Change in Antidepressant Use After Initiation of ADHD Medication in Japanese Adults with Comorbid Depression: A Real-World Database Analysis

PURPOSE: To better understand the treatment of comorbid depression in adults with attention-deficit/hyperactivity disorder (ADHD) by investigating the prescription patterns of antidepressants, anxiolytics, and hypnotics after commencing ADHD medication. PATIENTS AND METHODS: In this retrospective observational study in Japan, the data of patients initiating ADHD medication while already receiving antidepressants (ADHD group) and of patients prescribed antidepressants but not diagnosed with ADHD (control group) were extracted from an electronic medical record database. Additionally, one-to-one matching for patients in both groups was performed using sex, age, baseline dosage of antidepressants, and any comorbid psychiatric disorders as covariates. The observation period included a 1-month baseline period and a 6-month follow-up period. The percentage of patients prescribed antidepressants and the mean prescribed dosages were compared between matched-cohort groups. Prescriptions for anxiolytics and hypnotics were also assessed. RESULTS: In the matched cohorts, consisting of 239 patients in the ADHD group and 239 patients from the unmatched control cohort of 10,485, the percentage of patients prescribed antidepressants decreased from baseline in both groups to 94.1% in the ADHD group and 89.5% in the control group during the first month of follow-up, and 77.0% and 78.7%, respectively, during the last month. There were no significant differences between groups in the percentages of patients prescribed antidepressants or in the mean prescribed dosages of antidepressants at any time point over the follow-up period. Prescribed dosages of anxiolytics and hypnotics tended to be lower in the ADHD group. CONCLUSION: The two groups were medicated similarly with respect to their depressive symptoms over 6 months. Our results suggest that in patients with ADHD and comorbid depression, which is more likely to be more severe than in depression without ADHD, depressive symptoms are managed following initiation of add-on ADHD medication, without requiring higher antidepressant dosages than in patients with depression only.