As I wrote in an earlier post, it is common for health organizations in Canada (or even corporations involved in mental health awareness, such as Bell Canada), to use the statistic of "1 in 5" when describing lifetime prevalence of mental illness. I thought this estimate was too low because it is nowhere close to the U.S. data, and after a little reading, I presumed that the 20% figure originated from an error in interpreting a report from 2002. I subsequently contacted Bell Canada, the Canadian Mental Health Association, and Health Canada to seek information.
Health Canada has been the only organization to fully respond thus far. They forwarded my inquiry to the Public Health Agency of Canada (PHAC). An agent from this government organization was kind enough to send a fairly detailed response. The government agent wrote that the 20% statistic comes from Statistics Canada’s 2002 Canadian Community Health Survey on Mental Health and Wellbeing (CCHS 1.2). This national survey estimated the 12 month and lifetime prevalence of the following disorders:
- Major Depression
- Bipolar Disorder (only BP I - not II)
- Panic Disorder
- Agoraphobia
- Social Phobia
- Substance Dependence
Results from the study found the 1 in 10 Canadians had at least one of these disorders over a 1-year period, and 1 in 5 will experience one of these disorders in their lifetime. Anyone familiar with mental health and psychopathology should immediately recognize the problem with this estimate based on the list of disorders above. These represent only a portion of the mental health disorders that exist. Indeed, here are some of the major disorders missing from the list (I include in brackets the lifetime prevalence of each disorder based on U.S. estimates):
- Specific Phobia (12.5%)
- Generalized Anxiety Disorder (5.7%)
- PTSD (6.8%)
- OCD (1.6%)
- Dysthymia (2.5%)
- ADHD (8.1%)
- Oppositional Defiant Disorder (8.5%)
- Conduct Disorder (9.5%)
- Intermittent Explosive Disorder (5.2%)
- Schizophrenia (1%)
- Personality Disorders (14.8%)
As you can see, there were a large number of disorders omitted from the Canadian survey, which explains the discrepancy between the Canadian and US prevalence estimates. The PHAC agent who emailed me recognized the cause of the discrepancy and acknowledged that "it is an incomplete list of conditions."
Furthermore, the PHAC representative wrote that because of the limitations in the Canadian survey "we use the wording that 'more than one in five Canadians will experience a mental illness in their lifetime.'(italics added)"
There are two problems with this approach. First, saying "more than 1 in 5" gives absolutely no clear way of knowing just how many more Canadians are affected by mental illness. It could 20.1% or 50%. This approach obscures just how serious and widespread mental illness is in Canada.
The second problem with this approach is that there is a risk that the "more than 1 in 5" phrase will morph into just "1 in 5" by health organizations and government officials. Indeed, this has already happened in several instances. In fact, look no further than the actual report itself (see here).
Although the report acknowledges that the true estimate of prevalence is more than 20%, it quickly shifts to the simpler 20% figure. In fact, seven paragraphs into the first page, it states that "[m]ental illness affects approximately 20% of Canadians during their lifetime." Health Canada also notes the 20% figure several times on its website (having dropped the "more than" specifier). Also, as previously mentioned, both the Canadian Mental Health Association and Bell Canada (the "Let's Talk" initiative) both cite the 20% figure.
Unfair and Biased
How unfair is this approach to estimating? Imagine if the true prevalence of cancer in Canada was somewhere around 50%, but the government of Canada estimated the prevalence to be approximately 20% because they only 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 money 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.
Unfortunately, the lack of a representative list of mental health disorders was not the only problem with the Canadian survey. The survey excluded the following groups of people:
- 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
This list of excluded groups only highlights just how low and biased the 20% figure appears to be. 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.
Recognition Needed
The 20% prevalence estimate of lifetime mental illness is a terrible estimate of prevalence, and is no better served by adding "more than" as a specifier. While I believe that the Canadian survey authors did not intend to underestimate the prevalence of mental illness and hinder the promotion of mental health in Canada, more should have been done to provide a clearer statistic that best represented the prevalence of mental illness in Canada. Even if this involved using U.S. data to fill in the gaps left by the Canadian survey, it would at least be a much more accurate representation of prevalence, which is the ultimate goal of such research.
Such a statistic would aid greatly in both the promotion of mental health awareness and in the reduction of stigma. Furthermore, it would allow those individuals interested in advocating for more government-assisted treatment of mental illness to have greater ammunition in their quest to convince government officials of the pressing need for more support.
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.
Health Canada has been the only organization to fully respond thus far. They forwarded my inquiry to the Public Health Agency of Canada (PHAC). An agent from this government organization was kind enough to send a fairly detailed response. The government agent wrote that the 20% statistic comes from Statistics Canada’s 2002 Canadian Community Health Survey on Mental Health and Wellbeing (CCHS 1.2). This national survey estimated the 12 month and lifetime prevalence of the following disorders:
- Major Depression
- Bipolar Disorder (only BP I - not II)
- Panic Disorder
- Agoraphobia
- Social Phobia
- Substance Dependence
Results from the study found the 1 in 10 Canadians had at least one of these disorders over a 1-year period, and 1 in 5 will experience one of these disorders in their lifetime. Anyone familiar with mental health and psychopathology should immediately recognize the problem with this estimate based on the list of disorders above. These represent only a portion of the mental health disorders that exist. Indeed, here are some of the major disorders missing from the list (I include in brackets the lifetime prevalence of each disorder based on U.S. estimates):
- Specific Phobia (12.5%)
- Generalized Anxiety Disorder (5.7%)
- PTSD (6.8%)
- OCD (1.6%)
- Dysthymia (2.5%)
- ADHD (8.1%)
- Oppositional Defiant Disorder (8.5%)
- Conduct Disorder (9.5%)
- Intermittent Explosive Disorder (5.2%)
- Schizophrenia (1%)
- Personality Disorders (14.8%)
As you can see, there were a large number of disorders omitted from the Canadian survey, which explains the discrepancy between the Canadian and US prevalence estimates. The PHAC agent who emailed me recognized the cause of the discrepancy and acknowledged that "it is an incomplete list of conditions."
Furthermore, the PHAC representative wrote that because of the limitations in the Canadian survey "we use the wording that 'more than one in five Canadians will experience a mental illness in their lifetime.'(italics added)"
There are two problems with this approach. First, saying "more than 1 in 5" gives absolutely no clear way of knowing just how many more Canadians are affected by mental illness. It could 20.1% or 50%. This approach obscures just how serious and widespread mental illness is in Canada.
The second problem with this approach is that there is a risk that the "more than 1 in 5" phrase will morph into just "1 in 5" by health organizations and government officials. Indeed, this has already happened in several instances. In fact, look no further than the actual report itself (see here).
Although the report acknowledges that the true estimate of prevalence is more than 20%, it quickly shifts to the simpler 20% figure. In fact, seven paragraphs into the first page, it states that "[m]ental illness affects approximately 20% of Canadians during their lifetime." Health Canada also notes the 20% figure several times on its website (having dropped the "more than" specifier). Also, as previously mentioned, both the Canadian Mental Health Association and Bell Canada (the "Let's Talk" initiative) both cite the 20% figure.
Unfair and Biased
How unfair is this approach to estimating? Imagine if the true prevalence of cancer in Canada was somewhere around 50%, but the government of Canada estimated the prevalence to be approximately 20% because they only 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 money 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.
Unfortunately, the lack of a representative list of mental health disorders was not the only problem with the Canadian survey. The survey excluded the following groups of people:
- 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
This list of excluded groups only highlights just how low and biased the 20% figure appears to be. 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.
Recognition Needed
The 20% prevalence estimate of lifetime mental illness is a terrible estimate of prevalence, and is no better served by adding "more than" as a specifier. While I believe that the Canadian survey authors did not intend to underestimate the prevalence of mental illness and hinder the promotion of mental health in Canada, more should have been done to provide a clearer statistic that best represented the prevalence of mental illness in Canada. Even if this involved using U.S. data to fill in the gaps left by the Canadian survey, it would at least be a much more accurate representation of prevalence, which is the ultimate goal of such research.
Such a statistic would aid greatly in both the promotion of mental health awareness and in the reduction of stigma. Furthermore, it would allow those individuals interested in advocating for more government-assisted treatment of mental illness to have greater ammunition in their quest to convince government officials of the pressing need for more support.
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.
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