L-Methionine and L-Tryptophan Feedings in Non-Psychotic and Schizophrenic Patients With and Without Tranylcypromine

The acute effects of oral (‐)‐tryptophan in human subjects.

“…The former agents might lead to increased blood glucose which would tend to decrease free fatty acids (Dole, 1966) and hence produce a fall in plasma free tryptophan (Lipsett, Madras, Wurtman & Munro, 1973); the latter contain caffeine which increases free fatty acids (Bellet, Kershbaum & Finck, 1968) and therefore might increase the proportion of tryptophan which is unbound: both were therefore unacceptable in our study. Nausea has been reported in other studies (Pare, 1963;Alexander et al, 1963;Carroll, 1970) and together with our findings emphasizes the need for a more palatable formulation should the substance be given therapeutically (Wyatt et al, 1970;Brezinova et al, 1972). Headache was the only symptom to be significantly affected by tryptophan, although the increase in headache was slight.…”

“…The main findings are an increase in drowsiness (Alexander, Curtis, Sprince & Crosley, 1963;Pare, 1963;Coppen, Shaw & Farrell, 1963) amounting to a hypnotic effect (Hartman, 1967;Wyatt, Engelmann, Kupfer, Fram, Sjoerdsma & Snyder, 1970;Griffiths, Lester, Coulter & Williams, 1972), such that claims have been made that tryptophan is a 'natural sedative' (Wyatt et al, 1970). However, its soporific effect is not sufficient to make it a practical substitute for patients habituated to conventional hypnotics (Brezinova, Loudon & Oswald, 1972).…”

Transmethylation Hypothesis of Schizophrenia: Methionine and Nicotinic Acid

“…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. Similarly, Haydu et al (1965), who administered methionine with trifluoperazine for 2 months and then methionine alone for 2 more months, found worsening of clinical status in 7 of 9 chronic schizophrenic patients.…”

“…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.…”

“…The response of 2 nonpsychotic control subjects to methionine loading (without MAOI) for 1 week was studied by Alexander et al (1963) in a single-blind study which followed a Latin square design. They found that both subjects exhibited behavioral changes similar to those seen in the schizophrenic group.…”