Here is the World Health Organization's definition of schizoaffective disorders:
These are episodic disorders in which both affective and schizophrenic symptoms are prominent within the same episode of illness, preferably simultaneously, but at least within a few days of each other. Their relationship to typical mood (affective) disorders and to schizophrenic disorders is uncertain. They are given a separate category because they are too common to be ignored. Other conditions in which affective symptoms are superimposed upon or form part of a pre-existing schizophrenic illness, or in which they coexist or alternate with other types of persistent delusional disorders, are classified under the appropriate category. Mood-incongruent delusions or hallucinations in affective disorders do not by themselves justify a diagnosis of schizoaffective disorder. Patients who suffer from recurrent schizoaffective episodes, particularly those whose symptoms are of the manic rather than the depressive type, usually make a full recovery and only rarely develop a defect state.
Diagnostic GuidelinesA diagnosis of schizoaffective disorder should be made only when both definite schizophrenic and definite affective symptoms are prominent simultaneously, or within a few days of each other, within the same episode of illness, and when, as a consequence of this, the episode of illness does not meet criteria for either schizophrenia or a depressive or manic episode. The term should not be applied to patients who exhibit schizophrenic symptoms and affective symptoms only in different episodes of illness. It is common, for example, for a schizophrenic patient to present with depressive symptoms in the aftermath of a psychotic episode. Some patients have recurrent schizoaffective episodes, which may be of the manic or depressive type or a mixture of the two. Others have one or two schizoaffective episodes interspersed between typical episodes of mania or depression. In the former case, schizoaffective disorder is the appropriate diagnosis. In the latter, the occurrence of an occasional schizoaffective episode does not invalidate a diagnosis of bipolar affective disorder or recurrent depressive disorder if the clinical picture is typical in other respects.
Schizoaffective Disorder, Manic TypeA disorder in which schizophrenic and manic symptoms are both prominent in the same episode of illness. The abnormality of mood usually takes the form of elation, accompanied by increased self-esteem and grandiose ideas, but sometimes excitement or irritability are more obvious and accompanied by aggressive behaviour and persecutory ideas. In both cases there is increased energy, overactivity, impaired concentration, and a loss of normal social inhibition. Delusions of reference, grandeur, or persecution may be present, but other more typically schizophrenic symptoms are required to establish the diagnosis. People may insist, for example, that their thoughts are being broadcast or interfered with, or that alien forces are trying to control them, or they may report hearing voices of varied kinds or express bizarre delusional ideas that are not merely grandiose or persecutory. Careful questioning is often required to establish that an individual really is experiencing these morbid phenomena, and not merely joking or talking in metaphors. Schizoaffective disorders, manic type, are usually florid psychoses with an acute onset; although behaviour is often grossly disturbed, full recovery generally occurs within a few weeks.
Schizoaffective Disorder, Depressive TypeA disorder in which schizophrenic and depressive symptoms are both prominent in the same episode of illness. Depression of mood is usually accompanied by several characteristic depressive symptoms or behavioural abnormalities such as retardation, insomnia, loss of energy, appetite or weight, reduction of normal interests, impairment of concentration, guilt, feelings of hopelessness, and suicidal thoughts. At the same time, or within the same episode, other more typically schizophrenic symptoms are present; patients may insist, for example, that their thoughts are being broadcast or interfered with, or that alien forces are trying to control them. They may be convinced that they are being spied upon or plotted against and this is not justified by their own behaviour. Voices may be heard that are not merely disparaging or condemnatory but that talk of killing the patient or discuss this behaviour between themselves. Schizoaffective episodes of the depressive type are usually less florid and alarming than schizoaffective episodes of the manic type, but they tend to last longer and the prognosis is less favourable. Although the majority of patients recover completely, some eventually develop a schizophrenic defect.
(excerpted from the ICD-10 - Classification of Mental and Behavioural Disorders, World Health Organization, 1992)
