title: Predictors of subgroups based on maximum drinks per occasion over six years for 833 adolescents and young adults in COGA.
abstract: OBJECTIVE
  A person's pattern of heavier drinking often changes over time, especially during the early drinking years, and reflects complex relationships among a wide range of characteristics. Optimal understanding of the predictors of drinking during times of change might come from studies of trajectories of alcohol intake rather than cross-sectional evaluations.
  
  
  METHODS
  The patterns of maximum drinks per occasion were evaluated every 2 years between the average ages of 18 and 24 years for 833 subjects from the Collaborative Study on the Genetics of Alcoholism. Latent class growth analysis identified latent classes for the trajectories of maximum drinks, and then logistic regression analyses highlighted variables that best predicted class membership.
  
  
  RESULTS
  Four latent classes were found, including Class 1 (69%), with about 5 maximum drinks per occasion across time; Class 2 (15%), with about 9 drinks at baseline that increased to 18 across time; Class 3 (10%), who began with a maximum of 18 drinks per occasion but decreased to 9 over time; and Class 4 (6%), with a maximum of about 22 drinks across time. The most consistent predictors of higher drinking classes were female sex, a low baseline level of response to alcohol, externalizing characteristics, prior alcohol and tobacco use, and heavier drinking peers.
  
  
  CONCLUSIONS
  Four trajectory classes were observed and were best predicted by a combination of items that reflected demography, substance use, level of response and externalizing phenotypes, and baseline environment and attitudes.
authors.affiliation: University of California, San Diego, La Jolla, California.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Schuckit
authors.affiliation: University of California, San Diego, La Jolla, California.
authors.forename: Tom L
authors.initials: TL
authors.lastname: Smith
authors.affiliation: University of California, San Diego, La Jolla, California.
authors.forename: George P
authors.initials: GP
authors.lastname: Danko
authors.affiliation: Washington University in St. Louis, St. Louis, Missouri.
authors.forename: Kathleen K
authors.initials: KK
authors.lastname: Bucholz
authors.affiliation: Washington University in St. Louis, St. Louis, Missouri.
authors.forename: Arpana
authors.initials: A
authors.lastname: Agrawal
authors.affiliation: Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Dick
authors.affiliation: Indiana University, Bloomington, Indiana.
authors.forename: John I
authors.initials: JI
authors.lastname: Nurnberger
authors.affiliation: University of Iowa, Iowa City, Iowa.
authors.forename: John
authors.initials: J
authors.lastname: Kramer
authors.affiliation: University of Connecticut, Storrs, Connecticut.
authors.forename: Michie
authors.initials: M
authors.lastname: Hesselbrock
authors.affiliation: University of California, San Diego, La Jolla, California.
authors.forename: Gretchen
authors.initials: G
authors.lastname: Saunders
authors.affiliation: University of Connecticut, Storrs, Connecticut.
authors.forename: Victor
authors.initials: V
authors.lastname: Hesselbrock
mesh_terms: D000293:Adolescent; D000428:Alcohol Drinking / Q000453:epidemiology* / Q000235:genetics*; D000434:Alcoholic Beverages; D003299:Cooperative Behavior; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult