Lifespan in Functional Neurological Disorder
FND does not shorten lifespan or cause death—it is not a degenerative or life-threatening condition, with mortality rates equivalent to the general population. 1
Why FND Does Not Affect Life Expectancy
The fundamental reason FND does not reduce lifespan is that it arises from a potentially reversible miscommunication between the brain and body rather than from structural damage or degenerative disease to the nervous system. 2 The symptoms reflect altered brain network function and miscommunication, not tissue destruction, lesions, or progressive neurodegeneration. 2
Key Distinguishing Features from Fatal Neurological Conditions
FND does not involve ongoing destruction of neural tissue, unlike conditions such as ALS, multiple sclerosis, or Parkinson's disease, which are associated with progressive neurodegeneration and shortened lifespan. 2
No structural neurological damage occurs in FND, with symptoms demonstrating variability and distractibility that can improve with appropriate treatment. 2
Recovery patterns in FND show remission and exacerbation rather than inexorable decline, with 60-96% of patients reporting improvement after intervention. 2, 1
Important Caveats About Secondary Complications
While FND itself does not threaten life expectancy, prolonged immobility or reduced activity can lead to secondary problems such as deconditioning and muscle atrophy, which can become more difficult to reverse but still do not affect mortality. 2
Functional dysphagia can lead to unintended weight loss, malnutrition, and social withdrawal, which requires clinical attention but is manageable. 2
Maladaptive movement patterns and use of assistive devices can create new musculoskeletal problems such as secondary pain syndromes. 2
Quality of Life Considerations
While FND does not affect lifespan, those affected frequently experience high levels of distress, disability, unemployment, and reduced quality of life. 1 This burden reflects the impact of symptoms and associated stigma, not a life-threatening disease process. 2
Psychiatric comorbidities are common, including anxiety (51%), depression (43%), panic (20%), and PTSD (22%), which contribute to disability but not mortality. 3
Multiple symptom comorbidities are typical, with patients reporting an average of 9.9 current symptoms, including fatigue (93%), memory difficulties (80%), and headache (70%). 3
Measurable improvements occur across mobility, depression, and quality of life domains with multidisciplinary treatment, with realistic timelines for improvement being 12-25 months. 1
Prognosis and Long-Term Outlook
Early diagnosis and treatment are critical for optimal outcomes, with recovery often following a pattern of symptom remission and exacerbation rather than linear improvement. 2 The potential for symptom reversal remains throughout the disease course. 2
When explaining the diagnosis, clinicians should emphasize that symptoms are real but potentially reversible, avoiding language that suggests permanent neurological injury or shortened lifespan. 2
The median FND symptom duration is 5 years, with median time from first symptom to diagnosis being 2 years, highlighting the chronic nature for many patients despite normal life expectancy. 3