Biochemical Correlates of Behavior in Schizophrenic Patients

Transmethylation Hypothesis of Schizophrenia: Methionine and Nicotinic Acid

“…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. The same results were obtained by Berlet et al (1965a), who adminis tered methionine with tryptophan for 30 days to 4 chronic schizophrenic patients. In contrast to these two studies, Alexander et al (1963) found deterioration of psychosis in 2 of 6 chronic schizophrenic patients loaded with methionine for 1 week.…”

“…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. This effect can be interpreted as the result of a breakdown of body protein or as an inhibition of the tryptophan pyrrolase pathway.…”

Mono-amine Oxidase Inhibitors and Schizophrenia

“…Behavioural improvement following cessation of treatment did not occur in Berlet's series of patients [Berlet et al, 1965], Several patients from their series reached a peak of worsening only after treatment had been discontinued.…”

“…It would seem safer to accept intensifications of such symptoms as thought disorder, delusions, hallucinations and passivity ex periences as evidence of exacerbation of the specific schizophrenic symptoms so as to distinguish what may be two different clinical and biological phenomena. Berlet et al [1965] suggest that a biochemical distinction may exist here: increase in urinary indoles is more likely to accompany the specific type of exacerbation mentioned above.…”

“…There have been several reports of the effects of amino acid feeding in schizophrenics [Alexander et al, 1963;Berlet et al, 1965;Brune and H imwich, 1962;H aydu et al, 1965;Park et al, 1965;Pollin et al, 1961 andBrune, 1965].…”