Psychology of pain

• Disease (biomedical): biological deviance from what currently considered normal = traditionally prime concern of medicine, guides traditional treatment
• Illness (biopsychosocial): subjective experience with psychological and social meanings attached to perceived biological deviance (or existing in the absence of one) based on symptoms = what patients present with, may not respond to traditional treatment
• Sensation: a physiological process - detecting a stimulus and converting it into neural activity e.g. vision via rods and cones in eye; nociception via sensory receptors in skin
• Perception = an active psychological process - the neurophysiological processes, including memory, by which an organism becomes aware of and interprets external stimuli or sensations. Search for best interpretation of sensory evidence based on knowledge i.e. perception and cognition not distinct
• Symptom = consciously appreciated sensation of a physiological problem
• Perception of physical symptoms dependent on active interpretation of body signals, not an automatic reaction to sensations. There is poor correlation of self-reported sensations, symptoms with objective measures e.g. wound size, respiratory flow, heart rate, nasal congestion
• Perception involves creation of a 'mental model' influenced by:

  • attention to sensation
  • processing in light of previous experience (emotions, cognitions)
  • interpretation depending on context (meaning)
• Attention

  • unconscious psychological mechanisms switch brain's limited processing capacity to one stimulus or another
  • awareness of sensation, changes in sensation depends on:
  • strength vs other internal/external stimuli
  • degree of internal focus
  • cognitive schema and social models
• Attention to symptoms

  • explains why symptom perception, reporting influenced by:
  • unemployment, boring/unsatisfying work
  • living alone, social isolation
  • unhappiness, depression, anxiety
  • personality e.g. monitors vs blunters
  • busyness with other things, priorities
• Symptom interpretation = making sense of sensations, labelling as symptoms, illness (distinct entity apart from person)

  • attribution to a cause e.g. normal functions, age, stress, illness
  • can be influenced by
  • expectations e.g. sensations as +ve or -ve depending on cues; placebos, side effects
  • knowledge e.g. medical students syndrome, mass psychogenic illness
  • meaning e.g. meaning of pain for soldiers in war
• Misattributions

  • attributing normal sensations to illness
  • interpretation of physical sensations from exercise, stress as symptoms
  • illness templates in psychogenic illness, functional syndromes
  • failure to attribute symptoms to illness
  • ambiguous symptoms associated with stress
  • attributing to existing illness
  • stereotypical beliefs about illness
  • use of avoidance/denial as a coping strategy
• High burden of pain: common presentation in GP, and as medically unexplained symptom in secondary care
• Self-management and psychological approaches should be first-line treatment (e.g. as per initiatives in Cornwall) to avoid negative cycle of chronic pain and dangers of opioid over-prescribing
• Pain: an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage
• Language of pain = sensory, affective (emotion), evaluative (cognitive) dimensions
• Pain but little/no damage

  • phantom limb pain
  • headaches
  • period pain
  • paper cut
• Damage but little/no pain

  • some cancers
  • battlefield injuries
  • bruises
• peripheral and central sensitisation

  • sensitisation at original site of damage and in central nervous system
  • places threat detection system on high alert
  • persistent pain modifies receptors, immune cells and chemicals in the physiological system
  • increased sensitivity: more pain with less stimulation
  • amplification of normal sensory signals, pain fades more slowly
  • reduced descending inhibition
• Physical factors that amplify pain:

  • temperature
  • weather
• Physical factors that dampen pain:

  • temperature
  • TENS
• Psychosocial factors that amplify pain:

  • stress
  • depression
  • anger
  • social isolation
  • alexithymia
  • catastrophising
  • pain anxiety
• Psychosocial factors that dampen pain:

  • cognitive balance
  • high self-efficacy/perceived control
  • goal setting
  • social support
  • effective communication
• Behavioural factors that amplify pain:

  • rushing/pushing on
  • inactivity
  • deconditioning
  • insomnia
  • diet
• Behavioural factors that dampen pain:

  • pacing
  • exercise
  • relaxation
  • sleep
  • diet
• Chemical factors that amplify pain:

  • nicotine
  • chemical dependency
• Chemical factors that dampen pain:

  • some medications
• Structural factors that amplify pain:

  • some surgery
  • extensive trauma
• Structural factors that dampen pain:

  • some surgery
• Recommendations for managing chronic pain:

  • physical activity including group exercise
  • psychological therapies including acceptance and commitment therapy, cognitive-behavioural therapy
  • acupuncture
  • anti-depressants
  • mindfulness and relaxation therapies, social prescribing
• Breathlessness common symptom but correlates poorly with objective lung function. Stems from activation of sensory receptors in lungs, chest and brain by mechanical or chemical stimuli. Sensory signals processed in brain regions that control breathing, underpin emotional processing and match to mental representations
• Emotions and respiratory symptoms

  • negative emotions/psychiatric conditions and respiratory symptoms are closely linked. Negative emotional states:
  • increase attention to, and negative evaluation and awareness of, respiratory symptoms regardless of respiratory function
  • alter respiratory patterns e.g. emotional breathing, which may affect physiology and perception
  • e.g. fear, may decrease activity/fitness, further increasing dyspnoea
  • can be associated with overperception and underperception of bronchoconstriction
  • interact with cognitions