Knowledge and expectation of postconcussion symptoms in the general population.

OBJECTIVE: Beliefs about mild traumatic brain injury (MTBI) may affect complaints and their persistence. This study investigates the relationships between knowledge, experience, and expectation in the general population.

METHODS: One hundred seventy-one people reported symptoms expected from vignettes about MTBI, depression, posttraumatic stress disorder (PTSD), and orthopedic injury. Then they completed a postconcussional syndrome (PCS) checklist about these vignettes and about personal symptoms.

RESULTS: The ability to generate symptoms from vignettes was poor for PCS, depression, and PTSD, and was greatly improved using a PCS checklist, probably by symptom guessing. No postconcussion symptoms were associated specifically with MTBI. Those with more personal symptoms expected more symptoms. Past experience of MTBI did not improve symptom knowledge. Beliefs about the 'undesirability' of conditions were associated with expected outcomes.

CONCLUSIONS: People know little about PCS. Expectations about MTBI are influenced by psychological factors that are relevant if we consider information given in hospitals. Symptom overlap means that psychological conditions such as depression may be misdiagnosed as PCS, and checklists should not be used for diagnosis.