| Paper authors: | Alisson Trevizol, Jonathan Downar, Fidel Vila-Rodriguez, Kevin Thorpe, Zafiris Daskalakis, Daniel Blumberger |
| Year of paper publication: | 2020 |
| Post authors: | Alice Erchov, Lisa Ridgway, Fidel Vila-Rodriguez |
| Download the research article: | Trevizol (2020): Predictors of remission after repetitive transcranial magnetic stimulation for the treatment of major depressive disorder: An analysis from the randomised non-inferiority THREE-D trial |
Introduction
Even though repetitive transcranial magnetic stimulation (rTMS) is largely effective at treating depression even for those who do not respond to antidepressants, there is still a fraction of individuals who do not improve with rTMS. Predicting who may respond best to rTMS may help clinicians and patients make better choices as to what treatments to pursue, with the ultimate hope to better treat depression.
Trevizol et al. (2020) used data from a clinical trial run by the NINET Lab at UBC called THREE-D to determine if there are characteristics that can help predict whether someone would benefit from rTMS.
Methods
Participants got either rTMS or its accelerated version, iTBS, every weekday for 4-6 weeks. Those who completed at least 1 rTMS/iTBS treatment were included in analyses, which was a total of 388 people. The researchers chose what characteristics to look at based on previous studies suggesting what could predict rTMS outcomes. This included participants’ age, employment status (as a measure of functional ability), anxiety, depressive severity, length of depression, use of benzodiazepine medication, and degree of treatment-resistance (how many antidepressants a person has not responded to in the past).
“Remitters” are those who finished treatment with scores so low that the severity of their depression is likely no longer clinically-relevant.
Results
- People were least likely to have their depression remit in response to rTMS if they…
- Had higher levels of anxiety,
- more severe depression symptoms,
- were unemployed, and
- failed 2 or more antidepressants in the past
- Whether or not people used benzodiazepines did not appear to directly impact the likelihood of rTMS remission
- The length of depressive episode also did not appear to directly impact the likelihood of rTMS remission
- Age only seemed to impact the likelihood of remission for individuals under/around middle age (~45 years old)
- For those under ~45 years old only, being younger was associated with having a lower chance of remission
Conclusion
Researchers continue to determine predictors of rTMS response so that clinicians and patients can better understand and personalize depression treatments. It appears that rTMS may be more likely to work for people who have less anxiety, less severe depression, are employed, and have failed less than 2 antidepressants in the past. However, this does not mean that response is impossible for these individuals; Trevizol et al. (2020) note there is still more work to be done before using rTMS response predictors to guide clinical judgement. For example, future research can consider incorporating biological markers (e.g., brain scans, heart rate) to increase the accuracy of our predictors. In any case, this line of research hopes to inform treatment approaches and ultimately help those with depression get the help that is right for them.