Comorbidity of Major Depression and Migraine-A Canadian Population-Based Study

Article excerpt

Objective: To estimate the prevalence of major depressive episodes (MDEs) in patients with migraine and to compare the strength of association with that of other long-term medical conditions.

Methods: This study used a large-scale probability sample (over 130 000 sample) from the Canadian Community Health Survey (CCHS), a cross-sectional survey conducted by Statistics Canada. The CCHS screened for a broad set of medical conditions. Major depression was evaluated with the Composite International Diagnostic Interview Short Form for Major Depression, and the diagnosis of migraine was self-reported. The annual prevalence of major depression was calculated in the general population, in subjects with migraine, and in those with chronic conditions other than migraine.

Results: The prevalence of major depression in subjects reporting migraine was higher than that in the general population or in subjects with other chronic medical conditions (17.6%, compared with 7.4% and 7.8%, respectively).

Conclusions: There is a strong association between major depression and migraine. The migraine-MDE association may account for a large fraction of the chronic condition-MDE association. The association between migraines and MDE differs from that of other chronic conditions, as the association persists into older age groups.

(Can J Psychiatry 2005;50:832-837)

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Clinical Implications

* Because of the high participation rate and sampling procedure, the results reported here can be interpreted as representative of the entire Canadian population and are less susceptible to the bias of studies of clinical samples.

* This information is essential for planning health services and prioritizing further research in this area.

* It is important for both psychiatrists and health care clinicians in routine clinical setting to be aware of the high, increased risk of MDE associated with migraine in all age groups.

* Clinicians are challenged to recognize that MDE and migraine coexist and to take this coexistence into account when developing treatment strategies. Possibly, more patients could benefit from a multidisciplinary intervention.

Limitations

* The presence of migraine was self-reported and not diagnosed. Some patients suffering from chronic headaches might have been diagnosed with migraine.

* This was a cross-sectional study, and causality cannot be concluded from this analysis.

Key Words: major depressive episode, migraine, comorbidity, prevalence

Abbreviations used in this article

CCHS Canadian Community Health Survey

CI confidence interval

CIDI Composite International Diagnostic Interview

CIDI-SFMD CIDI Short Form for Major Depression

MDE Major depressive episode

OR odds ratio

Depression is one of the most common major psychiatric disorders. In 2003, the National Comorbidity Survey Replication reported a lifetime prevalence of CIDI-diagnosed major depression of 16.2% (95%CI, 15.1%to 17.3%)(1).The WHO estimates that, by the year 2020, unipolar major depression will become the second leading cause of disease burden worldwide, second only to ischemie heart disease (2). These data ask for an aggressive approach to identifying factors that may affect the diagnosis of, and treatment strategies for, depression. Among these factors, the complex relation between depression and other medical conditions requires particular attention. In a prospective, community-based study in a Canadian population, Patten described an increased risk of developing depression with almost any long-term conditions and reported that, alternatively, depression may increase the risk of chronic medical conditions (3). Other reports (4-8) support these results. A limited number of studies have addressed the importance of comorbidity between depression and migraine, a chronic condition with a high prevalence rate of 18% for women and 6% for men (9). …