Real-world assessment of treatment inertia in the management of patients treated for major depressive disorder in the USA.

Aim: Major depressive disorder (MDD) is a debilitating illness in which depressive symptoms may persist after treatment. Treatment inertia is the continued use of the same pharmacotherapy regimen when treatment goals are not met. This study assessed the frequency of treatment inertia among adult patients with MDD treated in a real-world setting. Patients & methods: This was a retrospective, observational study of patients with MDD identified in the Decision Resources Group Real World Evidence US Data Repository from January 2014 to June 2018. Patients (≥18 years) had an elevated Patient Health Questionnaire-9 (PHQ-9) score (≥5) following 8 weeks of stable baseline antidepressant use with/without mental-health outpatient therapy. Treatment inertia, modification and discontinuation were evaluated over a 16-week follow-up period (timeline based on the APA Practice Guidelines). The primary outcome was the proportion of MDD patients experiencing treatment inertia. Results: 2850 patients (median age, 55 years; 74% female) met the study criteria. Of these patients, 834 (29%) had study-defined treatment inertia, 1534 (54%) received treatment modification and 482 (17%) discontinued treatment. Use of mirtazapine (Odd ratio [OR]: 0.63; 95% confidence interval [CI]: 0.50-0.79), selective serotonin reuptake inhibitors (OR: 0.64; 95% CI: 0.54-0.75) or bupropion (OR: 0.71; 95% CI: 0.60-0.84) in the baseline period was associated with an increased likelihood of treatment modification versus not receiving treatment with these medications. Frequency of treatment inertia may differ among those who do not have a documented PHQ-9 score. Conclusion: Effective symptom management is critical for optimal outcomes in MDD. Results demonstrate that treatment inertia is common in MDD despite guidelines recommending treatment modification in patients not reaching remission.