Income and Relationship Status
"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."
Degenhardt, Louisa; Chiu, Wai-Tat; Sampson, Nancy; Kessler, Ronald C.; Anthony, James C.; Angermeyer, Matthias; Bruffaerts, Ronny; Girolamo, Giovanni de; Gureje, Oye; Huang, Yueqin; Karam, Aimee; Kostyuchenko, Stanislav; Lepine, Jean Pierre; Mora, Maria Elena Medina; Neumark, Yehuda; Ormel, J. Hans; Pinto-Meza, Alejandra; Posada-Villa, Jose´; Stein, Dan J.; Takeshima, Tadashi; Wells, J. Elisabeth, "Toward a Global View of Alcohol, Tobacco, Cannabis, and Cocaine Use: Findings from the WHO World Mental Health Surveys," Plos Medicine (Cambridge, United Kingdom: Public Library of Science, July 2008) Vol. 5, Issue 7, p. 1062.