Opioid tolerance and opioid-induced hyperalgesia are conditions that negatively affect pain management. Tolerance is defined as a state of adaptation in which exposure to a drug induces changes that result in a decrease of the drug's effects over time. Opioid-induced hyperalgesia occurs when prolonged administration of opioids results in a paradoxic increase in atypical pain that appears to be ...

Pain catastrophizing is associated with the pain experience; however, causation has not been established. Studies which specifically manipulate catastrophizing are necessary to establish causation. The present study enrolled 100 healthy individuals. Participants were randomly assigned to repeat a positive, neutral, or one of three catastrophizing statements during a cold pressor task (CPT). Out...

OBJECTIVE To assess the influence of the body weight in functional capacity and pain of adult and elderly individuals with knee osteoarthritis. METHODS The sample consisted of 107 adult and elderly patients with knee osteoarthritis divided into two groups (adequate weight/adiposity and excessive weight/adiposity) according to body mass index and percent of body fat mass, assessed by electric ...

BACKGROUND Cognitive models explaining medically unexplained complaints propose that activating illness-related memory causes increased complaints such as pain. However, our previous studies showed conflicting support for this theory. PURPOSE Illness-related memory is more likely to influence reporting of complaints when its activation is enmeshed with that of self-related memory. We, therefo...

Stress and chronic pain have been shown to prevent the development of tolerance to morphine analgesia, which appears to be related to neuroendocrine activity and alternation in neurochemicals. Also the involvement of nitric oxide (NO) has been implicated in tolerance to morphine analgesia. In our pervious study, we showed that co-administration of swim stress (ss) with chronic morphine, prevent...

Pain contributes to health care costs, missed work and school, and lower quality of life. Extant research on psychological interventions for pain has focused primarily on developing skills that individuals can apply to manage their pain. Rather than examining internal factors that influence pain tolerance (e.g., pain management skills), the current work examines factors external to an individua...

OBJECTIVE Several physiological processes exhibit 24-hour oscillations termed circadian rhythms. Despite numerous investigations on the circadian dynamics of pain perception, findings related to this issue remain inconsistent. This study aimed to assess the effect of time-of-day on multimodal experimental pain perception in healthy males, including "static" and "dynamic" quantitative sensory te...

OBJECTIVE To examine relationships among trait anxiety sensitivity, state task-specific anticipatory anxiety, and laboratory pain responses in healthy children and adolescents. METHODS Participants (N=118, 49.2% female, ages 8-18 years) completed a measure of anxiety sensitivity and rated anticipatory anxiety prior to undergoing thermal, pressure, and cold pain tasks. Linear and logistic regr...

Results supported the relevancy of cognitive information effects on pain tolerance, in that subjects who were given a rational and accurate explanation of what to expect showed greater tolerance than those who received irrelevant information. Accurate monitoring of hand temperature did not seem necessarily advantagous as an influence on pain tolerance. It appears merely watching a monitor, rega...

Cancer-induced bone pain can severely compromise the life quality of patients, while tolerance limits the use of opioids in the treatment of cancer pain. Monocyte chemoattractant protein-1 (MCP-1) is known to contribute to neuropathic pain. However, the role of spinal MCP-1 in the development of morphine tolerance in patients with cancer-induced bone pain remains unclear. The aim of the present...