Research has shown that an exact delineation of prototypic disorders, such as schizophrenia and mood disorders, is not possible. There are presumably genetically determined overlaps between a schizophrenic and an affective spectrum giving rise to psychotic disorders that have features of both prototypes. Such psychoticdisorders, which are called paratypes, for example schizoaffective disorder or acute and transient psychotic disorder, have clinical and paraclinical similarities and form a continuum between the two prototypes. This is supported by numerous strong arguments in the fields of premorbidity, phenomenology, course of disorder, prognosis, genetics, biology and neuropsychology.
A. Μarneros (page 275) - Full article