Psychological models of chronic pain
Psychological factors are implicated when there is no empirical evidence to support an isomorphic relationship between the physiological factors such as inflammatory processes, degenerative changes, structural deformities, traumatic incidents, and muscular or ligamentous strain (Loeser 1980), and CBP (e.g. Harris et al. 1999; Jinkins et al. 2004; McCabe et al. 2005). More recently, the lack of association between CBP and physical factors has focused attention on the interaction between physiological and psychological factors, including subconscious learning and cognitive- affective variables. Flor et al. (1990) proposed that the development and maintenance of chronic pain is a function of several interacting components: (1) a predisposition to respond with a specific bodily system; (2) external or internal aversive stimulation; (3) maladaptive information processing of and coping with pain-related social and/or physiological stimuli, and (4) operant, respondent, and observational learning processes. These authors defined psychobiological mechanisms that impact the development and maintenance of somatosensory and affective pain memory in chronic pain patients (see also, Gracely et al. 2002, 2004). The various models of learning and their relationship to CBP are presented below.