After the first year of substance use onset the probability of transition to dependence was almost 2.0% for nicotine, alcohol and cannabis users and 7.1% for cocaine users. The probability estimates of transition to dependence a decade after use onset was 15.6% among nicotine users, 14.8% among cocaine users, 11.0% among alcohol users, and 5.9% among cannabis users. Lifetime cumulative probability estimates indicated that 67.5% of nicotine users, 22.7% of alcohol users, 20.9% of cocaine users, and 8.9% of cannabis users would become dependent on those substances at some time in their life. Half of the cases of nicotine, alcohol, cannabis and cocaine dependence were observed approximately 27, 13, 5 and 4 years after use onset, respectively (Figure 1).
