Browse by Audience
Pain, fatigue, and depression commonly co-occur as a symptom cluster in pathological inflammatory states. Psychosocial stressors such as loneliness may lead to similar states through shared mechanisms. We investigated the association of loneliness with pain, fatigue, and depression in older adults. Using Health and Retirement Study data ( = 11,766), we measured cross-sectional prevalence of frequent, moderate to severe pain; severe fatigue; depressive symptoms; and co-occurrence of symptoms surpassing threshold levels (i.e., symptom cluster). Logistic regression models evaluated associations with loneliness. Pain, fatigue, and depression were reported in 19.2%, 20.0%, and 15.3% of the total sample, respectively. The symptom cluster was seen in 4.9% overall; prevalence in lonely individuals was significantly increased (11.6% vs. 2.3%, < .0001). After adjusting for demographic variables, loneliness associated with the symptom cluster (adjusted OR = 3.39, 95% CI = 2.91, 3.95) and each symptom (pain adjusted OR = 1.61, 95% CI = 1.48, 1.76; fatigue adjusted OR = 2.02, 95% CI = 1.85, 2.20; depression adjusted OR = 4.34, 95% CI = 3.93, 4.79). Loneliness strongly associates with the symptom cluster of pain, fatigue, and depression. Further research should examine causal relationships and investigate whether interventions targeting loneliness mitigate pain, fatigue, and depression.
Most patients with chronic pain do not find adequate pain relief with a single treatment, and accumulating evidence points to the added benefits of rational combinations of different treatments. Given that psychological therapies, such as mindfulness-based interventions (MBIs), are often delivered in conjunction with concomitant analgesic drug therapies (CADTs), this systematic scoping review examines the evidence for any interactions between MBIs and CADTs. The protocol for this review has been published and registered. MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, and PsycINFO databases were searched until July 2019. We included randomized controlled trials that evaluated the efficacy of MBIs for the treatment of chronic pain. A total of 40 randomized controlled trials (2978 participants) were included. Thirty-nine of 40 (97.5%) included mindfulness-based clinical trials allowed the use of CADTs. However, only 6 of these 39 (15.4%) trials provided adequate details of what these CADTs were, and only 4 (10.3%) trials controlled for CADTs. Of great relevance to this review, none of the included trials analyzed the interactions between MBIs and the CADTs to determine whether they have an additive, synergistic, or antagonistic effect on chronic pain. Adverse events were inconsistently reported, and no judgment could be made about safety. Future trials assessing the interactions between MBIs and CADTs, with better harms reporting, are needed to better define the role of MBIs in the management of chronic pain.
To evaluate the association between adverse childhood experiences (ACEs) and chronic pain during childhood and adolescence.
The nucleus accumbens (NAc) has been implicated in sleep, reward, and pain modulation, but the relationship between these functional roles is unclear. This study aimed to determine if NAc function at the onset and offset of a noxious thermal stimulus is enhanced by rewarding music, and if that effect is reversed by experimental sleep disruption. Twenty-one healthy subjects underwent functional MRI (fMRI) scans on two separate days following both uninterrupted sleep and experimental sleep disruption. During fMRI scans, participants experienced noxious stimulation while listening to individualized rewarding or neutral music. Behavioral results revealed that rewarding music significantly reduced pain intensity compared to neutral music and disrupted sleep was associated with decreased pain intensity in the context of listening to music. In whole-brain FWE cluster-corrected analysis, NAc was activated at pain onset, but not during tonic pain or at pain offset. Sleep disruption attenuated NAc activation at pain onset and during tonic pain. Rewarding music altered NAc connectivity with key nodes of the corticostriatal circuits during pain onset. Sleep disruption increased reward-related connectivity between the NAc and the anterior midcingulate cortex (aMCC) at pain onset. This study thus indicates that experimental sleep disruption modulates NAc function during the onset of pain in a manner that may be conditional on the presence of competing reward-related stimuli. These findings point to potential mechanisms for the interaction between sleep, reward, and pain, and suggest that sleep disruption affects both the detection and processing of aversive stimuli that may have important implications for chronic pain.
Structural and functional analyses of the human claustrum, a poorly understood telencephalic gray matter structure, are hampered by its sheet-like anatomical arrangement. Here, we first describe a functional magnetic resonance imaging (fMRI) method to reveal claustrum signal with no linear relationship with adjacent regions in human subjects. We applied this approach to resting state functional connectivity (RSFC) analysis of the claustrum at high resolution (1.5 mm isotropic voxels) using a 7T dataset (n = 20) and a separate 3T dataset for replication (n = 35). We then assessed claustrum activation during performance of a cognitive task, the multi-source interference task, at 3T (n = 33). Extensive functional connectivity was observed between claustrum and cortical regions associated with cognitive control, including anterior cingulate, prefrontal and parietal cortices. Cognitive task performance was associated with widespread activation and deactivation that overlapped with the cortical areas showing functional connectivity to the claustrum. Furthermore, during high cognitive conflict conditions of the task, the claustrum was significantly activated at the onset of the task, but not during the remainder of the difficult condition. Both of these findings suggest that the human claustrum can be functionally isolated with fMRI, and that it may play a role in cognitive control, and specifically task switching, independent of sensorimotor processing.
Emotional disorders are common comorbid conditions that further exacerbate the severity and chronicity of chronic pain. However, individuals show considerable vulnerability to developing chronic pain under similar pain conditions. In this study on male rat and mouse models of chronic neuropathic pain, we identify the histone deacetylase SIRT1 in central amygdala as a key epigenetic regulator that controls the development of comorbid emotional disorders underlying the individual vulnerability to chronic pain. We found that animals that were vulnerable to developing behaviors of anxiety and depression under the pain condition displayed reduced SIRT1 protein in central amygdala, but not those animals resistant to the emotional disorders. Viral overexpression of local SIRT1 reversed this vulnerability, but viral knockdown of local SIRT1 mimicked the pain effect, eliciting the pain vulnerability in pain-free animals. The SIRT1 action was associated with CaMKIIα downregulation and deacetylation of histone H3 lysine 9 at the promoter. These results suggest that, by transcriptional repression of in central amygdala, SIRT1 functions to guard against the emotional pain vulnerability under chronic pain conditions. This study indicates that SIRT1 may serve as a potential therapeutic molecule for individualized treatment of chronic pain with vulnerable emotional disorders.Chronic pain is a prevalent neurological disease with no effective treatment at present. Pain patients display considerably variable vulnerability to developing chronic pain, indicating individual-based molecular mechanisms underlying the pain vulnerability, which is hardly addressed in current preclinical research. In this study, we have identified the histone deacetylase Sirtuin 1 (SIRT1) as a key regulator that controls this pain vulnerability. This study reveals that the SIRT1–CaMKIIaα pathway in central amygdala acts as an epigenetic mechanism that guards against the development of comorbid emotional disorders under chronic pain, and that its dysfunction causes increased vulnerability to developing chronic pain. These findings suggest that SIRT1 activators may be used in a novel therapeutic approach for individual-based treatment of chronic pain.
Slow deep breathing (SDB) is commonly employed in the management of pain, but the underlying mechanisms remain equivocal. This study sought to investigate effects of instructed breathing patterns on experimental heat pain and to explore possible mechanisms of action. In a within-subject experimental design, healthy volunteers (n = 48) performed four breathing patterns: 1) unpaced breathing (UB), 2) paced breathing at the participant's spontaneous breathing frequency (PB), 3) SDB at six breaths per minute with a high inspiration/expiration ratio (SDB-H), and 4) SDB at six breaths per minute with a low inspiration/expiration ratio (SDB-L). During presentation of each breathing pattern, participants received painful heat stimuli of three different temperatures and rated each stimulus on pain intensity. Respiration, heart rate, and blood pressure were recorded. Compared to UB, participants reported less intense pain during each of the three instructed breathing patterns. Among the instructed breathing patterns, pain did not differ between PB and SDB-H, and SDB-L attenuated pain more than the PB and SDB-H patterns. The latter effect was paralleled by greater blood pressure variability and baroreflex effectiveness index during SDB-L. Cardiovascular changes did not mediate the observed effects of breathing patterns on pain. Perspective: SDB is more efficacious to attenuate pain when breathing is paced at a slow rhythm with an expiration that is long relative to inspiration, but the underlying mechanisms remain to be elucidated.