Depression in Canada: Cannabis Abuse and Dependence Found in About 5% of Those Affected
Among Canadians with past-year major depression, 2.5% had cannabis abuse and 2.9% had cannabis dependence, while 63% sought treatment and 6.6% had attempted suicide.
Quick Facts
What This Study Found
This national epidemiological survey assessed major depressive disorder in 25,113 Canadians using diagnostic interviews. The past-year prevalence of major depression was 3.9%.
Among those with depression, substance use was notable: 4.8% had alcohol abuse, 4.5% had alcohol dependence, 2.5% had cannabis abuse, and 2.9% had cannabis dependence. Generalized anxiety disorder co-occurred in nearly 25%.
Treatment seeking had improved compared to earlier Canadian surveys (63.1% sought treatment), but antidepressant use remained stable at 33.1%. A concerning 37.5% of those accessing treatment perceived stigma from others about their condition. Suicide attempts were reported by 6.6%.
Key Numbers
25,113 respondents; past-year MDD prevalence 3.9%; cannabis abuse 2.5% and dependence 2.9% among those with MDD; 63.1% sought treatment; 33.1% on antidepressants; 6.6% attempted suicide; 37.5% perceived stigma
How They Did This
National population-based survey (Canadian Community Health Survey - Mental Health, 2012) of 25,113 respondents using an adaptation of the WHO Composite International Diagnostic Interview. Complex survey design methods were used for prevalence estimates.
Why This Research Matters
This study quantifies the overlap between depression and cannabis use disorders in a national population, while also showing that depression remains significantly undertreated and stigmatized despite being common.
The Bigger Picture
The co-occurrence of depression and cannabis use disorders raises questions about whether people use cannabis to self-medicate for depression or whether cannabis use contributes to depression. Either way, integrated treatment addressing both conditions may be beneficial.
What This Study Doesn't Tell Us
Cross-sectional survey cannot determine causal direction between depression and cannabis use. Self-reported diagnoses and treatment. Household survey may miss homeless or institutionalized populations with higher depression rates.
Questions This Raises
- ?Does cannabis use worsen depression outcomes, or are depressed people self-medicating with cannabis?
- ?Would addressing cannabis use improve depression treatment outcomes?
- ?Has stigma around depression decreased since 2012?
Trust & Context
- Key Stat:
- 2.5% cannabis abuse + 2.9% cannabis dependence among those with depression
- Evidence Grade:
- Large national survey with validated diagnostic instruments and representative sampling, providing reliable population-level estimates.
- Study Age:
- Published in 2015 using 2012 data. Canada has since legalized recreational cannabis, which may have changed use patterns among those with depression.
- Original Title:
- Descriptive epidemiology of major depressive disorder in Canada in 2012.
- Published In:
- Canadian journal of psychiatry. Revue canadienne de psychiatrie, 60(1), 23-30 (2015)
- Authors:
- Patten, Scott B(2), Williams, Jeanne V A, Lavorato, Dina H, Wang, Jian Li, McDonald, Keltie, Bulloch, Andrew G M
- Database ID:
- RTHC-01037
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
How common is cannabis use among people with depression?
In this Canadian survey, about 5.4% of people with major depression had cannabis abuse or dependence (2.5% abuse, 2.9% dependence). This is higher than the general population rate, suggesting an association between the two conditions.
Does treating depression reduce cannabis use?
This study did not test that directly. It found that 63% of depressed Canadians sought treatment, but the relationship between depression treatment and cannabis use was not examined.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-01037APA
Patten, Scott B; Williams, Jeanne V A; Lavorato, Dina H; Wang, Jian Li; McDonald, Keltie; Bulloch, Andrew G M. (2015). Descriptive epidemiology of major depressive disorder in Canada in 2012.. Canadian journal of psychiatry. Revue canadienne de psychiatrie, 60(1), 23-30.
MLA
Patten, Scott B, et al. "Descriptive epidemiology of major depressive disorder in Canada in 2012.." Canadian journal of psychiatry. Revue canadienne de psychiatrie, 2015.
RethinkTHC
RethinkTHC Research Database. "Descriptive epidemiology of major depressive disorder in Can..." RTHC-01037. Retrieved from https://rethinkthc.com/research/patten-2015-descriptive-epidemiology-of-major
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.