The role of operant conditioning for the development and maintenance of chronic pain was examined in 30 chronic back pain patients (CBP) and 30 matched healthy controls. Half of each group was reinforced for increased, half for decreased pain reports while EEG, EOG, heart rate, skin conductance and muscle tension levels were recorded. Both groups showed similar learning rates, however, the CBP patients displayed slower extinction of both the verbal and the cortical (N150) pain response. In addition, the CBP group displayed prolonged elevated electromyogram levels to the task. These data suggest that CBP patients are more easily influenced by operant conditioning factors than healthy controls and this susceptibility may add to the maintenance of the chronic pain problem.

The brief group CBT intervention showed some superiority to the PE programme, which could be of considerable clinical and economical importance.

Although Quality of Life (QoL) is of growing interest in schizophrenia research, little is known about putative causal determinants of this multidimensional construct. The present study explored the utility of objective indicators, psychopathological symptoms and psychosocial concepts drawn from empirical findings in community samples and the vulnerability-stress-coping model of schizophrenia for predicting general subjective QoL in post acute patients with schizophrenia. The analyses were based on cross-sectional data from 66 post acute patients with schizophrenia. The relationships between QoL and possible determinants were investigated using correlational analysis, regression analysis and structural equation techniques. As a result no significant relationships between objective indicators and general QoL were found. The strongest significant determinants were depressive symptoms and the psychosocial concepts of negative coping, perceived social support and self-efficacy. The empirical causal modelling results indicated that depression led to a direct negative impact upon QoL, whereas the other determinants had direct negative or positive effects on depression and affected QoL indirectly. One could conclude that to enhance patients' QoL, improvements in depressive symptoms, negative coping style, social support and self-efficacy seem to be most effective.

The processing of pain-related, body-related and neutral words was assessed in chronic pain patients and matched healthy controls. During and after word presentation at perception threshold, electromyographic activity (EMG), heart rate, skin conductance level and electroencephalographic (EEG) data from 11 electrode sites were recorded. Startle responses were measured to suprathreshold word stimuli. Although the patients did not recognize more pain-related words, they produced an enhanced left-hemispheric N100 and N200 to pain-related as compared to neutral words. In addition, the patients did not show a distinct P300 but a continuous positive shift to all words extending into the 800-ms range. Skin conductance levels to the pain-related words were also enhanced in patients only. These data partially support the notion of pain-related implicit memory structures in the brain of chronic pain patients that may selectively draw attention to pain-related stimuli and may thus enhance pain perception.

The processing of pain-related, body-related, and neutral words was assessed in individuals with prechronic pain and matched healthy controls. Integrated surface electromyogram, heart rate, skin conductance level, and visual event-related potentials from 11 electrode sites were recorded during the presentation of three word types at perception threshold. Startle responses were recorded from words presented above perception threshold. The patient and control groups did not differ in recognition performance. Pain-related words evoked an enhanced early component (N100) of the visual event-related potential only in the prechronic pain group. In both groups the late slow wave and the startle response were enhanced for body- and pain-related words compared with those for neutral words. All word types elicited larger late positivities in the prechronic pain group and in the right compared with the left hemisphere. These data suggest differential cortical processing of pain-related material in persons at a prechronic pain stage.