COMT and schizophrenia: Although these data should still be regarded as preliminary, several studies suggest that male patients with high-activity COMT may have greater severity of endophenotypes associated with prefrontal deficits in schizophrenia, such as eye movement disturbances (Rybakowski et al., 2002) prefrontal noise (Winterer et al., 2006) and schizotypal traits (Ma et al., 2007).