Tryptophan metabolism: novel targets and biomarkers towards personalized neuropsychopharmacology

The metabolism of the essential amino acid tryptophan through the serotonin and kynurenine pathways has emerged as a central hub linking neurotransmission, immune signaling, and the gut–brain axis. Alterations in these interconnected pathways are increasingly recognized as key contributors to the pathophysiology of major psychiatric disorders, including depression, bipolar disorder, schizophrenia, and insomnia. At the same time, advances in analytical, molecular, and imaging approaches are revealing how tryptophan-derived metabolites can serve as both biomarkers and therapeutic targets.

This campfire session will explore how perturbations in serotonin and kynurenine metabolism shape brain function and behavior, and how these insights can inform personalized treatment strategies. Mechanistic findings from preclinical and clinical research will be integrated to illustrate how these pathways influence neuroinflammation, synaptic plasticity, and neurocircuit regulation. Particular emphasis will be placed on translational efforts to modulate the tryptophan system pharmacologically, the identification of peripheral and central biomarkers to stratify patient populations, and the implications for drug development in neuropsychiatric disorders.

By weaving together evidence from molecular biology, psychopharmacology, and systems neuroscience, this session will highlight the promise of tryptophan metabolism as a framework for developing precision neuropsychopharmacological interventions. The discussion will focus on conceptual and methodological challenges, emerging therapeutic opportunities, and future directions for translating these discoveries from bench to bedside.