Alterations in Reward-Related Decision-Making in Boys with Recent and Future Depressive and Anxiety Disorders

Background: Reduced pursuit and experience of reward is postulated to be a feature of depression. Investigating reward processing may be especially valuable to understanding earlyonset depressive and anxiety disorders, which are likely to precede depression during adulthood. Methods: Reward-related decision-making was examined within a longitudinal study of 221 11year-old boys, 50 of whom had depressive or anxiety (i.e., internalizing) disorders at age 10 or 11. Participants completed a behavioral decision-making task involving varying probability and magnitude of obtaining reward. Results: Under conditions involving a high probability of obtaining a large reward, boys with internalizing disorders chose the reward-related option less frequently than did others. Boys with externalizing disorders at age 10 or 11 did not differ from others in their reward-related decisions. Low frequency of choosing the high-probability, largereward option at age 11 predicted internalizing disorders and self-reported depressive symptoms one year later. Furthermore, reward-related decisions predicted later internalizing disorders even when adjusting for the continuity of internalizing disorders and the presence of concurrent externalizing disorders. Conclusions: Findings are consistent with affective neuroscience models of altered reward processing and diminished positive affect in depression. This study represents a step toward elucidating the motivational and emotional aspects of early-onset internalizing disorders. Alterations in Reward-Related Decision-Making in Boys with Recent and Future Internalizing Disorders Approaches to understanding the development of affective disorders have emphasized not only clinical symptoms of increased negative affect, but also symptoms and behavior reflecting diminished positive affect. Emotion-based, motivational, and behavioral models of depression postulate reduced experience of positive affect (Clark and Watson 1991), reduced activity in the behavioral facilitation system (Depue and Iacono 1989; Fowles 1988; Gray 1990), and reduced frequency of experiencing positive reinforcement (Lewinsohn et al 1985), respectively. Reduced positive affect may be especially critical to understanding internalizing disorders (i.e., depressive or anxiety disorders) that occur during childhood and adolescence. Internalizing disorders with onset during this developmental period are associated with academic and interpersonal impairment (Glied and Pine 2002; Ialongo et al 1995). In addition, children and adolescents with these disorders often experience severe, recurrent depression later in life (Costello et al 1999; Kovacs et al 1989; Lewinsohn et al 1999; Pine et al 1998). Pathways to later depression tend to involve both depressive and anxiety disorders, which often co-occur (Angold et al 1999) and may have similar underlying etiological influence (Silberg et al 2001). Reduced positive affect is relevant to these disorders because studies of early symptoms have indicated that anhedonia is particularly important in predicting major depressive episodes during adulthood (Pine et al 1999). From an affective neuroscience perspective, positive affect can be parsed into several components related to reward (Rolls 1999). These include the motivation to obtain rewards, the execution of reward-seeking behaviors, and the hedonic aspects of experiencing a reward. In this perspective, depression is postulated to be accompanied by alterations of reward processing