These guidelines mark a change in approach from the task force's 2005 guidelines, which recommended screening adults in primary care settings where there were integrated staff-assisted systems to manage treatment.
"In the absence of a demonstrated benefit of screening, and in consideration of the potential harms, we recommend not routinely screening for depression in primary care settings, either in adults at average risk or in those with characteristics that may increase their risk of depression," writes Dr. Michael Joffres, chair of the CTFPHC's depression guideline writing group and member of the Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, with coauthors.
The recommendations do not apply to people with known depression, with a history of depression or who are receiving treatment for depression.
- No routine screening in primary care settings for adults at average risk of depression.
- No routine screening in primary care settings for adults in subgroups of the population who may be at increased risk of depression, including people with a family history of depression, traumatic experiences as a child, recent traumatic life events, chronic health issues, substance abuse, perinatal and postpartum status, or Aboriginal origin.
However, clinicians should be alert to the possibility of depression, especially in patients with characteristics that may increase their risk of depression, and should look for it when there are clinical clues, such as insomnia, low mood, anhedonia (inability to experience pleasure) and suicidal thoughts.
Guidelines in other countries differ slightly from the Canadian guidelines. The US Preventive Services Task Force recommends universal screening where supports exist to ensure follow-up treatment. In the United Kingdom, the National Institutes for Health and Clinical Excellence recommends a targeted approach, focusing on people with a history of depression rather than general screening.
"These recommendations do not apply to people with known depression, with a history of depression or who are receiving treatment for depression. Patients who present with symptoms or other clues to the presence of depression should be appropriately assessed for depression," explained Dr. Gabriela Lewin, member of the CTFPHC working group.
The task force calls for high-quality randomized controlled trials with an unscreened control group to understand the effect of screening, the potential harms of screening, such as false-positive diagnoses with subsequent unnecessary treatment, as well as the implications of earlier detection of depression through screening.
In a related commentary, Dr. Roger Bland, Department of Psychiatry, University of Alberta, and coauthor write, "There is no question, as the task force amply illustrates, that depression constitutes a major public health problem. Although milder cases may require only watchful waiting rather than treatment, about 15% of people with major depression go on to a chronic course, with much residual disability. Family physicians have been criticized for failing to recognize depression. However, studies have shown that many missed cases are those of milder depression, which often remits spontaneously, and that patients with milder forms of depression may experience adverse effects and other complications if the depression is treated."