['To investigate social, psychological, and environmental factors related to heavy drinking by 15-year-old Finnish school pupils.', 'Each of 240 pupils completed a questionnaire about alcohol use, smoking, and illicit drug use; an Offer Self-Image Questionnaire; an Inventory of Parent and Peer Attachment; and a Psychosomatic Symptoms Questionnaire. Teachers assessed each pupil according to a Social Skills Rating Scale. Academic achievement was assessed on the basis of report grades.', 'Heavy drinking was associated with smoking, trial of drugs, poor social skills in class, and poor school achievement in both boys and girls. In girls, heavy drinking was associated with psychosomatic symptoms and a negative social self-image. Girls who drank heavily also had more difficulty with concentration and externalizing problems and more problems with teachers than those who were abstinent or consumed alcohol moderately. The self-images of boys who drank heavily were more negative than those of alcohol-abstinent boys. In boys, heavy drinking was associated with higher numbers of peer relationships.'] Is heavy drinking associated with more severe psychosocial dysfunction among girls than boys in Finland?