Investigating Depression in Older Adults with Multimorbidity

Abstract

The thesis consists of three studies investigation multi-morbidity and depression. A meta-analyses revealed that the risk for depressive disorder was twice as great for people with multi-morbidity compared to those without multi-morbidity [RR: 2.13 (95% CI 1.62 to 2.80) p<.001] and three times as great compared to those with no any chronic physical condition [RR: 2.97 (95% CI 2.06 to 4.27) p<.001]. Analyses of characteristics and symptom measures of 302 older adults revealed that number of illnesses, pain, disability and ruminative thinking were predictive of depressive symptoms. A mediation analysis demonstrated that pain and disability mediated the relationship between number of illnesses and depressive symptoms providing support for models which attribute the relationship between illness and depression to activity restriction and loss of control. 308 participants aged 65 years and over, who had multimorbidity but did not meet criteria for a depressive disorder were randomised to an intervention group who received a five session iCBT or to a control group who received treatment as usual.The intention to treat, chi-square analyses indicated there were significantly fewer cases of depressive disorder in the treatment group compared to the control group by six month follow-up (χ²(1, N=302) = 5.21, p = .02). There was no longer a significant difference between the groups by twelve months (χ² (1, N=302) = 2.61, p = .11), although the results remained in the direction of fewer cases in the intervention group (10.7%) than the control group (17.1%). The findings support that iCBT is effective for delaying depressive disorder but further research is required to determine whether iCBT can be effective for preventing depressive disorder in this population over time.