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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Hamilton, Paul, et al.
(författare)
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Striatal dopamine deficits predict reductions in striatal functional connectivity in major depression: a concurrent C-11-raclopride positron emission tomography and functional magnetic resonance imaging investigation
- 2018
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Ingår i: Translational Psychiatry. - : NATURE PUBLISHING GROUP. - 2158-3188. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Major depressive disorder (MDD) is characterized by the altered integration of reward histories and reduced responding of the striatum. We have posited that this reduced striatal activation in MDD is due to tonically decreased stimulation of striatal dopamine synapses which results in decremented propagation of information along the corticostriatal-pallido-thalamic (CSPT) spiral. In the present investigation, we tested predictions of this formulation by conducting concurrent functional magnetic resonance imaging (fMRI) and C-11-raclopride positron emission tomography (PET) in depressed and control (CTL) participants. We scanned 16 depressed and 14 CTL participants with simultaneous fMRI and C-11-raclopride PET. We estimated raclopride binding potential (BPND), voxel-wise, and compared MDD and CTL samples with respect to BPND in the striatum. Using striatal regions that showed significant between-group BPND differences as seeds, we conducted whole-brain functional connectivity analysis using the fMRI data and identified brain regions in each group in which connectivity with striatal seed regions scaled linearly with BPND from these regions. We observed increased BPND in the ventral striatum, bilaterally, and in the right dorsal striatum in the depressed participants. Further, we found that as BPND increased in both the left ventral striatum and right dorsal striatum in MDD, connectivity with the cortical targets of these regions (default-mode network and salience network, respectively) decreased. Deficits in stimulation of striatal dopamine receptors in MDD could account in part for the failure of transfer of information up the CSPT circuit in the pathophysiology of this disorder.
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| 3. |
- Karayannis, Nicholas Vasilis., et al.
(författare)
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Pain acceptance and psychological inflexibility predict pain interference outcomes for persons with chronic pain receiving pain psychology
- 2023
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Ingår i: Scandinavian Journal of Pain. - : Walter de Gruyter. - 1877-8860 .- 1877-8879. ; 23:3, s. 464-475
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Awareness (being present), acceptance, and engagement (committed action) are three dimensions of psychological flexibility. Understanding these in the context of chronic pain may identify treatment targets to help refine individual treatment. Our objective was to test the predictive capacity of three dimensions within the psychological flexibility model on the longitudinal trajectory of pain interference.Methods: Patients receiving pain psychology treatment at a pain management center participated in this pragmatic clinical longitudinal study (n=86 with at least three assessments; Mean age=51 years; Gender=60 females, 26 males). Measures included the Five Facet Mindfulness Questionnaire (FFMQ-SF); Chronic Pain Acceptance Questionnaire (CPAQ-8); Psychological Inflexibility in Pain Scale (PIPS-12); and Committed Action Questionnaire (CAQ-8). The dependent variable was the Patient Reported Outcomes Information System (PROMIS) Pain Interference (PI). We used latent growth modelling to analyze scores assessed within 180 days of patient care.Results: Psychological inflexibility (PIPS-12) and pain acceptance (CPAQ-8) measured at baseline predicted PI outcomes (n=86). PIPS-12 showed a direct relationship with pain interference (PI), where higher PIPS-12 scores predicted significantly higher PI mean scores on average across the study period (ρ=0.422, r2=0.382) but also predicted significantly greater decreases in PI across time (ρ=−0.489, r2=0.123). Higher CPAQ-8 scores predicted significantly lower PI mean scores on average across the study period (ρ=−0.478, r2=0.453) but also significantly smaller decreases in PI across time (ρ=0.495, r2=0.076). Awareness (FFMQ-SF) and engagement (CAQ-8) were not predictive of PI outcomes.Conclusions: Patients who entered pain psychology treatment with lower pain acceptance and higher psychological inflexibility showed the largest reductions in pain interference across time. These results contribute towards a novel prognostic understanding of the predictive roles of an enhancing dimension and limiting dimension of psychological flexibility.
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