27/02/2013 09:04 GMT | Updated 28/04/2013 06:12 BST

Can Botox Cure Depression?

Botox as a mood enhancer - this is the latest theory from American Dermatologist Eric Finzi. It's a controversial suggestion, but one not without evidence. His book The Face of Emotion: How Botox Affects our Mood and Relationships reports that in about 50% of cases Botox can dramatically improve both mood and relationships.

This might have only hit the headlines recently, but it's nothing new within the industry. At my treatments centres, nationwide chain Courthouse Clinics, I've been chronicling the positive effect of Botox cosmetic procedures on my clients for years- including some who have previously suffered from mild depression.

In 2009 Dr. Michael Lewis and I had a study published in the Journal of Cosmetic Dermatology demonstrating that the paralysis of frown muscles of the forehead leads to weaker facial feedback for negative emotions. This means that a negative mood is harder to maintain, and so generally Botox patients find themselves comparably more positive than their un-Botoxed counterparts.

Botox is a cosmetic dermatology practise. Treatment involves the injection of Botulinum Toxin A (Botox is actually a brand name, then) into the frown muscles, paralysing them for anything up the six months. The result is a smoother, less-lined forehead, making the patient appear more youthful as wrinkles seemingly disappear.

Frown muscles are responsible for lines, but are also universally important in the expression of negative emotions, including sadness, fear, anger and distress. When a patient has undergone Botox it is then physically impossible for the paralysed muscles to form the expression necessary to portray these emotions- the forehead cannot be furrowed in frustration, or brows knitted together in worry.

As early as the 17th century Charles Darwin suggested that facial muscles are not only responsible in the expression of emotion, but also in the experience and perception of it. Limiting the illustration of our feelings limits physical response. This could also be attributed to the toxin interrupting signals to the brain that indicate the body is under stress, struggling to cope, or nervous and anxious.

I tested this theory in 2008 with Dr. Lewis. The mood of 25 female Botox patients was measured and compared with patients of other cosmetic treatments. We observed that patients treated with Botox for glabellar frown lines showed significantly less negative temperament. We suspected that this could be attributed to feelings of attractiveness after treatment, but further research led us to conclude that this was not an explanatory variable.

My work goes a long way to underpinning the theory that far beyond the "feel good" factor that a cosmetic treatment can provide, there are also psychological mechanisms at work that can improve our state of mind after Botox.

Moreover, from what is known of the psychology of emotions and their correlation to behaviour, Botox could possibly impact risk evaluation, empathy, and communication as well. The treatment, against all fashionable opinion, seems to trigger much more than a simple confidence boost.