Functional MRI of the brain is a technique that localizes regions of activity in the brain following task activation. It is useful to neuroscientists interested in interrogating the localization of certain brain functions. Alcohol misuse is a complex, multidimensional disorder involving problematic ethanol ingestion and reflected in behavior. Genetic factors play an important role in the etiopathogenesis of alcohol abuse in adolescents. Alcohol use disorders tend to run in families with 40-60% of the variance of risk explained by genetic influences. Numerous well-designed twin, adoption, and family studies have demonstrated that genetic factors are important in determining vulnerability to alcohol use disorders. There is a tendency for people who misuse alcohol to marry individuals who also abuse alcohol (assortative mating). Thus, many adolescent alcohol misusers are from families with a high proportion of alcohol abuse or dependence. It has been shown that alcohol abusing adolescents have a number of cognitive deficits. Neuropsychological studies of adolescents with alcohol use disorders have reported decrements in language skills, problem solving, verbal and non-verbal retention, working memory, and visuospatial performance. Some cognitive deficits may be present before an adolescent starts drinking and contribute to the development of alcohol use disorders. Data suggest that neuropsychological dysfunction may play a role in determining risk for suicidal acts. Therefore, studies of cognitive impairments and the neural substrate of these impairments in alcohol abusing adolescents may help develop methods of identifying teenagers who are at increased risk for suicide and contribute to our knowledge of the neurobiology of suicidal behavior and may lead to the development of new treatment methods.