RESUMO
Objective: Research suggests positive relationships between aerobic fitness and cognition in older adults; however, limited research has adequately investigated the relationship between objectively measured aerobic fitness and broad cognitive functioning in healthy adolescents and young adults without psychiatric or physical health disorders. Further, studies to date have disproportionately examined males and failed to examine sex differences. Here we examine the relationship between aerobic fitness and neuropsychological functioning in physically healthy youth and whether sex moderates these findings. Design: Sixty-four healthy emerging adults (16-25 years-old; 32 female) underwent measurement of objective aerobic fitness (VO2 max) and neuropsychological assessment. Exclusion criteria included: left-handedness, prenatal medical issues or alcohol/illicit drug exposure, Axis-I psychiatric disorders, major medical disorders including metabolic conditions such as diabetes, hypertension, hyperlipidemia, major neurologic disorders, LOS greater than 2 min, intellectual disability or learning disability, regular substance use (e.g., greater than biweekly use of cannabis) or positive drug toxicology testing. Method: Multiple regressions examined VO2 max, sex, sex*VO2interaction in relation to neurocognition, controlling for objectively measured body fat percentage. Results: Prior to including body fat percentage, higher VO2 max related to improved working memory (Letter-Number Sequencing; p = .03) and selective attention (CPT-II hit response time standard error; p = .03). Aerobic fitness significantly interacted with sex, as higher-fit males had better performance on two sustained attention tasks while females did not demonstrate this pattern (CPT-II variability standard error, p = .047; Ruff 2&7 Total Speed, p = .02). Body fat percentage was positively slower cognitive flexibility (D-KEFS color-word switching/inhibition, p = .046). Conclusions: VO2 independently predicted better working memory and selective attention. Increased aerobic fitness level related to increased performance on sustained attention tasks in males but not females. Therefore, aerobic fitness may be positively related to better cognitive functioning in physically healthy adolescents and emerging adults without metabolic conditions. Further research into factors (e.g., intensity or type of activity) that may relate to beneficial outcomes by sex are needed.
RESUMO
OBJECTIVE: Research has demonstrated comorbidity between Attention-Deficit Hyperactivity Disorder (ADHD) and cannabis use, and some have proposed that subclinical ADHD symptoms may explain attentional deficits in cannabis users. Here we investigated whether subclinical ADHD symptoms and cannabis use independently or interactively predict performance on attention tasks in adolescents and young adults. METHOD: Seventy-two participants (cannabis users (MJ) = 34, Controls = 38) completed neuropsychological tasks of inhibition and attention. Parent report on the Child Behaviors Checklist reflected current ADHD symptoms. Multiple regression analyses examined whether ADHD symptoms and cannabis use independently or interactively predicted cognitive outcomes. RESULTS: Cannabis use was significantly associated with slower CPT hit rate response. Subclinical ADHD symptoms did not independently predict or moderate cannabis effects. CONCLUSIONS: Cannabis users demonstrated slower response rate during an attentional task. Subclinical ADHD symptoms did not predict any deficits. As such, attention deficits seen in cannabis users are more related to substance use than ADHD symptomatology.
