Overall, these studies indicate that heavy drinking during adolescence may be associated with decrements in cognitive performance and brain health. However, longitudinal studies are critical to determine if substance use causes these abnormalities, or if these features predated the onset of regular substance use. One such study prospectively examined the influence of alcohol on neuropsychological functioning prior to initiation of drinking. For girls who transitioned into moderate or heavy drinking, more drinking days in the past year predicted a greater reduction in visuospatial task performance from baseline to 3-year follow-up. For boys, a tendency was seen for more past year hangover symptoms to predict poorer sustained attention (Squeglia et al. 2009).
