Use of pharmacotherapies for treatment resistant depression in finland: A nationwide cohort study

INTRODUCTION: There is a lack of knowledge on utilized pharmacotherapies for treatment resistant depression (TRD). OBJECTIVES: To investigate the courses of treatment of TRD. METHODS: All patients aged 16-65 years and diagnosed with depression in Finland during 2004-2016 were included (identified from nationwide registers for inpatient and specialized outpatient care, sick leaves and disability pensions). New antidepressant users were identified with six-month washout period and followed up for two years to observe the possible emergence of TRD, which was defined as initiation of a third treatment after having two failed pharmacological treatments with adequate duration. Pharmacological treatments were analyzed using PRE2DUP-method. RESULTS: During follow-up, 177,144 persons had their first registered depression (mean age:39.5, 62.5% women). Of them, 10.9% (N=19,322) met TRD criteria. Among the TRD patients, most common first and second lines antidepressants were as follows: SSRIs (44.6%), mirtazapine (19.0%) and SNRIs (16.5%). As the third line of treatment, 44.2% of TRD patients had antidepressant monotherapy, 32.1% a combination of ≥2 antidepressants, 15.8% antipsychotic or mood stabilizer augmentation and an antidepressant, 4.9% both combination of antidepressants and an augmentation with a mood stabilizer or antipsychotic, 2.7% antipsychotic or mood stabilizer monotherapy and 0.3% ECT monotherapy. Of TRD patients, 36.2% (N=6985) progressed to the fourth line of treatment and most common treatments were antidepressant monotherapy (37.5%), antidepressant combinations (30.8%) and augmentation (20.3%). CONCLUSIONS: Although antidepressant combination and augmentation strategies became more frequent, antidepressant monotherapies were still the most common third and fourth lines of depression treatment. DISCLOSURE: The study was funded by Janssen and SR is an employee of Janssen.