Childhood trauma interacted with BDNF Val66Met influence schizophrenic symptoms

The gene – environment (G × E) interaction effect is involved in severe mental disorders. However, whether the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism participates in the childhood-abuse influenced schizophrenic symptoms remains unclear. We examined the interaction between BDNF Val66Met, and childhood trauma (ChT) on psychotic symptoms in a Chinese Han population. To estimate the G × E interaction, psychiatric interviews, self-report questionnaires for ChT, and genotyping for BDNF Val66Met were carried out on 201 schizophrenic patients. G × E interactions were analyzed by generalized multifactor dimensionality reduction (GMDR). Among all patients, 11.9%, 19.4%, 23.4%, 26.4%, and 73.6% reported emotional abuses, physical abuses (PA), sexual abuses (SA), emotional neglects (EN), and physical neglects (PN), respectively. Significant negative correlations were observed between anxiety/depression factors, and ChT total scores. Patients with 3 different BDNF genotypes showed significant differences in anxiety/depression scores. Significant 2-way interactions were found for Val66Met × PN, 3-way interactions were found for Val66Met × PN × PA, and four-way interactions were found for Val66Met × PN × PA × EN with regard to the excitement scores. Our findings suggested an involvement of BDNF Val66Met polymorphism after ChT in terms of risk for schizophrenia symptoms.