A history of suicide attempts among individuals with schizophrenia is associated with tryptophan degradation via the salivary kynurenine pathway

The findings suggest that a history of suicide attempts is associated with alterations in salivary tryptophan concentration and the metabolic shift from tryptophan to kynurenine. These results contribute to the understanding of the potential biochemical factors involved in suicidal behavior, especially among individuals with schizophrenia. Given its non-invasive nature, monitoring salivary kynurenine metabolic shifts may serve as an early-warning biomarker for suicidal behavior.