Secure Attachment and Depression Predict 6-Month Outcome in Motor Functional Neurological Disorders: A Prospective Pilot Study

Background: The relationships between baseline neuropsychiatric factors and clinical outcome in patients with functional neurological disorder (FND)/conversion disorder remain poorly understood. Objective: This prospective, naturalistic pilot study investigated links between predisposing vulnerabilities (risk factors) and clinical outcome in patients with motor FND engaged in usual care within a subspecialty FND clinic. Methods: Thirty-four patients with motor FND were enrolled and completed baseline and 6-month follow-up psychometric questionnaires. Univariate screening tests followed by multivariate linear regression analyses were used to investigate neuropsychiatric predictors of 6-month clinical outcome in patients with motor FND. Results: In univariate analyses, baseline secure attachment traits and depression as measured by the Relationship Scales Questionnaire and Beck Depression Inventory-II positively correlated with improved Patient Health Questionnaire-15 scores. In a multivariate linear regression analysis adjusting for the interval time between baseline and follow-up data collection, baseline secure attachment and depression scores independently predicted improvements in Patient Health Questionnaire-15 scores. In additional analyses, patients with a diagnosis of psychogenic nonepileptic seizures compared to individuals with other motor FND subtypes showed a trend toward worse 6-month physical health outcomes as measured by the Short Form Health Survey-36. Conclusion: Future large-scale, multi-site longitudinal studies are needed to comprehensively investigate neuropsychiatric predictors of clinical outcome in patients with motor FND, including functional weakness, functional movement disorders, and psychogenic nonepileptic seizures.