Chapter 25

Chronic pain and psychiatric problems

OVERVIEW

Patients with chronic pain often face many life difficulties. Such patients can benefit not only from conventional medical therapies, but also psychological therapies. An awareness of the particular physical, psychological and social problems that accumulate for people with long-term pain and disability, and an ability to identify and appropriately manage these problems, allows healthcare professionals to obtain more successful outcomes and satisfaction for patients.

In this chapter, the manner in which psychosocial disturbances can develop and present in people with chronic pain will be described. An overview will be given of the association between chronic pain and psychiatric disorders, before a number of specific psychiatric syndromes will be described. Key terms are defined in Box 25.1.

Box 25.1 Key terms defined

Somatization – The presentation of emotional problems as if they are symptoms of physical disorders.

Post-traumatic stress disorder – A condition that develops after a person is exposed to a major life-threatening event whereby the event is frequently re-experienced, with symptoms of persisting arousal.

Dissociation – Where a person reacts to some part of their conscious experience as if detached.

Kinesiophobia – The fear and avoidance of activity.

THE ASSOCIATION BETWEEN PAIN AND PSYCHIATRIC DISORDERS

Chronic pain occurs in about 10–15% of the general population, with many also having a psychiatric disorder, either pre-existing or consequential (Dworkin & Caligor 1988). Merskey & Spear (1967) reported that pain is as frequent a complaint in the psychiatric clinic as it is in medical clinics. Spear (1967) found that 45–50% of patients with psychiatric problems attending a psychiatric clinic reported pain problems, with the highest incidence occurring in patients with anxiety states. These problems were not such as to lead to consultations, and were not compared to any appropriate group without pain. Large (1986) found that, in a consecutive series of 50 patients presenting for psychosocial evaluation at a pain clinic, 94% had a psychiatric disorder and 96% had a physical disorder. In other words, most had both psychiatric and physical disorders. Associations between chronic pain and psychiatric disorders can be psychiatric disorders coincidental with pain, pre-existing factors which predispose to both chronic pain and psychiatric disorders, and/or chronic pain causing psychiatric disorders.

PSYCHIATRIC DISORDERS COINCIDENTAL WITH PAIN

An illness such as schizophrenia is associated with difficulty defining, understanding and resolving problems. The illness leads patients to have major perceptual, affective and cognitive impairment, which can lead to misinterpretations, at times to a psychotic degree. This distortion might lead to over-reporting or under-reporting of problems. Pain can be a confounding experience for a person with a major psychiatric illness. Occasionally someone with a delusional illness, such as schizophrenia, may develop a delusional misinterpretation of a physical symptom. For example, a patient who had excruciating back pain from degenerative spinal disease ‘knew’ that this was caused by aliens having implanted electronic stimulators in his spine that they turned on and off at will.

In rare cases the pain may be a true ‘psychogenic’ phenomenon, a hallucination, which is associated with a delusional interpretation. Chronic patients hospitalized with schizophrenia tend to complain less about pain than patients with depression. However, it has been demonstrated (Whitlock 1967) that when a major psychiatric disorder such as schizophrenia, major depression or conversion disorder is diagnosed, then it is in fact more likely that the person will also have an underlying physical illness, rather than the reverse. Increased vigilance in assessing possible physical contributions is indicated, rather than prematurely attributing the patient’s complaints to their psychiatric disorder. The case study in Box 25.2 is illustrative of the difficulties people with a major mental illness can face when a coincidental pain problem arises.

Box 25.2 Case study: Mrs DB

Mrs DB had been at an international conference in Europe. Post-conference, she sustained a fractured humerus after a bicycle accident. Her arm was set and she returned home. She went to her GP for further management. Her regular doctor was unavailable, so she was seen by another doctor.

He couldn’t understand why she was in pain. The surgery had a computer system which allowed the doctor to see what medications she was prescribed. He saw that she was taking some psychotropic medication and asked her who her psychiatrist was.

Mrs DB couldn’t understand that he needed to speak with the psychiatrist as it was her arm that was broken and not her head. He inferred that the pain she was experiencing was due to her mental illness.

He sent her for an X-ray, commenting that if she insisted on being referred to an orthopaedic surgeon he would do this, but that he was too busy that day to make the referral.

She became angry and decided that she wouldn’t push the matter with this doctor.

The pain did not abate and eventually she rang the surgery for a referral to an orthopaedic surgeon after her family and friends insisted that she do this.

Fortunately, she was seen quickly by the orthopaedic surgeon, who expressed surprise at how the bone had been set, and told her that if she had left it much longer she would have had irreversible damage in her left arm. He operated the next day, placing two pins in the break.

Mrs DB was impressed at how the orthopaedic surgeon explained the pros and cons of operating prior to the operation and included her in the decision-making process. This involvement allowed her to own the outcome and the rehabilitation process involved.

The surgeon carefully explained to Mrs DB the possible risks involved in surgery and took considerable time in fully explaining these risks. Mrs DB felt like any other person with a broken arm and not a person with a mental illness with a broken arm.

This was in stark contrast to the way Mrs DB felt after her encounter with the GP.

When depressed, a person’s judgement is clouded by a very bleak, pessimistic outlook, a withdrawn, narrow focus, such that the person has difficulty concentrating and conceptualizing, and difficulty shifting focus sufficiently to accurately interpret new information. This point is illustrated by the case study in Box 25.3.

Box 25.3 Case study

A gentleman sat with a handkerchief carefully laid out between the hem of his shorts and his legs, because he found the discomfort of the touch of his shorts against his legs quite intolerable.

He had a recurring unipolar depressive illness, and complained of headache, chest pain and many other physical symptoms with each episode, with relief coinciding with effective treatment of his depression.

It was as if he became exquisitely aware of his body whenever he was depressed.

PRE-EXISTING FACTORS PREDISPOSING TO BOTH CHRONIC PAIN AND PSYCHIATRIC DISORDERS

A person’s chronic pain and behaviour may be affected by psychosocial factors, many of which are present well before the onset of the pain. This psychosocial contribution to a person’s pain is consistent with the IASP definition of pain and with the knowledge of the interaction between physical and psychosocial factors as explained in the gate control theory of pain (Melzack & Wall 1965), albeit rare in our experience.

Problems such as family dysfunction, abuse (substance, emotional, physical, sexual), unemployment, personal and family illness, poverty, isolation and deprivation are all over-represented in the histories of chronic pain patients (Feuerstein et al 1985; Goldberg et al 1999; Katon et al 1985). Such predisposing problems may result in the patient taking excessive risks, insufficient attention to personal welfare and isolation. However, such problems may not have any strong intrinsic link with pain. In fact, they may often arise because of independent concomitant difficulties and the same problems occur as complications of other physical or psychological disorders – if not as some of their causes. A sense of entrapment, and perceived loss of control over one’s destiny and well-being, may lead to ‘fight or flight’ defences, including depression and anxiety, dependency or over-activity, instability and aggression. Patients may be distrustful and reluctant to accept reasonable advice regarding well-being, their pain becoming a symbol of ongoing dissatisfaction and conflict with the world.

People who have been disadvantaged in life are more likely to have occupations and lifestyles with higher rates of injury and illness, and often have fewer personal, financial and social resources to cope with these experiences. In fact, nearly all physical and psychological illnesses occur more frequently in lower socioeconomic groups. For example, illiteracy is often associated with considerable early life disruption and is over-represented among patients with chronic pain. The disadvantage of illiteracy is magnified considerably when needing to participate in learning processes that are required for rehabilitation. It is worthwhile considering the mechanisms by which these factors can impact on a person. A person who is stressed, insecure and distracted does not learn well. Unhelpful attitudes and habits may be acquired. This limits the person’s ability to develop the academic, vocational, personal and social skills and resources that would best equip her for life.

The predisposing factors may not have actually caused any problems, distress or dysfunction before the illness or accident, especially as people very often develop coping strategies. However, these factors do make people vulnerable while still able to continue functioning, in the same manner as rust affects a car. At the moment of illness or accident, with the preoccupation of the immediate trauma, the importance of pre-existing factors is often not considered, even though the impact of the trauma is worse because of them.

Accepting a particular behaviour as predisposing to problems can be difficult for a patient, especially if a person previously had a very high level of functioning, such as working 16 hours per day, 6 days per week, sick or not. This socially encouraged behaviour might conceal significant problems with pacing, time-management, self-care, anxiety, excessive worry about others’ approval or poor management skills.

Many people disregard the effects of earlier life experiences, focusing only on the physical aspects of pain. Others become very sensitive to further disruptions to life, and may find it difficult to muster and maintain the personal strength necessary to confront and deal with further problems.

In the health system, the dependency of the socially accepted sick role can be a welcome refuge from life’s cruelty, especially as the price of continuing illness may remain hidden. Unfortunately, at times the supports offered, such as compensation payments, can have the unintended effect of prolonging illness, a contradiction that continues to trouble society at large.

Therapies aimed at improving function, when accepted, can have a powerful effect in overcoming any sense of threat, in turn decreasing levels of depression, anxiety and anger in the patient. The benefits of occupational therapy and physiotherapy in relieving the emotional distress experienced by patients should not be underrated.

The case study in Box 25.4 illustrates the unexpected ways in which the crisis of a pain syndrome can uncover pre-morbid psychopathology, which then requires treatment in its own right.

Box 25.4 Case study: AM

AM was a 35-year-old rock musician. Her career was terminated by a debilitating forearm pain and weakness. Occupational overuse syndrome was diagnosed. She faced the grief of losing not only her career, but also the joy of playing the keyboards. She changed to a career of sound engineering, and made some adjustment to her loss, with gradual alleviation of her arm pain.

In the course of treatment, AM revealed intermittent self-mutilation, stormy arguments with her partner and intense mood swings. Psychiatric assessment revealed an atypical dissociative disorder, with significant early childhood sexual abuse.

She engaged in long-term psychotherapy, which helped her gradually integrate her fragmented memories, and she settled into a more stable pattern and relationship with her partner.