Evaluation of neurotoxicity through inflammation and kynurenine pathways in the treatment of alcohol and heroin dependence

This study evaluated the biochemical, neuroinflammatory, and psychiatric effects of treatment for alcohol and heroin addiction; it also analysed the indirect effects of treatment on psychiatric recovery through pre- and post-treatment and control group comparisons, as well as clinical risk factors (duration of addiction, psychiatric comorbidity) through immunological biomarkers. Neopterin levels decreased significantly in both the alcohol and heroin dependence groups after treatment (p = 0.032 and p = 0.021). TNF-α levels decreased in both groups after treatment (p < 0.05), but changes in IL-6 and IFN-γ were not significant. In terms of psychiatric recovery, BAPI-K total scores decreased significantly in both the alcohol and heroin dependence groups (p < 0.001). Post-treatment improvement was observed in the SCL-90-R general symptom level (GSI) and all subscales. Notably, significant improvements were observed in the depression, anxiety, and obsessive-compulsive subscales. Regression analyses identified TRP (p = 0.002) and neopterin (p = 0.003) as predictors of BAPI-K changes in the alcohol dependence group. Educational level was found to have a positive effect (p = 0.005), while the presence of comorbid psychiatric disorders had a negative effect (p = 0.016). In the heroin dependence group, duration of use (p = 0.028) and neopterin level (p = 0.020) were the strongest negative predictors. This study highlights the critical role of immunological and neuroinflammatory processes in the success of addiction treatment. The findings indicate that biochemical improvement progresses in parallel with psychiatric improvement during treatment and that neopterin levels and the Kynurenine/Tryptophan (KYN/TRP) ratio have both diagnostic and prognostic value.