Physical Comorbidity, Clinical Correlates, and Inpatient Management Burden in Hospitalized Patients With Major Depressive Disorder

Background: Major depressive disorder (MDD) is frequently accompanied by physical comorbidity, which may complicate inpatient assessment and management. However, large-scale patient-level studies investigating physical comorbidity and its impact on inpatient resource utilization among hospitalized patients with MDD remain limited. This study aimed to characterize the profile of physical comorbidity in MDD and examine its adjusted associations with indicators of inpatient management burden. Methods: In this large-scale cross-sectional study, we analyzed data from 8463 patients with MDD admitted to a major psychiatric center. Patients were stratified according to the presence or absence of physical comorbidity. We assessed the prevalence and spectrum of physical comorbidity, compared demographic and clinical characteristics between groups, and used multivariable regression models to identify factors associated with physical comorbidity, as well as to examine its associations with length of stay, internal medicine consultation, and the use of physical therapies. Results: Physical comorbidity was identified in 56.9% of hospitalized patients with MDD. Among those with physical comorbidity, 65.2% had physical multimorbidity (≥2 conditions). Diseases of the circulatory system (80.7%) and endocrine, nutritional, and metabolic diseases (35.4%) were the most common disease categories. Older age, farming occupation, and greater severity of depressive episodes were independently associated with physical comorbidity. Physical comorbidity was also associated with a longer length of stay and substantially higher odds of requiring internal medicine consultation. Conclusions: This large inpatient cohort demonstrates that physical comorbidity is common, multisystemic, and clinically relevant among hospitalized patients with MDD. These findings support the routine assessment of physical health and timely multidisciplinary care during hospitalization, particularly for older patients, farmers, and those with severe depressive episodes.