Wednesday, December 13, 2017

Major Depression Epidemiology in Canada

Traditionally, information about psychiatric epidemiology (including the patterns of major depression in Canada) has come from national surveys, such as the two major surveys conducted by Statistics Canada on mental health. One of these was conducted in 2002 and another in 2012. However, a lot of information is available from general health surveys too - and of course from other data sources. The challenge when there are bits and pieces of information available from different sources is to be able to synthesize this information in a meaningful way. Fortunately, there are good statistical tools available for this task. Many of the posts in this blog have described specific results from these data synthesis strategies. In 2015 I presented an update of some of these results at a conference sponsored by Canada's Research Data Centres. The presentation is available on Youtube, if you would like to see it, please click here.

This supplements early summaries (including an earlier one that is recorded on Youtube also, to see it click here). A more formal summary of some of the basic descriptive epidemiology has been published in the Canadian Journal of Psychiatry, here.

Monday, August 21, 2017

Major Depression and Secondhand Smoke Exposure

Epidemiologically, the association between smoking and common mental disorders is well characterized, it has been consistently observed in population-based studies. I don't think that the association has been taken very seriously. This is a shame because the settings in which the common mood and anxiety disorders are managed are well situated to help people quit smoking. A recent meta-analysis of studies of smoking cessation that included mental health outcome measures indicated that improvements that follow smoking cessation resemble those of antidepressant medications (when quantified as effect sizes) [1]. This challenges the perceptions that are gained by mental health professionals and people who smoke - which is that smoking makes them feel better, something that is undoubtedly true in the short term during nicotine withdrawal. Over the longer term, it appears that smoking cessation leads to improvements in mental health. Mental health professionals may have a tendency to assume that people smoke to self-medicate their symptoms and because of this assumption may have neglected to energetically tackle smoking cessation. Another angle is that of secondhand smoke exposure. Secondhand smoke inhalation has many of the adverse biological effects of smoking, which include things like increased markers of inflammation [2] but it is unlikely that people would inhale secondhand smoke for self-medication purposes. We recently looked at whether secondhand smoke exposure is associated with major depression in the general population of Canada - and found that it is strongly and consistently associated [3].

There is increasing evidence that smoking cessation should be a component of psychiatric treatments, and clinicians should be aware that secondhand smoke exposure may be something that contributes to poor outcomes among their patients. People who've struggled with depression should seek to quit - it is short term pain for long-term gain. They should also avoid secondhand smoke "like the plague."

1.  Taylor, G., McNeill, A., Girling, A., Farley, A., Lindson-Hawley, N., Aveyard, P., 2014. Change in mental health after smoking cessation: systematic review and meta-analysis. BMJ 348, pp. g1151

2.  Jefferis, B.J., Lowe, G.D., Welsh, P., Rumley, A., Lawlor, D.A., Ebrahim, S., Carson, C., Doig, M., Feyerabend, C., McMeekin, L., Wannamethee, S.G., Cook, D.G., Whincup, P.H., 2010. Secondhand smoke (SHS) exposure is associated with circulating markers of inflammation and endothelial function in adult men and women. Atherosclerosis 208, pp. 550-556


Friday, March 17, 2017

Decision Support Tools for People with Depression

For years decision support tools have been available for certain diseases, but not usually for mental health. However, there has recently been an emergence of some on-line calculators for supporting important clinical decisions such as "should I take an antidepressant" and "should I stop my antidepressant." The extent of evidence underpinning the decision support is difficult to discern, but these tools are interesting because they walk a person though a decision making process, soliciting ratings from the decision-maker to inform the final decision.