Decision making and binge drinking: a longitudinal study.

Alcohol dependent individuals perform worse than controls on tests of neurocognitive functions. For example, persons with a history of alcohol dependence display disadvantageous decision making compared with persons without substance dependence (Bechara et al., 2001). Also, diminished executive functions, that is, self-regulatory functions necessary for goal-directed behavior, have been found in persons with alcohol dependence (for a review, see Giancola and Moss, 1998). Heavy social drinkers (i.e., 21 drinks or more per week) have also been found to display mild deficits on a variety of neurocognitive functions, such as attention, memory, and visuospatial abilities (for a review, see Parsons and Nixon, 1998). Notably, recent neurobehavioral addiction theories have highlighted relations between substance dependence and neural dysfunction, particularly in the ventromedial prefrontal cortex, striatum, and basal ganglia (Goldstein and Volkow, 2002). These brain areas are important in neurocognitive functions involving the evaluation and appraisal of positive and negative consequences, functions which play a role in decision making (Krawczyk, 2002). To date, however, no studies have examined the relation between different longitudinal patterns of alcohol use and decision making or other affective neurocognitive functions. Decision-making skills may be especially important during late adolescence and young adulthood, as this is often a time of change, identity development, and educational and career development. In addition, young adulthood is often a period of heavy alcohol use. For example, a recent study reported that 23% of college students were frequent binge drinkers, and 44% engaged in binge drinking in the past 2 weeks (Wechsler et al., 2000). Some studies suggest that the adolescent brain may be particularly vulnerable to the harmful effects of alcohol. Recent studies indicate that binge drinking has a more detrimental effect on brain structure and functioning in adolescent, compared with adult rats (Crews et al., 2000; Monti et al., 2005). Notably, in humans, the pre-frontal lobes mature throughout adolescence, and into early adulthood (Casey et al., 2000). Therefore, decision-making skills, which rely on prefrontal lobe functioning, may be especially vulnerable to the effects of heavy alcohol use during adolescence. Recent research has highlighted considerable variability in drinking patterns (Cho et al., 2001; Mundt et al., 1995; Searles et al., 2000), and it is unclear whether different drinking trajectories are differentially related to neurocognitive functioning. Therefore, in this study, 200 participants were selected from a large longitudinal study, based on their drinking course over a recent 2.5-year period. Four groups of college students were included, differing in onset and amount of binge drinking. Thus, we were able to investigate what patterns of heavy (binge) drinking were related to diminished decision making. In the alcohol and drug-use literature, an abundance of studies indicate that different developmental trajectories exist for binge drinking. These studies consistently find the existence of stable-low, increasing, and stable-high subgroups (Chassin et al., 2002; Hill et al., 2000; Tucker et al., 2003), with increasing and stable-high subgroups having a higher prevalence in college student samples (Schulenberg and Maggs, 2002). When different drinking trajectories are associated with differences in decision making, this could have consequences for the way in which prevention and intervention strategies target binge drinking, such as targeting groups with a specific binge drinking trajectory (Jackson et al., 2004). Another possibility in explaining differences in decision-making abilities and drinking patterns, may be differences in age of onset of drinking. Differences in age of onset of drinking may indicate being in a more advanced phase of a progression of drinking behavior, or a more severe binge-drinking pattern. Therefore, the effect of age of onset of drinking was examined as well. Recently, controversy surrounds the definition of binge drinking, as the traditional definitions of binge drinking (5/4 drinks per occasion) may be too low for patterns of binge drinking in college students (White et al., 2006). We sampled students on the traditional measure of 5 drinks within 1 sitting, and thus, this measure of binge drinking may underestimate heavy binge drinking. However, binge drinking and a measure of quantity/frequency of alcohol use in this college student sample are highly correlated. We therefore refer to heavy (binge) drinking, or to alcohol use trajectories, and not solely to binge drinking. The current study thus examined relationships between several longitudinal patterns of heavy (binge) drinking, and decision-making skills in a sample of young adults. Decision making was studied using the Iowa Gambling Task (IGT; Bechara et al., 1999). In the IGT, participants play a computerized card game in which they attempt to develop a winning strategy by selecting cards from advantageous, as opposed to disadvantageous decks. Participants have to learn, over the course of the task, which decks are advantageous and which are disadvantageous. Disadvantageous choice patterns on the IGT have been found in a substantial number of studies of people with ventromedial prefrontal lobe damage (Bechara et al., 1994, 2001; but see Manes et al., 2002), and populations with a variety of disinhibited behaviors (Goudriaan et al., 2005; Grant et al., 2000; Rotherham-Fuller et al., 2004; van Honk et al., 2002; Whitlow et al., 2004). Other factors have also been found to affect IGT performance. In particular, attention deficit hyperactivity disorder (ADHD) is negatively related to performance on decision-making tasks (Ernst et al., 2003a, 2003b; Murphy et al., 2001; Raghunathan and Pham, 1999) and is also associated with alcohol dependence (Farrell et al., 2001; Kessler et al., 1997). Higher impulsivity has been related to both poor IGT performance (Crone et al., 2003) and heavy alcohol use (Waldeck and Miller, 1997). A secondary aim of this study therefore was to investigate the influence of both externalizing psychopathological symptoms and impulsivity, on IGT performance. We were also interested in the relation between gender and decision making. The literature on gender and IGT performance is mixed. Two studies of IGT performance have found that women perform less well than men (Bolla et al., 2004; Reavis and Overman, 2001), but other studies have not found gender differences in performance levels (Crone et al., 2003; Fein et al., 2004, 2006; Hooper et al., 2004). One of these studies did indicate a difference in frequency of punishment preference between girls and boys, with both girls and boys preferring lower frequency punishments of a higher amount, but girls having a stronger preference for this response option (Hooper et al., 2004). A brain imaging study reports that men and women also activated different orbitofrontal brain areas during IGT performance (Bolla et al., 2004). Our study consisted of a comparatively large young adult sample with equal gender distribution, and was thus especially suitable for studying the effects of gender on IGT performance and contingency preferences. In summary, the current study is the first to examine relations between decision making and longitudinal heavy (binge) drinking patterns in a large, mixed-gender sample of young adults. In addition, this study examined the degree to which externalizing psychopathology, impulsivity and gender affected the IGT/binge-drinking relation. We aimed to determine whether low-binge drinkers differed from (a) students who engaged in moderate-binge drinking, (b) students who increased their binge drinking when entering college, (c) students who engaged in high-binge drinking both before entering college, and throughout the first 2 college years. We hypothesized that consistent high levels of binge drinking and heavy alcohol use would have a detrimental effect on decision making, as measured by the IGT.