RESEARCH PAPERS: PDF OnlyAn association between a polymorphism of the tryptophan hydroxylase gene and aggression in schizophrenia and schizoaffective disorderNolan, Karen A.a; Volavka, Jana; Lachman, Herbert M.b; Saito, TakuyabAuthor Information aNathan S. Kline Institute for Psychiatric Research, Orangeburg, New York, USA;bDepartment of Psychiatry, Albert Einstein College of Medicine, Bronx, New York, USA Correspondence to Karen A. Nolan, Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA. E-mail:[email protected] Received 28 March 2000; accepted 21 September 2000 Psychiatric Genetics: September 2000 - Volume 10 - Issue 3 - p 109-115 Buy Abstract Serotonergic pathways have been implicated in impulsive and aggressive behavior. Polymorphisms in the regulatory region of the serotonin transporter (5-HTT), in intron 7 of the tryptophan hydroxylase (TPH) gene and in the MAOA gene were previously reported to be associated with mood and anxiety disorders, impulsivity and aggression. In this study, we analyzed these polymorphisms in men and women with schizophrenia or schizoaffective disorder (n= 84) who met our criteria for violence (history of two or more assaults on others) or nonviolence (no history of either assaultive or threatening behavior). In males, a modest association between TPH genotype and history of violence (chi-square test = 6.703, degrees of freedom = 2,P= 0.035) was not statistically significant after correction for multiple comparisons (correctedP= 0.21). The TPH L allele was more frequent in violent males (chi-square = 5.323, degrees of freedom = 1,P= 0.021) but this difference also failed to withstand correction (correctedP= 0.126). No significant associations were found for either the 5-HTT or MAOA polymorphisms in males or females. These results tend to support previous reports by Newel al.(1996; 1998) of an association between the TPH L allele and impulsive aggression in males with personality disorder, but larger studies are needed. © 2000 Lippincott Williams & Wilkins, Inc.