Aaron D. Fobian, PhD; Lindsey Elliott, MA
Functional neurological symptom disorder (FNSD) is characterized by neurological symptoms that are unexplained by other traditional neurological or medical conditions. Both physicians and patients have limited understanding of FNSD, which is often explained as a physical manifestation of psychological distress. Recently, diagnostic criteria have shifted from requiring a preceding stressor to relying on positive symptoms. Given this shift, we have provided a review of the etiology of FNSD. Predisposing factors include trauma or psychiatric symptoms, somatic symptoms, illness exposure, symptom monitoring and neurobiological factors. Neurobiological research has indicated that patients with FNSD have a decreased sense of agency and abnormal attentional focus on the affected area, both of which are modulated by beliefs and expectations about illness. Sick role and secondary gain may reinforce and maintain FNSD. The integrated etiological summary model combines research from various fields and other recent etiological models to represent the current understanding of FNSD etiology. It discusses a potential causal mechanism and informs future research and treatment.
Submitted Sept. 22, 2017; Revised Feb. 23, 2018; Accepted Mar. 26, 2018; Published online July 31, 2018
Acknowledgments: A. Fobian is funded by award number 5K23DK106570 from the National Institute of Diabetes and Digestive and Kidney Diseases. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute, National Institute of Diabetes and Digestive and Kidney Diseases, or the National Institutes of Health.
Affiliations: From the Department of Psychiatry, University of Alabama at Birmingham, Birmingham, AL (Fobian); and the Department of Psychology, University of Alabama at Birmingham, Birmingham, AL (Elliott).
Competing interests: None declared.
Contributors: A. Fobian conducted a literature review, integrated previous research, and outlined and described the summary model. L. Elliott also also conducted the literature review. Both authors wrote and reviewed the article, approved the final version for publication, and can certify that no other individuals not listed as authors have made substantial contributions to the paper.
Correspondence to: A.D. Fobian, 1720 2nd Ave. South, Sparks Center 1025, Birmingham, AL 35294-0017; email@example.com