Botox and Depression

From What If Botox Could Ease Both Wrinkles *and* Depression? by Tess Bonn

How does Botox help treat depression?

Specifically, the idea of utilizing botulinum toxin A to treat mental health disorders is primarily based on what’s known as the “facial feedback hypothesis,” which suggests that our emotional experiences are influenced by our facial expressions. For example, smiling typically makes us feel happier while frowning can make us feel more sad. 

The theory was first developed by evolutionary biologist Charles Darwin and the “father” of American psychology William James in the 19th century. While we typically use facial expressions to signal how we’re feeling to others, they can influence how we feel ourselves. In many cases, this self-reflection can reinforce negative thoughts and feelings. 

The article talks about some studies that show some positive results, but it's not a cure all.