| Paper Authors: | Tyler Kaster, Jonathan Downar, Fidel Vila-Rodriguez, Danielle Baribeau, Kevin Thorpe, Zafiris Daskalakis, Daniel Blumberger |
| Post Author(s): | Alice Erchov, Sarah Kessler, Fidel Vila-Rodriguez |
| Download the research article: | Kaster et al. – 2023 – Differential symptom cluster responses to repetitive transcranial magnetic stimulation treatment in depression |
Introduction
Everyone experiences depression differently. As an example, some may have severe physical symptoms (e.g., low appetite, weight loss, insomnia, gastrointestinal issues) while others may have more emotional symptoms (e.g., depressive mood, suicidality, worthlessness) – or any combination of the two! Few studies have looked at how individual symptoms change across treatment, and how they might be related. Specifically, we were interested in individuals with treatment-resistant depression and how they respond to new, effective repetitive transcranial magnetic stimulation (rTMS) treatments (or the shortened version: iTBS).
Methods
We looked at two past studies conducted at NINET: THREE-D and CARTBIND. Depression symptoms were tracked over a 4 (THREE-D) to 6-week (CARTBIND) period, and grouped symptoms into 4 similar categories.
Results
- The 4 symptom groups were:
- Mood: depressed mood, agitation, cognitive (thinking) slowing, work and activity difficulties, guilt, and suicidality
- Somatic (body) symptoms: loss of sexual interest, weight loss, appetite loss, and other physical symptoms
- Insomnia: falling asleep, staying asleep, and waking up early
- Anxiety symptoms: agitation, cognitive (thinking) slowing, health anxiety, physical anxiety symptoms (e.g., gastrointestinal issues), and general anxiety
- Mood, somatic, and insomnia symptoms improved relatively more than anxiety
- All symptoms improved over rTMS/iTBS treatment
- These findings were replicated in both studies, meaning we can be quite confident in the accuracy of these results
Conclusion
For those considering rTMS/iTBS treatment, this study indicates that we would expect less relative improvement in anxiety symptoms when compared to core mood, insomnia, and somatic symptoms. However, most people can expect improvement in all four areas, overall.
This study looks at stimulating a part of the brain called the dorsolateral prefrontal cortex. Future studies might see if targeting different parts of the brain could improve different symptoms. It would also be interesting to see how symptoms may respond to different treatments (e.g., with antidepressants compared to rTMS). This study moves us one step closer to being able to individualize treatment recommendations and approaches for every person, based on their specific depression symptoms.