Pain, avoidance, and suffering

In this issue of PAIN, Drs. Vlaeyen and Linton [2] present a cogent review of research regarding the fear-avoidance model of chronic musculoskeletal pain, a model that Dr. Vlaeyen has pioneered. The model was developed in order to explain how persistent fear-based avoidance behavior could produce much of the suffering and disability associated with pain states. They highlight the key role of fear in developing pain avoidance behaviors. Pain can be considered an unconditioned stimulus (US) that activates immediate reactive measures in the acute setting. In the longer term, conditioned stimuli (interoceptive, exteroceptive, or proprioceptive) become associated with the US and then conditioned responses, such as fear/avoidance result from exposure to the conditioned stimuli. Direct experience or indirect experience, such as verbal information or observations, may influence fear, avoidance, and pain perceptions. The authors review a number of studies demonstrating the powerful effects of such indirect experience in research settings. They describe how in vivo exposure procedures have emerged as an important means of reducing fear-induced avoidance behaviors associated with pain. The model joins the latest generation of psychotherapies that focus on acceptance, mindfulness, and decreased experiential avoidance. For example, in current cognitive behavioral approaches to anxiety disorders, individuals learn techniques to decrease experiential avoidance of feared situations. For instance, individuals may fear a phobic object, a social situation, or a panic attack. The fear may increase with time, leading the individual to have marked avoidance, such as agoraphobia in panic disorder. In the cognitive behavioral therapies with the most success, the individual gradually increases his or her exposure to the feared situation, and as a consequence learns that no catastrophe ensues. Individuals with panic disorder may still have panic episodes, but they do not have to experience them as catastrophic events to be avoided at all costs. Vlaeyen and Linton note that similar exposure therapies have shown significant success in diminishing the disability associated with physical pain. In Acceptance and Commitment Therapy (ACT), [1] individuals learn to identify important values in their life, and to allow these values to be naturally positive reinforcers. For example, identifying an occupation that one cherishes or a family that one loves is a very different value-orientation for the individual’s life than is getting pain relief. Many, if not most, patients coming to pain clinics have narrowed their life focus to the latter. In the ACT approach, individuals learn that they can continue to focus on their values, despite pain. They are taught techniques for shifting perspective (‘‘defusing’’) on painful sensations, affective states, and thoughts. The emphasis is not on pain management but rather on being able to