Bridging Disciplinary Boundaries (January 11 - 14, 2007)
METHOD: Alcoholics in treatment were invited to participate, along with their first and second degree relatives. Comparison families from the community were recruited. Over 1800 families representing 13,000+ individuals from six different sites nationwide have participated. A comprehensive, age appropriate assessment battery was assembled for children, adolescents, and adult. Participants completed a detailed psychiatric history, including information on the family environment and relationships with parents and siblings. Parents were also interviewed about children under 17 years of age. Temperament traits, teacher reports and information on family / friend social support were assessed. DNA information was obtained from blood samples provided by subjects. Children and adolescents have completed multiple assessments, providing for a prospective view of their adolescent and young adult outcomes.
RESULTS: COGA has identified several genes contributing to the risk for both alcoholism as a diagnosis [GABRA2] and relevant related features such as depression [CHRM2], alcohol taste preference [TAS2R16], craving [SNCA], withdrawal [GRIK3], and alcohol metabolism [ADH4]. A region on chromosome16 is related to the subjective effects of alcohol consumption, while a region on chromosome 2 appears to hold genes common to several externalizing behaviors frequently associated with alcoholism. Many of these initial findings have been replicated by several other research groups.
Still, genetic factors account for only about 50% of the variance in the liability for developing alcohol related problems. Psychosocial and environmental factors contribute an additional 50%. Clearly psychosocial and environmental influences in combination influence the expression of these susceptibility genes. One initial finding found that marital status affects the probability of developing alcohol dependence, even among those individuals carrying the GABRA2 susceptibility gene.
Developmental milestones [ages of first use, first regular use, onset of problems leading to alcohol dependence] are being examined. Age of first regular alcohol use is a well known indicator of later problems, and COGA has shown that family structure and status in childhood influence early drinking. Further, the initial subjective responses and taste preference for alcohol influence the onset of early alcohol use. These early problem behaviors can lead to increased exposure to alcohol. Findings regarding the role of these and other psychological, environmental and possibly genetic factors to the developmental trajectories for developing alcohol problems will be presented.
IMPLICATIONS FOR PRACTICE: Social workers often have a poor understanding of the role of genetic factors in the development of substance abuse problems, including alcoholism. Genetic factors contribute to, and interact with, a variety of psychological and environmental factors that lead to several different poor childhood and adolescent outcomes. This presentation will focus on our understanding of several putative psychological, environmental and genetic risk factors that may contribute not only to the initiation of substance use, but also the maintenance of substance use behavior, and, in some individuals, substance use problems. Potential critical time points for intervention will also be identified.