A2 SCHIZOPHRENIA - CLASSIFICATION AND DIAGNOSIS Flashcards
What proportion of the general population suffers from schizophrenia and who does it affect more?
Schizophrenia affects approximately 1% of the general population.
Working class people, as well as those who live in a city are more susceptible to sch. than middle class people and those who live outside of the city.
Sch. also seems to affect men more than women.
What is the difference between psychosis and neurosis?
Psychosis is when the patient loses touch with reality and is unaware that their behaviour is abnormal or that anything is wrong. Schizophrenia is an example of a psychotic illness.
Neurosis is when the patient is aware that their behaviour is abnormal, for example depression.
What are the two classification systems for sch. and what do they require for diagnosis?
The DSM-V (Diagnostic and Statistic Manual, Edition 5) was created by the American Psychiatric Association. To be diagnosed with sch., you need one positive symptom.
The ICD-10 (International Classification for Diseases and Disorders, Edition 10) was created by the World Health Organisation (WHO) and requires two negative symptoms for diagnosis.
The DSM is only used in America; the rest of the world uses the ICD.
Define and give two examples of positive symptoms of sch.
Positive symptoms are unusual additional experiences or beliefs that go beyond “normal” existence. These include:
- Hallucinations; unusual sensory experiences, most commonly visual and auditory, e.g. hearing voices, seeing animals etc.
- Delusions; irrational beliefs, most commonly paranoid delusions e.g. belief that the government is watching them or that someone is coming to kill them, or grandiose delusions i.e belief that they are here for a special reason or that they are some sort of historical figure e.g. that they are Jesus, belief that they were sent by God, etc.
Define and give two examples of negative symptoms of sch.
Negative symptoms are the loss of the usual abilities and experiences. These include:
- Avolition; difficulty in beginning or keeping up goal orientated activity, reduced motivation/activity levels and poor hygiene.
- Speech poverty; could be one of three major symptoms; reduction in speech, delayed speech or incoherent speech (also known as “word salad” or “disorganised speech”)
Describe the reliability of the diagnosis of sch. and give a supporting study.
Reliability is the consistency of the diagnosis. It’s the ability for two or more mental health professionals to arrive at the same diagnosis for the same patient. If they do come to the same conclusion, then diagnosis has good inter-rater reliability.
Cheniaux (2009) had two psychiatrists diagnose the same 100 ppts, each using both the ICD and the DSM.
P1: DSM - 24 patients diagnosed
ICD - 44 patients diagnosed
P2: DSM - 13 patients diagnosed
ICD - 24 patients diagnosed
Cheniaux shows that diagnosis is unreliable as the two separate mental health professionals arrived at drastically different conclusions for the same patients.
Describe the validity of the diagnosis of sch. and give a supporting study.
Validity is the accuracy of diagnosis. It’s the ability for the two different classification systems to arrive at the same conclusions for the same patient.
Cheniaux (2009) had two psychiatrists diagnose the same 100 ppts, each using both the ICD and the DSM.
P1: DSM - 24 patients diagnosed
ICD - 44 patients diagnosed
P2: DSM - 13 patients diagnosed
ICD - 24 patients diagnosed
Cheniaux shows that diagnosis is invalid as the ICD seems to be largely over-diagnosing whilst the DSM seems to be largely under-diagnosing. This has negative impacts for patients; over-diagnosing means that some people are incorrectly diagnosed with sch., which stays with you for life and can hinder job applications etc. Under-diagnosing means that some people who genuinely do have sch. are going without treatment which makes their condition very difficult to deal with on a day-to-day basis.
Define comorbidity, give a supporting study and describe its effects on the classification and diagnosis of schizophrenia.
Co-morbidity refers to two or more conditions occuring at the same time.
Buckley (2009) found that out of a group of sch. patients:
- 50% also suffered from depression
- 47% also suffered from substance abuse
- 29% also suffered from PTSD
- 23% also suffered from OCD
This questions the validity of our system; if half of sch. patients also have depression, it could be that we are not very good at diagnosing schizophrenia (problem for diagnosis), or that the combination of both sch. and depression could actually be a whole new condition (problem for classification)
Define symptom overlap and describe its effects on the classification and diagnosis of sch.
There is considerable overlap between the symptoms of sch and other conditions, e.g. bipolar depression and schizophrenia.
Both of these conditions include positive symptoms like delusions, and negative symptoms e.g. avolition.
If there is a big symptom overlap between sch. and bipolar depression, then they could actually be a whole new disorder or in fact the same thing (problem for classification).
A large symptom overlap means that it is often difficult to arrive at the correct diagnosis as it may seem ambiguous (problem for diagnosis).
Describe gender bias in the diagnosis of schizophrenia.
Men seem to be diagnosed with sch. more than women do. This could be due to genuine genetic differences between men and women that make men more vulnerable to sch. Men and women also cope with stress differently, with men having higher rates of substance abuse as a coping mechanism. Substance abuse can lead to psychosis which can then in turn lead to the development and diagnosis of schizophrenia.
However, it has also been suggested that women may be better functioning with their schizophrenic symptoms and so may appear to be less severely affected, which can reduce the rate of diagnosis (gender bias).
Describe culture bias in the diagnosis of schizophrenia.
Some cultures seem to be diagnosed with sch. more than others, e.g. African Americans and English Afro-Carribeans are several times more likely to be diagnosed with sch. than white British people.
There is a very small chance that this is due to some form of genetic vulnerability, as the high rates are not consistent in Africa. Also, this demographic may experience racism in day-to-day life which may increase stress levels and consequently trigger sch. over time.
However, some behaviours that are encouraged in African cultures are seen as abnormal here which may lead us to diagnose with sch. (culture bias). Language barriers between patient and psychiatrist may also lead to miscommunication and consequently misdiagnosis (culture bias).
