Adolescent and adult time trends in US hallucinogen use, 2002-19: any use, and use of ecstasy, LSD and PCP

Background and aims: Hallucinogen use is potentially harmful. Information on whether such use has increased in recent decades is lacking. This study assessed overall and age-specific time trends in the prevalence of 12-month hallucinogen use in the US general population. Design: Cross-sectional. Setting: Data from the US National Survey on Drug Use and Health, 2002-19. Participants: Respondents aged ≥ 12 years (n = 1 006 051). Measurements: Predictors were continuous years. Outcome variables included any hallucinogen use and use of lysergic acid diethylamide (LSD), ecstasy and phencyclidine (PCP) in the past year. Socio-demographic variables (gender, age, race/ethnicity, educational level and family income) were covariates. Findings: Overall, hallucinogen use increased between 2015 and 2019 [prevalence difference (PD) = +0.44, P < 0.05]. Since 2002, hallucinogen use has increased in adults aged ≥ 26 years (PD, 2002-14 = +0.24, P < 0.05; PD, 2015-19 = +0.45, P < 0.001) and decreased in adolescents aged 12-17 years (PD, 2002-14 = -1.60, P < 0.0001; PD, 2015-19 = -0.73, P < 0.001). Ecstasy use has decreased in adolescents (PD, 2002-14 = -0.56, P < 0.001), adults aged 18-25 years (PD, 2015-19 = -0.96, P < 0.01) and ≥ 26 years (PD, 2015-19 = -0.13, P < 0.05). LSD use between 2002 and 2019 increased overall (PD = +0.71, P < 0.0001) and in all age groups (12-17: PD = +0.67, P < 0.001; 18-25: PD = +3.12, P < 0.0001; ≥ 26: PD = +0.36, P < 0.0001). Conversely, PCP use between 2002 and 2019 decreased overall (PD = -0.06, P < 0.001), in adolescents (PD = -0.24, P < 0.001) and young adults (PD = -0.32, P < 0.0001). Conclusions: Since 2002, hallucinogen use in the United States has decreased among adolescents but increased in adults and is now estimated to affect more than 3 million adults aged 26+ years and more than 5.5 million adults aged 18+ years.