COMT and schizophrenia: Other investigators, who also had small sample studies, have reported associations between COMT and other psychiatric conditions, such as schizophrenia [42,43,44,45,46,47,48,49,50], bipolar disorder [47,50,51]; alcoholism [52,53], substance use disorders [54,55], depression [56,57], and anorexia nervosa [58].