Classification Of Schizophrenia Flashcards
What is Scizophrenia classified as
It is classified as a psychotic disorder characterised by severe symptoms in the areas of judgement, emotions, perceptions and behaviour. It derives from the Greek words meaning split and mind.
Positive symptoms of schizophrenia (acute)
This is the addition to normal behaviour
- delusions
- hallucinations
- disorganised speech or thinking
- grossly disorganised behaviour
- other symptoms like unusual motor behaviour, depersonalisation
Negative symptoms of schizophrenia (chronic)
An absence of normal behaviour
- alogia - speech poverty- short empty replies
- affective flattening - reduction in range and intensity in emotional expression
- catatonic behaviours - decrease in reaction to immediate environment - motionless, unawareness, rigid or bizarre postures
- avolition - reduction in goal orientated behaviour and showing disinterest in previously enjoyed things
What is test retest reliability
Occurs when a clinician makes the same diagnosis on a separate occasion
What is inter rater reliability
Different clinicians make identical independent diagnosis on the same patient
What is predictive validity
If diagnosis leads to successful treatment then diagnosis is valid
What is descriptive validity
Patients with schizophrenia should differ in symptoms from patients with other disorders
Rosenhan - being sane in insane places study
Aim - to see whether it was possible to tell the difference between sanity and insanity in someone in a hospital setting
Method - 8 pseudopatients tried to gain admission to 12 hospitals in 5 different states. Each of the pseudopatients would call a hospital and pretend to be hearing voices saying empty, hollow and thud.
Once admitted, they immediately acted normal with no mention of the symptoms again and they were only able to leave if discharged
Results - 7/8 pseudopatients were admitted with a diagnosis of SZ and discharged with a diagnosis of SZ in remission. Their stay ranged between 7-52 days with an average of 19 days.
EVALUATION - Is the way that schizophrenia is classified reliable and valid?
CRITICISM OF RELIABILITY - cultural and gender biases in diagnosis - CULTURAL - Copeland gave 134 US and 194 British psychiatrists a description of a patient. 69% of US diagnosed SZ compared to 2% of British ones. There is also a greater chance of being diagnosed with SZ as a black ethnicity than white ethnicity in the UK. GENDER - Loring and Powell found from 290 randomly selected male and female psychiatrists, 56% gave a diagnosis when the case was described as male rather than female (20%). Explain - This questions the reliability of the diagnosis as not everyone with the same symptoms is classified in the same way due to culture and gender. Link - furthermore calls into question whether mental health can be assessed objectively as it is not like physical health and there are subjective biases
CRITICISM POOR INTER RATER RELIABILITY- in Rosenhans study there was inconsistency in diagnosing SZ as it took between 7-52 days for pseudopatients to be released when showing no symptoms- This proves poor inter rater reliability as if reliable then all pseudopatients would have been released after 2 days which didn’t happen. This is supported further by Whalley who found a 0.11 inter rater reliability which is concerning as it means treatment needed may depend on who is assessing the patient - however it could be argued there was an element of inter rater reliability in that 7/8 were diagnosed showing the same indpendent diagnoses were made however invalid as not genuine.
CRITICISM OF VALIDITY - comorbidity and symptom overlap- COMORBIDITY - most people diagnosed with SZ also tend to be diagnosed with another disorder for example 50% have also been diagnosed with depression, 47% with substance abuse and 12% full OCD criteria. SYMPTOM OVERLAP - also an overlap with mode disorders eg people with Dissociative Identity Disorder display more schizophrenia symptoms than someone with schizophrenia- This shows schizophrenia is not a distinct classification of its own - therefore need to be careful giving SZ diagnosis due to the impact on the person
