Rationale: There is increasing interest in and evidence for the negative impacts of cannabis use in cognitive performance and symptoms of attention-deficit/hyperactivity disorder (ADHD), with age of first cannabis use as a potential amplifier of these associations. However, the existing literature is inconsistent, which may be due to methodological limitations, including small sample sizes.
Objective: To examine current cannabis use and age of first cannabis use in relation to neurocognitive task performance and ADHD symptoms in a large sample of binge-drinking young adults.
Methods: Participants were young adults (N=730, M age=21.44, 52.6% female) assessed for current cannabis use, neurocognitive task performance, and ADHD symptoms. Three-group ANCOVAs compared individuals reporting frequent (daily/multiple times daily), occasional (weekly/monthly), or no cannabis use.
Results: Covarying alcohol use, tobacco use, age, sex, income, and education, daily cannabis users exhibited significantly more impulsive delay discounting and hyperactive-impulsive ADHD symptoms compared to both other groups. However, cannabis use was not associated with inattentive ADHD symptoms, verbal intelligence, working memory, probability discounting, short-term verbal memory, or behavioral inhibition. Age of initiation of cannabis use exhibited neither main effects nor interactions in relation to any domains of cognitive performance or ADHD symptomatology.
Conclusions: The current findings provide support for a link between cannabis use in relation to immediate reward preference and symptoms of hyperactive-impulsive ADHD in young adults, but only among frequent users. No other neurocognitive domains exhibited associations with cannabis and age of first use was neither independently nor interactively associated with cognitive outcomes.
Keywords: Age of first use; Attention-deficit/hyperactivity disorder; Cannabis; Cognition; Delay discounting; Emerging adults; Frequency; Impulsivity; Marijuana; Neuropsychology.