Reward responsiveness in patients with chronic pain
Journal article, Peer reviewed
Permanent lenke
http://hdl.handle.net/11250/2385739Utgivelsesdato
2015Metadata
Vis full innførselSamlinger
Sammendrag
Background: It is proposed that changes in reward processing in the
brain are involved in the pathophysiology of pain based on experimental
studies. The first aim of the present study was to investigate if reward
drive and/or reward responsiveness was altered in patients with chronic
pain (PCP) compared to controls matched for education, age and sex.
The second aim was to investigate the relationship between reward
processing and nucleus accumbens volume in PCP and controls. Nucleus
accumbens is central in reward processing and its structure has been
shown to be affected by chronic pain conditions in previous studies.
Methods: Reward drive and responsiveness were assessed with the
Behavioral Inhibition Scale/Behavioral Activation Scale, and nucleus
accumbens volumes obtained from T1-weighted brain MRIs obtained at
3T in 19 PCP of heterogeneous aetiologies and 20 age-, sex- and
education-matched healthy controls. Anhedonia was assessed with
Beck’s Depression Inventory II.
Results: The PCP group had significantly reduced scores on the reward
responsiveness, but not reward drive. There was a trend towards smaller
nucleus accumbens volume in the PCP compared to control group.
There was a significant positive partial correlation between reward
responsiveness and nucleus accumbens volume in the PCP group
adjusted for anhedonia, which was significantly different from the same
relationship in the control group.
Conclusions: Reward responsiveness is reduced in chronic pain
patients of heterogeneous aetiology, and this reduction was associated
with nucleus accumbens volume. Reduced reward responsiveness could
be a marker of chronic pain vulnerability, and may indicate reduced
opioid function.