The World Health Organization estimates the number of people suffering from depression
to be over 264 million. Current monoamine transmission modulating therapeutics, even
with proper adherence and acceptable tolerability, are not effective for nearly one
third of the patients, leading clinicians to explore other therapeutic options such
as electroconvulsive therapy, transcranial magnetic stimulation, ketamine infusions,
and, more recently, glabellar botulinum toxin, BoNT, injections. The scale and mechanism
of antidepressant action of BoNT is unclear and maybe hypothetically attributed to
the disruption of proprioceptive facial feedback reinforcing negative emotions. Here
we verify the antidepressant effect of botulinum toxin by analysis of over 40 thousand
BoNT treatment reports out of thirteen million postmarketing safety reports in the
FDA Adverse Event Reporting System, FAERS. The results of the analysis indicate that
patients who received BoNT injections to treat hyperhidrosis, facial wrinkles, migraine
prophylaxis, spasticity, and spasms, had a significantly lower number of depression
reports when compared to patients undergoing different treatments for the same conditions.
These findings suggest that the antidepressant effect of BoNT is significant, and,
surprisingly, is observed for a broad range of injection sites.
