Fractal Analysis of Brain Activity During Risky Drinking in Adolescents and Young Adults

<b>Background/Objectives</b>: Despite widespread negative effects on physical and societal well-being, the neurological effects and risk factors of alcohol misuse are far from being fully understood. To broaden knowledge about inherent differences and possible changes in the brain reflecting alcohol use, we investigated functional Magnetic Resonance Imaging data in a group of young adult and adolescent individuals with varying levels of alcohol consumption from the National Consortium on Alcohol and Neurodevelopment in Adolescence dataset. <b>Methods</b>: We evaluated fractal complexity, or long-term self-memory of brain activity, using the Hurst Exponent, spontaneous neural activity using Amplitude of Low Frequency Fluctuations, and local coherence/synchronization using Regional Homogeneity. Regional values for these measures of interest were compared between risky drinkers and light drinkers, as well as between the same groups of individuals before development of any risky drinking habits. <b>Conclusions</b>: Significant differences (Cohen's d > 0.557) in the varying measures were identified between risky and light drinkers that may point to abnormal activity patterns in regions including the insula, precuneus, and inferior frontal lobe. Importantly, a control comparison between the same groups of individuals at younger, non/light drinking ages revealed distinct differences in brain patterns, potentially consistent with the interpretation that differences in brain activity patterns among the older groups are a result of drinking patterns rather than a cause. In contrast, the differences identified in the younger groups may be potential risk factors indicating increased likelihood of engaging in heavier drinking habits.