Joint Effect of Depression and Chronic Conditions on Disability: Results From a Population-Based Study

Department of Psychiatry, McGill University, Douglas Hospital Research Centre, Montreal Canada.
Psychosomatic Medicine (Impact Factor: 3.47). 06/2007; 69(4):332-8. DOI: 10.1097/PSY.0b013e31804259e0
Source: PubMed


To estimate and compare the prevalence of functional disability in individuals with both chronic medical conditions and comorbid major depression and individuals with either chronic medical conditions or major depression alone and to determine the joint effect of depression and chronic conditions on functional disability. Evidence exists that major depression interacts with physical illness to amplify the functional disability associated with many medical conditions.
We used data from the Canadian Community and Health Survey Cycle 2.1 (n = 46,262), a nationally representative survey conducted in 2003 by Statistics Canada. Depression, chronic conditions, and functional disability were assessed by personal/telephone interview.
Prevalence of functional disability was higher in subjects with chronic conditions and comorbid major depression (46.3%) than in individuals with either chronic conditions (20.9%) or major depression (27.8%) alone. With no chronic conditions and no major depression as reference and after adjusting for relevant covariates, the odds ratio of functional disability was 2.49 (95% confidence interval (CI), 1.91-3.26) for major depression, 2.12 (95% CI, 1.93-2.32) for chronic conditions, and 6.34 (95% CI, 5.35-7.51) for chronic conditions and comorbid major depression.
The results suggest that there is a joint effect of depression and chronic conditions on functional disability. Research and social policies should focus on the treatment of depression in chronic conditions.

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    • "In other studies, a joint effect of mental and various somatic conditions towards disability, as limitations in performing activities of daily living, have been shown (Schmitz et al. 2007; Scott et al. 2009), but not on DP. "
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    ABSTRACT: Background: The aim of this study was to analyse a possible synergistic effect between back pain and common mental disorders (CMDs) in relation to future disability pension (DP). Method: All 4 823 069 individuals aged 16-64 years, living in Sweden in December 2004, not pensioned in 2005 and without ongoing sickness absence at the turn of 2004/2005 formed the cohort of this register-based study. Hazard ratios (HRs) and 95% confidence intervals (CIs) for DP (2006-2010) were estimated. Exposure variables were back pain (M54) (sickness absence or inpatient or specialized outpatient care in 2005) and CMD (F40-F48) [sickness absence or inpatient or specialized outpatient care or antidepressants (N06a) in 2005]. Results: HRs for DP were 4.03 (95% CI 3.87-4.21) and 3.86 (95% CI 3.68-4.04) in women and men with back pain. HRs for DP in women and men with CMD were 4.98 (95% CI 4.88-5.08) and 6.05 (95% CI 5.90-6.21). In women and men with both conditions, HRs for DP were 15.62 (95% CI 14.40-16.94) and 19.84 (95% CI 17.94-21.94). In women, synergy index, relative excess risk due to interaction, and attributable proportion were 1.24 (95% CI 1.13-1.36), 0.18 (95% CI 0.11-0.25), and 2.08 (95% CI 1.09-3.06). The corresponding figures for men were 1.45 (95% CI 1.29-1.62), 0.29 (95% CI 0.22-0.36), and 4.21 (95% CI 2.71-5.70). Conclusions: Co-morbidity of back pain and CMD is associated with a higher risk of DP than either individual condition, when added up, which has possible clinical implications to prevent further disability and exclusion from the labour market.
    Psychological Medicine 10/2015; DOI:10.1017/S003329171500197X · 5.94 Impact Factor
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    • "In terms of effects on functioning, the authors review data suggesting that, when occupational performance was compared, " depressed workers had significantly greater performance deficits than control workers (who had rheumatoid arthritis) with regard to performing mental interpersonal tasks, time management, output tasks and physical tasks… clinical improvement did not result in full recovery of job performance " (Patten et al. 2009, p. S9). We also note the observation that there is a joint effect on disability when depression is combined with chronic physical diseases (Schmitz et al. 2007). "
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    • "To provide further insight on the joint relationship of CRP and depressive symptoms with diabetes, we tested for the occurrence of biological interaction. An additive effect is when two conditions, acting independently of each other, are both needed to cause a disease outcome; that is, the risk of having a combination of two risk factors equals the sum of the risks from only one factor [42]. Biological interaction exists when the risk of disease having both conditions is in excess of what would be expected under the additive model [43]. "
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    ABSTRACT: Objectives : Raised levels of C-reactive protein (CRP), an inflammatory biomarker, and depressive symptoms are both independently linked to risk of diabetes. The purpose of this study was to assess the joint association of CRP and depressive symptomatology with diabetes incidence in a representative sample of English people ≥ 50 years old. Method : Data were from the English Longitudinal Study of Ageing, a prospective study of community-dwelling older adults. The sample was comprised of 4955 participants without self-reported doctor-diagnosed diabetes at baseline. High CRP level was dichotomized as > 3 mg/L. Elevated depressive symptomatology was defined as ≥ 4 using the 8-item Center for Epidemiologic Studies Depression Scale. Incident diabetes was determined based on newly self-reported doctor-diagnosed diabetes. Cox proportional hazard regressions were used to examine the association between CRP and depressive symptoms with incidence of type 2 diabetes. Results : During approximately 63.2 months of follow-up, 194 participants reported diabetes diagnosis. After adjustment for socio-demographics, lifestyle behaviours, clinical factors, and BMI, the hazard ratio for diabetes was 1.63 (95% CI 0.88-3.01) for people with elevated depressive symptoms only, 1.43 (95% CI 0.99-2.07) for people with high CRP only, and 2.03 (95% CI 1.14-3.61) for people with both high CRP and elevated depressive symptoms. Conclusion : The presence of both high CRP levels and elevated depressive symptoms was associated with risk of diabetes. Further investigation into this relationship could aid in understanding the mechanisms underlying inflammation, depression, and diabetes.
    Journal of Psychosomatic Research 09/2014; 77(3). DOI:10.1016/j.jpsychores.2014.07.012 · 2.74 Impact Factor
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