- Response to citalopram 20 or 40mg/d, as defined as a reduction in baseline HAM-D of >= 50%, and HAM-D score of 10 or below; or response to citalopram defined as not meeting DSM-IV criteria for major depression and Clinical Global Impression - severity of mildly ill, borderline ill, or normal and a Clinical Global Impression - improvement of much improved or very much improved impression.