The psychology of pain

 

Gemma Bettens and Dr Abigail Billin give a psychological perspective to understanding the role of thoughts and emotions on behaviour in patients with pain.

The days of considering pain as a purely physical sensation have long been left behind, with contemporary approaches recognising and appreciating the importance of using a biopsychosocial approach when working with pain. Butler and Moseley’s seminal text, Explain Pain (2003), proposes that pain is the output of complex calculations by the brain, and, as psychologists working in a physiotherapy setting for pain management, we see the complex layers that contribute to a patient’s pain presentation. Using a cognitive-behavioural framework (figure below), this article will review how pain-related thoughts and emotions can amplify physical sensations, and how these factors in turn influence a patient’s behaviour and their ability to rehabilitate. We will outline ways to collect information regarding mental wellbeing, and importantly, when it is necessary to refer to a psychologist.

Figure: cognitive behavioural therapy (CBT) model.

Pain-related thoughts

The way a person thinks about their pain can have a profound impact on the person’s pain experience and rehabilitation. Self-efficacy refers to an individual’s belief in their ability to implement behaviours required to produce detailed performance outcomes, and reflects their confidence regarding motivation and control of their actions (Bandura 1977). This is an important concept for treating physicians to be aware of, as patients with poorer self-efficacy will be unlikely to think that a favourable outcome is possible, and in turn, may result in them developing a self-fulfilling prophecy. These have been found to be significantly detrimental to achieving positive treatment outcomes (Jepma et al 2018). Pain catastrophising (rumination, excessive magnification and feelings of helplessness; Sullivan et al 1995) also plays a significant role in rehabilitation. In our psychology sessions we regularly observe patients catastrophising, often signalled by the patient becoming distracted by the conversation and returning to thoughts such as ‘but the pain is so bad’, or ‘there must be something really wrong with me’. We find patients with excessively negative thoughts about their pain appear unable to take on any new information because of their fixation on their symptoms, which hinders their ability to rehabilitate. It makes sense that pain catastrophising has been reliably linked to increased physical disability for both chronic and acute pain (Leung 2012), and is a vital piece of the puzzle to address in pain management.

Another important facet of pain cognitions are memories triggered by the fear or sensation of pain. During the brain’s calculation of nociceptive signals, the hippocampus, a part of the brain responsible for memory, is evoked to retrieve information relevant to the stimuli (Basic & Schmidt 2017). A person’s pain experience may therefore trigger memories of traumatic material relevant to the injury causing the pain, or may even bring up memories from previous traumatic experiences. This can set off its own cascade of thoughts, such as perceived injustice of an injury, anger towards perpetrator/s, feelings of helplessness and low self-worth. Patients’ core beliefs about themselves and the world can be triggered by memories, such as ‘I am not good enough’, or ‘everyone will eventually mistreat me’. When working with patients in pain management, we find that conversations about pain can quickly lead to discussions of difficult memories, which the patient will often feel are irrelevant, but when we put it in the context of the CBT model, they can see why this is so important to address as part of their treatment. Therefore, emotional processing of traumatic memories can remove significant road blocks to recovery.

Pain-related emotions

When a person has a thought, such as ‘my pain is never going to go away’, the person reacts to this thought because it feels real. Emotions such as sadness, fear, anger, disappointment, guilt and worry are all commonly expressed by patients at our service, and are often valid. However, some patients may be experiencing clinical levels of emotional distress, due to how the injury was sustained, or the impact it has had on their quality of life. Depending on what a person has lived through previously, they may have a predisposition to developing a mood or anxiety disorder (if they have experienced trauma in their childhood or adolescence); they may even have a pre-existing diagnosis (eg, depression, anxiety, PTSD) that needs to be taken into consideration.

The mean prevalence rate of comorbid major depressive disorder in patients with chronic pain has been found to range from 18 per cent in population-based settings, up to 85 per cent in specialised pain clinics (De Jong et al 2018, Bair, Robinson, Katon, & Kroenke 2003), and similarly, generalised anxiety disorder has also been found to be more prevalent among chronic pain conditions compared to the general population (Csupak et al 2018). A significant finding in these studies highlighted that patients with chronic pain and comorbid depression and/or anxiety also experience greater pain intensity; therefore, if treating physicians find that one of their patients is reporting a greater severity of pain intensity than what may be expected based on their level of injury, then it may be necessary to check-in regarding that patient’s mental health. In saying this, it is important not to assume that if a patient becomes upset during your session it equates to them not being able to cope, or being depressed or anxious; it may just be that they need validation or understanding as to the difficulty of what their situation is. However, if that same patient is crying every time you see them, or they tell you that they become teary frequently because of their low quality of life or fears that their pain or injury will never improve, then this may be a sign to consider a psychological referral to complement the pre-existing treatment plan.

Pain-related sensations

Thoughts and emotions triggered by pain feed directly back into the person’s pain experience, setting up the vicious cycle postulated by the CBT model. If a person thinks an activity is going to hurt, it is more likely to be painful. This is shown in classic experiments where pain can be manipulated by pairing the stimuli with something that is perceived to be dangerous, such as the colour red or a threatening noise (eg, Moseley & Arntz 2007). We find that just talking about physical and emotional pain can increase a patient’s pain behaviours in the therapy room, often leading the person to become uncomfortable and move positions, rub the sore area, or even vocalise their pain. This is thought not only to be increased attention to the area, but also a result of changing processes in the brain and nervous system. For example, catastrophising thoughts have been shown to increase cortical activation in response to pain, and even cause maladaptive responses to non-painful stimuli (Campbell & Edwards 2009). Furthermore, areas of the brain such as the amygdala are responsible for processing pain-related emotional responses and pain modulation (Neugebauer 2015), indicating an inextricable link between pain emotional experience and pain sensations. This would explain why highly anxious patients with post-traumatic stress symptoms are observed to have higher pain severity, along with higher pain catastrophising and lower self-efficacy (eg, Guimmarra et al 2012).

Pain-related behaviours

Understanding the link between thoughts, emotions and sensations allows us to make sense of a person’s pain behaviours. Clinicians working with pain patients are familiar with fear avoidance and boom-bust behaviours, but identifying the drivers for these patterns can help patients break the cycle. For example, a fear-avoidant patient may not want to move in a certain way because it reminds them of a trauma. One of our patients refused to do a bending exercise, and when explored in therapy, we learned that it reminded her of when she injured herself. The exercise elicited intrusive memories of the injury, causing her body to be flooded with anxiety, leading to an exacerbation in pain, just in response to even thinking about the movement.

Likewise, patients who boom-bust may have specific psychological barriers to changing this behaviour. For example, one of our patients with a history of childhood neglect relentlessly pushed past his pain in an attempt to please others and gain love and attention. For this patient, his thoughts and beliefs were much louder than his body signals, making it impossible to modify this behaviour without addressing the underlying cognitions. Covert psychological barriers may also be present in the patient who appears disengaged or disinterested. They may be surrendering to their core belief that they are helpless, or believe that all people will abuse or abandon them in the end, so what is the point? It would be easy to discount this patient, but spending a little time to explore the drivers may help the patient engage and rehabilitate.

Appropriate questioning

Below are some examples of the types of questions that could be helpful when first assessing your patient:

  • explore how the patient sustained their injury. Do they have intrusive memories about a trauma? Are they struggling with emotions like guilt, shame, injustice, anxiety or depression? How does this impact their functioning?
  • find out how confident a patient is about their ability to rehabilitate. Has this been a theme for them in the past? How do they think they can get better? Do they think this is something that they are in control of or are they expecting to be passive recipients of treatment?
  • ask about sleeping habits. Sleep is often impacted by pain, making it more difficult to get to sleep, or waking up numerous times during the night, which can have implications for people trying to rehabilitate from an injury. Sleep is a pivotal process required to ensure our emotions remain regulated, and can amplify pain sensitivity if we receive less than our recommended eight hours a night
  • find out about their quality and breadth of interpersonal relationships. Are relationship difficulties (stress, conflict, domestic violence, caregiving roles) interfering with their ability to rehabilitate? Do they have enough support between sessions to engage with treatment?
  • do they have a current mental health diagnosis, such as depression, anxiety or post-traumatic stress disorder? If so, has this developed post-injury or was it pre-existing?
  • are they using avoidance behaviours like substance misuse, binge eating, or social withdrawal to cope with their pain or injury? Patients who use substances to assist in emotional avoidance or sleep are at risk of becoming reliant upon these substances to cope with their discomfort, which may lead to dependency issues and negatively impact their work or interpersonal relationships.

Aggressive behaviour or substance abuse or misuse may be indicative of a referral to support services, particularly if either of these things resulted in them obtaining their injury. Using motivational interviewing techniques can be helpful, particularly finding out how confident a patient is about their ability or how hopeful they are about being able to rehabilitate. Finally, it is important to ask patients about their thoughts and feelings relating to their injury and situation; however, be prepared to act on the information they give you if necessary.

When to refer, and how?

Seeking assistance from a psychologist may not be something an individual experiencing pain would spontaneously do; however, as their treating clinician it will likely be your recommendation to engage in this collaboration that encourages them to seek a complementary support option. If you believe a patient would benefit from psychological engagement then direct your patient to their local general practitioner to access a mental healthcare plan to see a pain psychologist in the community. If patients decline a psychology referral, there are also online resources available to patients, such as Mindspot, which is an online CBT resource designed to assist patients manage their pain and maintain a good quality of life (mindspot.org.au). Lastly, if a patient makes any mention of hopelessness and identifies that they are experiencing imminent thoughts about hurting themselves, or others, advise them to contact emergency services or their local crisis team immediately.

Email inmotion@australian.physio for references.

Gemma Bettens (MPsych Clin) and Dr Abigail Billin (DPsych, & MSC Health Psychology) are psychologists working in the neuropsychology/orthopaedics physiotherapy specialist clinic at the Princess Alexandra Hospital in Brisbane.
 

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