V.- Antidepressants not allowed: MAOIs, Tricyclic antidepressants, mixed 5HT & NE reuptake inhibitors (eg. Duloxetine). SISR are not allowed as a recent prescription, moreover they are allowed in case of chronic use (more than 6 weeks). If those drugs are used for less than 6 weeks, patients could participate in the study after a washout period.