Although the age of substance use initiation varies by substance, in more than 50% of cases, initiation of use occurs in the first 2 decades of life, according to a recent study. Furthermore, although most risk factors for substance use initiation are common across substances, some are substance‐specific. Analyses were conducted on Wave 1 participants of the National Epidemiological Survey of Alcohol and Related Conditions (NESARC) (n=43,093). Estimates of the cumulative probability of substance use initiation were obtained separately for nicotine, alcohol, cannabis, and cocaine. Researchers found:

• The lifetime cumulative probabilities of substance initiation were 45.5% for nicotine, 82% for alcohol, 19.6% for cannabis, and 6.4% for cocaine.
• Among respondents with lifetime nicotine use, 50% had used it by age 15.3, whereas for alcohol, cannabis, and cocaine the respective ages were 17.8, 16.6, and 19.8.
• Previous use of another substance, being male, having a cluster B personality disorder, family history of substance use disorder, and being separated, divorced, or widowed increased the risk of use of all the substances assessed, whereas social anxiety disorder and some personality disorders were associated with specific substances.