Legal and illegal use of drugs was most strongly associated with age, sex, and income. Higher income was associated with a greater likelihood of drug use for all drug types examined, which is perhaps not surprising given that drug use requires disposable income. Relationship status was linked to illegal (but not legal) drug use: both cocaine and cannabis use were more likely among persons who had never been married or previously been married. These associations remained statistically robust after adjustment for age, sex, and the other variables considered here. These associations are consistent with previous research in the developed countries, which has linked illegal drug use with an individual's marital status.
