Imagine your daughter has lost the ability to walk, and so you take her to the emergency room. How would you feel if you then overheard the doctor who saw your child laughing at her situation with colleagues? This scenario may sound absurd, but it's based on a true story.

In 2021 researchers published several anecdotes from real cases involving functional neurological disorder (FND). What the vignettes reveal is that medical professionals, including nurses, ambulance drivers and physicians, sometimes treat this condition without concern, as though patients were simply faking their behavior. In my own experience as a neurologist, I have overheard doctors dismiss and laugh at their patients' FND symptoms when they are behind closed doors.

Although the disorder is not well known to the public, FND is actually one of the most common conditions that I and other neurologists encounter. In it, abnormal brain functioning causes physical symptoms to appear. FND comes in many forms, with symptoms that can include seizures, inability to move a limb and movement disorders. People may lose consciousness or their ability to move or walk, or they may experience abnormal tremors or tics. The ailment can be highly disabling and just as costly as neurological conditions with structural origins such as amyotrophic lateral sclerosis (also known as Lou Gehrig's disease), multiple sclerosis and Parkinson's disease.

Although men can develop FND, young to middle-aged women receive this diagnosis most frequently. During the first two years of the COVID pandemic, FND briefly made international headlines when vocal and motor tics such as repeating words or clapping uncontrollably spread with social media usage, particularly among adolescent girls.

So why would a medical professional accuse someone who has lost control of their limbs or has experienced a seizure of faking their symptoms? Unfortunately, many such professionals have a poor or outdated understanding of FND, despite the frequency with which they encounter it. Because nothing is structurally wrong with the patient's brain—clinical testing reveals no obvious injury—physicians may write symptoms off as “all in their head” or dismiss them as psychological. That response, recent research shows, can harm a person who is already suffering. Fortunately, there is another path forward, rooted in sensitivity, respect and new evidence-based approaches.

Historically FND was called conversion disorder. The term came from the belief that traumatic stress was “converted” into functional neurological symptoms via psychological mechanisms. We now know that this understanding is incomplete. Stress and trauma can play a part. In fact, some researchers believe the unique global stressors our society faced during the COVID pandemic increased some people's susceptibility to the condition. But not every person with FND has experienced a traumatic event. New research suggests that biological susceptibility and exposure to stressful events over a lifetime may make a person more vulnerable to developing FND. In fact, relatively minor stressful events such as work-related stress, a viral infection or a small physical accident often precede the onset of FND symptoms.

Recent advances in brain imaging indicate that FND is caused by abnormalities in the functioning of brain networks. Some experts use the analogy that the brain's hardware (or structure) is fine, but the software (or processing) is malfunctioning. For example, studies suggest that in FND, several networks of electrical and chemical signaling pathways between groups of neurons or larger brain regions are not working together as typically expected. These networks include structures of the limbic system, such as the amygdala, that are important in our brain's processing of emotions or stress. Among people with FND, the amygdala is more active when subjected to sad or fearful stimuli. Other brain functions involved in FND include how we plan and interpret sensations in response to our movements, as well as our abilities to pay attention, be aware of our body and experience the feeling of control over our person.

Neuroimaging underscores that people with FND are not “faking” anything. Scientists have found decreased activity in supplementary motor areas and the right temporoparietal junction, which influence whether a patient's symptoms feel under their control. There are also abnormalities in the connections between brain areas responsible for interpreting internal physical sensations and motor planning. These differences in brain activity may help explain one key way that FND differs from other disorders that feature tics, such as the structural neurological condition Tourette's syndrome. As a research team at the University of Calgary in Canada explored in a paper published last November, people with Tourette's report some degree of control in suppressing their tics. In contrast, the symptoms of FND feel entirely involuntary.

Clinicians are also finding better ways to diagnose FND. In the past, neurologists considered conversion disorder to be a diagnosis of exclusion, meaning a diagnosis was made after physicians had ruled out structural neurological abnormality through examination, radiological imaging, laboratory studies and neurophysiological testing such as electroencephalography (EEG). As a result, many patients with FND felt their doctor had told them what they didn't have, not what they did have.

But in the past decade neurologists have developed diagnostic criteria to determine which symptoms are linked to functional brain abnormalities. These emphasize characteristic “positive,” or “rule-in,” findings based on a neurologist's physical examination, which can predict FND as the basis for a patient's symptoms. For example, a FND patient's symptoms may be inconsistent or change when distracted with another task. A combination of a thorough neurological examination, EEG, brain imaging and lab testing can show whether a person's symptoms are consistent with a structural brain pathology—for instance, a stroke or a brain tumor—or a functional condition such as FND.

Together these advances in the diagnosis and understanding of FND mean doctors are in a better position than ever to identify and understand this disorder. Nevertheless, many patients still have the disorienting, distressing experience of being treated with dismissal or disbelief by medical professionals.

This reaction has damaging consequences. In January a collaboration of researchers at the University of Sheffield in England, Arizona State University and the New York–based Northeast Regional Epilepsy Group laid out case studies and other evidence that clinicians' unsupportive responses to their patients may contribute to a sense of shame in people who are already suffering psychologically from their functional symptoms. In fact, being prone to shame may itself be an additional risk factor for FND.

This connection to shame and stigma takes on an even greater weight when we consider that marginalized groups such as members of the LGBTQ+ community may be at increased risk for functional disorders. A person experiencing stressors such as discrimination, bias and stigma because of their identity can internalize feelings of shame when their psychosocial support systems and coping mechanisms are inadequate or overwhelmed. If someone in this situation has FND, receiving treatment from a doctor who lacks empathy or a current understanding of the condition only makes things worse. Telling a patient their condition is “in their head” contributes to medical misinformation and further stigmatizes people with these disorders.

But this problem can be addressed. Researchers have found that how empathetically a doctor informs their patient about an FND diagnosis influences that patient's likelihood of accepting the diagnosis and successfully completing treatment. And appropriate treatment works. Therapy may combine psychoeducation, medication for any coexisting mental health conditions, psychotherapy and physiotherapy. Outcomes for people who receive sensitive and appropriate care are actually very good.

This year my colleagues and I will publish our observations on the treatment of LGBTQ+ people with FND. Our preliminary findings are promising. Most patients had improvement or complete resolution of their functional symptoms after treatment. In some of our patients, these results can be quite important. We have treated people with functional blindness who then regained the ability to see, and we have watched those in wheelchairs regain the ability to walk. In short, care and compassion can be powerful medicine.