Illness perceptions in functional neurological disorder: a ‘think-aloud’ study of the Revised Illness Perception Questionnaire using content and thematic analysis

OBJECTIVE: To examine the responses of people with Functional Neurological Disorder (FND) regarding issues arising in the interpretation or application of the revised Illness Perception Questionnaire (IPQ-R). Secondly, to elicit themes relevant to understanding how people with FND conceptualise their illness. METHODS AND MEASURES: Nine participants with various FND symptoms took part in 'think-aloud' interviews whilst completing the IPQ-R. Participants' responses were examined with content and thematic analysis. RESULTS: 221 issues emerged during IPQ-R completion, with the most frequent being participants' uncertainty and insufficient knowledge about FND or treatments, leading to 'I don't know' verbal comments and 'neither agree nor disagree' responses. Themes revealed 1) lack of personalised formulation, 2) significant impact of FND and comorbidities on quality of life and functioning, 3) isolation and difficulties in accessing support, and 4) nuanced ideas about the role of trauma and neurodiversity and maintaining hope. CONCLUSION: Illness perceptions in FND reflect a dynamic relationship between the complexity and uncertainty of the condition, comorbidities, stigma and treatment access difficulties. Co-produced qualitative work should explore different FND subtypes at serial timepoints in treatment to adapt the IPQ-R as a meaningful and sensitive measure for FND, which considers neurodivergent people and trauma survivors.