understanding pain and mental illness impact on management ... · • nerve endings can...
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Understanding pain and mental illness Impact on management principles
Chris Alderman Consultant Psychopharmacologist
Copyright © 2014
Pain and mental illness - context
PAIN
OTHER FACTORS (personality, history. context) MENTAL ILLNESS
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Aspects of Pain and Mental Illness:
• Both can take many forms
• More than one manifestation of either or both can be present at the same time
• Both can be acute or chronic
• Significant interplay between the two
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Pain and Mental Illness: A complicated relationship
• Often comorbid
• One may precede the other, or both arise at once
• Treatment for one can complicate the other
• Treatments for either can interact • Adversely • Beneficially
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Pain – some basics
• What is pain?
“An unpleasant sensory and emotional experience associated with
actual or potential tissue damage” • Pain is whatever the experiencing person says it is. • May not be directly proportional tissue injury • Highly subjective
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“Describing pain only in terms of its
intensity is like describing music
only in terms of its loudness”
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PAIN HISTORY
• Description: severity, quality, location, temporal features, frequency, aggravating & alleviating factors
• Previous history
• Context: social, cultural, emotional, spiritual factors
• Meaning • Interventions: what has been tried?
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Types of Pain
Can be classified by physiology: • Nociceptive pain (stimuli from somatic and visceral
structures) • Neuropathic pain (stimuli abnormally processed by the
nervous system)
• Both types can be present simultaneously
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How does nociceptive pain happen?
• Nerve endings can differentiate between noxious and innocuous stimulus
• Stimulus can be: • Mechanical (incision or tumor growth) • Thermal (burn) • Chemical (toxic substance)
• Tissue damage accompanied by release of various by the damaged tissue → movement of pain impulse to the spinal cord.
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Substances released…
• The substances released from the traumatized tissue include but are not limited to:
• prostaglandins • bradykinin • serotonin • substance P • histamine
• Create nerve impulse
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Transmission of pain impulses
• Impulse à spinal cord à brain à pain processed
• Neurotransmitters help convey the impulse from the spinal cord to the brain
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Perception and modulation of pain
• Pain perception probably occurs in the cortical structures
• Modulation happens after other impulses from the brainà spinal cord
• Descending fibers release substances that can reduce transmission of noxious stimuli. Helps explain wide variations of pain among people.
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Neuropathic Pain
• Abnormal processing of the impulses either by the peripheral or central nervous system
• Many underlying causes • injury (amputation and subsequent phantom limb pain) • scar tissue from surgery • nerve entrapment (carpal tunnel) • Nerve damage (diabetic neuropathy)
• Can occur in absence of enduring pathology
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Pain terminology
• Acute pain: lasts less than six months, subsides once the healing process is over
• Chronic pain:
• Involves complex processes • Often associated with altered anatomy and neural pathways • Constant and prolonged, lasting longer than six months
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Chronic Pain Syndrome
• Pain can become the primary focus of life
• Relationships altered
• Sometimes arise from acute, unrelieved pain e.g. multiple trauma, phantom limb pain after amputation, repeated back surgery
• Sometimes from neuro-muscular disorders such as fibromyalgia, rheumatoid arthritis, multiple sclerosis
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Chronic Pain
• Sometimes unwelcome in the doctor’s surgery or emergency departments - very complex, time consuming, no easy answers or quick fixes
• Behavioral medicine may help - learning different coping mechanisms, biofeedback, non-opioid interventions
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Mental illness and the complexity of the brain
• 100 billion neurons in the cerebral cortex alone (more than the stars in the Milky Way)
• Additional trillion neurons in cerebellum
• 1,000 – 10,000 dendrites, spines and synapses per neuron, + feedback loops
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Consequences of mental illness
• Enormous suffering • Stigma • Social isolation and withdrawal • Occupational disability • Markedly increased health service utilisation • Comorbid substance use disorders and sequelae of
these
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Consequences of mental illness
• Poor physical health • Child abuse and neglect • Relationship and family difficulties • Treatment and hospitalisation costs • Medicines expenditure • Self-injurious behaviour (SIB) • Suicide risk
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10 Leading Causes of Disability in the World (WHO)
• Unipolar Depression • Iron-deficiency Anemia • Falls • Alcohol Use • COPD • Bipolar disorder • Congenital anomalies • Osteoarthritis • Schizophrenia • Obsessive-compulsive
disorder
10.7% 4.7 4.6 3.3 3.1 3.0 2.9 2.8 2.6 2.2
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Australian National Survey of Mental Health & Wellbeing of Adults
• 18% of the survey cohort affected by one of the mental illnesses in preceding 12/12
• Higher incidence amongst younger (18-24) – 27% • Lower incidence amongst older (> 65) – 6.1%
• Anxiety disorders (12 vs 7.1%) and depression (7.4 vs 4.2%) more prevalent for women
• Substance use disorders more common for men (11 vs 4.5%)
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Psychotropic pharmacoepidemiology • Australian National health Survey: 26,000 households relating to preceding 2/52
• 19% of adults reported use of medication (either prescribed medication and/or vitamins, minerals or herbal treatments) for their mental wellbeing
• Of these 27% reported using antidepressants, 23% used sleeping tablets and 10% said that they had used medications for anxiety or nerves
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Pain and mental illness - context
PAIN
OTHER FACTORS (personality, history. context) MENTAL ILLNESS
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Medications – in general
• All medicines are poisons, it just depends on the dose
• Not all medicines are prescription medicines
• Not all medicines have scientific proof to back them
• All medicines have side effects
• Most medicines can interact with other medicines
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Medications – in general
• Medicines influence the person, the person influences the medicine
• People don’t necessarily take medicines as they are intended to be taken
• Some people become confused about medicines
• Not all medicines work for everyone who takes them
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Medications for pain
• Various different types of analgesia – “pain killers”
• Medicines used to manage symptoms associated with pain
• Medicines used to manage the side effects associated with pain medicines
• Interactions with other medicines used for other purposes
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Treatment for pain
• Non-drug approaches – alternative or adjuvants to pharmacotherapy:
• Heat, cooling • Exercise • Behavioural approaches • Mindfulness and meditation • Physiotherapy • Therapeutic massage • Acupuncture • TENS
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Simple analgesia • Topical treatments
• Counter-irritants • Anti-inflammatory products
• Paracetamol • Not entirely harmless • Can be hugely beneficial
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) • Very commonly used (Nurofen, Celebrex, Voltaren, Mobic) • Effective but can cause serious side effects
» GI, asthma, kidneys, bleeding risk, drug interactions
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Step Two: Opioids and Adjuvants • Mild-moderate opioids
• Codeine • Buprenorphine • Dextropropoxyphene
• Can be used in combination with simple agents
• Range of predictable adverse effects • Sedation • Respiratory suppression • Constipation • Nausea
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Adjuvant medicines • Antidepressants
• SSRIs • TCAs • Others
• Anticonvulsants • Carbamazepine • Pregabalin and gabapentin
• Local anaesthetics • Sedatives • Others (e.g. ? Cannabinoids)
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Powerful Opioids • No longer referred to as ‘narcotics’
• Many examples: • Morphine • Oxycodone • Methadone • Tramadol
• Predictable pattern of adverse effects • Additional concerns regarding dependence, tolerance
and diversion
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Mental illness and rehabilitation
PAIN
OTHER FACTORS (personality, history. context)
Comorbid mental illness
Substance abuse & diversion
Coping strategies Disability
Existential despair
Side effects of drugs
Effects on relationships
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Mental illness, pain and rehabilitation: The “Big Five” • Affective disorders
• Depression • BPAD • Adjustment disorders
• Somatoform disorders • Anxiety disorders
• PTSD • Panic disorder
• Substance use disorders • EtOH • Illlicit drugs • Prescription drugs
• Personality disorders
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Psychotropic drugs • Antidepressants
• SSRIs • SNRIs • TCAs • Others
• Anticonvulsants • Carbamazepine • Pregabalin and gabapentin
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Psychotropic drugs
• Antipsychotics
• Anxiolytics
• Hypnosedatives
• Mood stabilisers
• Medications for substance use
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Psychotropic drugs – it’s complicated …
• What is a mental illness, what is a personality trait, what is a normal human reaction to pain, suffering and possible ill-treatment by authority figures?
• Grief and loss • Influence of upbringing • Belief systems
• Conventional medicine • Alternative medicines
• Concepts of strength, coping and self-efficacy
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I didn’t see that coming… (part one) • Immediate side effects of drugs
• Constipation • Nausea • Sexual dysfunction • Sleep disturbances
• Latent side effects of drugs • Weight gain, metabolic side effects • Hormonal changes • Anaemia • Respiratory depression
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I didn’t see that coming… (part two) • Effects of drugs on fitness to drive
• Adverse impact of weight gain upon exercise capability
• Significant weight gain – bones, joints and spine
• Effects on dentition
• Cognitive impairment
• Polypharmacy and drug interactions
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I didn’t see that coming… (part three) • Effective treatment of pain can have a (very) positive
impact upon the course of mental illness
• Effective treatment of a mental illness can have a (very) positive impact upon pain
• Medication is not always forever
• Medication is sometimes forever
• Either way, functional recovery is possible
Thanks for your attention – questions?