Depression and multimorbidity - Results from a nationwide study

Background and objectives: Most studies concerning the relationship between depression and chronic physical disease focused on a single physical disease and did not consider multimorbidity or depression severity. We aimed to characterize this relationship considering chronic physical diseases’ type and number, and depression severity. Methods: We undertook a cross-sectional study, using data from a phone household panel, with “chronic physical disease” as the exposure and “depression” as the outcome. The sample is representative of the Portuguese population. Adjusted logistic and multinomial regression analyses were conducted between depression presence/severity and chronic physical disease presence/type/number. Odds ratio and 95% confidence intervals adjusted for possible confounders were calculated. Results: 1027 individuals were included. Of the population, 8.9% had depression and 72.1% had at least one chronic physical disease. There was no statistically significant relationship between depression and physical disease in general (OR=1.68 [CI95%:0.55, 5.15]), but there was with allergy (OR=2.08 [CI95%:1.02, 4.25]) and COPD (OR=3.04 [CI95%:1.21, 7.61]). The risk of depression was smaller with two physical diseases (vs. three or more, OR=0.32 [CI95%:0.15, 0.68]). Conclusions: A relationship between COPD, allergy and a higher number of physical diseases and depression was observed. Clinicians should be aware of these relationships. Evaluating the presence of depression in people with multimorbidity, COPD and allergy is recommended.