Methionine Effects on Chronic Schizophrenics

Transmethylation Hypothesis of Schizophrenia: Methionine and Nicotinic Acid

“…This clinical phenomenon has been confirmed in ten studies by several independent groups of investigators and it has not been, so far, contradicted by anyone (Pollin et al, 1961;Brune and Himwich, 1962a;Alexander et al, 1963;Berlet et al, 1965b;Haydu et al, 1965;Park et al, 1965;Kakimoto et al, 1967, Ananth et al, 1970Jus et al, 1970;Antun et al, 1971b; also see reviews by Wyatt et al, 1971 andCohen et al, 1974). In their review of the ten methionine loading studies, Cohen et al (1974) revealed that 62 of 107 (57.9%) chronic schizophrenic patients given methionine, alone or in combination with a MAOI, manifested one or more of the following: auditory Pollin et al (1961) observed that methionine loading alone (without MAOI) for 1 week did not produce any behavioral changes in 3 chronic schizophrenic patients.…”

“…These behavioral changes were conceived to resemble symptoms brought about by the administration of a hallucinogen. At variance with these findings, Park et al (1965) reported that according to unpublished data of Pollin et al (1961), 3 normal control subjects showed no behavioral changes at the same dose levels of methionine in combination with iproniazid (a MAOI) and after the same time exposure which did cause exacerbation of psychopathology in schizo phrenic patients. Since the number of nonschizophrenic patients studied thus far is small and the results contradictory, it is impossible to evaluate whether or not the methionine-induced psychosis is specific to chronic schizophrenic patients.…”

“…5), it was pro posed that MAOI drugs slow down the degradation of methylated amines and, therefore, increase the concentration and clinical effect of any psychotomimetic that might be formed as a result of abnormal transmethylation. In favor of this proposal are the findings of Park et al (1965), that both MAOI drugs tested (iproniazid and isocarboxazid), but not placebo, elevated the ratio of tryptamine:indoleacetic acid in the urine of schizophrenic patients. In another series of experiments, it was found that when methionine loading was combined with a MAOI the increase in excretion of tryptamine in the urine of schizophrenic patients was much greater than the increase produced by the MAOI alone Berlet et al, 1965a;Spaide et al, 1968Spaide et al, , 1969.…”

D4 dopamine receptor-mediated phospholipid methylation and its implications for mental illnesses such as schizophrenia

“…18 There is an extensive literature documenting impaired methionine metabolism in schizophrenia. Studies by Kety and his colleagues found that methionine supplementation could precipitate an acute psychotic episode in many schizophrenic patients, while it had no effect in normal individuals, 19,20 a finding which has been replicated many times (for a review see reference 21 ). Moreover, the rate of whole body methionine metabolism in people with schizophrenia (including untreated individuals) is reduced to less than one-third that of controls.…”

Blood Flow and Oxidative Metabolism of the Brain in Patients with Schizophrenia

“…F. Linder on the occasion of his 65th birthday. genic amines or other transmitter substances (20,21,23) than to disorders in oxidative brain metabolism in schizophrenic reactions. Only a small number of measurements of cerebral blood flow (CBF), oxygen and glucose consumption of the brain in patients with schizophrenia have been performed, mostly about 20 years ago.…”