Narrative review analyzing the roughly 3:1 female predominance in functional neurological disorder by synthesizing biological (notably sex hormones), psychological (trauma, dissociation), and social (gender norms, socioeconomic) contributors and diagnostic biases.

Limited direct value for Parkinson's therapeutic discovery, but the paper highlights sex/gender, hormonal, and psychosocial factors that are important to consider in neurodegeneration research, trial design, and understanding comorbid neuropsychiatric presentations.

BACKGROUND: Functional neurological disorder (FND) is a common and disabling neuropsychiatric condition in which women comprise approximately 75% of cases. This paper examines whether the gender imbalance seen in FND is unique among neurological and psychiatric conditions and explores the biological, psychological, and social contributors to this disparity. METHODS: A narrative review was conducted using MEDLINE, PsycINFO, and Web of Science. Gender ratios were compared across depression, anxiety, post-traumatic stress disorder, schizophrenia, eating disorders, Parkinson's disease, and multiple sclerosis. Evidence regarding sex hormones, early life trauma, gender-based social determinants, and diagnostic biases were synthesized thematically. RESULTS: Amongst the psychiatric and neurological conditions reviewed, FND shows a pronounced female predominance (approximately 3:1), placing it amongst the most gender imbalanced disorders in our sample, with only eating disorders showing a larger female predominance. Biological factors (particularly the influence of estrogen and progesterone on stress reactivity, neuronal excitability, and agency), may heighten female vulnerability. Social determinants (increased exposure to trauma, socioeconomic inequality, and gender norms) further contribute to this risk. FND shares clinical and demographic similarities with other internalizing disorders and conditions linked to dissociation and trauma. The literature suggests FND emerges from a bidirectional interaction between gonadal hormones and psychosocial stressors. CONCLUSIONS: The marked gender imbalance in FND arises from the interplay of biological vulnerability and gendered social adversity. Understanding these intersecting influences is essential for reducing stigma and guiding future research, diagnosis, and treatment. The findings support the need for a gender-sensitive, biopsychosocial approach to FND care, and investigation.