|A disorder characterized by
eccentric behaviour and anomalies of thinking and affect
which resemble those seen in schizophrenia, thought no
definite and characteristic schizophrenic anomalies have
occurred at any stage. There is no dominant or typical
disturbance, but any of the following may be present:
(a) inappropriate or constricted
affect (the individual appears cold and aloof);
The disorder runs a chronic course with fluctuations of intensity. Occasionally it evolves into overt schizophrenia. There is no definite onset and its evolution and course are usually those of a personality disorder. It is more common in individuals related to schizophrenics and is believed to be part of the genetic "spectrum" of schizophrenia.
This diagnostic rubric is not recommended for general use because it is not clearly demarcated either from simple schizophrenia or from schizoid or paranoid personality disorders. If the term is used, three or four of the typical features listed above should have been present, continuously or episodically, for at least 2 years. The individual must never have met criteria for schizophrenia itself. A history of schizophrenia in a first-degree relative gives additional weight to the diagnosis but is not a prerequisite.