Associations between depression, chronic physical health conditions, and disability in a community sample: A focus on the persistence of depression

Background: Previous research has demonstrated that comorbid depression and chronic physical health conditions are associated with disability. The distinction between persistent and transient depression in the relationship between physical health conditions and disability, however, is poorly understood. The present study examined the interactive effects of major depressive disorder (MDD) and chronic physical health conditions on disability in a community sample; the effects of persistent or transient depression on disability were also examined.

Methods: Participants were from the Epidemiological Catchment Area of Montreal South-West Study (total N=2202). Past 12-month MDD, chronic physical conditions, functional disability, and disability days experienced within the past month were concurrently assessed. A subsample (n=1226) was used to examine the persistence of depression across three waves of data collection over approximately six years.

Results: Individuals with comorbid MDD and chronic physical health conditions were approximately thirteen times more likely to have moderate to severe functional disability and had the highest mean number of disability days compared to those without MDD or a chronic physical health condition. Persistent MDD was most strongly associated with functional disability and disability days, and persistence of MDD interacted with physical health conditions to increase likelihood of concurrent disability.

Limitations: Our study is limited by a single assessment point for disability and chronic health conditions and by the use of self-report.

Conclusions: Our findings suggest that MDD, particularly when persistent, is associated with disability among individuals with a broad range of chronic physical health conditions.