The finding:
This is a multicenter, randomized, double-blind, sham-controlled trial investigating the efficacy of repetitive transcranial magnetic stimulation (rTMS) as an add-on therapy for women with fibromyalgia. The study found that rTMS applied to the motor cortex (M1) significantly reduced pain intensity for up to eight weeks, with functional improvements persisting for sixteen weeks, despite a waning of the direct analgesic effect. While the analgesic effects decreased over time, the intervention demonstrated a good safety profile and suggests rTMS as a viable treatment option for refractory fibromyalgia. Interestingly, the TMS had worsened mood symptoms, but those on antidepressants in the TMS arm had decreasing dosages over the length of the study.

Strength and weaknesses:
The study is a first-of-its-kind, making an important contribution to our knowledge about TMS for fibromyalgia. It also has a robust design in terms of a methods and global population inclusion. The addition of rTMS to the subjects’ existing fibromyalgia management reflects a realistic clinical scenario, and despite the heterogeneity of the underlying regimens, the pain reduction outcome was robust at week 8. They also conducted a blinding assessment which showed adequate blinding. Overall, the outcomes suggest good feasibility internationally. There is a significant gap in generalizability between sexes however, as only women were studied. While the length of follow up was better than previous studies, longer term safety and efficacy is not known. Pain reduction was also temporary, and pain reduction was less when looking at subjects on opioid therapy. The impact of opioid use on response also affects generalizability, as at least in the US, around one third of fibromyalgia patients are on opioid medications. A feature of this study that may be viewed as a strength or a weakness was using such a high threshold in pain score reduction from baseline (30% or 50%); this helps demonstrate robustness, but a lower reduction may still be clinically significant for individuals in severe pain.

Relevance:
This study provides valuable insights into a non-pharmacological treatment option for a complex patient population often seen by consultation-liaison psychiatrists, addressing issues of treatment refractoriness, concurrent antidepressant use, and the challenges of concomitant opioid use. Interventional psychiatry methods continue to be explored for chronic pain conditions, and TMS is being studied for other chronic pain conditions as well. As psychiatrists who see chronic pain patients in the hospital and outpatient setting, we may be uniquely poised to help field questions about new possible interventions for chronic pain conditions and help. This particular study may give more credence to our warning about opioid use is fibromyalgia and may help us create guidance about not prematurely decreasing antidepressant doses while receiving other treatments that may be reducing pain.