Increased cortical COMT activity, inferred from genetic changes, was linked to increased midbrain TH mRNA in normal subjects;64 however, we find no change in midbrain COMT mRNA levels in people with schizophrenia compared with controls, supporting previous studies in other brain regions finding that changes in COMT mRNA levels do not appear to be a predominant mechanism associated with the pathophysiology of schizophrenia.64, 65, 66, 67. This evidence concerns the gene TH and schizophrenia.