Psychology of Pain Flashcards
Classify pain by pathophysiology
Nociceptive – thermal, mechanical, chemical injury, well localized (somatic), described as sharp, aching etc
Neuropathic – injury to nerves in CNS or the periphery; burning, tingling, shooting pain
Nociplastic – altered nociception despite no tissue damage, disease or lesion of the somatosensory system
What is the early pain theory?
Pre-cartesian: pain attributed to gods, assumes pain=punishment
Descartes (1664): Specificity theory - extent of pain directly proportional to degree of tissue damage
Biomedical & Freudian: mind / body dualism: pain = damage OR ‘hysteria’
What roles does pain expectancy and controllability have in the extent of pain we feel?
Predictability and controllability of pain determine perceived pain intensity- they can’t tolerate pain they have no control over
Uncontrollable noxious stimuli are more unpleasant than controllable, predictable stimuli
Directly seeing positive outcomes in sham patient improves treatment in chronic pain group
Placebo drugs highly effective in chronic pain
Expectation-induced placebo analgesia mediated by PFC
What is the open hidden paradigm?
Open-hidden paradigm: Post-op patients needed much higher dose than usual to reduce pain by 50% when in hidden group- ie group that can’t see their medication being given
What is a way to deal with the questionable ethics of giving placebos?
Pain and open-label placebo (OLP)- patient knows they are taking placebo, but this still has a therapeutic effect:
Carvalho 2016: First study to show beneficial placebo effect in lower back pain sufferers who knew they were taking ‘fake pills’;
Use of pain medication decreased substantially in OLP group
Benefits largely maintained at 5-year follow-up
What are the limitations of early pain theories?
Don’t explain pain without damage
Don’t explain damage without pain
Don’t explain differences in analgesic effects
Don’t explain ‘normal’ variations in pain perception as related to individual differences in genetics AND environment
Describe the revolution in pain theory
Pain is the natural response to what the brain thinks is a THREAT
Pain experience does not necessarily correlate with tissue damage
Experience of pain is multi-factorial and relies on sensory cues internally and externally
Psychological and social factors influence pain experience
What do current pain perception models integrate?
Explain how sensory factors affect the level of pain we feel.
Current pain perception models integrate affective, cognitive and sensory cues within social contexts.
Thermal stimuli are perceived as hotter and more painful when delivered w a red light compared to a blue light (Moseley2007)
In burning mouth syndrome, a visual illusion of a blue tongue reduced pain experienced in the tongue
Individuals w persistent pain over-estimate the distance and effort needed to walk to a target
What is persistent pain?
Pain that persists beyond the normal time of healing
Pain lasting more than 3-6 months
Compelling argument that pain is a pathologic entity in its own right
Each year over 5 million people in the UK develop chronic pain, but only ²/3 will recover (Donaldson Sir L., 2008)
25% of sufferers lose their jobs
16% feel suicidal
What is the effect of persistent pain on the brain?
Persistent pain can change brain structure and re-wire patients so that how they think and what they pay attention to is biased
Persistent pain often alters brain activity and contribute to “central sensitization”
This is an amplification of neural signaling within the CNS that elicits pain hypersensitivity (Woolf, 2010)
What is the risk of persistent pain? 3 groups it is more common in
Severe and long-lasting nociception
Genetically sensitive to noxious stimulation
Depression/anxiety
Certain vocations (e.g., truck driving)
Trauma survivors (early life stress)
Lower socioeconomic status + low job satisfaction
What is the biopsychosocial model of pain?
Biological change, psychological status and sociocultural context all need to be considered
Represents shift from viewing (chronic) pain from a unidimensional biological or psychogenic standpoint
Model allows for a dynamic view of pain with experience unique to each person
Emphasises distinction between contributors and causes of pain syndromes and pain-related disability
Draw a diagram explain the Biopsychosocial Theory
Biopsychosocial interventions for pain management?
Psychological: CBT, counselling, ACT, mindfulness
Biological pain management: medications
Somatic: TENS, injection therapy, acupuncture
Relaxation techniques: biofeedback, visualisation
Body strengthening: physiotherapy, yoga
Can be used alone or w other (usually multidisciplinary) treatments
Psychological interventions for persistent pain?
CBT - Goal is not to reduce pain, rather to improve QOL through, education, coping strategies, increasing perceived control and self-efficacy
ACT / Mindfulness approaches - mindfulness-based stress reduction (MBSR) and ACT focuses on observing and being aware of thoughts, feelings, physical sensations and changing individual’s relationship w pain
