There are many lines of evidence to suggest that a proportion of psychosis has an autoimmune basis, however to date there have not been any biomarkers to identify individuals that might benefit from immune modifying treatments. This has potentially changed with the discovery of pathogenic antibodies in patients with autoimmune encephalitis. There are many parallels between autoimmune encephalitis and primary psychotic disorders, however whilst this new knowledge has led to a rapid and widespread change in clinical practice in neurology, there has not been an equivalent change in practice for psychiatry. I will discuss the current level of evidence around the concept of autoimmune psychosis and how psychiatry needs to transform to be able to adequately investigate and treat patients with psychosis.