Updated CANMAT Guidelines for Treatment of Major Depressive Disorder

This issue of The Canadian Journal of Psychiatry (CJP) includes updates to the popular Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines for the management of major depressive disorder. This is the third iteration of these guidelines for major depressive disorder, the first being published in 2001¹ and then updated in 2009.² It is important to emphasize that these and other CANMAT guidelines are not endorsed by the Canadian Psychiatric Association. CJP has previously published guidelines developed by other independent groups.^3,4

The series consists of 6 articles focusing on burden and principles of care,⁵ psychological treatments,⁶ pharmacological treatments,⁷ neurostimulation treatments,⁸ complementary and alternative medicine treatments,⁹ and special populations.¹⁰

What is immediately apparent from the CANMAT guidelines is their distinctiveness. There are contemporary quality assessment and reporting guidelines for projects of this type, called Appraisal of Guidelines for Research & Evaluation II (AGREE II).^11,12 As a consequence of AGREE II, recently published guidelines have become increasingly standardized in their methodology and reporting. The CANMAT guidelines fulfill many of the items listed in AGREE II but not all. Rather than tailoring their reporting to AGREE II, CANMAT instead uses a question-and-answer format that has been well received by clinicians in previous versions of their guidelines. Central to the process of parsing evidence into clinical guidance is a grading of the quality of evidence and strength of recommendations. Internationally, the current standard for doing so is the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system.¹³ CANMAT has chosen not to use this approach and instead uses its own level of evidence and ‘lines of treatment’ rating systems. Perhaps the most distinctive feature is CANMAT’s explicit incorporation of expert opinion in assessment of lines of treatment. These are based on evidence plus ‘clinical support’, the latter being assigned through the expert opinion of the CANMAT committees. Most evidence-based guidelines emphasize minimization of the role of expert opinion. They view opinion as a weak source of evidence that risks distorting stronger forms of evidence (i.e., that deriving from randomized controlled trials and meta-analyses). CANMAT makes no apologies for going in a different direction. It believes that the integration of levels of evidence with expert opinion renders its recommendations more usable and realistic, and also that the ‘lines of treatment’ concept produces an alignment of the guidelines with stepped-care management concepts.

The AGREE II checklist includes an item assessing ‘competing interests’, which is a component of the AGREE II ‘Editorial Independence’ domain. Readers will note that some members of the CANMAT authorship group disclose multiple relevant financial activities, whereas other members report none. CJP requires disclosure of activities “that could be perceived to influence, or that give the appearance of potentially influencing” the work under consideration. In keeping with the editorial stance of most peer-reviewed journals, authors are encouraged to be inclusive, reporting “interactions with ANY entity that could be considered broadly relevant to the work.” This approach allows readers to decide the extent to which such information may affect their acceptance or interpretation of the guidance provided.

The approaches taken by the CANMAT group, while distinct from those of many other depression guidelines, have been embraced by clinicians and widely discussed both within Canada and internationally. These guidelines offer an interesting approach and texture to the provision of clinical guidance for the management of major depressive disorder. They also represent a considerable investment of effort by a notable group of Canadian psychiatrists and scientists, and we are proud to provide them to the readership of CJP in this issue.