Schizophrenia – what’s wrong
with this joke?
What the Specification Says:
Candidates will be expected to:
• develop knowledge and understanding of theories
and studies relevant to the content for each area of
psychology in this unit
• analyse and evaluate theories and studies
relevant to the content for each area of psychology
in this unit
• undertake practical research activities involving
collection, analysis and interpretation of qualitative
and quantitative data.
Schizophrenia
• Schizophrenia is not a multiple personality
• A psychotic disorder involving a break with
reality
• Many different manifestations with a few
shared features
Schizophrenia diagnosis
• At least two of the following:
– Hallucinations (us. auditory or somatic)
– Delusions (oft. linked to hallucinations)
– Disorganised speech
– Disorganised or catatonic behaviour
– Negative symptoms
• Social & occupational dysfunction
• Duration of several months
Schizophrenia diagnosis
• Diagnostic subtypes
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–
–
–
Paranoid
Catatonic
Disorganised
Undifferentiated
• Type 1 - Episodic, mainly positive symptoms
• Type 2 - Chronic, mainly negative symptoms
Schizophrenia prevalence
• 1% lifetime risk in general population
• Holds true for most geographical areas
although rates do vary
– Abnormally high in Southern Ireland, Croatia;
significantly lower rates in Italy, Spain (Torrey,
2002)
• Risk factors include low SES, minority
ethnicity, urban residence
Schizophrenia onset
Source: CIHI (2001)
Schizophrenia prognosis
• ‘Rule of the thirds’ (rule of thumb):
– 1/3 recover more or less completely
– 1/3 episodic impairment
– 1/3 chronic decline
• Confirmed in US & UK (Stevens, 1978)
• With treatment about 60% of patients manage a
relatively normal life
• Prognosis better in non-industrialised societies
Diagnosis
• Most mental disorders are categorised into
groups
• Diagnostic and Statistical Manual of Mental
Disorders (DSM) is produced in the US
• International Classification of Diseases (ICD)
produced in Europe
• Schizophrenia is major example of psychotic
illness
Nature of Schizophrenia
• Characterised by a profound disruption of
cognition and emotion which affects a person’s
language, thought, perception, affect and even
sense of self.
• Media often links to violence. However only 8%
of diagnosed Schizophrenics in a year will commit
a serious act of violence.
This is less than the percentage of depressives or
people with personality disorders who will commit
an act of violence
Positive Symptoms
•
•
•
•
Delusions
Experiences of Control
Hallucinations
Disordered Thinking
Negative Symptoms
• Affective flattening
• Alogia
• Avolition
RELIABILITY
Can Scientists Agree on the same Diagnosis?
• DSM III introduced in 1980. Designed
specifically to provide more reliability
• Subsequent revisions but still questions over
reliability
• Recent studies found inter-rater reliability
correlations as low as 0.11 (Whaley 2001)
RELIABILITY
• Positive symptoms may be more suited for
diagnosis - Klosterkotter et al (1994)
• Argued that Schizophrenia is too broad a category
for it to be a useful diagnosis. Two patients could
have completely different symptoms
• Mojtabi and Nicholson (1995)
– 50 US psychiatrists asked to distinguish bizarre and
non-bizarre delusions. Inter-rater reliability
correlation of around 0.40
VALIDITY
Can Scientists agree on what schizophrenia is?
• Bentall et al (1988) – comprehensive review of
symptoms (aetiology), prognosis (outcome)
and treatment concluded that Schizophrenia is
not a useful scientific category.
• Schneider (1959) ‘first rank’ symptoms –
designed to uniquely identify schizophrenia
• Ellason and Ross (1995) people with DID
(dissociative identity disorder) have more first
rank symptoms than schizophrenics!
VALIDITY
• Little predictive validity – prognosis varies
massively
• c. 20% recover to previous levels of functioning,
10% achieving lasting improvement, 30% some
improvement with relapses.
• Malmberg et al. (1998) – Prognosis is more to do
with Gender
• Harrison et al. (2001) – Prognosis is more to do
with psychosocial factors.
Rosenhan 1973
• http://www.youtube.com/watch?v=jXpANr8jAQ&feature=related
Cultural Differences
• Copeland et al (1971)
• Description of a patient to 134 US and 194
British psychiatrists
• 69% of the US psychiatrists diagnosed
schizophrenia
• 2% of the UK psychiatrists diagnosed
schizophrenia
Questions
a) Outline clinical characteristics of
schizophrenia. (6 marks)
b) Explain issues of reliabiility and validity
associated with the classification and
diagnosis of schizophrenia. (3+ 16 marks)