Alcohol and drug uses are common in today's society and it is well-known that they can lead to serious consequences. Studies have been conducted in order, for example, to understand short- or long-term temporal processes of alcohol and drug uses. This paper discusses statistical modeling for joint analysis of alcohol and drug uses and several models and the corresponding estimation approaches are presented. The methods are applied to a prospective study of alcohol and drug uses on college freshmen, which motivated this investigation. The analysis results suggest that female subjects seem to have much less consequences of alcohol and drug uses than male subjects and the consequences of alcohol and drug uses decrease along with ages.