Background: In spite of its global importance, the interaction between depression and chronic comorbid diseases remains incompletely understood with regard to prevalence, severity of disease, and potential causative factors mediating this interaction.
Objective: The authors sought to compare overall medical costs in nondepressed and depressed individuals.
Method: Insurance claims for 618,780 patients were examined for total annual non-mental health cost of care in 11 chronic diseases. In each disease cohort, median annual non-mental health cost was calculated for individuals with and without depression.
Results: Patients with depression had higher median per-patient annual non-mental health costs than patients without depression in all 11 diseases studied. There was a higher-than-random comorbidity between depression and all 11 chronic comorbid diseases.
Conclusion: Even when controlling for number of chronic comorbid diseases, depressed patients had significantly higher costs than non-depressed patients, in a magnitude consistent across 11 chronic comorbid diseases.