EPIGENETIC PATTERNS IN REWARD SYSTEMS LINKING ADVERSE EXPERIENCES TO SENSATION SEEKING

Sensation seeking has been linked to adaptive outcomes, as well as to vulnerabilities including addiction, impulsivity, and antisocial behavior. Adversity in childhood or adulthood often correlates with sensation seeking, but this association is inconsistent, likely due to different psychobiological mechanisms. Reward-related systems may help explain this variability: the dopaminergic system, which governs reward anticipation and motivation, and the opioid system, which regulates reward consumption, and relief. Both systems are influenced by epigenetic regulation, including DNA methylation, which can alter gene expression and affect sensitivity to reward and risk-taking. This study examined whether divergent epigenetic patterns within dopamine- and opioid-related genes help explain why some individuals develop heightened sensation-seeking behaviors after adverse experiences, whereas others do not.
Data were collected from 382 adult participants, who completed measures of childhood and adulthood adverse events, and the sensation-seeking subscale of the HEXACO-60. Saliva samples were analysed using the Methylation EPIC v2.0 array to quantify DNA methylation in dopamine- and opioid-related genes.
The epigenetic analysis revealed three distinct clusters: low methylation in both systems among participants regardless of adverse childhood experiences, reflecting compensatory sensation seeking; high dopaminergic and low opioid methylation among participants without adverse childhood experiences, indicating compulsive sensation seeking; and low dopaminergic and high opioid methylation among participants with adverse childhood experiences, reflecting adaptive sensation seeking centred on high-quality experiences.
These findings suggest that adverse life events may shape epigenetic pathways in reward systems, supporting compensatory, maladaptive or adaptive forms of sensation seeking as routes to coping, meaning-making and resilience.