Affecting over 120 million people, major depressive disorder (MDD) is characterized by low mood, lack of interest and a cluster of other vegetative and cognitive symptoms causing significant distress of functioning. It has a relapsing and recurring course and frequently becomes chronic. Thus, there is a need to further develop therapeutic techniques to improve the course and the prognosis of depressive disorders. Recent clinical trials suggest that botulinum toxin (BTX) treatment may also have an antidepressant effect.

The authors aim to conduct a non-systematic review in order to understand the relationship between MDD and BTX treatment.

To assess whether current evidence supports the BTX to treat major depressive patients.

A non-systematic review of English scientific literature was conducted through research in the PubMed search engine, using the keywords “botulinum toxin” and “depression”.

There is a small but growing body of evidence suggesting that botulinum toxin may be useful for the treatment of depression. The main hypothesis for the proposed beneficial effects of botulinum toxin is through the facial feedback. Low mood and depression are often associated with a sad facial expression. Injecting botulinum toxin and improving facial expression would lead to the improvement of depression symptoms.

Positive effects on mood have been observed in subjects who underwent treatment of glabellar frown lines with botulinum toxin. It supports the concept that the facial musculature not only expresses, but also regulates mood states.

The authors have not supplied their declaration of competing interest.