STUDY:

JOURNAL: American Journal of Psychiatry 03

AUTHORS:

ABSTRACT: The branched-chain amino acids, leucine, isoleucine and valine, help to control tardive dyskinesia among patients taking antipsychotic drugs. Tardive dyskinesia is a disorder that occurs frequently among long-term antipsychotic drug users, characterized by twitching and other involuntary movements.

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COMMENTARY: Sixity-eight men with tardive dyskinesia randomly received low-dose, medium-dose or high-dose branched chain amino acids or a placebo three times daily for three weeks. The amino acid formula consisted of valine, isoleucine and leucine in a ratio of 3:3:4.

Tardive dyskinesia movements were videotaped for analysis. At the study's conclusion, the men who received the high dose exhibited a highly significant decrease in their symptoms compared to the placebo group, with diminishment of symptoms occurring as soon as one week following treatment.

Some other differences were seen between the groups before and after the trial, including changes in blood glucose or medication levels. Mild gastrointestinal symptoms were the only side effects noted.



While blood levels of the branched-chain amino acids were measured after three weeks, an increase in their levels was observed in the groups receiving them. The aromatic amino acids phenylalanine, tyrosine and tryptophan simultaneously declined in these groups and correlated with the decrease in tardive dyskinesia movements, leading the researchers to suggest reduced synthesis of monoamine neurotransmitters (dopamine, noradrenaline, and serotonin) from aromatic amino acid precursors as a possible mechanism of action for isoleucine, leucine and valine against tardive dyskinesia symptomps in this study.