title: Genetic and environmental etiology of nicotine use in Sri Lankan male twins.
abstract: Little is known about the prevalence and etiology of tobacco use in Asian populations. This study aims to test whether the finding of substantial heritability for tobacco-related phenotypes in Western populations is generalizable to developing countries. The twin method was used to estimate the relative contribution of genetic and environmental influences on nicotine-related phenotypes. Participants were selected from the population based Sri Lankan Twin Registry. The Composite International Diagnostic Interview was administered to 1,804 male individuals to assess five phenotypes: nicotine use; desire and unsuccessful attempts to quit smoking; subjective feeling of being tobacco dependent; and two DSM-IV diagnoses; nicotine dependence and nicotine withdrawal. Almost one-third of the male twins were life-time smokers. The genetic results were consistent with the previously reported findings from Western and Chinese populations, in that the nicotine use traits were significantly heritable, with environmental influences being of the non-shared nature. The results derived from the Causal Contingent Common pathway model (CCC) supported previous findings that show that liabilities to regular smoking and subsequent problem smoking have both shared and specific genetic influences.
authors.affiliation: Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Kings College, London, SE5 8AF, UK. Helena.zavos@kcl.ac.uk
authors.forename: Helena M S
authors.initials: HM
authors.lastname: Zavos
authors.forename: Yulia
authors.initials: Y
authors.lastname: Kovas
authors.forename: Harriet A
authors.initials: HA
authors.lastname: Ball
authors.forename: David
authors.initials: D
authors.lastname: Ball
authors.forename: Sisira H
authors.initials: SH
authors.lastname: Siribaddana
authors.forename: Nick
authors.initials: N
authors.lastname: Glozier
authors.forename: Athula
authors.initials: A
authors.lastname: Sumathipala
authors.forename: Peter
authors.initials: P
authors.lastname: McGuffin
authors.forename: Matthew
authors.initials: M
authors.lastname: Hotopf
authors.forename: Frühling V
authors.initials: FV
authors.lastname: Rijsdijk
mesh_terms: D000328:Adult; D015984:Causality; D003627:Data Interpretation, Statistical; D059647:Gene-Environment Interaction; D006801:Humans; D008297:Male; D008957:Models, Genetic; D016540:Smoking Cessation / Q000523:psychology; D013188:Sri Lanka / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014029:Tobacco Use Disorder / Q000453:epidemiology* / Q000235:genetics*; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic