Age-related patterns of cocaine and methamphetamine use across the life course in the United States: Disparities by gender and sexual identity among adults.

Purpose: Research showing substance use decreases over the life course has focused primarily on heterosexual adults. We examined how age-related patterns of cocaine and methamphetamine use vary by sexual identity and gender among a national sample.

Methods: We included 191,954 adults aged 18-64 from the 2015-2019 National Survey on Drug Use and Health. We described the weighted prevalence of past-year cocaine and methamphetamine use and used logistic regressions to estimate relative odds of past-year cocaine and methamphetamine use by age, stratified by gender and sexual identity (heterosexual, gay/lesbian, bisexual).

Results: Cocaine and methamphetamine use was highest among lesbian, gay, and bisexual (LGB) adults compared to their heterosexual counterparts. Gay/lesbian men and women and bisexual men were also more likely to use cocaine at later ages. Heterosexual adults ages 26-34 (adjusted odds ratio [aOR] = 0.73; confidence interval [CI] = 0.65-0.83) were less likely than those 21-25 to report past-year cocaine use, but there were no differences between those ages 26-34 and 21-25 among any LGB sub-group. Heterosexual (aOR = 1.62; CI = 1.28-2.04) and gay (aOR = 2.93; CI = 1.26-6.80), men ages 26-34 were more likely to report past-year methamphetamine use than their counterparts ages 21-25. There were no age-related differences in past-year methamphetamine use between bisexual men and gay/lesbian women.

Conclusions: Patterns of cocaine and methamphetamine use across the life course for LGB individuals differ from those of heterosexuals. This has implications for targeted prevention efforts to address stimulant use among minoritized populations.