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

“It’s all in your head.”

By the time many people with functional neurological disorder arrive in our clinic, they have heard these five words more times than they can count. They are told their brain scan was normal. Their electroencephalogram, a test that measures the brain’s electrical activity, is reassuring. “The good news is you don’t have epilepsy,” they’re told.

No test can explain why they can’t walk without falling, why their leg won’t stop trembling, or why they experience seizures that leave them exhausted for hours, even days. Some begin to wonder if they really are imagining it.

Over the past several years working as the program manager of one of the few multidisciplinary clinics for functional neurological disorder, I have watched the same story unfold again and again, from long diagnostic journeys and deep uncertainty to the profound relief of finally being believed. Dr. Laura Strom, one of the neurologists at the clinic, often reassures patients, “Well, it’s good that it’s all in your head – because that’s where your brain is.”

For decades, this gap between normal test results and very real, debilitating symptoms had left patients with few answers. Today, neuroscience offers a different explanation.

Understanding functional neurological disorder

Every movement you make, every sensation you feel and every emotion you experience begins with your brain. The question was never whether the brain was involved in creating the distressing physical symptoms of functional neurological disorder, but how.

Brain imaging studies suggest that the networks responsible for movement, attention, emotion, body awareness and sensory processing are constantly communicating with one another. Rather than acting independently, these networks work together to create thoughts, perceptions and actions.

How these brain networks communicate, and occasionally miscommunicate, is one of the central questions researchers are trying to answer about functional neurological disorder.

One of the leading theories helping explain this condition is known as predictive processing. Rather than simply reacting to your world, this theory suggests that the brain is constantly making predictions. It combines past experiences, information from your surroundings and signals from inside your body to create your everyday experiences.

Think about walking up a flight of stairs. You don’t consciously calculate where to place every foot or which muscles to contract. Your brain has already predicted the movement before you make it. Most of the time, these predictions are remarkably accurate.

As new information reaches the brain, the brain compares it with existing expectations or predictions – shaped by current and past experiences – along with signals from the body. If the new information it receives doesn’t match up, the brain then updates its predictions. Scientists call this mismatch prediction error. Researchers believe the disruption of this updating process may be one mechanism behind this neurological disorder.

Although there is no single cause of functional neurological disorder, factors such as injury, illness, pain or significant stress may make the brain more likely to rely on prior predictions instead of new information. If the brain places too much weight on prior expectations or certain bodily signals, it can make adjusting predictions in response to new information more difficult.

For example, after an injury has healed, the brain may continue predicting that a movement or activity is unsafe. This could contribute to persistent weakness or difficulty walking despite no ongoing harm to the body. The result is symptoms that are involuntary, physically real and profoundly disabling, even though there is no damage happening to the brain or nervous system.

History of functional neurological disorder

Our current understanding of functional neurological disorder as a disconnect between the brain and body marks a dramatic shift from how doctors and researchers have perceived the brain over the past century.

At different points in history, this condition has been called hysteria or conversion disorder. It was conceptualized as “psychogenic,” meaning symptoms were thought to originate primarily from psychological factors rather than biological changes in the brain. Each name reflected the best explanation medicine had at the time but did not represent what people were actually experiencing.

Many of the symptoms now recognized as part of the disorder were primarily attributed to the emotional and psychological state of women and subsequently dismissed. These explanations reflect broader gaps and biases in how doctors approached women’s health concerns throughout history, contributing to decades of stigma and misunderstanding around functional neurological disorder and other conditions.

As neuroscience advanced, researchers began recognizing that symptoms could arise from changes in brain function rather than visible changes to the brain, such as injury or abnormalities seen through brain imaging. Today’s models focus more on brain networks and the dynamic, interconnected relationship between the brain, body and environment.

How common is functional neurological disorder?

Functional neurological disorder is more common than many people may realize. A 2025 review estimated that up to 5 million Americans are living with the condition, and people across the lifespan experience symptoms. Researchers estimate that mortality rates among patients with the condition are more than twice that of the general population.

Yet despite its prevalence, access to specialized care remains limited. The condition exists in a treatment desert, likely due to a mismatch in supply and demand for specialists and limited funding. Many healthcare professionals receive little to no formal education about functional neurological disorder during training.

Delayed diagnosis is only one consequence of misunderstanding this condition. Patients are frequently told they are exaggerating, faking symptoms, seeking attention or that everything is “just anxiety.” These misconceptions not only perpetuate stigma around the condition, they also delay appropriate treatment and expose people to unnecessary medical interventions.

Patients often become the ball in a game of medical ping-pong. Psychiatry refers them to neurology because the symptoms appear neurological. Neurology refers them back to psychiatry because their scans are normal. In this game, the only loser is the patient.

People with functional neurological disorder experience disproportionately high use of healthcare services, cycling repeatedly through emergency departments and specialty clinics in search of answers and validation. Some receive medications they don’t need. Others undergo invasive procedures before receiving the correct diagnosis.

Trauma, anxiety, depression and post-traumatic stress disorder are more common among people with the disorder, but many develop it without any history of trauma. Biological, psychological and social factors all play a role, highlighting how there is no single pathway that leads to the condition.

Future research and treatment

The story of functional neurological disorder is beginning to turn a corner. New multidisciplinary clinics are opening, research is accelerating, and, with that, understanding of the disorder continues to grow.

The treatment landscape for the disorder is evolving to help the brain learn new, healthier patterns to process the world. Psychotherapy, physical therapy, occupational therapy and speech therapy each play a role in retraining disrupted brain networks. Recovery looks different for everyone, but growing evidence shows that improvement is possible.

The most important step forward, however, happens before any therapy begins: when a healthcare provider believes their patient.

Maybe the medical community has misunderstood what “It’s all in your head” means all along. While every movement, sensation, emotion and thought begins with the brain, that does not make these symptoms imagined. It makes them neurological.

For the millions of people living with the disorder, understanding may be the beginning of recovery rather than another dead end.