To help address these issues we present data from a 30-year prospective study of a nonclinical and relatively high functioning sample of 397 men to test five hypotheses: 1) the presence of either an AUD or a SUD will increase the risk for the other diagnosis; 2) earlier life externalizing and internalizing characteristics will relate to both future AUDs and SUDs; 3) a low LR to alcohol will predict AUDs but not SUDs; 4) the development of combined AUDs plus SUDs will be related to the combination of a low LR as well as externalizing and internalizing characteristics; and 5) the presence of AUDs and SUDs together will be associated with a greater intensity of use of substances and related problems for both conditions.
