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Could some mental health conditions be caused by an immune malfunction

The Victorians routinely sent people with Syphilis to the asylum until it was discovered that the real cause of their mental disturbance was an infectious disease.
Recent research has shown that these sorts of diagnostic misunderstandings aren’t just a thing of the past.

Some patients who exhibit classic symptoms of psychosis may not actually have a psychiatric condition, but a rare form of encephalitis. This is when antibodies produced by the immune system attack the brain’s own proteins, in this case its NMDA receptors. This receptor is involved in learning and memory, therefore sufferers exhibit the same problems experienced by patients with psychosis, such as visual and auditory hallucinations.

The biological cause for this condition is now increasingly recognized by psychiatrists and neurosurgeons. Patients have been successfully treated with immunotherapy, which removes the rogue antibodies from the patient’s blood. This treatment has led to patients making a dramatic recovery.

So, in these cases, what initially appears to be a psychiatric illness is caused by an immune malfunction requiring a completely different kind of treatment. This discovery is leading to a seismic shift in our understanding of mental illness and opening up a new field of medical investigation.

At the forefront of the research is consultant psychiatrist Professor Belinda Lennox from the University of Oxford. She began to look at patients diagnosed with schizophrenia. She wanted to see whether some might also have an autoimmune condition that had gone unrecognised. To find out, she carried out blood tests on a group of patients to see if they had the same rogue antibodies as found in cases of anti-NMDA encephalitis. She found that around 1 in 11 patients matched positive for these antibodies.

These patients were treated with immunotherapy and made a dramatic if not total recovery.

Prof Lennox’s trial holds the promise that in future, patients who appear to have symptoms of a severe mental illness could be tested for an autoimmune condition, and in some cases treated with immunotherapy. It’s such an exciting prospect that research has already begun at other universities to see if immunotherapy might also be used in more common mental health conditions such as depression.