Related Experiment Video
Updated: Jun 7, 2026

Experimental Protocol for Examining Behavioral Response Profiles in Larval Fish: Application to the Neuro-stimulant Caffeine
Published on: July 24, 2018
Adolescent substance use, sleep, and academic achievement: evidence of harm due to caffeine
Jack E James1, Alfgeir Logi Kristjánsson, Inga Dóra Sigfúsdóttir
1School of Psychology, National University of Ireland, Galway, Ireland. j.james@nuigalway.ie
Abstract:
Using academic achievement as the key outcome variable, 7377 Icelandic adolescents were surveyed for cigarette smoking, alcohol use, daytime sleepiness, caffeine use, and potential confounders. Structural equation modeling (SEM) was used to examine direct and indirect effects of measured and latent variables in two models: the first with caffeine excluded and the second with caffeine included. A substantial proportion of variance in academic achievement, which might otherwise have been attributed to the harmful effects of cigarette smoking and alcohol use, was found to be attributable to caffeine. Evidence was obtained that daytime sleepiness, which was found to be independently associated with usage of licit substances (nicotine and alcohol) and caffeine, may be an important mediator of the negative impact of those substances on academic achievement. Findings suggest the importance of including measurements of caffeine consumption in future studies of adolescent substance use.
Related Concept Videos
Substance Use Disorders Affecting Sleep
Understanding the concepts of physical dependence,...
Insufficient Sleep and Sleep Deprivation
Sleep deprivation is a more severe form of sleep loss...
Stimulants
Cocaine can be administered via snorting, injection, or smoking. It primarily functions by blocking the reuptake of dopamine, resulting in a euphoric high characterized by an intense sensation of happiness and...
Attention-Deficit/Hyperactivity Disorder
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings.
CNS Depressants: Alcohol and Nicotine
CNS Stimulants: Cocaine, Amphetamines and Cannabinoids

