Bimodal distribution of serum trypotphan level.

Area of Science:

• Neuroscience
• Biochemistry
• Psychiatry

Background:

• Endogenous depression is a complex mood disorder.
• L-tryptophan (L-TP) is a precursor to serotonin, a key neurotransmitter.
• Electroconvulsive therapy (ECT) is a treatment for severe depression.

Purpose of the Study:

• To investigate the effect of L-tryptophan (L-TP) and electroconvulsive therapy (ECT) on serum L-TP levels in patients with endogenous depression.
• To explore potential correlations between L-TP levels and treatment response or characteristics.

Main Methods:

• Serum total L-tryptophan (L-TP) levels were measured before and during treatment.
• Patients received L-TP (6 g daily) and unilateral ECT.
• Statistical analysis was performed to compare L-TP levels and clinical variables.

Main Results:

• Initial L-TP concentrations shifted from a Gaussian to a bimodal distribution during treatment.
• Two distinct groups emerged: low-concentration and high-concentration L-TP levels.
• Patients in the high-concentration group required more ECT sessions, possibly due to L-TP's effect on seizure duration.

Conclusions:

• The observed bimodality of L-TP levels during depression treatment may be genetically determined.
• L-tryptophan supplementation and ECT can alter L-TP serum concentrations.
• Further research is needed to elucidate the genetic basis and clinical implications of these findings.