Decision Making in Alcohol Dependence: Insensitivity to Future Consequences and Comorbid Disinhibitory Psychopathology

ALCOHOL DEPENDENCE (AD) is a heterogeneous disorder that is frequently comorbid with other types of disinhibitory psychopathology including childhood conduct disorder, adult antisocial personality, marijuana, and other drug abuse/dependence (Finn et al., 1997; Hesselbrock et al., 1986; Krueger et al., 2002; Zucker et al., 1996). These disinhibitory disorders seem to share a disadvantageous approach to decision making that favors larger immediate rewards even when there are long-term negative consequences (Bechara et al., 1994, 2001; Grant et al., 2000; Mazas et al., 2000). Although insensitivity to future negative consequences is characteristic of individuals with antisocial problems (Finn et al., 2002; Lykken, 1957; Newman, 1987; Schmauk, 1970) and alcohol abuse (Finn et al., 1994, 2002), the association between decision-making mechanisms and the broader spectrum of disinhibitory disorders is not well understood. Various laboratory tasks have been developed and used to investigate the mechanisms underlying this kind of decision making. For example, disadvantageous decision making on the Iowa Gambling Task (IGT; Bechara et al., 1994, 1997, 2001) is thought to reflect a general predisposition to disinhibitory psychopathology (Bechara et al., 1994). Using the IGT, disadvantageous decision making has been observed in individuals with AD (Dom et al., 2006; Fein et al., 2004; Mazas et al., 2000), high levels of binge drinking (Goudriaan et al., 2007), other substance abuse (Bechara and Damasio, 2002; Bechara and Martin, 2004; Bechara et al., 2001; Grant et al., 2000; Petry et al., 1998; Rotheram-Fuller et al., 2004; Stout et al., 2005), psychopathy or antisocial personality (Mazas et al., 2000; Mitchell et al., 2002; Van Honk et al., 2002), borderline personality (Dom et al., 2006), a history of childhood conduct disorder (Kim et al., 2006), and attention deficit/hyperactivity disorder (Ernst et al., 2003). A limitation of many of these findings is that the effects of comorbidity among AD and other disinhibitory disorders (Krueger et al., 2002; Zucker et al., 1996) on decision making cannot be evaluated directly. By contrast, in those studies where it has been considered, AD comorbid with antisocial or borderline personality is associated with a greater disadvantageous decision bias than AD alone (Dom et al., 2006; Mazas et al., 2000). There is increasing evidence that the significant covariation of AD and other disinhibitory disorders reflects a single dimension of externalizing psychopathology (Krueger and Markon, 2006; Krueger et al., 2002, 2005) that is highly heritable and genetically distinct from internalizing disorders, such as major depression (Kendler et al., 2003; Krueger et al., 2002). Thus, the initial aim of this study was to assess the influence of degree of severity of co-occurring symptoms of AD, childhood conduct disorder (CCD), adult antisocial behavior, marijuana dependence, and other drug dependence on decision making. Two theoretically distinct measures of decision-making performance on the IGT were evaluated: (i) insensitivity to future consequences (IFC), and (ii) preference for larger versus smaller rewards (PLvS). Although previous research suggests that disadvantageous decision biases observed on the IGT reflect a general IFC (e.g., Bechara and Damasio, 2002; Bechara et al., 2001; Grant et al., 2000), the original task confounds immediate reward magnitude and long-term net gain/loss. That is, decks with larger immediate rewards, in previous studies, have carried less frequent but larger magnitude losses. In this study, the decks were modified so that reward magnitude and net gain were counterbalanced and the probability of a loss was the same across all decks. This study also included a between-groups manipulation of reward “salience” that was related to a larger investigation designed to test the hypothesis that a vulnerability to substance abuse is associated with increased approach motivation manifested as an increased sensitivity to rewards (see Colder and O'Connor, 2002; Finn, 2002; Fowles, 1983). The basic study design was a 2 × 2 [AD:CCD] independent-groups model which allows for an estimate of the relative influences of both AD and CCD on decision making. We chose to include CCD as a factor because our sample is younger (ages 18 to 30) and, while a history of CCD is a prerequisite for adult antisocial personality, it is often not assessed in studies of early-onset AD. Our primary hypothesis was that the combination of AD and a history of CCD would be associated with more disadvantageous decision making than AD without CCD, because the combination of AD and CCD represents a more severe form of externalizing psychopathology (Finn et al., 2002). Additionally, structural equation modeling was used to examine the association between a dimensional model with a single latent disinhibitory disorders factor and decision making on the task. Our recruitment strategy was designed to ensure sufficient variation and range in severity of lifetime problems with alcohol, marijuana, other drugs, CCD, and adult antisocial behavior. Because they are thought to reflect a general disinhibitory vulnerability, our hypothesis was that IFC and PLvS would be associated with the covariance among these disorders, rather than being specific to any one disinhibitory disorder.