 Depression is frequently accompanied by a specific sad facial expression. This expression is in part mediated by the same muscle activity that produces frown lines. Based on the assumption that there is a positive feedback between depressed mood and the correspondent facial muscle activity facial feedback the investigators will conduct a randomized controlled pilot study in which the investigators will apply a classical cosmetic treatment of frown lines with injections of botulinum toxin to depressed patients who did not sufficiently respond to antidepressant medication. The investigators hypothesize that this treatment will contribute to the amelioration of depressive symptoms in these patients. This hypothesis is supported by a previous open case series in which remission of depression was reported after such treatment Finzi and Wasserman, 2006. 