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The diagnosis of schizophrenia like many medical conditions is not made on the basis of one symptom but on the occurrence of several symptoms which together support the diagnosis of the syndrome.
Schizophrenia was first recognised as a discrete syndrome in the middle of the last century, though the term schizophrenia was first used by Bleuler in 1911.
Historical Perspective
Morel 1856:
Demence Precoce - Bizarre behaviour and mental function, withdrawal and self neglect starting in adolescence.
Kahlbaum 1868:
Katatonie - stereotyped movements, outbursts of excitement and stupor.
Hecker 1871:
Hebephrenia - similar to Demence Precoce.
Kraepelin 1896:
Dementia praecox - grouped together all of the above with the addition of dementia paranoides. He considered hallucinations, delusions, thought disorder, negativism and emotional blunting to be characteristic of dementia praecox. He also observed that the onset was usually in early adult life and often progressed to a "demented" end stage. However he realised that the breakdown was not intellectual, the onset was not necessarily in adolescence and the prognosis was not always poor.
Bleuler 1911:
Schizophrenia - He described the four "A's", symptoms which he thought were characteristic of schizophrenia: Ambivalence, Autism, flattened Affect, loosening of Associations.
Increasing confusion arose as the term schizophrenia was used to describe a wide spectrum of disorders in America and Europe. In the 1950's with the advent of research into the new groups of drugs used in the treatment of schizophrenia there was an increasing need for clear diagnostic criteria.
Schneider 1959:
First Rank Symptoms - a group of symptoms that Schneider proposed were diagnostic of schizophrenia in the absence of overt brain disease.
- Auditory hallucinations of a specific type:
- Audible thoughts: a voice anticipating or repeating the patients thoughts aloud.
- Two or more voices discussing the patient in the third person.
- Voices commenting on the patient's behaviour.
- Thought alienation:
- Passivity phenomena:
- Experiences of bodily influence.
- Made acts/impulses/affects - experiences which are imposed on the individual or influenced by others.
- Delusional perceptions (A two stage process) where first a normal object is perceived then secondly there is a sudden intense delusional insight into the objects meaning for the patient e.g. "The traffic light is green therefore I am the King".
The problem with Schneider's symptoms is that they are:
Not specific for schizophrenia - 8% of psychotic patients with these symptoms are not schizophrenic for example they may be suffering from delusions or hallucinations in the context of a severely elated or depressed mood state or an organic disorder.
Not present in some patients with schizophrenia - 20% of chronic schizophrenics do not have them and never had. This is partly explained by the fact that Schneider concentrated on the acute phase of the illness when formulating his first rank symptoms.
Schneider's work stimulated the search for optimal diagnostic criteria - one set of criteria used both in clinical work and research are those published in I.C.D.-10 Classification of Mental and Behavioural Disorders. These diagnostic criteria enable a diagnosis of schizophrenia to be made in both acute and chronic phases of the illness. They also reduce the likelihood of the misdiagnosis schizophrenia in those with primary disorders of mood (depression and mania) and organic syndromes such as toxic confusional states and epilepsy.
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