Objective
To investigate development of cognitive and motor functions in
healthy adolescents and to explore whether hazardous drinking affects the
normal developmental course of those functions.
Method
Participants were 831 adolescents recruited across five United States
sites of the National Consortium on Alcohol and NeuroDevelopment in
Adolescence (NCANDA): 692 met criteria for no/low alcohol exposure, and 139
exceeded drinking thresholds. Cross-sectional, baseline data were collected
with computerized and traditional neuropsychological tests assessing eight
functional domains expressed as composite scores. General additive modeling
evaluated factors potentially modulating performance (age, sex, ethnicity,
socioeconomic status, and pubertal developmental stage).
Results
Older no/low-drinking participants achieved better scores than
younger ones on five Accuracy composites (General Ability, Abstraction,
Attention, Emotion, and Balance). Speeded responses for Attention, Motor
Speed, and General Ability were sensitive to age and pubertal development.
The exceeds-threshold group (accounting for age, sex, and other demographic
factors) performed significantly below the no/low-drinking group on Balance
accuracy and on General Ability, Attention, Episodic Memory, Emotion, and
Motor speed scores and showed evidence for faster speed at the expense of
accuracy. Delay Discounting performance was consistent with poor impulse
control in the younger no/low drinkers and in exceeds-threshold drinkers
regardless of age.
Conclusions
Higher achievement with older age and pubertal stage in General
Ability, Abstraction, Attention, Emotion, and Balance suggests continued
functional development through adolescence, possibly supported by
concurrently maturing frontal, limbic, and cerebellar brain systems. Whether
low scores by the exceeds-threshold group resulted from drinking or from
other pre-existing factors requires longitudinal study.