Opinion

Pain and psychological conditions

9th Mar 2017

'Which comes first, the chicken or the egg?'

In independent medical assessments, experts often mention the effect of painful conditions on mental health and the effect of mental health conditions on an individual’s pain.

There is a complex relationship between physical and non-physical conditions that determine how an individual experiences pain. Psychiatrists skilled in the assessment of pain play a central role by determining the correct diagnosis, treatment, causation and apportionment of physical and psychological factors.

Psychosocial and non-organic influences on pain and suffering

When an individual’s pain cannot be clearly explained, or seems disproportionate to their underlying medical condition, terms such as ‘psychosocial factors’ or ‘non-organic factors’ are often loosely used in lieu of a real diagnosis to explain the gap between an expected level of pain and suffering and that which is observed. Skilled interviews that explore and detail the origin and nature of psychosocial factors are psychiatrists’ ‘bread and butter’, and can provide an informed opinion as to how non-physical factors can affect a person’s pain and suffering.

For the non-clinician, psychological factors are best thought of as those factors arising from within the individual that influence an individual’s pain, whereas social factors refer to ‘external factors’ (sometimes referred to as environmental influences) on pain and suffering.

Psychological factors

Social factors

Co-existing mental illness

E.g. depressed mood, anxiety, post-traumatic stress, somatisation disorder

Workplace bullying

Cognitive processes

E.g. ‘pain means harm’

Cultural beliefs;

Religious beliefs

Effects of pain-relieving medication

E.g. long term narcotic use

Reinforcement

E.g. family members

Self-esteem

Reinforcement of pain behaviours;

Ongoing litigation

Table 1 Psychological and social factors that may influence pain and suffering

Depression, anxiety and pain

Depressive disorders are the most common psychiatric disorders associated with chronic pain, followed by anxiety disorders, post-traumatic stress disorders and substance misuse. Over 60% of patients with chronic pain report depressive symptoms while the prevalence of major depression in patients with chronic pain is 30-40% (with 15% reporting suicidal thoughts).

Because persistent pain impacts negatively on work, physical activity and socialisation, depression in chronic pain patients is more likely to be a consequence of, rather than the cause of, an individual’s pain and suffering. The relationship between a person’s pain and their mental health is also bi-directional in that pain may cause worsening depression and under-treated depression and anxiety will cause an individual to experience more pain than if they were not depressed or anxious.

Under-treated depression and anxiety impairs optimal responses to any other pain-directed treatment and should not be ignored. There are biological and behavioural connections between depression and anxiety and the perception of pain or ‘pain threshold’; the neurochemical imbalances seen in depression and anxiety can enhance the transmission and processing of painful stimuli, and at the same time neuro-vegetative sequelae of depression and anxiety (disturbances in sleep, sexual function, appetite, concentration and motivation) can lead to physical deconditioning, reduced pain tolerances and ‘boom and bust’ behaviour.

Somatoform disorders and pain

Somatisation Disorder, Pain Disorder and Pain Disorder Associated with a General Medical Condition (PDAGMC) are three conditions easily confused by non-psychiatrists.

The first two of these conditions, Somatisation Disorder and Pain Disorder (see Table 2 below), are considered mental health disorders and belong to a group of mental health conditions known as the ‘somatoform disorders’. PDAGMC, however, is not considered a mental health disorder.

Somatoform Disorders also include Conversion Disorder, Hypochondriasis and Body Dysmorphic Disorder and are all characterised by the presence of physical symptoms that suggest an underlying medical condition but are not fully explained by that general medical condition. For example, a patient reporting altered sensation in different regions of the body that cannot be explained by any neurological disease might be suffering from a somatoform disorder. However, as our knowledge and understanding of the nervous system has grown, symptoms such as the various neuropathic pain states allodynia,[1] dysesthesia[2] and hyperalgesia[3] that were once not explained by a general medical process are now understood to arise from a re-wiring of the nervous system known as neuroplasticity, and can therefore be explained in terms of a general medical condition.

Somatisation Disorder

Pain Disorder

Recurring multiple somatic complaints which result in treatment or cause impairment of social or occupational function, the onset of which occurs before 30 years of age; and

Pain must be present in four different sites (e.g. head, arm, leg, eye), or functions (e.g. menstruation, eating, elimination); and

Two gastrointestinal symptoms other than pain (e.g. bloating, nausea, food intolerances); and

One sexual symptom (e.g. erectile dysfunction, menstrual irregularities); and

One or more symptom or deficit suggesting a neurological condition not related to pain (e.g. double vision, temporary weakness, loss of consciousness); and

Either:

(1) The symptoms cannot be fully explained by a recognised general medical condition or by side-effects of medication; or

(2) The symptoms are more than what would normally be expected of that general medical condition.

Pain in one or more anatomical sites;

Pain causes significant distress or impairment in social or occupational functioning;

Psychological factors are judged to have an important role ;

Symptom is not intentionally feigned;

Pain not better accounted for by other psychological condition e.g. depression or anxiety.

Table 2 Diagnostic criteria for pain-related somatoform disorders

 

In PDAGMC, the onset of pain is closely linked to the onset of a medical condition in which psychological factors (if present) are considered not to have a major role. Lower back pain is an example of PDAGMC.

Implications for independent medical assessments

The key to differentiating between a somatoform pain disorder and PDAGMC is a close, collaborative diagnosis between a psychiatrist (to assess the presence and relative contribution of psychological factors) and an appropriate expert physician who is able to assess and exclude symptoms that may be caused by any known general medical condition.

By Dr Marc Walden and Dr Kym Boon

Dr Marc Walden is a pain medicine physician, independent medical examiner and the principal of Greenslopes Medicolegal.

Dr Kym Boon is a psychiatrist and pain medicine physician and independent medical examiner.

This is the third and final article in a series on pain medicine. Greenslopes Medicolegal specialises in the provision of independent pain and psychiatric reports.

 

[1] Central pain sensitisation (increased response of neurons) following normally non-painful, often repetitive, stimulation.

[2] Defined as an ‘unpleasant, abnormal sense of touch’. It often presents as pain but may also present as an inappropriate, but not discomforting, sensation.

[3] An increased sensitivity to pain, which may be caused by nerve damage.

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