Neonatal temperament and neuromotor differences are predictive of adolescent alcohol intake in rhesus monkeys (Macaca mulatta).

Identifying predictors of teenage alcohol use disorder (AUDs) is a major health initiative, with studies suggesting that there are distinct personality-related traits that underlie patterns of alcohol intake. As temperament is biologically based, identifiable early in life, and stable across time, it is considered the foundation of personality. As such, we hypothesized that neonatal temperament traits would predict anxiety-mediated adolescent alcohol consumption. To test this, N = 145 rhesus macaque (Macaca mulatta) infants (14 days of age), reared in a neonatal nursery (n = 82) or in a control condition with their mothers (n = 63) were assessed with a widely used standardized nonhuman primate testing battery, the Infant Behavioral Assessment Scale (IBAS), modeled after the Brazelton Neonatal Assessment Scale, evaluating visual orienting, temperament, motor maturity and, more recently, sensory sensitivity. As adolescents (3-4 years of age), these same subjects were allowed unfettered access to a sweetened-alcohol solution for 1 hr/day, 4 days/week, over 5-7 weeks. Subjects were allowed to self-administer alcohol while housed alone (n = 70) or socially in their home cage (n = 55). Linear regressions showed that alcohol intake was predicted by neonatal orienting ability (β = -.35; p = .01), state control (β = -.19; p = .04), and motor maturity (β = -.24; p = .01). Poor neonatal orienting, state control (ease of consolability), and motor maturity were associated with higher adolescent alcohol intake in rhesus monkeys. These findings suggest that neonatal temperament is predictive of patterns of adolescent alcohol intake. To the extent that these results generalize to humans, they provide evidence that early-life temperament and neurodevelopment may be important risk factors for adolescent AUDs and that the IBAS may be used as an assessment tool for identifying such risk.