It was quickly identified as being especially useful in the treatment of affective psychosis.

To be blunt, dear, he's a manic-depressive; he has an affective psychosis, periodically.

Thus some investigators have argued that the association is one, not with schizophrenia, but with affective psychosis.

In his writings, Ziehen is credited with introducing the terms "affective psychosis" and "psychopathic constitution".

Although schizophrenia and the associated traits of 'schizotypy' have been the main focus of interest, research has also shown similar continuity with affective psychosis.

Over 70 per cent of both groups were considered psychotic, with rather more men schizophrenic and rather more women suffering affective psychosis.

Medcalf goes even further, quoting a clinician's opinion that Hoccleve suffered several episodes of a manic form of affective psychosis.

In addition to these signs of affective psychosis Kempe also showed features of schizophrenia, notably hallucinations, occurring in several modalities.

Furthermore, the symptoms of even full-blown affective psychosis and schizophrenia overlap considerably, suggesting that they simply represent different ways in which a common tendency to insanity can manifest itself.

Others respond to high-dose abuse with the kind of grandiosity and hyperactivity that leads to a false diagnosis of unipolar affective psychosis - mania, in lay terms.'

In addition to these informal clinical observations, there are several other, more scientific, reasons for believing that schizophrenia and affective psychosis are not as distinct from each other as was once thought.

It has been highly influential on modern psychiatric classification systems, the DSM-IV-TR and ICD-10, and is reflected in the taxonomic separation of schizophrenia from affective psychosis.

Her findings were that both the writers themselves and their families had a substantially raised incidence of mental illness, but especially of affective psychosis, including depression and forms of the disorder characterised by severe mood swings.

Such mixture of affective psychosis and schizophrenia may be revealed in changes in the symptom profile that are observed when the person is studied over a period of time, or it may be evident within a single episode of illness.

We can appreciate one reason for this if we examine the question, not from the viewpoint of symptoms used to try to distinguish schizophrenia from affective psychosis, but by looking at the underlying psychological processes that are responsible for the two states.

In these cases some psychiatrists resort to the description 'schizoaffective' which, although itself an old term, is now often used in recognition of the fact that the traditional categories of schizophrenia and affective psychosis really only represent varieties of insanity as they occur in their pure forms.

Although it is the mood disturbance that stands out in affective psychosis, individuals who meet the criteria for either the 'unipolar' or the 'bipolar'form (as they are sometimes called) sometimes also show features reminiscent of schizophrenia, as we shall see for several of the subjects evaluated in this book.

If terms like 'affective psychosis', 'schizophrenia' and 'schizoaffective disorder'have a use, therefore, it is merely as labels of convenience, as shorthand descriptors of the flavour of a given individual's form of insanity - and even then often only at a certain point in time and subject to qualifications as to the severity of disability.

In the modern era the concept of schizoaffective psychosis, which straddles the Kraepelinian divide, when delineated as a condition sharing a common causal pathway as both schizophrenia and affective psychosis, shares aspects of the more radical notion of unitary psychosis in regarding the individual psychoses as points on a continuum.