Pain Catastrophizing, Opioid Misuse, Opioid Use, and Opioid Dose in People With Chronic Musculoskeletal Pain: A Systematic Review

Assessing pain in persons with opioid use disorder: Approaches, techniques and special considerations

Pain and opioid use disorder (OUD) are inextricably linked, as the former can be a risk factor for the development of the latter, and over a third of persons with OUD suffer concomitant chronic pain. Assessing pain among people with OUD is challenging, because ongoing opioid use brings changes in pain responses and most pain assessment tools have not been validated for this population. In this narrative review, we discuss the fundamentals of pain assessment for populations with OUD. First, we describe the biological, psychological and social aspects of the pain experience among people with OUD, as well as how opioid-related phenomena may contribute to the pain experience in this population. We then review methods to assess pain, including (1) traditional self-reported methods, such visual analogue scales and structured questionnaires; (2) behavioural observations and physiological indicators; (3) and laboratory-based approaches, such as quantitative sensory testing. These methods are considered from a perspective that encompasses both pain and OUD. Finally, we discuss strategies for improving pain assessment in persons with OUD and implications for future research, including educational strategies for multidisciplinary teams. We highlight the substantial gaps that persist in this literature, particularly regarding the applicability of current pain assessment methods to persons with OUD, as well as the generalizability of the existing results from adjacent populations on chronic opioid therapy but without OUD. As research linking pain and OUD evolves, considering the needs of diverse populations with complex psychosocial backgrounds, clinicians will be better equipped to reduce these gaps.

The contribution of pain catastrophizing, depression and anxiety symptoms among patients with persistent pain and opioid misuse behaviours

BACKGROUND

Anxiety, depression and pain catastrophizing are independently associated with risk of opioid misuse in patients with persistent pain but their relationship to current opioid misuse, when considered together, is poorly understood. This study will assess the relative contribution of these modifiable, and distinct psychological constructs to current opioid misuse in patients with persistent pain.

METHODS

One hundred and twenty-seven patients referred to a specialized opioid management clinic for prescription opioid misuse within a tertiary pain service were recruited for this study. The Pain Catastrophizing Scale, Depression, Anxiety and Stress Scales and the Current Opioid Misuse Measure were administered pre-treatment. Pain severity and morphine equivalent dose based on independent registry data were also recorded.

RESULTS

Higher levels of pain catastrophizing, depression, and anxiety were significantly associated with higher current opioid misuse (r = .475, 0.599, and 0.516 respectively, p < .01). Pain severity was significantly associated with pain catastrophizing (r = .301, p < .01). Catastrophizing, depression, and anxiety explained an additional 11.56% of the variance (R2 change = 0.34, p < .01) over and above age, gender, pain severity and morphine equivalent dose. Depression was the only significant variable at Step 2 (β = 0.62, p < .01).

CONCLUSION

Findings show that in a sample of people with persistent pain referred for treatment for opioid misuse, depression contributes over and above that of anxiety and pain catastrophizing. Theoretical and clinical practice implications are presented.

Pain Catastrophizing: Controversies, Misconceptions and Future Directions

Recent reports have pointed to problems with the term "pain catastrophizing." Critiques of the term pain catastrophizing have come from several sources including individuals with chronic pain, advocates for individuals with chronic pain, and pain scholars. Reports indicate that the term has been used to dismiss the medical basis of pain complaints, to question the authenticity of pain complaints, and to blame individuals with pain for their pain condition. In this paper, we advance the position that the problems prompting calls to rename the construct of pain catastrophizing have little to do with the term, and as such, changing the term will do little to solve these problems. We argue that continued calls for changing or deleting the term pain catastrophizing will only divert attention away from some fundamental flaws in how individuals with pain conditions are assessed and treated. Some of these fundamental flaws have their roots in the inadequate training of health and allied health professionals in evidence-based models of pain, in the use of psychological assessment and intervention tools for the clinical management of pain, and in gender equity and antiracism. Critiques that pain scholars have leveled against the defining, operational, and conceptual bases of pain catastrophizing are also addressed. Arguments for reconceptualizing pain catastrophizing as a worry-related construct are discussed. Recommendations are made for remediation of the problems that have contributed to calls to rename the term pain catastrophizing. PERSPECTIVE: The issues prompting calls to rename the construct of pain catastrophizing have their roots in fundamental flaws in how individuals with pain are assessed and treated. Efforts to address these problems will require more than a simple change in terminology.

Anterior cingulate cortex regulates pain catastrophizing-like behaviors in rats

Negative pain expectation including pain catastrophizing is a well-known clinical phenomenon whereby patients amplify the aversive value of a painful or oftentimes even a similar, non-painful stimulus. Mechanisms of pain catastrophizing, however, remain elusive. Here, we modeled pain catastrophizing behavior in rats, and found that rats subjected to repeated noxious pin pricks on one paw demonstrated an aversive response to similar but non-noxious mechanical stimuli delivered to the contralateral paw. Optogenetic inhibition of pyramidal neuron activity in the anterior cingulate cortex (ACC) during the application of repetitive noxious pin pricks eliminated this catastrophizing behavior. Time-lapse calcium (Ca2+) imaging in the ACC further revealed an increase in spontaneous neural activity after the delivery of noxious stimuli. Together these results suggest that the experience of repeated noxious stimuli may drive hyperactivity in the ACC, causing increased avoidance of subthreshold stimuli, and that reducing this hyperactivity may play a role in treating pain catastrophizing.

Reductions in kinesiophobia and distress after pain neuroscience education and exercise lead to favourable outcomes: a secondary mediation analysis of a randomized controlled trial in primary care

ABSTRACT

Pain neuroscience education combined with exercise (PNE + exercise) is an effective treatment for patients with chronic spinal pain. Yet, however, little is known about its underlying therapeutic mechanisms. Thus, this study aimed to provide the first insights by performing a novel mediation analysis approach in a published randomized controlled trial in primary care where PNE + exercise was compared with standard physiotherapy. Four mediators (catastrophizing, kinesiophobia, central sensitization-related distress, and pain intensity) measured at postintervention and 3 outcomes (disability, health-related quality of life, and pain medication intake) measured at 6-month follow-up were included into the analysis. The postintervention measure of each outcome was also introduced as a competing candidate mediator in each respective model. In addition, we repeated the analysis by including all pairwise mediator-mediator interactions to allow the effect of each mediator to differ based on the other mediators' values. Postintervention improvements in disability, medication intake, and health-related quality of life strongly mediated PNE + exercise effects on each of these outcomes at 6-month follow-up, respectively. Reductions in disability and medication intake were also mediated by reductions in kinesiophobia and central sensitization-related distress. Reductions in kinesiophobia also mediated gains in the quality of life. Changes in catastrophizing and pain intensity did not mediate improvements in any outcome. The mediation analyses with mediator-mediator interactions suggested a potential effect modification rather than causal independence among the mediators. The current results, therefore, support the PNE framework to some extent as well as highlight the need for implementing the recent approaches for mediation analysis to accommodate dependencies among the mediators.

Opioid-induced analgesia among persons with opioid use disorder receiving methadone or buprenorphine: A systematic review of experimental pain studies

BACKGROUND

Treating acute pain among persons with opioid use disorder (OUD) on opioid agonist therapy (OAT) is complex, and the therapeutic benefits of opioids remain unclear when weighted against their abuse potential and respiratory depressant effects.

METHODS

We conducted a systematic review of experimental pain studies examining opioid-induced analgesia among persons with OUD on OAT. We searched multiple databases from inception to July 30, 2021. Study quality was assessed by previously established validity measures.

RESULTS

Nine studies were identified, with a total of 225 participants, of whom 63% were male, and 37% were female. Six studies included methadone-maintained persons with OUD; four studies included buprenorphine-maintained persons with OUD; and three studies included healthy persons as comparison groups. Either additional doses of OAT or other opioids - morphine, oxycodone, hydromorphone, or remifentanil - were administered. In seven studies, persons with OUD on OAT did not experience analgesia, despite receiving opioid doses up to 20 times greater than those clinically used to treat severe pain among the opioid naïve. Conversely, in two studies, high-potency opioids did produce analgesia, albeit with greater abuse potential. Notably, persons with OUD on OAT remained vulnerable to respiratory depression.

CONCLUSIONS

Although persons with OUD on OAT can derive analgesic effects from opioids, high-potency compounds may be required to achieve clinically significant pain relief. Further, persons with OUD on OAT may remain vulnerable to opioid-induced abuse potential and respiratory depression. Together, these finding have clinical, methodological, and mechanistic implications for the treatment of acute pain in the context of OAT.

Pain Medication Beliefs Mediate the Relationship Between Pain Catastrophizing and Opioid Prescription Use in Patients With Chronic Non-Cancer Pain

Little is known about the mechanisms by which pain catastrophizing may be associated with opioid use outcomes. This study aimed to investigate the potential mediating role of beliefs about the appropriateness of pain medicines for pain treatment on the association between pain catastrophizing and prescription opioid use in a community chronic non-cancer pain (CNCP) sample. Individuals (N = 420) diagnosed with CNCP participated in a cross-sectional online self-report study with validated measures of pain medication beliefs, pain catastrophizing, and current prescription opioid use. Two parallel multiple mediator analyses with percentile-based bootstrapping examined pathways to both prescription opioid use and high-dose use (≥ 100mg oral morphine equivalents/day), while controlling for pain intensity and other relevant covariates. Pain medication beliefs significantly mediated the association between pain catastrophizing and prescription opioid use (CI = 0.011, 0.033). A similar pattern of findings was found for high-dose opioid use, with pain medication beliefs significantly mediating the pain catastrophizing-high-dose use association (CI = 0.006, 0.050). Pain medication beliefs are a potentially modifiable psychological mechanism by which pain catastrophizing is associated with opioid use, including high-dose use. These findings have important implications for personalizing prevention and treatment programs.