Clinical Depression in Canada

2012-02-01T15:39:00.000-08:00

Two medical students at the University of Calgary have just received a Social Accountability Award for looking at the usefulness of screening in the Calgary Drop-in Centre. This is a major study that they organized and conducted while in the middle of Medical School. They are just beginning to analyze the data that they have collected. Once results are available, I will post information on the prevalence of depression in this population - one of several conditions that their study examined.

More Smoking and Depression

2011-12-15T00:20:00.001-08:00

Smoking isn't something that comes to mind for most people as an important risk factor for depression. However, studies have shown that smoking increases the risk of depression, and that is aggravates the course of depression. Although smokers often develop the impression that smoking is improving the mental well-being, in the longer term it seems to make things much worse.

See comments in this blog.

http://brainblogger.com/2011/12/10/risk-factors-for-recurrence-of-depression/

Smoking and Depression

2011-10-31T12:51:00.000-07:00

Dr. Ian Colman at the University of Ottawa has carried out a sophisticated analysis of predictors of a negative course using data collected in a longitudinal Canadian study. The intention was to identify indicators of negative outcome, as determined by subsequent recurrences of depression. Not surprisingly, past episodes were predictive of future ones and a psychological construct "mastery" was also predictive, however, a very strong association was found between smoking and negative course. This adds to mounting evidence linking smoking to depression. In the past there has been a tendency, for some reason, to treat the association between depression and smoking as an epiphenomenon, perhaps reflecting shared genetic vulnerability. But, this study adds weight to the idea that depression and smoking are a bad mix. Contrary to the beliefs of some smokers, who feel that smoking makes them feel better, smoking may be contributing to deterioration in mental health over the longer term. A copy of the paper may be found here.

Depression and Chronic Illness

2011-08-19T12:56:00.001-07:00

The association between depression and chronic illness and depression persists across the lifetime - the strongest connection is with painful conditions. A graduate student at the University of Calgary has examined this issue in elderly persons, the age category where chronic conditions are most common. Her results indicated that these associations are strong and important in elderly members of the general population - here is a media summary of her report.

Suicide

2011-08-19T12:43:00.000-07:00

Depression dramatically increases the risk of suicide, although many suicides occur in non-depressed persons. Schizophrenia and substance-use disorders are also associated with dramatically elevated risk. Canadians were recently reminded of these realities with the suicide of a professional hockey player that had long struggled with depression. Toronto Star link here.

Mental Health Commission - Opening Minds

2011-08-19T12:37:00.000-07:00

One of the things that creates a barrier between depressed people and treatment is stigma. Reducing stigma is one of the priorities of the Mental Health Commission of Canada. They have a lot of information about this issue on their website, which can be accessed here.

Vancouver Riots

2011-06-16T14:05:00.000-07:00

After the last Vancouver riot, we did a project looking at the applicability of an epidemic model to explain these superficially unexplainable outbursts. While it has become routine to blame criminal elements or political operatives, it is also true that crowd violence may have a contagious aspect. Many of the principles of crowd control can be understood in ways that fit with this "behavioral contagion" idea: e.g. separating (quarantine) trouble-makers, influencing factors that may affect the predilection or spread of violence (alcohol), one factor that stems largely from the epidemic model is the idea of an epidemic threshold - which implies that the size of a crowd will be an important predictor of a riot. This is perhaps a mathematical reality rather than an intuitively obvious one, such that it tends to be ignored to a greater extent than other factors. The abstract for this paper is here and here.

Frontiers: Perspective -Towards an anti-inflammatory strategy for depression.

2011-04-20T07:59:00.000-07:00

It is becoming increasingly apparent that links exist between inflammation and depression.
This may explain some of the epidemiological linkages between inflammatory conditions and depressive disorders.
An intriguing possibility is that this may also open up new avenues of treatment, see link.

Frontiers: Perspective -Towards an anti-inflammatory strategy for depression.

MDD During a Time of Economic Hardship

2011-02-25T20:27:00.000-08:00

My colleague at the University of Calgary, Dr. Jian Li Wang, is the lead investigator on a large prospective cohort study (a study that follows a large group of respondents forward in time). The main goal of this study is to evaluate the workplace and their role in mental health. However, his study happened to be ongoing at the time when the current economic crisis hit. In his cohort, the prevalence of major depression increased from 5.1% to 7.6%, a significant change. The prevalence of dysthymic disorder (chronic, low grade depression) also increased significantly. This is one of the first studies to demonstrate the sensitivity of this condition to environmental conditions, in this case socio-economic conditions.

A link to the abstract for the paper may be found
here.

Full text of the paper here.

Predictors of the Long Term Course of Major Depression

2011-02-17T08:24:00.000-08:00

In Canada (as in other countries), approximately 20% of those developing an episode of MDE have a decidedly negative course. In a recent study, we examined what factors may help to predict, or determine, a more favourable from a less favourable long-term outcome. The most important predictors of a negative course were: having a family history of depression, having a comorbid condition along with the depressive episode, having a more negative cognitive style, stress, smoking and pain. In some cases, these may be factors that both result from depression and which make the depression worse - in other words, dynamic factors that may contribute to depression becoming entrenched. In other cases, e.g. having a family history, these may simply be factors that identify a greater vulnerability to depression.

Social Support and Major Depression

2010-12-14T10:53:00.000-08:00

Low social support has long been considered a risk factor for depression.
However, it is also possible that connections go in the other direction: episodes of depression may lead to an erosion of social support.
This is potentially an interesting question because problems in the area of social support may be a kind of psychological "scar" left behind after and episode, and which may in turn increase the risk of occurrence of another episode.

We recently sought to examine this issue using the National Population Health Survey in Canada. We confirmed that deficient social support was strongly associated with the risk of developing major depression. In the other direction, though, only one type of social support (the form that involves expression of emotion with a trusted person - affective social support) was adversely affected by depression. Other types of social support (people being around to give advice or offer help) are easier to address in clinical settings - but this change may be an important part of the challenges of bouncing back from depression.

A link to the full report can be found here.

Post from another blog

2010-10-20T12:22:00.001-07:00

This is a posting from another blog.
Can't vouch for the accuracy of this information - but it is an interesting list to look at.

"I thought perhaps you would be interested in sharing the article with your readers? If so, you can find the article here: (http://www.nursingschools.net/blog/2010/10/50-famous-artists-thinkers-who-have-struggled-with-depression/). Or, you can just go straight to our homepage and find it there."

Trends in Antidepressant Use in Canada

2010-09-04T12:37:00.000-07:00

Depression is a common health issue, so it is not surprising that a fairly large proportion (between 5 and 6%) of the Canadian population are taking antidepressants. However, not all depressive episodes require antidepressant treatment. Some such episodes resolve on their own and some can be treated by psychotherapy, so it is not surprising that a sizable proportion of those with depression do not take antidepressants. The frequency of use of antidepressants increased a lot in the 1990s, but this increase has slowed (at least in adults) in recent years. In a recent study, we found an interesting trend: that most people taking antidepressants do not report past-year episodes and that this is the category in which the frequency of use is increasing the most. This probably means that those with severe episodes or highly recurrent episodes are taking these medications over the longer term in order to prevent relapse. If this is true, it is a positive indication of appropriate treatment. Of course, it is also possible that some people may be taking these medications for reasons other than for depression (e.g. to prevent migraines or for chronic pain), which could also explain this trend.

Occupation and Depression

2010-08-09T11:57:00.000-07:00

I received this link from another blog site concerned with depression.
It has a top 10 list of professions/occupations purported to be associated with depression.
There are no sources listed, so I can't vouch for its accuracy - can't tell, either, whether is meant by "highest risk." Usually, "risk" means incidence (the possibility that someone who is not depressed will become depressed), but the term is often used informally to denote prevalence (the frequency of occurrence at a point in time in a specified group).

Incidence of Major Depression

2010-07-21T07:35:00.001-07:00

Prevalence is the proportion of people in a population who have a condition, whereas incidence is the frequency or rate at which people "at risk" (non-depressed) become depressed over time. Recently, Jian Li Wang (a psychiatric epidemiologist at the University of Calgary) has examined the incidence of major depression in Canada. His analysis confirms that the condition is very common - over a six year period, nearly 6% of the population developed a new episode of major depression. The incidence was higher in women and in younger age groups, but the strongest risk factor was having a family history of major depression.

A link to the abstract is here.

Changes to DSM-V

2010-05-19T08:57:00.000-07:00

The Diagnostic and Statistical Manual of Mental Disorders has probably been the most widely used classification in clinical practice since the publication of DSM-III in 1980. The manual is now in its fourth edition (DSM-IV-TR) and work is underway to create the next edition, DSM-V. A major change is proposed to the diagnosis of Major Depressive Disorder. According to the current criteria, the occurrence of one or more major depressive episodes (MDE) is the main feature of Major Depressive Disorder, and one of the exclusion criteria for MDE is bereavement. In other words, the diagnosis should not be made if the syndrome follows the death of a loved one - unless the symptoms are too extreme or too persistent to represent bereavement. The proposal for DSM-V involves removing this bereavement criterion. This proposal, if it is accepted, has the advantage of making the criteria more free from judgment - ie. more purely empirical, which may increase their utility for research. However, it also represents a broadening of the diagnostic criteria. This will mean that episodes previously regarded as grief-reactions will now qualify for a diagnosis of a mood disorder. Whether such episodes should be treated 'as if' they were the same as other mood disorders is a different question - one suspects that they should not be. An argument has been put forward that in some respects the exclusion for bereavement is arbitrary - other losses (employment, relationship, health-related) are not treated as exclusions in DSM. On the other hand, depressive symptoms following losses may represent an adaptive response of some type - and certainly it seems to be a 'natural' response to many people. A general principle seems to hold true: that as diagnostic categories widen they become more heterogeneous which probably means that the clinical response to them should be more flexible.

Depression's "upside"

2010-03-18T07:34:00.000-07:00

Occasionally, the comment is made that depression may have a "upside." Depression in its clinical forms is usually destructive, sometimes disabling and dangerous, but in other of its manifestations it may be adaptive (e.g. bereavement). An interesting article has emerged on this topic, here is the link. This is actually a follow-up comment on the NY Times article cited below.

Does Depression have an Upside?

2010-03-01T04:55:00.000-08:00

A so called "teleological" problem concerning depression asks the question "why does it exist." Various authors have long postulated that depression, at least in its milder forms must serve some purpose. In DSM-IV there is diagnostic exclusion criterion for bereavement, recognizing that in circumstances of loss depression is not necessarily "abnormal." Darwin made some interesting observations on this point in relation to his own struggle with health. These are summarized in a recent NY Times article, available here.

The Bipolar Spectrum

2010-01-09T17:07:00.001-08:00

Over the past decade there has been an effort on the part of some psychiatric researchers to expand the boundaries of bipolar disorder. The most recent salvo is a paper published in the Archives of General Psychiatry in December. The title is: Heterogeneity of DSM-IV major depressive disorder as a consequence of subthreshold bipolarity. The study uses data from a longitudinal psychiatric epidemiological study conducted in Germany. About half of people diagnosed at a baseline interview with major depressive disorder had "subthreshold bipolarity" meaning that they had some symptoms of hypomania (a milder disturbance than the manic episodes seen in Bipolar disorders). This subset was found to more often have a family history of bipolar disorder (5.9% vs. 1.9%) and more often converted to bipolar disorder (7.2% vs. 1.7%), among other differences. Based on this, the authors imply that people with major depressive disorder should be more carefully screened for subthreshold bipolarity so that they can be receive more "adequate treatment." They do not emphasize the reality that more than 90% of this subthreshold group did not have a family history of bipolar disorder and did not convert to a bipolar disorder. These recommendations are, in my view, somewhat reckless. In the absence of evidence from randomized controlled trials that treating people with subthreshold bipolar symptoms as if they had a bipolar disorder leads to better outcomes that treating them as if they had a major depressive disorder. This is a strange deviation from accepted principles of evidence-based medicine and surprising to see in the world's most highly ranked psychiatry journal.

Antidepressants and Risk of Stroke

2009-12-31T10:57:00.001-08:00

The December issue of the Archives of Internal Medicine contains a paper based on the Women's Health Initiative dataset (a large cohort of community dwelling women aged 50-79 in the US) that describes a possible association between antidepressant use and stroke (link to abstract). Hemmorhagic stroke (strokes caused by bleeding in the brain) seemed to account for most of the association. The authors also looked for an association between antidepressant use and coronary heart disease - finding no association. This report may cause some alarm for people taking antidepressant medications, but it is important (in my view) to consider three factors when interpreting these results. First, depression itself is associated with cardiovascular disease, so studies such as this one are vulnerable to "confounding by indication" - a situation where the reason for use of a medication causes a problem that subsequently seems to be due to the medication itself. The study used sophisticated means to control for confounding by indication, but even the most sophisticated approaches are not always effective for controlling this type of bias. Second, this is not the first study to look at this possibility, and the literature as a whole has been inconsistent. On the other hand, some antidepressants are known to increase the risk of bleeding related complications, so what is being reported is biologically plausible. The risk-benefit trade-offs for antidepressant use need to be better delineated so that people can make informed decisions about depression treatment - this study is an example of one that is pursuing this goal. The risks and benefits may play out differently in people with severe depression and/or other risk factors for stroke - hopefully, research in this area will remain active until these issues are decisively resolved.

Depression and Employment Status

2009-12-25T14:19:00.000-08:00

We've recently been looking at the impact of depression on employment status in Canadians using longitudinal data from the National Population Health Survey. We felt that this was important since, although it is well known that unemployment and depression are associated, it is possible both that unemployment could cause depression and that depression could cause unemployment. We were particularly interested in looking at the latter question. We selected people who were all working at baseline, divided these into groups that experienced (or did not) an episode of major depression. The effect of depression was greatest in young people - perhaps reflecting the greater difficulties faced by younger people in coping with depression, or their greater vulnerability to its effects (for example, because they may be less well-established in their career). However, it is also possible that older people who were working at baseline represented a subset of those who were more effective at coping with the symptoms - ie. those whose careers had been interrupted by depression prior to the baseline interview (1994) would not have been eligible, a selective effect that may have occurred less often in the younger respondents.

The results are published in the Canadian Journal of Psychiatry, here.

Another blogger interested in depression

2009-11-10T11:07:00.000-08:00

Another blog about depression has just added a list of 10 myths about the condition. Here is the link.

Cohort Effects in Major Depression

2009-10-25T14:51:00.000-07:00

Since psychiatric epidemiologic surveys began being conducted in the 1980s a strange pattern has been seen in one of the commonly estimated parameters: lifetime prevalence (LTP). LTP refers to the proportion of a sample who report having major depression during their prior lifetime. Since older people have had longer lives and a greater chance of becoming depressed, intuition suggests that LTP should increase with age. In contrast, most studies have found that it increases in young adult life and then declines subsequently with age (see September posting to this blog). There are a variety of possible explanations: (1) that the first onset of of depression occurs commonly in young people but that this incidence declines with age - this could explain the flattening of an age specific prevalence curve - but not a decline, (2) higher mortality in people with depression, (3) recall bias- ie. people forgetting about, or reframing, their experience of depression when they were young as they get older. These explanations have largely been ignored, however, and most researchers have instead claimed that more recent birth cohorts (those of younger age in surveys) have a higher risk of depression. We have developed some simulations to assess these explanations - and (as noted below) have confirmed that a cohort effect is not a necessary or likely explanation. The other factors can explain the observed pattern, the simulations may be accessed here. If the pattern is due to a cohort effect, however, this will lead to a 10-fold increase in depression lifetime prevalence in elderly people in upcoming decades, a dynamic depicted here.

Major Depression Epidemiology

2009-09-05T17:39:00.000-07:00

The biggest project in psychiatric epidemiology lately is the World Mental Health Survey initiative, which is conducting standardized surveys in more than 30 different countries. A remarkable thing about these surveys is that almost all of the authors from each participating country have concluded that there is a cohort effect for major depression. The standardized interviews (the CIDI, version 3.0) all inquire about lifetime history of specific disorders. One expects that as people get older and have a longer time at risk, the frequency of a positive lifetime history would increase - but this doesn't happen. Instead, the lifetime history starts to decrease in middle age. The idea of a cohort effect is an interpretation of this finding - with the interpretation being that people born more recently (younger at the time of the survey) are at higher risk of depression and this means that there will be an increase in depression in older age groups as these recent birth cohorts age. However, there are other possible explanations - differential mortality (people with depression may die more often as they get older) and recall bias (people may forget about past episodes, or reframe those experiences, so they come out as lifetime negative later in life when they would have come out as positive had they been interviewed earlier). I have been looking at these issues in simulation models, and have produced a brief video showing the results, click here and follow the link to "view." As it turns out, expected levels of forgetting/reframing of past episodes can easily explain the observed pattern. There is no reason to suppose that a cohort effect will lead to higher rates of depression in the future.

Smoking and Depression

2009-08-08T14:06:00.000-07:00

Traditionally, the risk factors that have recieved most attention in research about depression are psychosocial factors such as cognitive style and loss events. An exception to this rule is the emphasis that has been placed upon the role of genes in etiology. However, over the years, many studies have suggested that there is a strong association between smoking and depression. There are several possible explanations: one possibility is that people with depression may use nicotine to self-medication their symptoms. Another possibility is that smoking is a risk factor for depression, or their may be shared risk factors for both things. A PhD student at the University of Calgary has recently confirmed the existence of a strong association in the Canadian population, see here.

Consensus Statement on Depression

2009-05-07T22:42:00.000-07:00

This is a consensus statement on what to do about depression in Canada.
It is the summary output of a conference that was held last year.
The report is not just an academic report, it had lots of diverse input.

You can get a copy of the report here.

Is Depression Much More Common than Experts Think?

2009-05-07T22:13:00.001-07:00

Standardized interviews to detect depression have been available since the 1980s. In order to determine the prevalence of major depression, most studies have adminstered these interviews to samples of people in the community. There is, however, a potentially serious problem with this approach. Not all episodes of depression are necessarily remembered. Furthermore, the instruments attempt to identifiy episodes by asking about specific symptoms, but people may not remember, for example, a series of weeks during which their sleep or appetite patterns were altered. Furthermore, of course, peoples' memories of events can change over time. The end result is that the prevalence of major depression in the population may be seriously underestimated. To explore this possibility, I recently examined the accumulation of depressive episodes during 14 years of follow-up in the National Population Health Survey. Since the participants in this cohort were interviewed every two years, they were probably much more likely to have episodes detected than other studies where they have been asked to recall episodes occuring much earlier in their life.

The hypothesis was confimed: the prevalence of depression as measured by the prospective approach was twice the usually cited figures for Canada. Major depression is probably much more common than is currently beleived. Details (in preliminary form) may be found here in the journal BMC Psychiatry.

Depression and Participation in Preventive Health Care Activities

2009-05-07T22:02:00.000-07:00

Prevention plays an important role in health care. Monitoring blood pressure is a way to detect elevated blood pressure and by treating this prevent strokes and heart disease. Procedures such as mammography and Pap tests can detect cancers earlier than they would normally be detected and at a stage when they are more likely to be curable. When people are struggling with depression they may be less likely to persevere with these kinds of preventive activities. Even mild depression can affect peoples' energy and motivation, which could have an impact. Also, while depressed, it is more difficult for people to think positively - and preventive health care is all about creating a healthier future. Finally, when people are severely depressed they may not value their life as much (the most extreme such manifestation being suicidality) and therefore not take steps to safeguard it.

Because of these concerns, we have examined the impact of major depression on participation in preventive health care activities in Canadians during the late 1990s and up to 2004. The results are available here. Surprisingly, no effect was found. The most likely explanation is that even though depression might cause reduced participation, this is offset by more frequenty contact with the health system. People with depression contact the health system more often because they are seeking or receiving treatment, and perhaps for other reasons as well (e.g. a tendency of depression to magnify pain complaints).

Does depression contribute to high blood pressure?

2009-04-22T17:28:00.000-07:00

According to population surveys, large number of medical conditions are associated with major depression. One of these is high blood pressure (hypertension). It is possible that being diagnosed with high blood pressure would lead to depression because receiving such a diagnosis may be a stressful even for some people. However, it is also possible that depression might increase the risk of high blood pressure. There are several mechanisms by which this might occur. One is that depression is characterized by activation of the autonomic nervous system, which is involved in the regulation of blood pressure. Another possibility is that immune activation, which occurs in depression, may lead to blood pressure changes. We recently used a Canadian health data source (a study called the NPHS) to explore the possibility that people with major depression would be more likely develop high blood pressure. The hypothesis was confirmed: an increased risk of high blood pressure was observed, see PubMed link. This does not necessarily mean that depression was causing high blood pressure. Another possibility is that there is a shared cause of both conditions. Nevertheless, people with major depression should be aware that they may be at higher risk and closer monitoring of their blood pressure may be warranted.

Immune Function, Allergies, and Depression

2009-01-26T16:03:00.001-08:00

Traditionally, there has been concern that depression may be associated with diminished immune function, such that people who are depressed may be more vulnerable to infectious diseases.

However, in recent years there has been increasing evidence of immune activation (e.g. higher levels of markers of inflammation in peripheral blood) in people who are depressed. It has been hypothesized that immune activation in depression may be a mechanism by which depression causes cardiovascular disease and increases mortality in cardiovascular disease. These observations dovetail with reports that certain immune modulators (particularly interferons), when used in the treatment of hepatitis C and malignant melanoma may trigger depression, and that antidepressants may prevent this from happening.

These possibilities cast new interest on the observation that allergies may be associated with depression. After all, allergies represent an immunologic "over response" to an environmental stimulaus. Unfortunately, the existing reports have been inadequate to explore this possibility. We have looked at this in a Canadian cohort in a recently published study and found that people with clinical depression have a higher risk of developing allergies. A full report can be found here.

Is depression contagious?

2008-12-08T12:22:00.000-08:00

A recent study that has been getting a lot of press coverage asserted that happiness may be contagious. This raises the question about whether depression may have a contagious element. The authors used social network theory to show that the probability of being happy was greater when other around you are happy - and found weaker effects for unhappiness. The idea of emotional contagion is a very old one, but its relevance to depressive disorders has not been confirmed. The outbreak of sports riots is another circumstance in which emotional contagion may play an important role, see here.

Stepped Care

2008-11-13T11:26:00.000-08:00

A trend in how people are understanding optimal treatment for depression is seen in the UK NICE guidelines on depression management, which adopt a "stepped care" approach. This means that an intervention should start with a basic approach and move systematically towards more intensive treatments if the basic interventions are not successful. This fits, in theory, with the idea that many (perhaps most) episodes of depression and mild and self-limited, but that at the other end of the spectrum, many episodes are highly persistent and recurrent (link to a paper on the topic) and need long-term proactive care. This is an idea that is gaining wider acceptance in Canada, see article in the Sudbury Star.

IHE Consensus Development Conference

2008-10-17T15:03:00.001-07:00

The Institute of Health Economics consensus development conference on depression is complete. The process for consensus development involved a variety of presentations from leading Canadian and International researchers in the field. These presentations were made to a Jury, which was then sequestered to produce a consensus statement on how to improve diagnosis, prevention and treatment of depression. I have added a link for the statement to the Blog along.

SP

Upcoming Consensus Conference

2008-09-07T10:02:00.000-07:00

A consensus conference on depression will be taking place in Calgary in October.
Registration is still open. More information and the program can be found by following this link.

On Line Resources

2008-07-26T17:59:00.000-07:00

The policy paper emphasizes a public health perspective.
There are also a lot of resources available on the Web that can support clinical care in major depression.
Materials for self-management have been developed by Dr. Dan Bilsker at Simon Fraser University and are freely available here.
An on-line version of CBT is freely available here, from the Australian National University. This version of computerized CBT was evaluated in a randomized controlled trial published in the British Medical Journal, link here.
Wikepedia has alot of information too, including definitions and history, here.
It includes a picture painted by Van Gogh in the year of his suicide.

2008-07-07T11:32:00.000-07:00

The issue of depression as a cause of workplace difficulties was, until recently, a neglected topic. This is no longer the case, probably as a result of some major international (e.g. the World Health Organization's Global Burden of Disease Project) and national (e.g. the Kirby Report) initiatives.

The concern is filtering down, as seen in the recent series in the Globe and Mail (see below). This week, there was also some coverage by the Edmonton Journal, see here.

SP

Mental Health in Canada: Globe & Mail

2008-06-24T11:12:00.000-07:00

This week the Globe and Mail have been running an excellent series on mental health, with articles covering topics including stigma, the impact on people, and today, on peoples' careers. Link to article in on-line edition. Later in the week, there will be an article on the topic of Stigma by Senator Michael Kirby, whose report on mental illness in Canada has had a huge impact. Link to the report here. Canada has some leading researchers in the stigma field, including Dr. Julio Arboleda-Florez (Queen's University). Here is a link to a related newspiece. Another is Dr. Heather Stuart, also at Queen's University, she has made some of her work available on the WWW, see here.

Profil de la dépression clinique au Canada

2008-05-15T16:33:00.000-07:00

Le rapport est maintenant disponible en français.Vous pouvez y accéder à l'aide des rubriques à gauche de l'écran, ou en suivant celien :Vous êtes invités a faire vos commentaires en français ou en anglais.

Profil de la dépression clinique au Canada

Migraine and Mood Disorders

2008-05-05T08:20:00.001-07:00

Depression is associated with many physical conditions.
The most commonly implicated conditions are those that involve either inflammation or chronic pain. In a recent analysis of data from the CCHS 1.2, Dr. Nathalie Jette has demonstrated the strong link between migraine and major depression. She has also shown that the association is not specific for major depression. An association was observed also for bipolar disorder, panic disorder and social phobia.

More information here.

Link to Relevant Papers in CMAJ

2008-04-22T06:45:00.000-07:00

The paper by Katz et al. mentioned in the previous post can be found in the Canadian Medical Association Journal, April 8th Issue. There are also a couple of commentaries on the issue of depression there. The same issue also has a systematic review of screening instruments for depression.

More About the Antidepressant Effectiveness Debate

2008-04-09T08:34:00.000-07:00

Recent media attention to the idea that antidepressants are less effective than claimed derived from studies re-analyzing data submitted to regulatory agencies. The methodological issue involved is publication bias - the extent of antidepressant effectiveness may have been exaggerated because the most favourable results were the ones that were eventually published, whereas less favourable results were not.

However, the discussion appears to have gone "over the top" and these studies have been mentioned many times in the past few months in the media as providing evidence that the medications are completely ineffective.

The reaction has resulted in some new voices emerging: One is a communication to physicians from Dr. Patrick White, who is the current head of the Canadian Psychiatric Association:

Another is a cautionary note regarding suicide in youth - not a directly related issue has also appeared in the news media. The study, by Katz et al. has apparently not yet been published in the peer reviewed literature, but suggests a possible increased suicide rate in Manitoba youth in conjunction with reduced physician visits and antidepressant prescribing after a Health Canada warning about the medications. The possibility that reduced use of antidepressants in response to a Health Canada warning about their safety may have led to an increase in youth suicides in Manitoba cautions against overstated and rather sweeping criticism of medications such as these - as these can have negative effects.

It would be best if the debate about the proper role of these medications were guided by scientific evidence - and this is one of the goals of the policy paper that is the purpose of this blog. Incidentally, it was featured in the Statistics Canada "Daily" on April 9, 2008.

Is it true that antidepressants don't work?

2008-03-04T16:26:00.000-08:00

Lately, it has become popular to assert that antidepressants don't work, for example see this newspaper article.

It is true that in many antidepressant trials the observed effects have been modest, and the "placebo response" rates have been very high. However, the recovery rate from depression in people who are untreated is not always indicative of a placebo response. A placebo response implies that the recovery was due to the non-specific benefits of treatment (hope etc.).

The high rate of spontaneous recovery reflects the episodic nature of clinical depression. Many episodes of depression are brief (ie. they recover spontaneously and do not need treatment), but as they become more chronic the recovery rate diminishes. Many clinical trials actively recruit people with mild episodes and no comorbidity - exactly the group that is likely to recover rapidly.

So, despite the popularity of asserting that antidepressants don't work for depression, the reality is simpler: not all episodes of depression (especially mild ones) benefit from antidepressants.

A New Policy Paper on Clinical Depression in the Canadian Context

2008-03-04T16:02:00.001-08:00

Researchers across Canada are studying different aspects of major depression using Statistics Canada health survey data accessed primarily in Research Data Centres across Canada. A Profile of Clinical Depression in Canada is the first paper in a "Synthesis Series" designed to bring together research findings on socio-economic and health issues and make them known to policy makers and the public at large.

A Profile of Clinical Depression in Canada