Mania risk is characterized by an aberrant optimistic update bias for positive life events

BACKGROUND

Early cognitive models of mania posit that a cognitive triad consisting of unrealistically optimistic beliefs about the self, world and future may predispose vulnerable individuals to develop manic symptoms. Hypomanic personality traits (HYP) pose such a vulnerability factor in the etiopathogenesis of mania.

METHODS

To test the cognitive tenet of overly optimistic views of the future, 24 individuals with high-HYP and 24 age- and sex-matched controls (low-HYP) performed a belief update paradigm, during which they estimated their personal chances to experience future positive and negative life events. Afterwards, they were presented with the statistical likelihood of each event occurring to a peer living in the same socio-cultural environment and given the chance to adjust their initial estimates.

RESULTS

High-HYP individuals exhibited an asymmetric belief revision for positive events, reflected by an exaggerated incorporation of better-than-expected and an impaired integration of worse-than-expected information, relative to their low-HYP control counterparts. The strength of this optimistic update bias was linked to the trait sensitivity of the behavioral approach system. Furthermore, high-HYP individuals demonstrated a more optimistic initial prediction bias, characterized by greater overestimations of their likelihood to experience positive events, and reported enhanced trait optimism.

LIMITATIONS

The cross-sectional study relied on an extreme-group design to define mania risk.

CONCLUSIONS

Due to the crucial role of future-oriented beliefs in guiding decision-making and goal-directed behavior, this optimistic update bias for positive events may cognitively underpin the mania-typical engagement in highly pleasurable activities despite warnings for harmful consequences.

Role of Reward Sensitivity and Processing in Major Depressive and Bipolar Spectrum Disorders

Since Costello's (1972) seminal Behavior Therapy article on loss of reinforcers or reinforcer effectiveness in depression, the role of reward sensitivity and processing in both depression and bipolar disorder has become a central area of investigation. In this article, we review the evidence for a model of reward sensitivity in mood disorders, with unipolar depression characterized by reward hyposensitivity and bipolar disorders by reward hypersensitivity. We address whether aberrant reward sensitivity and processing are correlates of, mood-independent traits of, vulnerabilities for, and/or predictors of the course of depression and bipolar spectrum disorders, covering evidence from self-report, behavioral, neurophysiological, and neural levels of analysis. We conclude that substantial evidence documents that blunted reward sensitivity and processing are involved in unipolar depression and heightened reward sensitivity and processing are characteristic of hypomania/mania. We further conclude that aberrant reward sensitivity has a trait component, but more research is needed to clearly demonstrate that reward hyposensitivity and hypersensitivity are vulnerabilities for depression and bipolar disorder, respectively. Moreover, additional research is needed to determine whether bipolar depression is similar to unipolar depression and characterized by reward hyposensitivity, or whether like bipolar hypomania/mania, it involves reward hypersensitivity.