Veterans With Comorbid Depression and PTSD Can Be Effectively Treated With TMS

^aMental Health and Behavioral Sciences, James A. Haley Veterans’ Administration Hospital and Clinics, Tampa, Florida
^bDepartment of Psychiatry and Behavioral Neurosciences, Morsani College of Medicine, University of South Florida, Tampa, Florida
^cResearch Methodology and Biostatistics Core, Morsani College of Medicine, University of South Florida, Tampa, Florida
^dNursing Service, James A. Haley Veterans’ Administration Hospital and Clinics, Tampa, Florida
^eResearch Service, James A. Haley Veterans’ Administration Hospital and Clinics, Tampa, Florida
^fDepartment of Behavioral Sciences and Sociasl Medicine, Florida State University College of Medicine, Florida State University, Tallahassee, Florida
*Corresponding author: Michael J. Hernandez, MD (mjhernandez@usf.edu).

Published online: March 30, 2021.
Potential conflicts of interest: None.
Funding/support: None.
Disclaimer: The views expressed in this letter are those of the authors and do not necessarily reflect the official policy or position of the Department of Veterans Affairs or the US Government.

J Clin Psychiatry 2021;82(3):20l13751a

To cite: Hernandez MJ, Reljic T, Van Trees K, et al. Veterans with comorbid depression and PTSD can be effectively treated with TMS. J Clin Psychiatry. 2021;82(3):20l13751a.
To share: https://doi.org/10.4088/JCP.20l13751a

© Copyright 2021 Physicians Postgraduate Press, Inc.

See letter by Brigido et al.

To the Editor: We were heartened to learn that Brigido and colleagues have largely replicated our findings published in The Journal of Clinical Psychiatry that comorbid posttraumatic stress disorder (PTSD) is not a negative predictor for the treatment of depression with transcranial magnetic stimulation (TMS).¹ These findings are unique since, for many treatments of depression, comorbid PTSD is a strong negative predictor of outcome.

In addition to being a unique sample of patients being treated at another institution, the sample and analysis by Brigido et al differed from our own in a few other notable respects: (1) our sample consisted of 115 patients, whereas theirs included 57 patients; (2) we utilized the Quick Inventory of Depressive Symptomatology–Self-Report (QIDS-SR) and Montgomery-Asberg Depression Rating Scale (MADRS), whereas they utilized the Patient Health Questionnaire-9 (PHQ-9) for assessment of depressive symptoms; and (3) we determined presence or absence of current PTSD based on a detailed interview by an experienced psychiatrist versus their use of a cutoff score on the PTSD Checklist for DSM-5 (PCL-5). Also, as mentioned in the Discussion section of our article, we did not have a measure of severity of PTSD as was available in the analysis by Brigido et al. Despite these differences, Brigido et al found that neither the presence of PTSD diagnosis nor the severity of PTSD symptoms predicted the degree of improvement in depressive symptoms. Accounting for PTSD symptom severity with the PCL-5 is an important addition to the analysis of the relationship between MDD, PTSD, and TMS.

Conversely, their logistic regression provided some results that conflicted with ours when the presence and severity of PTSD were modeled with the categorical response or remission of MDD based on PHQ-9 score. In apparent contradiction to their first analysis, this logistic regression showed that both PTSD diagnosis by cutoff score and severity of PTSD symptoms predicted poorer response to TMS for depressive symptoms. In this model, PTSD diagnosis but not PTSD severity predicted lower odds of achieving remission. Our results previously demonstrated no difference in categorical outcomes (response and remission) based on presence of PTSD diagnosis for QIDS-SR or MADRS scores. A number of possibilities exist to explain this discrepancy between the findings. Most likely among them is the nature of defined cutoff scores for response (typically 50% reduction in score) and remission (typically achieving a minimum score such as PHQ-9 score < 5, QIDS-SR score ≤ 5, or MADRS score ≤ 10). Although the values used are generally agreed upon percentages and values for consistency, they can obfuscate the true outcome due to their somewhat arbitrary definition. For example, if a patient has a 49% improvement in PHQ-9 score or a final score of 5, they would be counted as neither a responder nor a remitter despite having a meaningful change in symptoms and experiencing a minimal degree of depressive symptoms. This is especially problematic for smaller-sample studies. We suspect that this may be playing a role in this current discrepancy in findings.

In summary, we agree with Brigido et al that veterans with comorbid depression and PTSD can be effectively treated with TMS. The direct replication of our finding that neither the presence of PTSD diagnosis nor severity of PTSD symptoms impacts the degree of improvement in depressive symptoms when treating with TMS is an important addition to the literature. These findings need to be confirmed in adequately powered and well-designed randomized controlled trials to generate conclusive evidence. Larger-sample studies in the future can address the discrepancy based on the categorical grouping of response and remission.