Classification of schizophrenia. Positive symptoms of schizophrenia, including hallucinations and delusions. Negative symptoms of schizophrenia, including speech poverty and avolition. Reliability and validity in diagnosis and classification of schizophrenia, including reference to co-morbidity, culture and gender bias and symptom overlap.

Classification of Sz

a type of psychosis characterised by a profound disruption of cognition and emotion.
affecting 1% of population
affects a person's language, thoughts, perceptions, and emotions
diagnosed through DSM-5 or ICD-10

It is more common in men, city-dwellers and lower socioeconomic groups.

Differences between DSM and ICD

DSM - at least one positive symptom, doesn't recognise sub types of schizophrenia

ICD - positive symptoms do not need to be present, recognises subtypes of schizophrenia e.g paranoid sz, catatonic sz.

The DSM-5 system says 1 positive symptom must be present for diagnosis

whereas the ICD-10 system argues 2 or more negative symptoms are sufficient for

diagnosis.

Positive symptoms of sz

Positive symptoms of schizophrenia are experiences added to normal functioning and involve a distortion of reality. Examples include hallucinations, such as hearing voices, and delusions, which are false beliefs.

Hallucinations

Hallucinations:
- distortions or unreal perception in any of the sense e.g auditory, visual, tactile, olfactory
- often involve hearing voices that others can't hear; may tell them to harm themselves or others.

Delusions

Delusions (or paranoia) are irrational beliefs in something that is very unlikely, bizarre or obviously untrue. For example, one may believe that someone is deliberately trying to mislead, manipulate or hurt them.

Different types of delusions

delusions of grandeur - idea that you are an important person, even god-like, e.g believe they're jesus christ

delusions of persecution - belief that others want to harm, threaten, or manipulate you. e.g government is out to kill them

delusions of control - individuals may believe that they are under the control of an alien force that has invaded their mind/body. e.g believing that people have implanted radio transmitters into them

Negative symptoms

reflect a reduction or loss of normal functioning, for example, speech poverty and avolition.

speech poverty

Speech poverty (alogia)
- reduction of speech fluency and productivity; blocked thoughts
- can be tested by a verbal fluency task e.g how many animals they can name in a minute. patients perform worse.
- result in less complex syntax - shorter utterances
(DSM classes speech disorganisation as positive symptoms)

avoilition

Avolition:
- reduction, difficulty, or inability to start and complete goal directed behaviour, often mistaken for apparent disinterest
- loss of motivation to carry out tasks
- may cause sitting in the house doing nothing
Andreasen identified three signs of avolition: poor hygiene and grooming, lack of persistence in work or education and lack of energy.

KEY STUDY - being sane in insane places

Rosenhan (1970s)

PROCEDURE:
- 8 pseudo patients sent to 12 psychiatric hospitals w/o revealing it to staff
- at apts, patients were told to say they're having unfamiliar voices that are unclear, and someone from their own sex
- "empty, hollow, thud"
- on admittance, ppts stopped simulating any psychiatric symptoms + engaged w/ staff as usual in everyday life.
- when asked, ppts said symptoms were fine and gone.

RESULTS:
- in 11 instances, ppts were diagnosed with sz
- in 1 instance, ppt was admitted + diagnosed with manic-depressive psychosis
- stays ranged from 7 - 52 days, with a mean of 19 days
- findings provided convincing evidence against the accuracy and validity of psychiatric diagnoses

POSSIBLE AO3:
- small sample size
- temporal validity: DSM has been updated since
- shows issues surrounding diagnosis + validity

study lacks temporal validity

P: One limitation of Rosenhan’s study is that it may lack temporal validity.

E: Rosenhan conducted his research in the early 1970s, when diagnostic procedures and attitudes towards mental illness were very different from those used today.

E: Since then, diagnostic systems such as the DSM have been revised and mental health professionals receive more standardised training. This means psychiatric hospitals may be much better at distinguishing between genuinely ill patients and those without a disorder than they were when Rosenhan conducted his study.

L: Therefore, the findings may not accurately reflect the reliability and validity of modern psychiatric diagnosis, reducing the temporal validity of the study.

The importance of reliability and validity within diagnosis

Since the ICD and DSM are used to provide guidance on diagnosis and classification of SZ must be reliable and have validity

reliability in diagnosis

Reliability is the extent to

which the diagnosis of SZ is consistent, i.e. over time and/or between clinicians

issue of reliability- culture bias