http://www.sciencemag.org/news/2021/06/can-botox-ease-depression-eliminating-frowns-researchers-have-doubts

Botox injections make frowning hard. Could that break a feedback loop?

By using a bacterial neurotoxin to paralyze facial muscles, Botox treatments get rid of forehead wrinkle lines. They can also make it hard to frown. That has led some clinicians to the unusual idea that by eliminating negative emotional feedback that frowns feed the brain, Botox can relieve depression. Botox offers “another option for severely depressed people, especially those that can’t tolerate medication,” says Michelle Magid, a psychiatrist at the University of Texas, Austin, who has prescribed Botox to dozens in her own practice. In a March meta-analysis combining data from five trials, Magid and colleagues found what they say is top-quality evidence that should “pave the way” for Botox’s widespread use in psychiatry.