CN Psychology - Schizophrenia
-Schizophrenia is a type of psychosis, a severe mental disorder characterised by a profound disruption of
cognition and emotion so that contact with external reality and insight are impaired.
-This affects a person's language, thought, perception, emotions and even their sense of self.
-It is an episodic disorder, which means that sufferers can have periods of normal functioning and varying degrees
of affected episodes.
-These coils last for weeks, or even years at a time and vary greatly from one sufferer to the next.
-Severely interferes with everyday tasks, so many sufferers end up homeless or hospitalised.
Clinical Characteristics of Schizophrenia
-Schizophrenia affects 1% of the world population.
-No more than 1 in 5 individuals recover completely, even with the treatments available that can relieve many
symptoms.
-Schizophrenia is most diagnosed between the ages of 25 and 30 years of age, with males showing onset of the
disorder at an earlier age (4-5 years earlier).
-Most commonly diagnosed in men compared to women.
-Most commonly diagnosed in cities than in the countryside.
-More commonly diagnosed in the working class than middle class people.
Classification of Schizophrenia
-There is no one defining characteristics of schizophrenia to be diagnosed, but a cluster of symptoms that can be
shown by a sufferer. There are 2 major system for the classification of mental disorders:
● The WHO International Classification of Disease (ICD-10)
2 or more negative symptoms are sufficient for diagnosis, or 1 positive symptom.
The ICD-10 recognises a range of subtypes of schizophrenia. Ex. Paranoid schizophrenia which is
characterised by powerful delusions and hallucinations, but relatively few other symptoms. Hebephrenic
schizophrenia which involves primarily negative symptoms.
● The American Psychiatric Association’s Diagnostic and Statistical Manual (DSM-5)
2 of the positive symptoms must be present for diagnosis, but only 1 if delusions are bizarre or
hallucinations consist of a voice keeping up a running commentary on the person's behaviours or thoughts,
or 2 or more voices conversing together.
There must be continuous signs of disturbance for at least 6 months. For a significant period of time, 1
or more major areas of functioning must be markedly below the level achieved prior to onset.
Positive Symptoms
-Those which are an addition to an individual’s behaviour.
-Hallucinations = these are disturbances of perception in any sense.
-Some hallucinations are related to events in the environment, while others bear no relationship to what the
senses are picking up in the environment. For example, voices being heard talking to the sufferer or another
person, often criticising them.
-Hallucinations can be experienced in relation to any sense.
-The person may, for example, see distorted facial expressions, or animals that aren't there.
-Delusions = these are firmly held irrational beliefs (paranoia) that have no basis in reality.
● Delusions of persecution = the belief that others want to harm, threaten or manipulate you. Ex. the
government, aliens etc.
, ● Delusions of grandeur = the belief that they are an important individual, even god-like and have
extraordinary powers. Ex. the belief that they are Jesus Christ.
● Delusions of control = the belief that their body is under external control. Ex. being controlled by aliens or
the government (have implanted radio transmitters etc).
● Delusions of references = the belief that events in the environment appear to be directly related to them.
Ex. special personal messages are being communicated through the TV.
-As such, delusions can make a person act in ways that appear bizarre to others, but make sense to them.
Delusions can lead to aggressive behaviour, but sufferers are usually more likely to be victims themselves.
Negative Symptoms
-Atypical experiences that represent a loss of a usual experience (a diminution or loss of normal functioning).
-Avolition = sometimes called ‘apathy’, a lack of purposeful, willed behaviour, it is the reduction, difficulty, or inability
to start and continue goal-directed behaviours. Sufferers will have a sharply reduced motivation to carry out activities
and therefore have reduced activity levels. -People with schizophrenia often have a sharply reduced motivation to
carry out a range of activities.
-Ex. No longer being interested in going to meet friends, lack of persistence in work / education, staying at home all
day etc.
-Andreason (1982) = identified 3 identifying signs of avolition: poor hygiene and grooming, lack of persistence in
work or education and a lack of energy.
-Speech poverty = limited speech output, often repetitive content. It involves reduced frequency and quality of
speech. This is sometimes accompanied by a delay in the sufferer's verbal responses during conversation.
-It’s not that they don’t know the words, but that they have a difficulty in spontaneously producing them.
-The ICD-10 classifies speech poverty as a negative symptom as it results in a reduction in the amount and quality
of speech.
-NB. The DSM-5 uses the category of ‘speech disorganisation’ (which is when speech becomes incoherent or the
speaker changes topic mid-sentence) and classifies it as a positive symptom. This difference between the two
manuals highlights some of the issues with validity and reliability with diagnosing schizophrenia. This will be
covered in the evaluation points for part (a)
Rosenhaan (1973) - ‘On Being Sane in Insane Places’
-Aim = to test the validity of schizophrenia diagnosis using the DSM-II classification system.
-Procedure = 8 volunteers (Rosenham himself and 7 others) who did not suffer from mental illness presented
themselves to different mental hospitals, reporting a single symptom: hearing voices saying ‘empty’, ‘hollow’ and
‘thud’. All were admitted and then acted normally, being model patients, co-operating with staff and seeking to be
released. They recorded the responses of doctors and nurses when they spoke with them and the time taken to be
released for each ‘patient’.
Later a hospital was informed that an unspecified number of pseudo-patients would attempt entry over a 3 month
period. The number of suspected fake patients were recorded by the hospital during this period.
-Results = all 8 were admitted to hospitals. The volunteers took between 7 and 52 days to be released, with the
average stay being 19 days and in every case they were released with a diagnosis of schizophrenia in remission.
This is not surprising given the doctors and nurses lack of response to the pseudo-patients that were recorded. When
they were asked questions, doctors did not respond 71% of the time. Normal behaviours displayed by the volunteers
were interpreted as signs of schizophrenia, but 35 of the 118 actual patients suspected that the volunteers were
sane.
During the subsequent 3 month period, 193 patients were admitted, 83 of these were suspected to be fake patients,
however Rosenhan did not send any further pseudo-patients.
, Conclusions = the psychiatrists in this study were consistent with each other as they consistently made the same
diagnosis when presented with the same symptoms. However, the diagnosis given to the pseudo-patients were not
valid as they failed to recognise that aside from a single symptom, the ps had good mental health, thus suggesting
that classification may lack reliability and validity.
+ Accurate diagnoses can be made
Serper et al (1999) assessed patients with co-morbid schizophrenia and cocaine abuse, cocaine
intoxication on its own and schizophrenia on its own. They found that despite there being considerable
symptom overlap in patients with schizophrenia and cocaine abuse, it was actually possible to make
accurate diagnoses.
- Reliability
For a diagnostic system to be reliable, it means that there has to be a high degree of agreement between
different clinicians when diagnosing patients, this is known as inter-rater reliability, i.e. they would give the
same diagnosis to patients with the same symptoms. However this is an issue because psychiatric
diagnoses have been notoriously unreliable.
Beck (1961) gave two psychiatrists the same 153 patients to diagnose. The two only agreed 54% of the
time. Furthermore Cheniaux et al (2009) had two psychiatrists diagnose 100 patients using both the DSM
and the ICD criteria. One diagnosed 26 with SZ using the DSM, and 44 with SZ using the ICD. The second
diagnosed 13 using the DSM and 24 using the ICD. This suggests that there is low inter-rater reliability in
the diagnosis of Schizophrenia.
However it is important to note that the DSM-V has made significant improvements in reliability of diagnoses
as it now specifies that ‘two (or more) symptoms must be shown for significant position of time during a 1-
month or more period. Therefore It can be suggested that although there are issues of reliability, it has, and
will continue to improve in the future.
- Validity
Validity relates to how accurate a diagnosis is. However due to the large variability in symptoms, course,
treatment response and possible causal factors, it has been argued that schizophrenia is not a single
disorder and this leads to difficulties in accurate diagnoses being made.
There two main ways of assessing validity of diagnoses – criterion validity & predictive validity.
To have high criterion validity then the same patient should be diagnosed with the same disorder using the
same criteria, however Cheniaux et al’s findings show that this is often not the case.
Furthermore Birchwood & Jackson (2001) argue that as 20% of schizophrenics recover and never have
another episode but 10% are so affected they commit suicide, there is too much variety in the outcomes of
schizophrenia for predictive validity to be supported.
Therefore this shows that validity is clearly an issue for the classification & diagnosis of schizophrenia.
- Co-morbidity & symptom overlap
In practice, it is difficult to define the boundaries between schizophrenia and other disorders. For example,
those people who suffer from schizophrenia are also often suffering from a mood disorder at the same time,
such as major depression. This is the issue of co-morbidity (when two or more symptoms occur at the same
time).
Sim et al (2006) studied 142 hospitalised schizophrenic patients and found that 32% also had an additional
mental disorder. Further evidence is provided by Buckley et al (2009) who carried out a review and found
that 50% of patients with a diagnosis of SZ also have a diagnosis of depression, and 47% were also
diagnosed as having substance abuse. Also 29% also had PTSD and 23% OCD. This suggests that it can
be difficult for a valid and reliable diagnosis to be made.
A further issue is caused by symptom overlap. For example both SZ and bi-polar involve positive symptoms
like delusions & negative symptoms like avolition. However, the ICD and DSM have tried to address this
problem of symptom overlap by proposing mixed disorder categories such as schizo-affective disorder or
post-psychotic depression.
Ketter (2005) points out that misdiagnosis due to symptom overlap can lead to ears of delay in receiving
treatment, during which time suffering and further degeneration can occur, as well as high levels of suicide -
