Stress as a trigger for headaches: relationship between exposure and sensitivity

This study investigated the relationship between length of exposure to a stressor and capacity of the stressor to elicit head pain. Some 127 participants, 93 of whom suffered from regular headaches, were randomly assigned to five experimental conditions, defined by length of exposure to a stressor. Participants attended a single laboratory session divided into three phases: pre-intervention test, intervention and post-intervention test. The main finding was a significant cubic trend between length of exposure to the stressor and ratings of head pain. This trend indicated that very short exposure to the stressor increased sensitivity, whilst longer exposure decreased sensitivity, but even longer exposure increased sensitivity. These results build on earlier studies that suggest the traditional clinical advice to headache sufferers, that the best way to prevent headaches is to avoid the triggers, runs the risk of establishing an insidious sensitization process, thereby increasing headache frequency.