Background and objective: Clinical guidelines recommend monotherapy with antidepressants for the treatment of major depression. This study examined prescription patterns with regard to both duration and type of treatment used among patients with newly diagnosed non-psychotic major depression based on a claims database from health insurance societies between 2008 and 2011 in Japan.
Methods: A retrospective cohort (N = 600,000) followed up for 4 years was used to identify patients (age ≥18 years) with newly diagnosed non-psychotic major depression. The prescription patterns and polypharmacy were examined. Four different types of pharmaceutical drugs were defined as possible psychotropic agents for major depression: (1) first- and/or second-generation antidepressants; (2) benzodiazepines; (3) sulpiride; and (4) antipsychotics. The data were analyzed by an intent-to-treat approach at months 0, 1, 3, 6, and 12 from the date of diagnosis.
Results: A total of 7,338 patients (3,684 males and 3,654 females, mean age 36.8 ± 10.9 years) with newly diagnosed non-psychotic major depression were identified. The median duration of treatment was 122 days. The proportion of patients in the cohort prescribed at least one type of defined psychotropic agents was 75.6 % (month 0), 47.3 % (month 1), 36.0 % (month 3), 26.8 % (month 6), and 17.4 % (month 12). The proportion of patients in the cohort prescribed at least one first- and/or second-generation antidepressant was 50.2 % (month 0), 34.9 % (month 1), 27.5 % (month 3), 20.3 % (month 6), and 12.5 % (month 12). The proportion of patients receiving at least one benzodiazepine was 58.0 % (month 0), 36.7 % (month 1), 27.1 % (month 3), 20.0 % (month 6), and 12.0 % (month 12). The proportion of patients receiving an antidepressant as monotherapy was only 12.0 % (month 0), 7.8 % (month 1), 6.5 % (month 3), 4.8 % (month 6), and 2.9 % (month 12), whereas the proportion of patients treated with a benzodiazepine alone was 13.5 % (month 0), 6.9 % (month 1), 4.6 % (month 3), 3.5 % (month 6), and 2.7 % (month 12). Various combinations of polypharmacy were observed. The most common was a combination of at least one antidepressant and benzodiazepine, which was prescribed to 36.7 % (month 0), 25.8 % (month 1), 19.9 % (month 3), 14.9 % (month 6), and 9.2 % (month 12) of the cohort.
Conclusions: Based on analysis of prescription patterns and type of treatment used for treating non-psychotic major depression, a majority of patients were not treated according to the recommended guidelines in Japan. Various patterns of prescription and use of polypharmacy were observed over time. The median duration of treatment was shorter than the recommendation (6 months) in the guidelines.