Effect of BDNF rs6265 gene polymorphism on aggressive behaviors in patients with schizophrenia

Schizophrenia is a severe mental disorder in which disorders such as thought, emotion and behavior are seen, and patients live in their own world away from interpersonal relationships and reality. The positive symptoms of schizophrenia, a chronic psychiatric illness that continues with psychotic episodes, are delusions and hallucinations. Flattened affect and poor speech content are examples of the most important negative symptoms accompanying schizophrenia. Aggressive behavior is a more common problem in individuals with schizophrenia compared to the general population. It has been shown that genetic variations as well as environmental factors have an effect on aggressive behavior in twin and adoption studies. One of the genes shown to be effective in aggressive behavior is the BDNF gene. Therefore, in the proposed master's thesis, it is aimed to study for the first time the effect of BDNF rs6265 (Val66Met) gene polymorphism on aggression levels of individuals diagnosed with schizophrenia in Turkey. Schizophrenia patients (n=50) individual (19 women, 31 men) were included in the study. BDNF rs6265 polymorphism was analyzed with Polymerase Chain Reaction-Framement Fragment Length Polymorphism (PCR-RFLP). Aggression behavior was measured using the Buss-Perry aggression scale. In addition, 50 schizophrenia patients were assessed by the possibility of suicide scale, childhood trauma scale and Barratt Impulsivity Scale (BIS). The frequency of the G and A alleles were found 88% and 12%, respectively. When schizophrenia patients were compared according to the BDNF rs6265 genotypes in view of the total score of BIS, no significant difference was found between BDNF rs6265 genotypes (p>0.05). Additionally, there was a statistically significant relationship between BDNF rs6265 polymorphism and the possibility of suicide, childhood trauma scale and Barratt impulsivity scale (p<0.05). In conclusion, the present study indicated that BDNF rs6265 polymorphism had no effect on aggression behaviors in Turkish schizophrenia patients.