Objectives: This study examined the robustness of the postconcussion syndrome (PCS) expectation-as-etiology hypothesis using a variation on the typical study design and different symptom assessment methods.
Methods: Participants were 51 university students with no history of brain injury or neurological disease. Participants reported expected PCS symptoms after being exposed to an established vignette in which they were asked to imagine that they had had a car accident (expectation condition). One week later, they reported their current symptoms (control condition). Symptoms were elicited in both test sessions using each of 3 methods administered in the following fixed order: an open-ended question (eg, how have you been feeling over the past couple of weeks?), prompted interview questions (eg, have you experienced any troubling physical symptoms over the past few weeks?), and checklist (the British Columbia Postconcussion Symptom Inventory). All 3 methods were administered in a paper-and-pencil format.
Results: Findings revealed that (a) when responding to structured interview questions or the checklist, participants expected more PCS symptoms from an imagined mild traumatic brain injury when compared with their baseline, (b) the expectation effect was not present when symptoms were elicited by an open-ended question, and (c) almost all participants (approximately 98% of those reporting expected symptoms) met a caseness criterion when symptoms were assessed using a checklist or structured interview. Contrary to predictions, personal knowledge of someone with mild traumatic brain injury did not alter PCS expectancies.
Conclusions: The expectation-as-etiology hypothesis, which is one of several factors that has been associated with PCS, may be partly dependent on method of symptom assessment.