Classification Of Schizophrenia Flashcards
What are positive symptoms?
These are additional experiences beyond those of ordinary existence.
What are negative symptoms?
Those that appear to reflect a reduction or loss of normal functions. They weaken a persons ability to cope with everyday activities, affecting their quality of life and their ability to manage without significant outside help. The enduring presence of two or more negative symptoms for 12 months or longer is sometimes referred to as ‘deficit syndrome’. Negative symptoms respond poorly to antipsychotic treatment. However the newer atypical antipsychotic are claimed to be superior in this respect to the older typical antipsychotic treatment.
What is schizophrenia?
A severe mental disorder characterised by a profound disruption of cognition and emotion. It affects a persons language, thought, perception, emotions and sense of self. It ranks among one of the top ten cases of disability worldwide and effects about 4 in 1000 people some time in their lives (Saha et al. 2005)
What are the two major systems of classification?
World health organisations international classification of disease edition and the American Psychiatric Association’s Diagnostic and Statistical Manual edition.
The American classification requires one of the positive symptoms to be present whereas the WHO one just requires two negative systems. The WHO also recognises different types of schizophrenia, such as Paranoid schizophrenia-powerful delusions and hallucinations, or Hebephrenic schizophrenia which involves negative symptoms.
What is avolition?
The reduction, disability, or inability to initiate and persist in goal-directed behaviour, often mistaken for apparent disinterest.
Subtypes of schizophrenia (as described in the DSM-5h)
Disorganised type: disorganised behaviour and not goal directed. Symptoms include disturbances (delusions and hallucinations), an absence of expressed emotion, incoherent speech, large mood swings and loss of interest in life. This is usually diagnosed in adolescence.
Catatonic schizophrenia: diagnosed if the patient has severe motor abnormalities such as unusual gestures or use of body language. Sometimes patients gesture repeatedly, using complex sequences of finger, hand and arm movements, which appear to have some meaning for them. This often involves doing opposite to what is being asked or repeating everything that is said. Main feature is immobility at a time with the patient staring blankly.
Paranoid schizophrenia: involves delusions (persecution and grandeur); but the patient remains emotionally responsive. More alert than patients with other types of schizophrenia. They tend to be argumentative and has a later onset than other types.
Undifferentiated schizophrenia: includes patients who don’t clearly fit into another category.
Residual schizophrenia: they exhibit some symptoms which aren’t strong enough to merit by putting them into other categories. Consists of patients experiencing mild symptoms.
What is schizophrenia?
A type of psychosis, a severe mental disorder in which thoughts and emotions are so impaired that contact is lost with external reality. It is the most common disorder, affecting 1% of the population at some point.
When is schizophrenia most commonly diagnosed?
Between 15 and 35, with men and women equally affected.
Which classification is most commonly used in the US?
The DSM-5 (The Diagnostic and Statistical Manual of Psychiatric Disorders) which requires one of the following positive symptoms: delusions, hallucinations and disorganised speech.
Which classification is most commonly used in Europe?
The ICM-10 (International Classification of Disease) two or more negative symptoms are sufficient for diagnosis (eg, avolition and speech poverty)
What are the key issues in diagnosing SZ?
- Reliability: the extent to which the diagnosis of schizophrenia is consistent.
- Validity: the extent to which diagnosis and classification techniques measure what they are designed to.
- Co-morbidity: the occurrence of two illnesses together which confuses diagnosis and treatment.
- Symptom overlap: when two or more conditions share symptoms, questioning the validity of classification.
Give two examples of positive symptoms.
- Hallucinations - unreal perceptions of the environment which includes hearing voices, see visions when there are no sensory stimuli to create them, olfactory (smelling things others can’t smell) or tactile (e.g. Feeling that bugs are crawling on or under the skin).
- Delusions (beliefs that have no basis in reality) - sometimes can be paranoid, which involves a belief that they are being spied on or followed. They may believe their phone is tapped or cameras are filming them. May involve an inflated belief on the persons power or importance (may think they are famous or have special powers)
Give two examples of negative symptoms.
- Speech poverty-a reduction in the amount and fluency of speech. Accompanied by a delay in sufferer’s verbal responses during conversation. This is thought to be caused by slowing or blocked thoughts. This is not about not knowing as many words, but more a difficulty of spontaneously producing them. This is associated with long illness and earlier onset of the illness.
- Avolition-distinct from poor social function or disinterest which can be the result of other circumstances. For example a patient could have no contact with friends or family because they have none or because communication with them is difficult. This wouldn’t be considered avolition, which is specified as a reduction in self initiated involvement in activities that are available to the patient.
Limitation of diagnosis: low reliability.
Cheniaux et al. had two psychiatrists independently diagnose 100 patients using both DSM and ICD criteria. Inter-rater reliability was poor. One psychiatrist diagnosed 26 with schizophrenia using DSM and 44 using ICD. Second psychiatrist diagnosed 13 with DSM and 24 with ICD. This inconsistency between mental health professionals and the different classification systems is a limitation of the diagnosis.
Limitation in diagnosis: co-morbidity.
Co-morbidity is when two or more conditions occur together. If conditions occur together a lot of the time it might call into question whether they are actually a single condition. Buckley et al. concluded that around half of patients with a diagnosis of schizophrenia also have a diagnosis of depression or 47% with substance abuse. In terms of classification, if very severe depression looks like schizophrenia and vice versa, it may be they are a single condition. This confusing picture is a limitation.
