Background: Rates of substance use among adolescents have increased in the 1990s, however little is known about current patterns of substance use among youths entering adulthood.
Methods: We studied sex and age-specific rates of substance use (tobacco, alcohol, cannabis, other illicit drugs, inhalants and psychotropic medications) in a large sample of French youths aged 12-26 years (the GAZEL Youth study, n=1333).
Results: Prevalence rates of substance use were high and varied with age and sex. Tobacco, cannabis and polysubstance use were most frequent among 19-21 year-olds (regular tobacco use: 41.5% in males, 39.9% in females; regular cannabis use: respectively 23.9% and 10.9%; tobacco+alcohol+cannabis: respectively 9.9% and 4.6%). Regular alcohol use was most frequent among 22-26 year-olds (29.8% in males, 15.6% in females). Across successive birth cohorts, the age of initiation of tobacco and cannabis use decreased. Males were consistently more likely to use psychoactive substances than females (except for tobacco and psychotropic medications).
Conclusions: Rates of substance abuse peak in late adolescence but remain high among a subgroup of young adults. Moreover, substance use initiation appears to be occurring at increasingly younger ages.