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Collaborative care can be moderately effective at treating depression compared to usual care, whether or not people also have a long-term condition such as cancer or heart disease. Collaboration was provided by a case manager in primary care who was not a mental health professional. They coordinated a treatment plan with input from a GP and mental health professional. It is currently only recommended for people with depression and a long-term physical condition as prior to this review there was only consistent evidence of its effectiveness for people with both.

This NIHR-funded review pooled individual patient data from 31 trials, mostly from the US. The benefits were modest and were not compared to other approaches used in the UK such as direct primary care access to psychologists. In addition, a cost-effectiveness analysis was not performed. The evidence will help inform guideline updates but overall costs of implementation at scale will also be important for commissioners given the current pressures on the health service and the interest in new models of care.

Why was this study needed?

Depression affects nearly one in six people in the UK. It is the third most common reason for people seeing their GP. About 25% of people with two or more chronic health problems are depressed compared to only 3% of people who are physically healthy.

Collaborative care refers to treatment and support from a team of healthcare professionals largely within primary care. This usually involves a case manager (such as a practice nurse), a GP and input from a mental health specialist (such as a psychiatrist). The case manager has regular contact with the person, and organises the care package with the doctor and specialist.

Current NICE guidance only recommends collaborative care for people with both long-term physical conditions and depression. This was based on two separate analyses of trial data which suggested it is particularly effective for this group. This new study aimed to investigate if there are really differences in how well it works for people with depression with and without other physical conditions.

What did this study do?

Rather than pooling the published summaries of results from trials, the authors of the individual studies were contacted and asked to provide their full data sets. These were then combined into one large set of data.

The review used data from 10,962 adults with depression in 31 trials that compared collaborative care to usual care. This provided 36 comparisons in total. It looked at changes to depression symptoms reported at four to six months after the trials started.

The data is not representative of all of the published literature on collaborative care as full data sets were not available for 44 relevant studies. There were also differences between the studies in definitions of collaborative care and in how depression was measured. Eighteen of the studies were from the US and two from the UK which means the precise package of collaborative care and who was involved would need to be considered if applying these interventions in a UK setting.

What did it find?

  • Overall, collaborative care was associated with a small reduction in depression symptoms after four to six months compared to usual care (standardised mean difference [SMD] -0.22, 95% confidence interval [CI] ‑0.25 to ‑0.18). On the Patient Health Questionnaire-9 scale (a scale of 0-27 where 27 is the most severe depression) this is equivalent to a drop of about two points more than the change in the control participants.
  • Having a physical condition did not change the effectiveness of collaborative care for depression symptoms (interaction coefficient 0.02, 95% CI ‑0.10 to 0.13). For those with physical conditions, collaborative care reduced depression symptoms compared to usual care by SMD ‑0.21 (95% CI ‑0.27 to ‑0.15), versus SMD ‑0.23 [95% CI ‑0.32 to ‑0.12] for those without physical conditions.
  • The type of physical condition did not change the effects of collaborative care on depression symptoms.

What does current guidance say on this issue?

The NICE 2009 guideline on the Depression in adults: recognition and management recommends collaborative care for people who also have a chronic physical health problem and associated functional impairment. It recommends that people with severe or complex depression are managed in a program of co-ordinated care by specialist mental health services. This would be a more enhanced version of collaborative care.

The NICE 2009 guideline on the recognition and management of depression in adults with a chronic physical health problem also suggests that collaborative care should only be considered for people whose depression has not responded to initial high-intensity psychological treatment, drug treatment, or a combination of both.

What are the implications?

This evidence suggests that collaborative care is moderately effective for managing depression in all people, whether or not they also have long-term physical health conditions. However, the benefits of collaborative care are modest, and need to be balanced against its cost-effectiveness compared to other types of treatment.

For example, the Improving Access to Psychological Therapies (IAPT) programme in the UK has elements of collaborative care in addition to psychological treatment and so models of care that build on all these elements may be a more effective strategy.

Collaborative care should not be confused with enhanced care coordination, which is a higher level of support provided by specialist mental health services to people with severe mental illness, including depression.


Citation and Funding

Panagioti M, Bower P, Kontopantelis E, et al. Association Between Chronic Physical Conditions and the Effectiveness of Collaborative Care for Depression: An Individual Participant Data Meta-analysis. JAMA Psychiatry.2016;73(9):978-89

This project was funded by the National Institute for Health Research School for Primary Care Research (grant 212).



NHS Choices. Depression London: Department of Health; 2016.

NICE. Depression in adults: recognition and management. CG90. London: National Institute for Health and Care Excellence; 2009.

NICE. Depression in adults with a chronic physical health problem: recognition and management. CG91. London: National Institute for Health and Care Excellence; 2009.

Richards DA, Bower P, Chew-Graham C, et al. Clinical effectiveness and cost-effectiveness of collaborative care for depression in UK primary care (CADET): a cluster randomised controlled trial. Health Technol Assess. 2016;20(14).

Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre

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