Early life adversity and health-risk behaviors: proposed psychological and neural mechanisms

Abstract

Early life adversity (ELA) is associated with poorer health in adulthood, an association explained, at least in part, by increased engagement in health-risk behaviors (HRBs). In this review, we make the case that ELA influences brain development in ways that increase the likelihood of engaging in HRBs. We argue that ELA alters neural circuitry underpinning cognitive control as well as emotional processing, including networks involved in processing threat and reward. These neural changes are associated psychologically and behaviorally with heightened emotional reactivity, blunted reward responsivity, poorer emotion regulation, and greater delay discounting. We then demonstrate that these adaptations to ELA are associated with an increased risk of smoking cigarettes, drinking alcohol, and eating high-fat, high-sugar foods. Furthermore, we explore how HRBs affect the brain in ways that reinforce addiction and further explain clustering of HRBs.

Keywords: delay discounting; early life adversity; emotion regulation; emotional reactivity; health neuroscience; health-risk behaviors; reward responsivity.

Figure 1

Conceptual diagram of the psychological processes affected by early life adversity and their underlying neural substrates. We highlight the role of the amygdala in emotional reactivity, the ventral and dorsal striatum in reward responsivity, prefrontal–amygdala connectivity in emotion regulation, and prefrontal–ventral striatum connectivity in delay discounting.

Figure 2

The effect of two dimensions of early life adversity (ELA)—threat and deprivation—on brain development. Neural adaptations to ELA affect emotion, reward, and cognitive networks. These neural adaptations affect four psychological processes that have downstream consequences for health-risk behaviors. Smoking cigarettes, drinking alcohol, and overeating highly palatable foods further heighten emotional reactivity, hinder emotion regulation, increase delay discounting, and blunt reward responsivity, leading to a positive feedback loop for addictive behaviors.