Polymorphisms of COMT Val158Met and DAT1 3′-UTR VNTR in Illicit Drug Use and Drug-Related Psychiatric Disorders

Abstract

To investigate the involvement of COMT Val158Met and DAT1 3′-UTR VNTR genotypes in the pathogenesis of illicit drug use and drug-induced psychotic disorders (DIP), 187 substance users and 386 normal controls were recruited from Northern Taiwan. Substance users and normal controls significantly differed in allele frequencies of COMT Val158Met (p = 0.039) but not in allele frequencies of DAT1 3′-UTR VNTR (p = 0.879). However, neither allele frequencies of COMT Val158Met nor allele frequencies of DAT1 3′-UTR VNTR were associated with DIP. The findings should be confirmed in further studies of a larger sample size and a more homogenous patient group.

Keywords :

• COMT
• DAT1
• genotype
• dopamine
• substance use
• psychosis
• mood disorder
• suicide

THE AUTHORS

Chih-Ken Chen, M.D., Ph.D., is an attending doctor in the Department of Psychiatry at Chang Gung Memorial Hospital in Keelung, and a professor at the Chang Gung University School of Medicine. As the primary researcher and coordinator of this project, he gathered and analyzed the study's data, and wrote the first draft of the manuscript. His major research interests are heredity, psychopathology, and cognitive function among substance users.

Shih-Ku Lin, M.D., is an attending doctor and chief in the Department of Research and Teaching at Taipei City Hospital, Songde Branch. He is the joint first author of this manuscript. He assisted with the study's design, literature review, and in participant recruitment. His main research interests are psychopharmacology and substance misuse.

Shu-Chuan Chiang, M.D., M.S., is an attending doctor at the Taoyuan Psychiatric Center and a lecturer at Ching Yun University. She assisted with the study's design and in participant recruitment. Her main research interests are the epidemiology of substance misuse and drug-induced psychiatric disorders.

Lien-Wen Su, M.D., M.P.H., is an attending doctor at Taipei City Hospital, Songde Branch. He was responsible for protocol development and participant recruitment. His major research interests are substance misuse and prevention education for heroin dependence.

Liang-Jen Wang, M.D., M.P.H., is an assistant professor and chief in the Department of Child and Adolescent Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung city, Taiwan. He served as the main statistical consultant and edited the submitted manuscript. His major research interests are psycho-epidemiology and child psychiatry.

GLOSSARY

• COMT: the enzyme catechol-O-methyltransferase

• DAT1: dopamine transporter

• DIM: Drug-induced mood disorder

• DIP: Drug-induced psychotic disorder

• VNTR: variable number of tandem repeat

• 3′-UTR: the 3′-untranslated region