Nicotine dependence and alcohol abuse/dependence were both categorized into (0) no symptoms; (1) 1–2 symptoms; and (2) 3 or more symptoms. Other illicit use of any of the following drugs was considered: (a) sedatives, (b) cocaine, (c) amphetamines and other stimulants, (d) opioids, (e) hallucinogens, (f) dissociatives (phencyclidine, ketamine), (g) solvents, and (h) inhalants.
