Psychology

To investigate changes in analgesic use before and after supervised exercise therapy and patient education in patients with knee or hip osteoarthritis (OA).

This prospective study examined 1) whether antenatal pain is associated with postnatal maternal bonding disorder (MBD) through postnatal depression and 2) whether intimate partner violence (IPV) has a moderating effect on the association between antenatal pain and postnatal MBD. We analyzed 77,326 pregnancies of women who completed self-report questionnaires including the SF-8 bodily pain item, the Edinburgh Postnatal Depression Scale, the Mother-to-Infant Bonding Scale, and an assessment of IPV. We conducted a mediation analysis to assess whether postnatal depression mediated the association between antenatal pain and MBD 1 year after delivery. A moderated mediation model was used to examine the conditional effect of IPV during pregnancy on the association between antenatal pain and postnatal MBD, operating through postnatal depression. All analyses were adjusted for demographic factors, socioeconomic factors, perinatal and infant factors, medical history, and psychological status. Of the 77,326 pregnancies, 5,420 (7.0%) were characterized by persistent moderate-to-severe pain. The total effect of antenatal pain on MBD was significant (standardized path coefficient = 0.06, 95% CI, 0.05-0.06) and postnatal depression dominantly mediated the association between antenatal pain and postnatal MBD (70.8% mediation). Contrary to our hypothesis, IPV during pregnancy did not moderate the association between antenatal pain and postnatal MBD. However, IPV during pregnancy did have independent negative effects on both postnatal depression and MBD. Our findings suggest that antenatal pain and postnatal depression should be assessed and treated with consideration of the presence of IPV during pregnancy to better monitor and prevent the development of MBD.

The fear-avoidance model of chronic pain predicts that catastrophic (mis)interpretation of pain elicits pain-related fear that in turn may spur avoidance behaviour leading to chronic pain disability. Here we investigated whether performing a movement to avoid a painful stimulus in the context of a novel movement increases threat and pain-related fear towards this novel movement, and whether avoidance behaviour persisted when given the choice between performing the acquired movement to avoid a painful stimulus or an alternative, novel movement. Applying a robotic arm-reaching task, participants could choose between two movements to reach a target location: a short, but painful movement trajectory, or a longer non-painful movement trajectory. After avoidance acquisition, the option to choose the painful trajectory was removed. The Experimental Group (N=50) could choose between the longest trajectory or a novel intermediate trajectory, whereas the Control Group (N=50) was allowed to only perform the novel trajectory. In a final test, participants of both groups were allowed to choose any of the three trajectories. Post-acquisition, Experimental Group participants showed elevated pain-expectancy and pain-related fear towards the novel trajectory, compared to the Control Group. During test, the Experimental Group participants persisted in performing the longest pain-free (avoidance) trajectory, and were less likely to choose the novel trajectory. In addition, these participants maintained higher levels of pain-related fear for the novel trajectory compared to the Control Group. These findings suggest that avoidance in the context of other neutral activities/movements may lead to the development and maintenance of threat appraisals and irrational fears.

Central sensitization is present in different pain conditions, including chronic whiplash-associated disorders. In the absence of a gold standard method of assessment to determine the presence of central sensitization, quantitative sensory testing is currently understood as an optimal proxy. Laboratory sensory testing is, however, not feasible in clinical practice, and the Central Sensitization Inventory was developed as an alternative. The aim of the current study was to evaluate the convergent validity of the Central Sensitization Inventory in chronic whiplash-associated patients by determining the association between the Central Sensitization Inventory and quantitative sensory testing, pain intensity, fatigue, and psychosocial factors.

Approximately 50% of individuals with fibromyalgia (a chronic widespread pain condition) have comorbid insomnia. Treatment for these comorbid cases typically target pain, but growing research supports direct interventions for insomnia (eg, cognitive behavioural treatment for insomnia (CBT-I)) in these patients. Previous research suggests sustained hyperarousal mediated by a neural central sensitisation mechanism may underlie insomnia and chronic pain symptoms in fibromyalgia. We hypothesise CBT-I will improve insomnia symptoms, improve clinical pain and reduce central sensitisation. The trial will be the first to evaluate the short-term and long-term neural mechanisms underlying insomnia and pain improvements in fibromyalgia. Knowledge obtained from this trial might allow us to develop new or modify current treatments to better target pain mechanisms, perhaps reversing chronic pain or preventing it.