in DSM–IV–TR, a disorder in which the essential feature is an identical or similar delusion that develops in an individual who is involved with another individual (sometimes called the “inducer” or the “primary case”) who already has a psychotic disorder with prominent delusions. Shared psychotic disorder can involve many people (e.g., an entire family) but is most commonly seen in relationships of only two, in which case it is known as folie à deux. In DSM–5, the disorder is not recognized or included as a distinct diagnostic entity separate from delusional disorder. Formerly called induced psychotic disorder.