title: Substance abuse may be a risk factor for earlier onset of Huntington disease.
abstract: Environmental factors may contribute as much as one-third of the variance in Huntington disease (HD) age of onset. Substance abuse is a risk factor for other neurodegenerative disorders; however, whether substance abuse influences HD age of onset is not well established. This study investigated the relationships between alcohol, drug, and tobacco abuse and HD age of onset in 136 participants with symptomatic HD. CAG repeat length was used as a covariate in all analyses, as it represents the most significant determinant of HD age of onset. The relationship between substance abuse, HD age of onset, and sex was also examined, as women may experience greater medical harm from substance abuse. Lifetime alcohol abuse and lifetime drug abuse were associated with earlier age of HD onset; a similar trend was seen for current tobacco abuse. For women, lifetime alcohol abuse was associated with earlier onset of HD, with a similar trend for lifetime drug abuse. However, alcohol, drug, and tobacco abuse were not significantly associated with age of onset in men. Further work is needed to determine whether substance abuse is a causative risk factor for earlier onset of HD, and why the environmental factors associated with age of onset vary by sex.
authors.affiliation: Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA. joanne.byars@neurology.ufl.edu
authors.forename: Joanne A
authors.initials: JA
authors.lastname: Byars
authors.forename: Leigh J
authors.initials: LJ
authors.lastname: Beglinger
authors.forename: David J
authors.initials: DJ
authors.lastname: Moser
authors.forename: Pedro
authors.initials: P
authors.lastname: Gonzalez-Alegre
authors.forename: Peg
authors.initials: P
authors.lastname: Nopoulos
mesh_terms: D000367:Age Factors; D017668:Age of Onset; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000453:epidemiology*; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D019966:Substance-Related Disorders / Q000145:classification / Q000453:epidemiology*