One of the most common brain disorders is one of the most misunderstood – how functional neurological disorder is both ‘all in your head’ and beyond it

Functional neurological disorder, once known by various names like hysteria or psychogenic illness, is a brain condition that has long been misunderstood. Many patients arrive at clinics feeling that their symptoms are "all in their head" due to normal test results, leading to confusion and frustration. Despite normal scans and EEGs, patients experience debilitating symptoms like uncontrolled movements, tremors, and seizures-like episodes.

Research suggests that faulty communication between brain networks causes this disorder. The brain constantly makes predictions based on past experiences, surroundings and body signals to create our movements, emotions and thoughts. When new information doesn't match these expectations, the brain tries to update its predictions, a process called prediction error. Disruptions in this process may lead to the symptoms of functional neurological disorder.

While there's no single cause, factors like injury, illness, pain, or stress may make the brain overly reliant on old predictions, causing it to struggle adjusting to new information. This results in involuntary, real symptoms despite no visible damage to the brain or nervous system.

Historically, this condition was often misunderstood, labeled as "psychogenic" and dismissed, particularly affecting women. Advances in neuroscience now recognize this as a brain-body disconnect, with complex networks interacting. Although rare, the condition affects up to 5 million Americans and has higher mortality rates compared to the general population. Despite its prevalence, specialized care remains limited, highlighting the need for further understanding and treatment options.