To estimate (1) the prevalence of long-term medical conditions and of comorbid major depression, and (2) the associations between major depression and various chronic medical conditions in a general population of older adults (over 50 years of age) and in persons who are traditionally classified as seniors (65 years and older).
Data from the Canadian Community Health Survey- Mental Health and Wellbeing (CCHS-1.2) were analyzed. Non-institutionalized individuals over 15 years of age in the 10 Canadian provinces were sampled in the CCHS-1.2. The entire sample of the CCHS-1.2 consisted of 36,894 individuals, for the main analyses in this study the dataset was restricted to those aged 50 and over (n=15,591). Chronic health conditions were assessed using a self-report method of doctor diagnosis. The World Mental Health-Composite Diagnostic Interview was used to asses major depressive episodes based on DSM-IV criteria.
The overall prevalence of having at least one chronic condition in those over 50 years of age was 82.4%, compared to 62.0% in those under 50. The prevalence of a major depressive episode in those over 50 with one chronic condition was 3.7%, compared with 1.0% in those without a long-term medical condition. The top 3 chronic health conditions in seniors aged 65 or older were arthritis/rheumatism, high blood pressure and back problems. Chronic Fatigue Syndrome, fibromyalgia and migraine headache had the highest comorbidity with major depression in the senior population.
The use of self-report data on chronic health conditions, potential diagnostic overlap between conditions, and the inability to make causal inferences due to the cross-sectional nature of the data are all limitations of the current study.
Differences were found between rates of chronic conditions and major depression between the general population, older adults and seniors in this study. Further research is needed to delineate the direction of these relationships in seniors. Primary and secondary prevention efforts should target seniors who exhibit symptoms of depression or highly prevalent chronic health conditions.