BDNF and depressive symptom measurement: Rs6265 (CT/TT genotypes) interacted with physical neglect to predict lower depression/anxiety scores, whereas rs11030101 (TA genotype) interacted with sexual abuse to predict increased depression/anxiety and showed negative interactions with physical neglect and total CTQ scores in relation to negative symptoms.<h4>Conclusion</h4>These findings demonstrate that <i>BDNF</i> polymorphisms act as genetic modifiers of trauma-related symptom expression, supporting a gene-environment interaction model underlying phenotypic heterogeneity in schizophrenia.