Long-term medical conditions and major depression in the Canadian population.

OBJECTIVES: To evaluate associations between long-term medical conditions and major depression in the Canadian population, and to examine the impact of these conditions on health care service use and disability.
METHODS: Data from the first wave of the Canadian National Population Health Survey (NPHS) were used. The NPHS used a probability sample of 17,626 Canadians and included questions about long-term medical conditions, health care service use, and disability and a brief predictor of major depression. Contingency tables and graphical techniques were used to evaluate associations between the variables of interest.
RESULTS: Various chronic medical conditions were associated with an elevated prevalence of major depression. There was no evidence that subjects with major depression and comorbid medical conditions were more likely to be admitted to hospital or to be high users of physician services. However, major depression comorbid with chronic medical conditions was associated with a greater than expected extent of activity limitations.
CONCLUSIONS: Chronic illness may increase the risk of depression or the duration of depressive episodes; either effect could lead to an increased prevalence. Alternatively, major depression may predispose individuals to certain chronic illnesses. Comorbid major depression and chronic medical conditions are associated with a considerable burden of disability in the Canadian population but not excessive use of physician services.