Teenagers with easy access to drugs and alcohol in the home are more likely to drink and do drugs in their early and late 20s, according to an analysis of survey results  from around 15,000 participants in the National Longitudinal Study of Adolescent Health over the course of three waves - when the survey participants were, on average, 16, 22 and 29 years old.

According to Cliff Broman, professor of sociology
at Michigan State University, the effects were more significant among Caucasians and males, which may be odd defiance of stereotype or a confounder, since Hispanic and Asian participants generally had drugs and alcohol more easily available to them in the home during adolescence. 

What is obvious is that "the availability of illegal drugs and alcohol in the home while growing up is a critical factor in the later use of substances." This has been shown to be true in a lot of addictive behavior. Like smoking, drug and alcohol abuse is primarily a pediatric disease. Some people take them up later in life but those are outliers. The waves at average ages of 22 and 29 are much smaller.

Male participants, who had alcohol and illegal drugs more available to them in the home during adolescence than female participants, subsequently drank and did drugs more in adulthood than did females.