Decreased sensitivity to self-inflicted pain

Abstract

There is anecdotal and incidental research evidence suggesting that self-inflicted injury is experienced as less painful than when the same injury is applied by another person. We tested the hypothesis that the sensitivity and the ability to tolerate pain differs depending on the person applying the painful stimulus. Self-selected healthy undergraduate students were obtained from the University of Stirling participant panel. None were suffering chronic pain or taking any form of analgesic drug. The participants applied a pressure algometer to themselves and to other participants. Depending on the type of trial, each was terminated when the participant experienced the algometer as either "painful" (for threshold reading) or "unbearable" (for tolerance reading). Both measures of pain, threshold and tolerance, were significantly higher when the algometer had been self-applied compared with when it was applied by another person. The mean difference for pain thresholds was 0.27MPa (95% confidence interval 0.10-0.44, P=0.002), and the mean difference for pain tolerance readings was 0.25MPa (95% confidence interval 0.03-0.48, P=0.028). An unexpected finding was that the mean tolerance score was less when females applied the algometer (P<0.01). When a painful stimulus was self-inflicted this resulted in significantly less pain and a greater ability to tolerate the pain compared with when the same stimulus was applied by another person. If the findings generalized to a clinical context, certain painful or discomforting procedures, such as mammography, removal of wound dressings and lancet withdrawal of blood, should be adapted for self-application by patients.

Attitudes and emotions towards pain and sensitivity to painful stimuli among people routinely engaging in masochistic behaviour

“…Although pain catastrophizing correlated positively with pain intensity and unpleasantness in everyday life, fear of pain correlated negatively with the frequency of S&M sessions and the number of involved body regions. In populations engaged in self‐injury, the context effect is reflected by increased pain tolerance only under conditions of heightened stress (McCown et al., ; Gratz et al., ) or when pain is self‐inflicted as compared to when it is inflicted by another person (Braid and Cahusac, ). This resembles the association between pain thresholds, dissociation and aversive arousal among BPD individuals (Ludäscher et al., ) and supports the existence of divergent, context‐related pain experiences among our subjects.…”

Intensity of pain and biochemical changes in blood plasma in spinal cord trauma

“…If nociceptive stimuli are applied by another person, pain thresholds are lower than when the stimuli are applied by the experimental subject themselves. 18 Also, preparedness for pain may have a role. Such preparedness might have been present in patients who suffered their injury while engaging in a risky activity.…”

On the Interaction of Self-Regulation, Interoception and Pain Perception

“…This device is used to identify the pressure and/or force eliciting a pressure-pain threshold and tolerance level. This validated method has a high interrater reliability in the rate of force application [33,34,35]. Before testing, all involved investigators were familiar with the algometer following practice sessions.…”