RESEARCH NEWS: New Guidance on Autoimmune Encephalitis in Psychiatry

Sometimes psychiatric symptoms point to the immune system.

Recommendations have now been published on how psychiatric services should look for autoimmune encephalitis (AE).

Introduction

In September 2026, the German Network for Research on Autoimmune Encephalitis (GENERATE) published new recommendations in Molecular Psychiatry on how psychiatric services should look for AE.

The guidance, by Endres et al., brings together more than 50 psychiatrists and neurologists, and identifies AE as a real and treatable cause of psychiatric illness.

It stresses, however, that AE is a rare cause of psychiatric illness. Well-characterised antibodies turn up in fewer than 2% of German psychiatric CSF cohorts, and the authors warn of overdiagnosis, false-positive serum results, and inappropriate immunotherapy.

The guidance

The researchers recommend a stepwise approach that begins with clinical history and examination. Warning signs include gradual onset of neurological symptoms like seizures and altered sensorium. These are often accompanied or preceded by psychiatric symptoms such as psychosis, behavioural change or anxiety. Red flags in psychiatric patients include rapid decline, marked cognitive changes, and visual hallucinations; though none is conclusive on its own.

The next step should then be MRI, EEG, blood tests, and lumbar puncture (LP).

Subsequent antibody testing should use paired serum and CSF samples, acknowledging exceptions (e.g., for LGI1 antibodies). The authors recommend a two-stage approach to antibody testing: first a targeted panel of well-established antibodies, then more extensive testing only for patients where suspicion remains high or results are unclear. Importantly, they caution that a positive antibody result from blood alone, particularly at low levels, does not by itself constitute a diagnosis of AE or justify immune treatment.

Other recommendations

A scan known as FDG-PET ([¹⁸F]fluorodeoxyglucose positron-emission-tomography) can show how brain regions use glucose by revealing regional changes in metabolism even when structural MRI appears normal. Although not recommended for routine clinical work-up, it can be helpful in ambiguous cases after performing the aforementioned diagnostic tests.

The paper also proposes “immunoboards” where specialists including psychiatrists, neurologists, immunologists, neuropsychologists, and laboratory medicine specialists jointly review difficult cases. Regular interdisciplinary case conferences, the researchers contend, can reduce the risk of both under-recognition and over-diagnosis, whilst helping maintain consistency in the interpretation of ambiguous findings. The team points to tumour boards, well established in oncology, as a model for immunoboards.

The researchers

Two of the researchers, Carsten Finke and Frank Leypoldt, are members of Encephalitis International’s Scientific Advisory Panel, which provides expert professional guidance, and informs the organisation’s research strategy, information resources and guidance.

Carsten Finke is Heisenberg Professor for Cognitive Neurology and Consultant Neurologist at the Department of Neurology at Charité Berlin.

Frank Leypoldt is Head of the Neuroimmunology section at the Institute of Clinical Chemistry and Laboratory Medicine, Department of Neurology, Kiel University.

Conclusion

The authors stress that these are expert recommendations and not formal diagnostic criteria. They were developed through discussion among the network’s experts rather than a formal consensus process or systematic review.

The tools are practical: a stepwise plan for structured testing, paired blood and spinal fluid analysis, and interdisciplinary review.

Many questions remain open, including how to interpret novel antibodies and which patients truly benefit from extended testing. For now, the lesson for clinicians is: think broadly, test carefully, and interpret results in context.

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To read the full paper, click here.

To view our information on autoimmune encephalitis, click here.