For patients with major depressive disorder undergoing repetitive Transcranial Magnetic Stimulation (rTMS), concomitant therapy including a psychostimulant medication showed more improvement than concomitant therapy with a benzodiazepine medication, according to a study published in Brain and Behavior.

Researchers of this retrospective chart review examined the association between psychotropic medications and rTMS in patients diagnosed with major depressive disorder. Psychotropic medication was determined through electronic medical records and then classified according to 13 mutually exclusive drug classes. rTMS therapy included 30 sessions over 6 weeks with a target dose of 10 Hz to the left dorsolateral prefrontal cortex and, if needed, an additional 1 Hz to the right dorsolateral prefrontal cortex. Data from the Inventory of Depressive Symptomatology Self Report was obtained at baseline and weeks 2, 4 and 6.

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Of the 181 patients included in the study, 98 were women, the mean age was 46.6 years old, the mean baseline Inventory of Depressive Symptomatology Self Report was 42.8, and 92% were taking at least 1 psychotropic medication. By week 2, there was a mean improvement of 7.9 points on the Inventory of Depressive Symptomatology Self Report, and by week 6, there was a mean improvement of 13.8 points.

Regression models at week 2 indicated benzodiazepines were associated with less improvement (P =.02) and psychostimulant was associated with more improvement (P =.05), even after controlling for covariates. This trend continued for psychostimulant medication through week 6. The response rates for patients improving 50% on the Inventory of Depressive Symptomatology Self Report from baseline to week 6 was 16.4% for patients taking benzodiazepines, 35.5% for patients not taking benzodiazepines (P =.008), 39.2% for patients taking psychostimulant medication, and 22% for patients not taking psychostimulant medication (P =.02).

This study was limited by its observational nature as well as its inability to control for underlying neurobiological variances, clinical differences, or possible comorbid psychiatric diagnoses of patients. Additionally, it didn’t correct multiple comparisons between the large number of categories of medications, potential false-negative results for the infrequently prescribed medications, and potential nonlinear effects of complex pharmacodynamics effects.

The researchers concluded that “concomitant medication use may, depending on the drug category or [mechanisms of action], impact rTMS treatment outcome favorably or unfavorably.”

Several researchers report association with professional organizations and pharmaceutical companies. Please see the original reference for a full list of authors’ disclosures.

Reference
Hunter AM, Minzenberg MJ, Cook IA, et al. Concomitant medication use and clinical outcome of repetitive Transcranial Magnetic Stimulation (rTMS) treatment of major depressive disorder [published online April 2, 2019]. Brain Behav. doi: 10.1002/brb3.1275