Substance use was assessed by having adolescents report their use of several drugs within the past 30 days (0 = no, 1 = yes), including: alcohol, marijuana, tobacco (cigarettes, chewing tobacco, snuff, and pipe), other drugs (cocaine/crack, heroin/other opiates, non-prescription methadone, hallucinogens, amphetamines, tranquilizers, inhalants, and other drugs). We collapsed responses to drugs other than alcohol, marijuana, and tobacco into an “other drugs” category, and created a new variable for ‘any drug use.’
