The Development and Course of Bipolar Spectrum Disorders: An Integrated Reward and Circadian Rhythm Dysregulation Model

Abstract

In this article, we present and review the evidence for two major biopsychosocial theories of the onset and course of bipolar spectrum disorders (BSDs) that integrate behavioral, environmental, and neurobiological mechanisms: the reward hypersensitivity and the social and circadian rhythm disruption models. We describe the clinical features, spectrum, age of onset, and course of BSDs. We then discuss research designs relevant to demonstrating whether a hypothesized mechanism represents a correlate, vulnerability, or predictor of the course of BSDs, as well as important methodological issues. We next present the reward hypersensitivity model of BSD, followed by the social/circadian rhythm disruption model of BSD. For each model, we review evidence regarding whether the proposed underlying mechanism is associated with BSDs, provides vulnerability to the onset of BSDs, and predicts the course of BSDs. We then present a new integrated reward/circadian rhythm (RCR) dysregulation model of BSD and discuss how the RCR model explains the symptoms, onset, and course of BSDs. We end with recommendations for future research directions.

Reward‐related cognitive vulnerability to bipolar spectrum disorders

“…The model also proposes that vulnerable individuals' reward hypersensitivity leads to behaviors that increase their exposure (via "stress generation" processes) to the very goal-and reward-relevant events that, in turn, precipitate excessive responses from their reward systems. To date, extensive self-report, behavioral, cognitive, life event, neurophysiological and neural evidence supports this reward hypersensitivity model of BSDs 3,4 .…”

“…Individuals' cognitive styles (i.e., the general filters they use to process information and construe events in their lives) may provide vulnerability to BSD symptoms and episodes. Indeed, individuals with BSDs exhibit cognitive styles with certain unique reward-relevant features 1,2 and these cognitive styles have been shown to predict the onset and course of BSDs 3 . According to the reward hypersensitivity theory 3,4 , individuals with or vulnerable to BSDs possess a hypersensitive reward system, linked to a dopaminergic fronto-striatal neural circuit subserving approach motivation and goal-directed behavior, that overreacts to goals or reward-relevant cues.…”

“…Indeed, individuals with BSDs exhibit cognitive styles with certain unique reward-relevant features 1,2 and these cognitive styles have been shown to predict the onset and course of BSDs 3 . According to the reward hypersensitivity theory 3,4 , individuals with or vulnerable to BSDs possess a hypersensitive reward system, linked to a dopaminergic fronto-striatal neural circuit subserving approach motivation and goal-directed behavior, that overreacts to goals or reward-relevant cues. This hypersensitivity leads to excessive approach-related affect and incentive motivation in response to life events involving goal-striving and attainment, which in turn leads to hypomanic/manic symptoms.…”

“…Its deleterious impact arguably accounts for 25% or more of the population-attributable risk for child psychopathology 1,3 , and in severe cases can extend to the lack of the minimum requirements for normative human development (food, hygiene, human interaction), physical injury, sexual exploitation and mutilation, permanent brain injury and death 4 , or be associated with perpetration of child abuse by victims when they reach adulthood 5 .…”

“…Its prevention requires the coordinated application of interventions that address key lapses in "species-typical" mechanisms of protection of the young: caregiving knowledge and competence, resource acquisition, surrogacy (i.e., the family or adult "village" surrounding a child to assist when a parent needs help), and close surveillance of the child 3 .…”