The term schizoaffective relates to conditions in which a person has mood episodes that will meet criteria for a diagnosis of bipolar disorder (mania, mixed and depressed) but in addition has symptoms of schizophrenia, typically psychotic symptoms such as hallucination, delusions, and disorganized thought processes, that persist after the mood episode has resolved.
Whether or not schizoaffective disorder, like all of the diagnostic labels we’ve been using, is truly a separate entity is a matter of debate and study. What may pan out to be true, or close to it, is that schizoaffective disorder is another twist on the notion that bipolar disorder, and schizophrenia as well, represents a continuum of illness, and the presence of persistent psychosis after the mood state has resolved is a variant. Genetic studies have found overlap between genes involved in schizophrenia, schizoaffective disorder and bipolar disorder. Family trees where these conditions, along with unipolar depression, are found at an increased frequency add support to the continuum theories.