Disaggregating the liability for drug abuse.

It is consensually accepted that the liability for developing a substance abuse disorder is not the same for all individuals in the population. Only marginal progress has been made, however, in determining the factors responsible for the variation in the liability to drug abuse, encompassing interacting biological, behavioral, and environmental processes. Since variation in the liability has a multifactorial basis, it is necessary, therefore, to identify the integral biobehavioral traits and to determine how a person’s position on these traits (phenotypes) covaries with environmental influences to determine liability status. Once this can be accomplished, it will be possible to specify with a high level of precision the liability for developing a drug abuse disorder for each individual in the population.