Human Studies

Youth with functional abdominal pain (FAP) experience significant pain-related distress and functional impairment. Although quantitative sensory testing protocols have identified alterations in pain modulatory systems that distinguish youth with FAP from healthy controls, the extent to which evoked pain responses predict subsequent trajectories of pain symptoms and disability over and above established psychosocial risk factors is unclear.

Interdisciplinary treatment (IDT) is an internationally recommended intervention for chronic pain, despite inconclusive evidence of its effects on sickness absence.

Recent evidence suggests that pain dampens attentional processes. However, much of this work has been based on higher-order attentional tasks that involve only spatial attention. Other aspects of the process through which pain engages and holds attention are relatively understudied, in particular, temporal attention. The present set of studies explored how naturally occurring pain (i.e., acute headache) and pain-valenced stimuli affect ability to recall the second of two targets presented in rapid succession. Across both experiments participants were required to indicate the presence of a predefined probe (T2) and, in the dual task, identify a target (T1). The probe (T2) was placed in three different temporal proximities (ranging from 70ms to 1000ms) following presentation of the target (T1). In experiment 1, thirty-six participants completed a task that comprised a rapid stream of letters. Experiment 2 manipulated the threat value, and the complexity, of the stimuli by replacing letters with words. In the dual task condition, T1 was a word from one of four affect categories (neutral, positive, negative, pain). Being in acute pain reduced the accuracy of identification. This reduction in performance occurred regardless of the temporal positioning of the probe consistent with previous work that suggests pain has an overall dampening effect. Further, when the affect category of the word was pain-related, T2 accuracy performance was negatively affected. These findings add to the previous evidence that pain has a general dampening effect on attention and that pain-related stimuli are difficult to disengage from.

Posttraumatic stress (PTS), depressive symptoms (DS), and musculoskeletal pain (MSP) are common sequelae of trauma exposure. Although these adverse posttraumatic neuropsychiatric sequelae (APNS) are often studied separately, clinical comorbidity is high. In a cohort of European American motor vehicle collision (MVC) trauma survivors (n = 781), substantial PTS (≥33, IES-R), DS (≥26, CES-D), and MSP (≥4, 0-10 NRS) were identified via a 6-month survey. Genetic risk was estimated using polygenic risk scores (PRSs) calculated from the largest available GWAS datasets of PTSD, MDD, and back pain. We then assessed comorbidity and genetic risk influence for developing chronic PTS, DS, and MSP after MVC. Secondary analyses explored whether common social determinants of health ameliorate genetic vulnerability. We found that 6 months after MVC, nearly half 357/781 (46%) of the participants had substantial PTS, DS, and/or MSP, and overlap was common (PTS + MSP (23%), DS + MSP (18%), PTS + DS (12%)). Genetic risk predicted post-MVC outcomes. PTSD-PRSs predicted PTS and DS (R = 2.21% and 2.77%, p < 0.01), MDD-PRSs predicted DS and MSP (R = 1.89%, p < 0.01) and 0.79%, p < 0.05), and back pain-PRS predicted MSP (R = 1.49%, p < 0.01). Individuals in the highest quintile of PTSD-PRSs had 2.8 and 3.5 times the odds of developing PTS and DS vs. the lowest quintile (95% CI = 1.39-5.75 and 1.58-7.76). Among these high-risk individuals, those living in non-disadvantaged neighborhoods and with college education had 47% (p = 0.048) and 52% (p = 0.04) less risk of developing PTS, and those with high social support had 60% (p = 0.008) less risk of developing DS. Overall, genetic factors influence the risk of APNS after MVC, genetic risk of distinct APNS are overlapping, and specific social determinants greatly augment genetic risk of APNS development after MVC.