By Dr. David Woo - February 25, 2022

TMS is proven to achieve high success rates in patients who do not respond to antidepressants, commonly referred to as treatment-resistant depression.(1) However, while many people see a major improvement in their depression symptoms with TMS, some people will only experience a small difference or, in some cases, not at all. 

Why is it that some people are more likely to respond to TMS? Below, we’ll discuss some of the predictive factors for TMS response.  

Age

Studies suggest that TMS response rates are smaller among patients aged 60 years old and higher with treatment-resistant depression (TRD), compared to patients younger than 60 years old with TRD. A study published in CNS Spectrum aimed to understand the relationship between age and TMS response. For this study, 102 patients diagnosed with treatment-resistant depression received three weeks of active TMS treatment. While patients of all ages did respond to TMS, and therefore saw improvements in their depression symptoms, researchers observed a greater response rate among patients younger than 60 years old. Depression symptoms were evaluated using the Hamilton Depression Rating (HAM-D) Scale, the most commonly used depression assessment tool administered by clinicians.(2)   

Personality Characteristics  

People with certain personality characteristics may be more likely to respond to TMS. A small study with 20 participants analyzed each participant’s personality traits using the Temperament and Character Inventory (TCI), a comprehensive patient self-reporting questionnaire, as they relate to TMS response. All participants received two weeks of TMS treatment. Of the 19 patients who completed the study, 11 responded to TMS. Researchers observed a positive relationship between persistence (perseverance) scores on the TCI and improvement in depression symptoms, according to the Hamilton Depression Rating (HAM-D) Scale. Individuals with “higher persistence scores” were more responsive to TMS treatment.(3) 

Brain Activity Prior to Treatment with TMS

The results of multiple studies suggest that brain activity prior to TMS treatment may predict whether someone responds to TMS. One study found that patients with better connectivity between certain regions of the brain, called the left dorsolateral prefrontal cortex and the striatum, are more likely to experience a better reduction in depression symptoms after treatment with TMS.(4) Another study observed that patients who have a higher volume of a certain part of the brain, called the ACC or anterior cingulate cortex, prior to TMS treatment experienced better treatment outcomes.(5)

The Severity of Diagnosis and Level of Treatment-Resistance

Treatment-resistant depression, or TRD, is a type of depression that occurs when someone does not see an improvement of their symptoms after trying at least two antidepressants of adequate dosing and duration.(6) A review of six studies that observed the effects of TMS on individuals with depression suggests that patients who are less treatment-resistant are more likely to experience better outcomes with  TMS.(7)   

Use of Anti-Depressants during TMS

A review published in BMC Psychiatry in 2014 suggests that some patients may benefit from TMS treatment as an augmentative therapy with an antidepressant.(8) Augmentative therapy is a treatment method where an additional treatment is combined with the original treatment to increase, or augment, the effects of the original treatment. In this case, TMS would be used to augment the effects of an antidepressant that the patient had been using.

According to the review, in which the data from seven clinical trials were analyzed, all study participants had tried an antidepressant without seeing improvement in their depression symptoms. Analysis of the results shows that the response and remission rate for participants who underwent augmentativeTMS was higher, at 46.6%, compared to participants who received sham (placebo) TMS, which was 22.1%.(9) 

Talk to Your Doctor About Whether TMS Is Right for You

Your doctor at Madison Avenue TMS & Psychiatry can help you understand if TMS is right for you. To make an appointment, contact us online or call (212) 731-2033.

Resources:

1. Carpenter LL, Janicak PG, Aaronson ST, et al. Transcranial magnetic stimulation (TMS) for major depression: A multisite, naturalistic, observational study of acute treatment outcomes in clinical practice. Depression and Anxiety. 2012;29(7):587-96. Link. Accessed January 17, 2022.

2. Pallanti S, Cantisani A, Grassi G, Antonini S, Cecchelli C, Burian J, Cauli G, and Quercioli L. rTMS age-dependent response in treatment-resistant depressed subjects: a mini-review. CNS Spectrums. 2012;17(1):24-30. Link. Accessed January 9, 2022.

3. Siddiqi SH, Chockalingam R, Cloninger R, Lenze EJ, and Cristancho, P. Use of the temperament and character inventory to predict response to repetitive transcranial magnetic stimulation for major depression. Journal of Psychiatric Practice. 2016;22(3):193-202. Link. Accessed January 9, 2022.

4. Avissar M, Powell F, Ilieva I, Respino M, Gunning FM, Liston C, Dubin MJ. Functional connectivity of the left DLPFC to striatum predicts treatment response of depression to TMS. Brain Stimul. 2017 Sep-Oct;10(5):919-925. Link. Accessed January 17, 2022.

5. Kar SK. Predictors of Response to Repetitive Transcranial Magnetic Stimulation in Depression: A Review of Recent Updates. Clin Psychopharmacol Neurosci. 2019 Feb 28;17(1):25-33. Link. Accessed January 17, 2022.

6. Jaffe DH, Rive B, Renee TR. The humanistic and economic burden of treatment-resistant depression in Europe: a cross-sectional study. BMC Psychiatry. 2019:19;247. Link. Accessed January 17, 2022. 

7. Fregni F, Marcolin MA, Myczkowski M, Amiaz R, Hasey G, Rumi DO, Rosa M, Rigonatti SP, Camprodon J, Walpoth M, Heaslip J, Grunhaus L, Hausmann A, and Pascual-Leone A. Predictors of antidepressant response in clinical trials of transcranial magnetic stimulation. The International Journal of Neuropsychopharmacology. 2006;9(6):641-54. Link. Accessed January 07, 2022

8. Barowsky J, Schwartz TL. An Evidence-Based Approach to Augmentation and Combination Strategies for: Treatment-Resistant Depression. Psychiatry (Edgmont). 2006;3(7):42-61. Link. Accessed January 17, 2022.

9.  L Bangshan, Zhang Y, Zhang L, and Li L. Repetitive transcranial magnetic stimulation as an augmentative strategy for treatment-resistant depression, a meta-analysis of randomized, double-blind and sham-controlled study. BMC Psychiatry. 2014;14:342. Link. Accessed January 10, 2022.

Dr. David Woo

Dr. Woo has been seeing patients in private practice since 2002, always with the goals of combining evidence-based medicine with psychodynamic psychotherapy and collaborating with other mental health professionals to ensure the best possible outcomes for his patients. He has been certified to administer TMS at his practice since 2017. His greatest clinical interests include helping patients suffering from depression, anxiety, and obsessive compulsive disorder.