Papers of the Week

Chronic pain is driven by factors across the biopsychosocial spectrum. Previously, we demonstrated MRI-based brain-predicted age differences (brain-PAD: brain predicted age minus chronological age) to be significantly associated with pain severity in individuals with chronic knee pain. We also previously identified four distinct, replicable, multidimensional psychological profiles significantly associated with clinical pain. The brain aging-psychological characteristics interface in persons with chronic pain promises elucidating factors contributing to their poor health outcomes, yet this relationship is barely understood. To examine the interplay between the psychological profiles in participants having chronic knee pain impacting function (n=164), brain-PAD and clinical pain severity. Controlling for demographics and MRI scanner, we compared the brain-PAD among psychological profiles, and over two years (n=90). We also explored whether profile-related differences in pain severity were mediated by brain-PAD. Brain-PAD differed significantly between profiles (p=0.039), Profile-3 (high negative/low positive emotions; p=0.047, Bonferroni-corrected) having ~4 years higher brain-PAD than Profile-1 (low somatic reactivity) and Profile-2 (high coping; p=0.027, uncorrected). No significant change in profile-related brain-PAD differences over time was observed; but there was a significant decrease in brain-PAD (p=0.045) for Profile-4 (high optimism/high positive affect). Moreover, profile-related differences in pain severity at baseline were partly explained by brain-PAD differences between Profile 3 and 1, or 2; but brain-PAD did not significantly mediate the influence of variations in profiles on changes in pain severity over time. PERSPECTIVE: Accelerated brain aging could underlie the psychological-pain relationship, and psychological characteristics may predispose individuals with chronic knee pain to worse health outcomes via neuropsychological processes.