['The brain-derived neurotrophic factor (BDNF) gene is a candidate gene in therapeutic responses to antidepressants. The aim of the study was to determine the effects of BDNF allelic variability on responses to escitalopram treatment at 3\xa0weeks after treatment initiation and at a 6-week endpoint.', 'We included 187 Caucasian subjects with depression; 153 completed the 6-week study. Clinical evaluation was performed using the Montgomery and Asberg Depression Rating Scale (MADRS) before and after 3-6 weeks of treatment.', 'After 3\xa0weeks of treatment, we saw significantly better treatment responses in the Met carriers and greater antidepressant resistance among the Val/Val homozygotes. Relative to Val/Val homozygous (59.78\xa0%), a significantly greater proportion of subjects Met-carriers (77.94\xa0%) responded to escitalopram treatment (χ (2)\u2009=\u20095.88, p\u2009=\u20090.015). After 6\xa0weeks, we found the same pattern of results but this effect did not reach statistical significance (χ (2)\u2009=\u20092.07, p\u2009=\u20090.15).'] Is the BDNF Val ( 66 ) Met polymorphism associated with escitalopram response in depressed patients?