Association among aggressiveness, neurocognitive function, and the Val66Met polymorphism of brain-derived neurotrophic factor gene in male schizophrenic patients.
BACKGROUND
The aim of this study was to investigate the association among aggressive behavior, neuropsychological function, and the Val66Met functional polymorphism of brain-derived neurotrophic factor (BDNF) gene in male schizophrenic patients.


METHODS
We examined 51 male patients with schizophrenia who had committed homicide (ie, H-SCZ), 50 male patients with schizophrenia who had not committed homicide (ie, NH-SCZ), and 50 healthy male controls. Patients were evaluated using the Positive and Negative Syndrome Scale, Life History of Aggression, and the Overt Aggression Scale. In addition, patients were given neurocognitive function tests, including Korean-Wechsler Adult Intelligence Scale short form, the Korean version of the Rey Memory Test, the Stroop Test, and the Wisconsin Card Sorting Test. The Val66Met polymorphism of the BDNF gene was also genotyped in all schizophrenic patients.


RESULTS
We observed no significant difference between patients in the H-SCZ and NH-SCZ groups, with regard to Positive and Negative Syndrome Scale scores. Total Life History of Aggression (P < .01) and Overt Aggression Scale scores for the most severe episode (P < .01) or for the previous month (P < .05) were higher in the H-SCZ group than in the NH-SCZ group. There were no significant differences in the genotype distribution or allelic frequency of the Val66Met polymorphism between the schizophrenic groups. In addition, we observed no significant differences between H-SCZ and NH-SCZ groups with regard to performance on neuropsychological tests. The Met allele of the Val66Met polymorphism was associated with poor intelligence quotient, memory quotient), learning, and delayed recall in the H-SCZ group. However, genotype did not seem to influence neurocognitive function in schizophrenic patients who had committed homicide.


CONCLUSIONS
The neurocognitive tests used in our study were unable to distinguish between violent and nonviolent schizophrenic patients. Furthermore, the Val66Met polymorphism was not associated with aggressiveness in patients with schizophrenia.
Chung
Seockhoon
S
Department of Psychiatry, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea.
Chung
Hye Yoon
HY
Jung
Jaeyeul
J
Chang
Jung Ki
JK
Hong
Jin Pyo
JP
D000328:Adult; D000339:Affect; D000374:Aggression / Q000502:physiology* / Q000523:psychology; D044466:Asian People / Q000235:genetics; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D003071:Cognition / Q000502:physiology; D005787:Gene Frequency; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012559:Schizophrenia / Q000235:genetics*; D012565:Schizophrenic Psychology
D019208:Brain-Derived Neurotrophic Factor