In May 2024, sisters Christine and Angie called in a psychiatrist to assess their mother, Mary, who had battled paranoia and delusions for decades and had been repeatedly diagnosed with schizophrenia. But to their surprise, the psychiatrist found no signs of mental illness. “The psychiatrist said, ‘Why have you called me here? She has no symptoms,’” Christine recalled. “And we said, ‘Exactly—that’s why we called you.’”
This marked the beginning of a medical mystery, explored in The New Yorker by Rachel Aviv. Mary’s long-standing psychiatric symptoms had faded—coinciding with her recent treatment for lymphoma. The treatment included rituximab, an immunosuppressant, which Christine and Angie now believe may have inadvertently alleviated their mother’s psychosis.
Aviv highlights other cases that suggest a potential link between immune system dysfunction and psychiatric illness. One woman, institutionalized for 25 years with schizophrenia, dramatically improved after being given rituximab to treat lupus. “It was like she woke from a 25-year coma,” said a Columbia University psychiatry professor involved in her care.
These stories are fueling new research into whether immune-based therapies, such as immunosuppressants, might benefit some psychiatric patients—particularly those diagnosed with schizophrenia. As Aviv notes, schizophrenia is not tied to a single cause or biological marker, making it difficult to treat universally.
While such cases are rare—some experts estimate only 1% to 5% of schizophrenia diagnoses may actually stem from underlying autoimmune issues—that still represents hundreds of thousands of people worldwide who might respond to different treatments. As one researcher put it, “Even 1% ends up being almost a million people globally who should be treated with a different kind of medicine.”