Research indicates that antibodies erroneously targeting the brain may contribute to disorders such as schizophrenia, dementia, and obsessive-compulsive disorder, reshaping views on mental health.
About 15 years ago, several women at a neurology facility in London exhibited similar unusual symptoms. Some appeared rigid and unresponsive, while others had convulsions or movement difficulties. Initially, their conditions resembled standard psychotic episodes, involving restlessness, visions, and false beliefs. During these episodes, some sought care at emergency rooms or mental health centers.
Neuropsychiatrist Thomas Pollak initially viewed their records as typical psychiatric cases. However, the diagnosis revealed autoimmune encephalitis, a brain inflammation triggered by the body’s immune response. This finding challenged the traditional separation between mental and neurological disorders, profoundly impacting Pollak.
Since then, Pollak, now based at King’s College London, has contributed to a growing research area demonstrating that autoimmune issues influence mental health more significantly than previously thought. While connections between schizophrenia and autoimmune diseases have been noted for years, recent studies by Pollak and colleagues have broadened this understanding, linking autoimmunity to conditions like post-traumatic stress disorder, obsessive-compulsive disorder, depression, and dementia.
This development opens the door to treating certain mental health issues with immune-modulating medications, an approach not commonly used by physicians. Psychiatrist Andrew Miller from Emory University School of Medicine in Georgia notes that the immune system’s role in behavior is underappreciated.
The immune system can protect against invaders like bacteria and viruses but sometimes malfunctions, directing components such as antibodies, cytokines, and T-cells against healthy tissues—a process known as autoimmunity. Christopher Bartley, who heads the Translational Immunopsychiatry Unit at the US National Institutes of Health, explains that autoimmunity affects every organ, including the brain.
The connection is most evident in psychotic disorders like schizophrenia. Two decades ago, researchers identified anti-NMDAR encephalitis, where specific antibodies attach to brain receptors, leading to symptoms like false beliefs, hallucinations, memory impairment, and unusual actions.
Although symptoms overlap, treatments differ: encephalitis responds to immune-suppressing drugs, while schizophrenia is often managed with antipsychotics, which fail for about one-third of patients.
Diagnosing autoimmune encephalitis can dramatically improve outcomes with straightforward therapies, according to psychiatrist Belinda Lennox at the University of Oxford, who researches psychotic disorders. However, it requires testing for autoantibodies or other immune irregularities, which may be overlooked in apparent psychiatric cases.
The women Pollak encountered were transferred after developing neurological signs like seizures and immobility, but some individuals with this condition mimic schizophrenia for extended periods, leading to prolonged stays in mental health facilities or unsuitable care. In a recent UK case, a young girl took her own life after medical professionals neglected to perform a spinal fluid test for the disorder, which a coroner’s panel determined might have played a role in her death.
Conditions like multiple sclerosis and lupus are recognized for causing neurological effects, and experts have long suspected autoimmunity’s involvement in schizophrenia. The identification of anti-NMDAR encephalitis has heightened interest in the intersection between these fields.
