorbidity implementation (MEQ)

(i) Definition vs co-location. Collaborative care (CoCM) is team-based, population-registered, measurement-driven management of common mental disorders in primary care with treatment-to-target and psychiatric caseload review. Co-location places a clinician on site but without registry, serial measures, and systematic caseload review is not CoCM fidelity.^[1][2]

(ii) Roles and principles. Roles: primary care provider; behavioural health care manager; psychiatric consultant. Principles: patient-centered team care; population-based care (registry); measurement-based treatment to target; evidence-based treatments; accountable caseload outcomes.^[1]

(iii) Measurement and red flags. Use PHQ-9 (0–27) and GAD-7 serially; common PHQ-9 screen threshold around 10; always action item 9 suicide content with structured risk assessment. Red flags for immediate specialty/crisis: active plan/intent, psychosis, mania, severe agitation, medical instability — not routine CoCM follow-up alone.^[6][2]

(iv) Evidence. IMPACT: late-life depression CoCM superior to usual care.^[1] TEAMcare: multicondition care improves depression and chronic disease control.^[3] Gilbody cumulative meta-analysis and Archer Cochrane: collaborative care improves depression (and anxiety in Cochrane) vs usual care.^[4][2] CADET: UK cluster RCT — effective, preferred by patients to 12 months.^[5]

(v) Pitfalls and step-up. Pitfalls: screening without capacity; fidelity decay; therapeutic inertia; overloaded care managers; mislabeling co-location as CoCM. Step up within programme when not at target; escalate to specialty for complexity/resistance/diagnostic doubt; crisis pathways for acute risk. Psychiatric consultant multiplies reach via caseload review rather than full intake of every mild case.^[1][2]