Lennox B, Palmer-Cooper EC, Pollack T et al. Lancet Psychiatry Jan 2017; 4(1):42-48

In recent years, anti-NMDA encephalitis has been shown to present with symptoms of first episode psychosis, leaving health professionals uncertain how commonly young people with first episode psychosis may have this underlying condition and whether or not they should be screened via blood tests and/or lumbar puncture at the time of diagnosis. Data from this multi-site study of over 200 young people in the UK revealed that 3% of patents with first episode psychosis had NMDAR antibodies compared with none of the healthy controls. There were no clinically distinguishing features between those with and without NMDAR antibodies, prompting the authors to call for routine screening of people with first-episode psychosis.

http://thelancet.com/journals/lanpsy/article/PIIS2215-0366(16)30375-3/abstract