CYP1A2 and schizophrenia: In a prospective study of 37 patients with schizophrenia or schizoaffective disorder treated with olanzapine, the influence of smoking and CYP1A2 polymorphisms on the disposition of olanzapine and its metabolite 4′-N-desmethylolanzapine in serum and cerebrospinal fluid was investigated [28].