09/24/2013 05:44 EDT | Updated 11/24/2013 05:12 EST

Why Mental Illness Goes Much Further Than Research Tells Us

Canadians recently learned the results of the Canadian Community Health Survey on Mental Health (2012), which revealed that 1 in 6 Canadians were in need of mental heath care. This is a large portion of the population and so the findings are not only significant, but they have garnered media attention and should assist in advocacy for mental health issues in Canada.

The problem is that the statistic is flawed.

The researchers excluded three critical groups:

1. "persons living on reserves and other Aboriginal settlements"

2. "full time members of the Canadian Forces"

3. "institutionalized populations"

The problem here is obvious -- the exclusion of these populations significantly lowers the number of people identified as having a mental health need. Native Canadians are known to suffer from problems with substance abuse, depression and high suicide rates, and the Canadian Armed Forces tend to have higher rates of PTSD and depression than the general population.

Furthermore, the researchers only assessed a small portion of mental illnesses -- depression, bipolar, generalized anxiety, and substance abuse/ dependence. Using a reduced number of disorders in the calculation and understanding of need biases the results.

So, the 1 in 6 figure significantly underestimates the mental health needs of Canadians.

There were other methodologcal issues that are also worth mentioning here, but my goal is not to tear down the methodological flaws of the research. Rather, I believe there is a larger and more important message to be delivered by examining the mental health statistics disseminated in Canada. Before making my broader point, let's look at a more popular mental health statistic that many readers would be familiar with.

Many Canadians have heard over the years that 1 in 5 Canadians will suffer from a mental illness in their lifetime. They were exposed to this statistic through the Bell Canada "Let's Talk" campaign or through the various health agencies in Canada, such as the Public Health Agency of Canada, the Canadian Mental Health Association (CMHA), and the Canadian Institute of Health Research.

These groups' websites are not the best at clearly citing their sources, but with a little bit research, one finds that the statistic usually comes from one of two reports:

1. The Report on Mental Illness in Canada by the Public Health Agency of Canada.

2. The Canadian Community Health Survey on Mental Health and Well-Being (2003).

The first report summarizes existing data and was used to paint a picture of mental illness in Canada.

The odd thing about this report is its clear problem with internal consistency.

The authors of the report assert on page 15 that 20% (1 in 5) of Canadians will experience a mental illness in their lifetime. Two pages later (p. 17) they write that "Canadian studies have estimated that nearly one in five Canadian adults will experience a mental illness during a one year period (my italics)." This appears to be a baffling mistake that confuses the reader about which statistic is correct.

The second report presents the findings of a national survey. Both one year and lifetime prevalence of various mental illnesses are presented. Results from this study found that 1 in 10 Canadians had at least one mental illness over a one year period, and 1 in 5 experienced one of these disorders in their lifetime.

These data are a significant improvement over the The Report on Mental Illness in Canada, which derived their data from smaller Canadian studies.

However, the problem with the CCHS survey is that only a portion of mental illnesses were examined. The researchers did not assess the prevalence of many disorders. To give an idea of the degree to which this exclusion of illnesses would bias the prevalence results, I have listed here the illnesses not included in the survey and the lifetime prevalence of each disorder based on U.S. estimates (1):

- Specific Phobia (12.5 per cent)

- Generalized Anxiety Disorder (5.7 per cent)

- PTSD (6.8 per cent)

- OCD (1.6 per cent)

- Dysthymia (2.5 per cent)

- ADHD (8.1 per cent)

- Oppositional Defiant Disorder (8.5 per cent)

- Conduct Disorder (9.5 per cent)

- Intermittent Explosive Disorder (5.2 per cent )

- Schizophrenia (one per cent)

- Personality Disorders (14.8 per cent)

As you can see, there were a large number of disorders not included in this Canadian survey. However, this is not the only problem. Similar to the more recent CCHS survey, the following groups were omitted from the study:

- those living in the three Canadian territories and resident of remote areas

- those living on Indian Reserves and Crown lands

- residents of institutions, and

- full-time members of the Canadian Armed Forces

When one considers that these groups were not included, in addition to the large swath of mental illnesses that were not evaluated, it becomes very clear that 1 in 5 Canadians is not even close.

Large scale American studies on prevalence of mental illness have found that 1 in 2 Americans will experience a mental illness in their lifetime.

While I certainly applaud these various health organizations for their efforts and hard work, I am quite dissatisfied with not only the biased statistics that have been formulated and disseminated, but also how no one has even noticed.

To help put into perspective the injustice of this problem, one only needs to surmise the reaction of politicians, health officials, advocates and indeed the general population if this same approach was used with a physical health problem like cancer.

Imagine if the true prevalence of cancer in Canada was somewhere around 50 per cent, but the government of Canada estimated the prevalence to be approximately 20 per cent because they included in their estimate only a portion of all possible cancers. The medical community would be in an uproar because there are important implications drawn from such data.

Health awareness in the community and funding for research and treatment are all affected by the estimated severity of a problem. And if you vastly underestimated cancer rates, the realistic danger is that cancer research and treatment would not receive the necessary attention and funding that it deserves, and the community at large would suffer. Thus, it is important to always have an accurate understanding of the severity of a particular health problem.

Well, guess what happens if mental illness is underestimated?

It is often said that mental health is the orphan of the Canadian health care system. Sadly, the lack of awareness in just how prevalent mental illness is in Canada only serves to further validate this conclusion.

Facts About Mental Health in Canada