Amino acids in schizophrenia: Evidence for lower tryptophan availability during treatment with atypical antipsychotics?

Abstract

Amino acids play a role in neurotransmitter availability in the central nervous system, in that e.g. the synthesis of brain serotonin depends on the concentration of its precursor tryptophan. Disturbances in amino acid metabolism have been implicated in the pathophysiology of schizophrenia. In the present study the effect of a 14 week treatment with atypical antipsychotics on the plasma levels of amino acids was investigated in patients with schizophrenia and compared to normal controls. Non-responders (≤20% decrease in BPRS at endpoint) demonstrated lower baseline values of methionine as compared to good responders (≥50% decrease in BPRS at endpoint; p <40%) decreased during treatment as compared to responders (≥40%; p