Antidepressant Effect of Escitalopram: Delay of Onset. Clinical Randomized Double-blinded Study With Three Parallel Treatment Groups (Escitalopram 20mg vs Escitalopram 30mg vs Escitalopram 20 mg + Pindolol 15 mg/Day

Antidepressant drug therapy is the primary therapeutic treatment option in moderate to severe Major Depressive Disorder. However, clinically significant antidepressant response needs sustained treatment during weeks to months. Indeed, in the largest effectiveness study conducted to date (STAR*D study) involving nearly 3000 depressed outpatients, only about one third of those who ultimately responded did so after 6 weeks of drug treatment and for most patients longer treatment periods were necessary. This delay implies prolonged suffering for the patients and their families. By its antagonist action on the serotonin 1A receptor pindolol is hypothesized to reduce the down-regulation mechanisms of antidepressants. It is therefore expected that addition of pindolol to escitalopram will shorten the therapeutic response. Clinical and preclinical data indicate that escitalopram at 30 mg/day might be more effective and perhaps be associated with a faster onset of action than 20mg. For this purpose the speed of action will be compared between three blindly randomized samples:

• escitalopram 20mg per day + placebo
• escitalopram 30mg per day + placebo
• escitalopram 20mg per day + pindolol 15mg per day (two doses of 7.5mg during 14 days).

Subjects will be followed for 6 weeks. The dose of 15mg pindolol per day (during 14 days) is based on the optimal occupancy of the serotonin 1A receptor.

At inclusion all subjects will be assessed by a trained psychiatrist using the SCID I mood disorder part which is based on DSM IV criteria, and by means of the French version of the MINI. Severity of depression will be assessed using the MADRS clinician rated and self-report questionnaire, and the French version of the QIDS.

Each week subjects will be assessed using the two versions of the Montgomery-Asberg Depression Rating Scale (MADRS) and the HCL-32 a self-report questionnaire assessing hypomania.