Sexual Behavior and Substance Use in Adolescence and Young Adulthood: Non-specific Associations Between a Range of Sexual Behaviors and Alcohol, Nicotine, and Marijuana Use

Sexual behaviors and substance use exhibit high rates of co-occurrence and similar patterns of age-related change, with typical initiation in middle adolescence followed by large increases in late adolescence and emerging adulthood. Because adolescent sexual behaviors are associated with negative health consequences including sexually-transmitted infections and substance use, adolescent sexual behaviors are often conceptualized within a health-risk framework. Sexual development, however, is a normative process important for healthy psychosocial adjustment, with the timing (early vs later initiation) and context (casual vs romantic partner) of sexual behaviors influencing their association with health risks. We tested whether seven common sexual behaviors could be conceptualized as markers along a continuum of sexual development (e.g., from kissing and making out to oral, vaginal, and anal sex) and then examined their associations with various measures of substance use in a sample of adolescents and young adults (N = 626; ages 13-22 years old). We found a 2-parameter logistic item response theory model provided a good fit to the prevalence and covariance among the sexual behaviors, with each behavior holding a different location on a trait representing the progression of sexual development. Each sexual behavior was associated with greater substance use even after adjusting for an early initiation of sexual behavior, current age, biological sex, and socioeconomic status. The results indicate that even normative sexual behaviors have strong and non-specific associations with substance use in adolescence and emerging adulthood.