Source: Raj Persaud

We look upset because we feel distraught. What could be more obvious?

But could it also be the other way around? Might it be that looking sad contributes to low mood?

This would have revolutionary implications for understanding the causes of low mood, and indeed the treatment of . How often have we intuitively felt that if someone just tried to look happier, it might have a positive impact on their mood?

Now a team of researchers led by Axel Wollmera and Tillmann Krugerb, based at the Hospital of the University of Basel, Switzerland and the Department of Psychiatry, Medical School Hannover, Germany, have indeed turned conventional thinking on its head. Their research, recently published in the Journal of Psychiatric Research, found that injecting Botox into the muscles most linked with low mood produces alleviation of depression.

Injection of botulinum toxin to the Glabellar region (just above the nose and between the eyes) is part of one of the most common procedures in aesthetic medicine, as the toxin inhibits the activity of the Corrugator and Procerus muscles in that region. This effect is used in the cosmetic treatment of "frown lines."

The obvious objection to a study which finds that Botox cheers you up is that it’s the aesthetic impact, or the "facelift," which is also lifting mood.

But the subjects recruited were suffering from long-standing clinical depression — on average 16 years of recurrent episodes with the current one lasting almost 30 months, and they were selected as a group unconcerned with their facial appearance (they would not have picked Botox if given a choice).

The study, "Facing depression with botulinum toxin: A randomized controlled trial," involved patients who had not previously benefited from standard prescription .

In Wollmera, Krugerb and colleagues’ clinical trial botulinum toxin was injected just once into a specific part of the face in 15 patients, while another 15 were injected with saltwater. Remarkable improvements in mood were achieved after just one injection. Six weeks after a single treatment scores on a standard depression rating scale for botulinum toxin recipients were reduced on average by 47.1% while the placebo-treated group experienced only a 9.2% reduction in the measurement of their depression.

Source: Raj Persaud

But this clinical trial also emphasized that the mood gains may have accrued through a very specific choice of two particular quite small muscles in the face, particularly associated with negative expressions, while Botox cosmetic treatments may target other muscles as well.

The Corrugator Supercilii is a narrow muscle at the corner of the eyebrow near the nose, and is responsible for pulling the eyebrows downward and towards the nose, producing vertical wrinkles of the forehead. This "frowning" muscle and could be regarded as key in expressing distress.

The other muscle activated when we’re upset is the "Procerus," which extends from the lower part of the nasal bone to the middle area in the forehead between the eyebrows. It pulls the skin between the eyebrows down, so it’s associated with transverse forehead lines and is usually targeted during treatment or correction of wrinkles.

Since the Victorian era, "the omega sign" of depression, or omega melancholicum, was well known, being the facial expression where wrinkling of the skin above the nose and between the eyebrows resembles the Greek letter omega. The Omega Sign was even believed to be diagnostic of a depressive disorder.

That this part of the face and body has been linked to depression before modern science began to recently re-discover it, is demonstrated by other names the area has attracted, including Veraguth’s folds, named by Otto Veraguth, a Swiss Neurologist at the beginning of the 20th Century. The skin fold running obliquely from the lower outside to the upper inside on the upper eyelid was specifically named partly because it was assumed to be characteristic of depression.

William James, a famous professor of psychology at Harvard University around the same period said “Refuse to express a passion, and it dies” in 1890 referring to a "facial feedback" hypothesis. Wollmera, Krugerb, and colleagues argue this suggests strong historical support for a mutual interaction between emotions and facial muscle activity, rather than just one-way traffic.

The theory here is that expressing an emotion causes you to feel that mood, not just the other way round.

To test this revolutionary idea, a number of scientific studies recently aimed to alter facial expression and then investigate whether emotional experience was subsequently effected. These studies, if they are properly scientific, have to carefully manipulate facial displays of emotion in a manner that eliminates or minimizes the participants’ awareness that they are being asked to produce an emotional expression.

For example, one experiment involved having subjects hold a pen between their teeth (a simulation of smiling but without the subjects realising this was the point of the experiment). This caused them to find cartoons funnier. In another previous experiment, two golf tees were attached to either side of subjects’ foreheads and the participants were asked to move the two tees together (a simulation of frowning without the subjects realising they were being asked to glower). When the tees were closer together, subjects rated unpleasant photographs more negatively.

The authors speculate that the botulinum toxin treatment may act comparably to a relaxation exercise — in which case you won’t even need to try Botox to get the benefits of this treatment, just learn relaxation techniques but apply them specifically to your facial muscles.

Another theory about how this treatment worked could be that it’s possible that a more positive facial expression improved social interaction, and this may have contributed to improved mood. Maybe looking in the mirror, subjects may have felt they looked more cheerful, and this could have led them to believe they were happier, which in turn, elevated mood.

However, the authors argue, one reason a purely aesthetic beneﬁt can be excluded as the main cause of mood improvement was that these patients in this clinical trial were not concerned about the appearance of their frown lines. The improvement in mood found did not turn on feeling better about an improvement in appearance. For example, one participant’s depression remitted with the Botox treatment, but in fact, disliked the facial appearance it produced.

Source: Raj Persaud

The authors conclude that their clinical trial shows facial expressions associated with depression are not just the consequences of low mood. In fact, they may be integral components of the disorder, and may, therefore, be targeted with much benefit as an entirely new approach to the treatment of clinically low mood.

Learning to smile more or frown less may just be the latest scientifically validated treatment for depression.

Dr. Raj Persaud is a Consultant Psychiatrist in private practice and Dr. Peter Bruggen is a retired Consultant Psychiatrist.

A version of this article appeared in The Huffington Post.