Pain-elicited responses and their role in predicting future pain duration and severity.

The first objective of this study was to carry out a prospective investigation of the behavioral and affective responses to headache pain over a 72 hr period. A sample of 74 headache sufferers provided self-reported ratings of affective and behavioral responses as measured by a composite of standardized questionnaires. Highly significant and clinically meaningful levels of both types of responses were found on the headache day. Interestingly, significant levels of behavioral and affective disturbances were also reported 24 hr after pain termination, indicating that responses to pain actually outlasted pain perception by at least 1 day. The second goal of this study was to investigate whether affective or behavioral responses were predictors of future pain intensity, duration or severity. A smaller sample of 25 subjects provided ratings on two sequential headaches. A series of time-lag analyses indicated that, unlike behavioral responses, strong affective responses during a given episode were associated with subsequently longer and more severe headaches. These results suggest that affective pain-elicited responses may be a risk factor for suffering a worse headache during the episode that follows.