SA63. Pilot Study Examining the Relationship of Childhood Trauma, Perceived Stress, and Medication Use to Serum Kynurenic Acid and Kynurenine Levels in Schizophrenia

Abstract

Abstract Background: The current pilot study examined whether variables such as stress/trauma and medications modulate levels of serum kynurenine and kynurenic acid (KYNA). Methods: Ten people (5 males and 5 females) with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder (SCZ) and 10 healthy controls (HCs; 5 males and 5 females) were included in the current study. All participants had a study visit that included a blood draw for serum KYNA and kynurenine levels, physiological measurements, demographic data, assessments of current anxiety and perceived stress measured by the State Trait Anxiety Inventory/Visual Analog Scale (STAI_VAS) and the Perceived Stress Scale (PSS), childhood trauma history measured by the Childhood Trauma Questionnaire (CTQ), and medication use. Results: In this pilot study, differences in KYNA and kynurenine between SCZ and HCs were not statistically significant (P > .05). Within SCZ, kynurenine levels were correlated with the total CTQ score (r = .63, P = .049) as well as the physical abuse domain (r = .74, P = .016). KYNA also tended to correlate with the total CTQ (r = .60, P = .069), emotional abuse (r = .42, P = .045), and physical abuse domains (r = .62, P = .058. There were not significant correlations noted between KYNA or kynurenine and CTQ scores in the HC groups. Kynurenine levels were positively correlated with the STAI tense domain also in SCZ subjects (r = .81, P = .004). With regard to differences in medication use, serum KYNA and kynurenine levels were significantly lower in people with schizophrenia taking medications for constipation (P < .05) and anticholinergic medications compared to patients not taking these medications. Conclusion: In this small sample, greater childhood trauma and/or perceived stress symptoms were found to be related to higher levels of serum KYNA and kynurenine in patients with schizophrenia. Further research is needed in a larger sample to assess whether childhood trauma and subsequent stress and/or anxiety symptoms relate to KYNA and kynurenine levels in patients with schizophrenia. Our data suggest that future investigations should also examine the effect of concomitant medications (particularly those with anticholinergic activity) on KYNA and kynurenine levels in schizophrenia. This information will help future investigations identifying psychopathological pathways, leading to studying specific schizophrenia phenotypes and deconstructing the illness.