Effects of Smoking on Aggression, Big Five Personality Factors, and Polymorphisms in HTR2A, DRD4, and MAOA among Egypt University Students

Introduction. To find genetic variants in the DRD4 and HTR2A genes’ promoter regions and exons that are associated with tobacco smoking and nicotine addiction in Egyptian university students as well as to study the association between personality traits and smoking status. Methods. A self-administered questionnaire about cigarette smoking and personality attributes (Big Five Inventory, ESPAD Questionnaire on Substance Abuse, and Buss-Perry Aggression Questionnaire). The participants in the study were 90 nonsmokers (NS) and 88 current smokers (CS), who were divided into two groups depending on their cigarette consumption per day (cpd): 55 heavy smokers (HS, >20 cpd) and 33 light smokers (LS, 1–10 cpd). Four and eight single nucleotide polymorphisms (SNPs) in the DRD4, HTR2A, and MOA genes, respectively, were genotyped. Results. Smokers scored lower on neuroticism, agreeableness, conscientiousness, openness, and extraversion than nonsmokers, but higher on aggression. Furthermore, the C allele of rs1800955 in DRD4 was associated with cigarette smoking in the HS vs. NS and LS vs. NS studies. The T allele of the HTR2A rs6313 gene was discovered to be strongly associated with cigarette smoking. There was no link discovered between MOA rs1137070 and MOA rs1137070. Conclusions. Using a comprehensive personality model (FFM), this study repeats and extends earlier research. Personality and genetic studies may aid in the development of a more complete and conclusive understanding of cigarette smoking, as well as more precise policies and guidelines for smoking cessation and quitting.