"In 2018, an estimated 5.5 million people aged 12 or older were past year users of cocaine (Figure 10), including about 757,000 users of crack. Stated another way, about 2.0 percent of the population in 2018 used cocaine (Figure 13), and 0.3 percent used crack (2018 DT 7.2).

"In these initial investigations, we found no evidence that I-502 enactment, on the whole, affected cannabis abuse treatment admissions. Further, within Washington State, we found no evidence that the amount of legal cannabis sales affected cannabis abuse treatment admissions.

"The bulk of outcome analyses in this report used the within-state approach to focus on identifying effects of the amount of legal cannabis sales. We found no evidence that the amount of legal cannabis sales affected youth substance use or attitudes about cannabis or drug-related criminal convictions.

"Concerns about laws and policy measures that may inadvertently affect youth drug use merit careful consideration. Our study does not show evidence of a clear relationship between legalization of marijuana for medical purposes and youth drug use for any age group, which may provide some reassurance to policymakers who wish to balance compassion for individuals who have been unable to find relief from conventional medical therapies with the safety and well-being of youth.

Illegal Drug Use and Marijuana Use in Lifetime, Past Year, and Past Month among Persons Aged 12 and Older in the US by Age, Gender, and Race/Ethnicity, 2015 and 2016

"By combining the data from 2012 and 2013, we can obtain more precise estimates of prevalence levels for cannabis use and differences between subgroups. The estimated LTP [lifetime prevalence], LYP [last year prevalence] and LMP [last month prevalence] rates among all adults (aged 16–64) were 21.3 per cent, 4.3 per cent and 1.6 per cent, respectively. Among young adults (aged 16–34), the corresponding LTP, LYP and LMP estimates are 30.2 per cent, 10 per cent and 3.4 per cent.

"Two per cent of the men and 0.9 per cent of the women reported some type of illicit drug use in the past 30 days, corresponding to approximately 53,000 men and 24,000 women or a total of 77,000 people. Adding to this the 50,000 people who in the past 30 days had used prescription medicine without a doctor’s prescription, the total figure increases to 127,000 people. The population study indicates that the highest proportion of regular drug use is found among young men between the ages of 15 to 24, while the highest proportion among women is observed in the ages of 25 to 34.

"In 2013, an additional cross-sectional study of drug use was conducted in a nationally representative sample of the population in Sweden (Ramstedt, 2014). A total of 15,576 individuals (59.3% of the total sample) participated in the study and 10.5% reported that they had used an illicit drug or used some prescription medication in a non-prescribed way during the past 12 months. In this study, cocaine and amphetamines were the most common illicit substance reported after cannabis.

"NSDUH’s overall estimates of SUD include people who met the DSM-IV criteria for either dependence or abuse for alcohol or illicit drugs. In 2017, approximately 19.7 million people aged 12 or older had an SUD in the past year, including 14.5 million people who had an alcohol use disorder and 7.5 million people who had an illicit drug use disorder (Figure 39).