Association of Comorbidity with Depression Treatment Adequacy among Privately Insured Patients Initiating Depression Treatment

Abstract

This study examined the association among comorbidity, type of depression treatment, and depression treatment adequacy among privately insured depression patients using claims data from 165,569 employees. Individuals newly diagnosed with depression (n = 2364) were identified using ICD-9 diagnosis codes. Logistic regression models were used to determine if certain medical and psychiatric comorbidities were associated with depression treatment type (medication only, psychotherapy only, or combined treatment) and treatment adequacy. Approximately half of the sample (56.7%) received medication only, 26.8% received psychotherapy and medication, and 16.5% received psychotherapy only. The medication only group had the highest rate (50.2%) of receiving minimally adequate treatment, while those who received the combined treatment had the lowest rate (21.0%). Patients with comorbid anxiety disorders were significantly more likely to receive combined treatment or psychotherapy alone. Those who had comorbid musculoskeletal pain were significantly more likely to receive combined treatment. After controlling for treatment type, patients with comorbid diabetes and asthma had higher rates of receiving adequate treatment than patients with other comorbid conditions. There is a continous need for practice-system level interventions to improve the proportion of privately insured patients with new depressive episodes who receive adequate depression treatment.