Effects of Different Imagery Strategies in the Psychological Treatment of Chronic Headache

This study investigates the effects of four different imagery techniques: pleasant imagery versus imaginative transformations, and response versus stimulus imagery. One may expect imaginative transformations to be more effective than pleasant imagery. Response imaginative transformations should be more effective than stimulus imaginative transformations, while the pleasant imagery conditions are not expected to have different effects. In a 2x2 design, treatment conditions were compared. Forty patients (33 females, seven males) with different types of chronic headache were referred by their physicians and took part in the study. Pain diaries and questionnaires of pain experience and pain behaviour were used as outcome measures. Imaginative transformations - irrespective of response or stimulus orientation - were found to be more effective than pleasant imagery in reducing headache frequency. Reductions remained stable over an eight-month follow-up. There are no significant differences between response and stimulus imagery. Treatment effects were manifested in a reduction of headache frequency, while headache duration and headache intensity did not change. Suffering and avoidance behaviours were reduced in all treatment groups, while the use of distraction strategies was increased. The reductions in suffering were significantly greater in the groups treated with imaginative transformations. In the eight-month follow-up, group differences in reductions in suffering were no longer significant, which is probably due to the reduced sample size. The results support the hypothesis that a cognitive redefinition is responsible for the beneficial treatment effects because only instructions to imagine a change in pain sensations and/or pain responses led to significant improvements.