Chronic pain and affect as a nonlinear dynamical system

Abstract

The relationship between pain and emotions has generated substantial research (Robinson & Riley, 1999). Pain co-occurs with negative affective states, such as depression, anxiety, anger, physical disease and PTSD (Kruegger et al., 2004; Von Korff et al., 2005). However, research indicates that individual patients experience chronic pain in different ways and that it is important to tailor treatment to the individual (Gatchel, 2005; Turk et al., 2004). For example, the classic work by Turk and and Rudy (1988) described subgroups of pain patients as dysfunctional, interpersonally distressed, and adaptive pain copers, with hybrid styles possible. Pain typically begins with nociception, but a patient might experience pain in the absence of nociceptive input, as in the case of phantom limb pain (see Chapter 7 by Melzack and Katz). Moreover, when nociception is present, there is often a poor correspondence between the severity of a wound or pathological condition and the intensity of pain reported subjectively. A linear description of the relationship between tissue damage and pain does not summarize well how pain occurs in response to injury.