The role of collaborative care in depression
Significant depressive symptoms occur in up to 20% of people with type 2 diabetes, and this affective disorder leads to a great deal of suffering. People with comorbid depression and diabetes have worse medical outcomes compared to people with diabetes alone, including a higher risk of macrovascular complications, like heart attack and stroke , and microvascular complications of the kidney and eye, dementia, and mortality.
Several systematic reviews have reported that both antidepressant medications and evidence-based psychotherapies (such as cognitive behavioural therapy) that have been shown to be effective in depressed patients without diabetes are also effective in treating comorbid depression in patients with diabetes. Despite the evidence that antidepressants and active types of psychotherapy that teach coping skills are effective in patients with depression and diabetes, few patients in our communities are receiving these efficacious treatments. Most people with diabetes are seen only by primary care physicians, and evidence from a large study in the United States found only approximately half of those with depression and diabetes had their depression accurately diagnosed by their primary care physician. Among the 50% who were accurately diagnosed, only approximately half received a minimum level of psychotherapy visits, or minimally adequate dose and duration of antidepressants. Thus, only approximately one quarter of patients with major depression receive minimally adequate treatment for depression (such as at least four counselling visits or three months of antidepressant treatment). These gaps in quality of depression treatment add to the risks of poor outcomes and increase medical costs.
In recent years, a new model of care, called collaborative depression care, has been developed and tested in primary care systems in the USA to enhance diagnosis and treatment of depression in people with diabetes. The key components of collaborative depression care include:
- enhanced patient education about the diagnosis and treatment of depression using books, CDs, and pamphlets;
- integration of a medically-supervised depression care manager into the primary care practice to improve adherence to recommended treatments (medication or psychotherapy), track side effects and response to depression treatment with a standard depression scale such as the Patient Health Questionnaire-9 (PHQ-9);
- use of a depression registry that allows tracking of visits, telephone contacts, and PHQ-9 depression scores in the population followed by the care manager;
- weekly caseload review of care manager cases by a psychiatrist and;
- stepped-care approaches where treatments are intensified based on persistent depressive symptoms.
Thus, in collaborative depression care, if a patient does not respond initially to psychotherapy or a low dose of an antidepressant, the psychiatry supervisor may recommend the addition of an antidepressant medication along with continuing psychotherapy, or an increase in the dose of the antidepressant. Recommendations by the physician supervisor are then communicated by the depression care manager to the patient’s primary care physician who writes all prescriptions in this model of care.
There are now four trials of collaborative depression care compared to usual primary care (where the physician is notified of the patient’s depression and can treat the patient as they would usually do in practice).All four trials have shown significant improvements in recovery from depression in collaborative care compared with usual care. The three trials that completed cost-effectiveness analyses found that the cost of the collaborative care intervention was offset by savings in medical costs over a two-year period. Collaborative care was associated with cost-savings compared to usual care of approximately $1000 per patient over a two year period. Although patients also had improved functioning associated with collaborative depression care, there was no significant improvement in glycaemic control in these four trials.
A more recent study developed a multi-collaborative care intervention for patients with poorly controlled diabetes and/or heart disease, and depression.11 These patients had either a glycated haemoglobin (HbA1c) of 8.5% or above (≥69 mmol/mol), a systolic blood pressure (SBP) >140 mmHg, or LDL cholesterol level >130 mg/dL (3.4 mmol/l ), as well as comorbid depression. The recommended levels of each of these disease control measures are HbA1c <7.0% (53 mmol/mol) or <7.5% (58 mmol/mol) in frail patients, SBP <130 mmHg, and LDL <100 mg/dL (2.6 mmol/l). This study utilized a nurse care manager, supervised weekly by both a psychiatrist and primary care physician, who recommended changes in medications to both improve treatment of depression and disease control of blood glucose, blood pressure, and LDL cholesterol. Compared to usual care, those treated with the multi-condition care management intervention had improved depression, systolic blood pressure, LDL cholesterol, and HbA1c outcomes. Patients in the intervention arm also had significant improvements in social and vocational functioning, quality of life, and satisfaction with medical care. Additionally, the intervention was associated with approximately $600 in cost savings per patient over a two year period compared to usual primary care.
Given the very robust evidence that collaborative care interventions for people with depression and diabetes are more effective than usual care and save medical costs, these interventions are being widely implemented into primary care systems in both the United States, Canada, and many European countries. Adaptations of collaborative depression care are also being tested in many developing countries such as India and Chile.
^ van der Feltz-Cornelis CM, Nuyen J, Stoop C, et al. Effect of interventions for major depressive disorder and significant depressive symptoms in patients with diabetes mellitus:a systematic review and meta-analysis. Gen Hosp Psychiatry. Jul- Aug 2010;32(4):380-395.
^ Katon WJ, Simon G, Russo J, et al. Quality of depression care in a populationbased sample of patients with diabetes and major depression. Med Care. Dec 2004;42(12):1222-1229.
^ Katon WJ, Von Korff M, Lin EH, et al. The Pathways Sa randomized trial of collaborative care in patients with diabetes and depression. Arch Gen Psychiatry. Oct 2004;61(10):1042-1049.
^ Williams JW, Jr., Katon W, Lin EH, et al. The effectiveness of depression care management on diabetes-related outcomes in older patients. Ann Intern Med. Jun 15 2004;140(12):1015-1024.
^ Ell K, Katon W, Xie B, et al. Collaborative care management of major depression among low-income, predominantly Hispanic subjects with diabetes: a randomized controlled trial. Diabetes care. Apr 2010;33(4):706-713.
^ Bogner HR, Morales KH, de Vries HF, Cappola AR. Integrated management of type 2 diabetes mellitus and depression treatment to improve medication adherence: a randomized controlled trial. Ann Fam Med. Jan-Feb 2012;10(1):15-22.
^ Katon W, Unutzer J, Fan MY, et al. Cost-effectiveness and net benefit of enhanced treatment of depression for older adults with diabetes and depression. Diabetes Care. Feb 2006;29(2):265-270.
^ Simon GE, Katon WJ, Lin EH, et al. Cost-effectiveness of systematic depression treatment among people with diabetes mellitus. Arch Gen Psychiatry. Jan 2007;64(1):65-72.
^ Hay JW et al. Cost-effectiveness analysis of collaborative care management of major depression among low-income, predominantly Hispanics with diabetes. Value Health. Mar-Apr 2012;15(2):249-254
^ Katon W, Russo J, Lin EH, et al. Cost-effectiveness of a multicondition collaborative care intervention: a randomized controlled trial. Arch Gen Psychiatry. May 2012;69(5):506-514.