We tested for association of NTRK2 with COMD in two independent samples: (a) a case-control sample matched on ethnicity and gender, consisting of 120 cases who met DSM III/IV criteria for major depressive or dysthymic disorder before age 14 or bipolar I/II before the age of 18, and controls, and (b) a family based control sample of 113 families collected in Hungary, identified by a proband between the age of 7 and 14 who met DSM IV criteria for major depressive disorder or bipolar I/II disorder.