Descriptive Patterns Emerging From Initial Antidepressant Treatment Episodes in Patients with Treatment-Resistant Depression

Background: TRD leads to excess healthcare costs and burden of illness. Early patterns of antidepressant use may signify patients at high-risk for TRD.

Methods: Eligible patients with major depressive disorder (MDD) initiating antidepressant treatment between 7/1/2014-1/1/2017 (index) and completing >1 treatment course of adequate dose and duration (qualifying) were selected from national integrated claims and electronic health record data. TRD criteria was met by initiating a 3rd antidepressant course following two failed qualifying courses.

Results: Of the 35,246 eligible, 7,098 (20.1%) met TRD criteria. TRD rate varied by index antidepressant class: highest rate for tricyclics (21%), then multi-classes (20.0%), serotonin modulators (19.4%), other antidepressants (17.8%), SNRIs (16.8%), SSRI’s (15.9%), and tetracyclics (15%). A total of 24,888 (70.6%) switched therapies at least once: 1,539 switched drugs within the same class (TRD: 30.3%). Of those who switched, the most common sequence was SSRI to anticonvulsants, SNRI-anticonvulsants, and SSRI-other antidepressant with TRD rates of 27.0%, 24.4%, and 35.6%. The highest TRD rates were observed among SSRI-tricyclic (39.3%) and SNRI-tricyclic (39.0%) therapy sequences. Only 24,369 (69.1%) started with a qualifying course (TRD: 24.4%); 10,884 started with a non-qualifying course (TRD: 7.3%). The most common reason for failing an initial qualifying course was discontinuation (47.5%), switching antidepressant (30.4%), augmentation with an anti-convulsant (14.1%), or antipsychotic (7.8%); however, the TRD rate varied substantially across these groups: 37.7%, 27.8%, 49.6%, and 47.4%, respectively.

Conclusion (Implications for Practice): Early patterns of antidepressant treatment selection, discontinuation, and augmentation can identify patients at-risk for TRD, providing opportunities for early intervention.

This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.