Collaborative care improves depression outcomes in both the short and medium term, a UK primary care study has found.

Fifty one practices were randomised to either collaborative care or usual care. Potential participants were identified by screening GP records for recent depression Read codes.

They were enrolled if they met the ICD-10 criteria for depression when interviewed by a research worker.

In total, 276 patients were recruited from the collaborative care practices and 305 from the usual care practices. Overall 86% of participants had moderate or severe depression.

The intervention was delivered by care managers in liaison with GPs under the supervision of mental health specialists.

Care managers were either graduate psychologists or primary care mental health professionals who had been trained to deliver the collaborative care protocol.1 They provided 6-12 patient contacts over a period of 14 weeks.

Collaborative care consisted of:

• Education about depression

• Medication management (monitoring of side effects, adherence and depression symptoms with appropriate treatment adjustments)

• Behavioural activation therapy (a form of CBT which focuses on reducing avoidance and increasing activity)

• Relapse prevention (teaching patients to recognise symptoms of depression relapse)

Compared with those receiving usual care, patients in the collaborative care group had lower mean adjusted depression scores at both 4 and 12 months follow-up (1.33 PHQ-9 points lower (95% CI:0.35-2.31) at 4 months and 1.36 points lower (95% CI:0.07-2.64) at 12 months).

The effect size (0.26) was small and less than expected. The number needed to treat for one additional patient to meet the criteria for recovery at 12 months was 6.5.

Collaborative care is known to produce a small but significant improvement in depression outcomes (mean effect size 0.25 at 6 months)2 but most of the studies have been carried out in the United States. This study demonstrates that similar results can be achieved in the setting of UK primary care.

Collaborative care is complex and expensive and the authors acknowledge the need to carry out a cost effectiveness analysis. Currently NICE only recommends collaborative care for patients with moderate to severe depression and a chronic physical health problem with associated functional impairment, whose symptoms have not responded to initial interventions.3

Case management (active follow-up, monitoring of adherence and depression symptoms with feedback of information to the GP) is a simpler and cheaper alternative which can be carried out by healthcare assistants.

A German study achieved an identical effect size (0.26) with telephone case management provided over a period of 12 months.4

The NICE Quality Standard on depression recommends regular reassessment of patients treated with antidepressants at 2-4 week intervals, identification of non-responders with treatment adjustment, and maintenance treatment for at least 6 months after remission.5 In my opinion, this cannot be achieved without some form of enhanced care. However, the case for complex collaborative care rather than simple case management remains to be proven.

Dr Phillip Bland