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Schizophrenia Exam Revision
Imogen Rackham

Neural Correlates
Neural correlates of schizophrenia:
Further research:
• Patterns of structure or activity in the brain that occur in conjunction with an
experience, and may be implicated in the origins of that experience
...

• Both positive and negative symptoms have neural correlates
...


Neural correlates of negative symptoms:
• One negative symptom is avolition, involving the loss of motivation
...

• Abnormality of the ventral striatum may be involved in the development of avolition
...

• Negative correlation between activity levels in the ventral striatum and the severity of
overall negative symptoms
...

Neural correlates of positive symptoms:
• Allen et al (2007) scanned brains of patients experiencing auditory hallucinations and
compared them to a control group
...

• Lower activation levels in the superior temporal gyrus and anterior cingulate gyrus
were found in the hallucination group
...

• Reduced activity in the superior temporal gyrus and the anterior cingulate gyrus is a
neural correlate of auditory hallucinations
...

• Boos et al (2012) found decreased grey matter density in schizophrenia
compared to controls
...
This is a negative correlation
...

• Although these studies are useful in identifying brain systems that may not
be working normally, this evidence leaves questions unanswered
...

• Another factor could influence both negative symptoms and ventral
striatum activity
...


Token Economies
Token economies:
• Form of behavioural therapy where desirable behaviours are encouraged by the use of
selective reinforcement
...

• Tokens can be exchanged for primary reinforcers, like favourite foods or privileges
...

• Attempt to challenge negative symptoms
...

Tokens:
• Tokens are given immediately to patients when they have carried out a desirable
behaviour that has been targeted for reinforcement
...

• This immediacy of a reward is important because it prevents delay discounting – the
reduced effect of a delayed reward
...


• Token economies are behavioural therapy based on operant conditioning
...


Token economies: evaluation
Cannot cure:
• This psychological treatment of schizophrenia aim to improve
quality of life but cannot cure schizophrenia
...

• These is valuable
...

Ethical issues:
• Token economy systems have proved controversial
...

• Most severely ill patients suffer discrimination in addition to
other symptoms and families have challenged the legality of this
...

• Abnormal processes within a family, like poor communication, cold parenting and high
levels of expressed emotion, could be risk factors for the development and maintenance
of schizophrenia
...

• Schizophrenogenic = schizophrenia causing
...

• Tends to create a family climate characterized by tension and secrecy
...


Double-bind theory:
• Gregory Bateson et al (1972) emphasized the role of communication style within a
family
...

• Feel unable to comment on the unfairness of the situation or seek clarification
...

• They are left understanding the world as confusing and dangerous, reflected in
symptoms like disorganized thinking and paranoid delusions
...


Expressed emotion:
• Level of emotion, particularly negative emotion, expressed towards a patient
by their carers
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• Hostility towards patient, like anger and rejection
...

• High levels of expressed emotions in carers directed towards the patient are a
serious source of stress
...

• Can also be a source of stress that triggers the onset of schizophrenia in an
individual who is already vulnerable due to genetic make-up (diathesis-stress
model)
...

• Read et al (2005) reviewed 46 studies of child abuse and
schizophrenia, concluding that 69% of adult female
schizophrenic in-patients had a history of physical and/or
sexual abuse in childhood
...

• Additionally, Berry et al (2008) found that adults with
insecure attachments to their primary carer were more
likely to have schizophrenia
...


• Furthermore, as mentioned, there is a lot of evidence supporting the broad principle that poor childhood
experiences in the family are associated with adult schizophrenia
...

• These theories are based on clinical observation of patients – whereby it may not be suitable to
generalise findings of niche idiographic case studies to all schizophrenics
...

• Disconcerting from the stance of modern psychology (Harrington 2012)
...

• Parents who have already suffered the distress of their child’s serious psychological disorder underwent
further trauma by being blamed for the condition
...

• The theory may simply be a controversial product of its time, based on problematic evidence, hence
reducing temporal validity
...

• Schizophrenia may have distorted patients’ recall of
childhood experiences, meaning the claims lack validity
...


Evaluation 3: evidence for biological factors is not adequately considered
• Family dysfunction explanations for schizophrenia can be hard to reconcile with biological explanations
...

• Therefore, this casts doubt on the family dysfunction explanation as a complete theory – because it is
contradicted by the findings of biological research, which deem the development of schizophrenia as the
result of nature and not nurture
...


Drug Therapy
Drug therapies:
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•
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•
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The most common treatment for schizophrenia involves the use of antipsychotic drugs
...

Some are available as injections, given every 2-4 weeks
...

Typical (traditional) and newer atypical (second generation)
...

• Chlorpromazine can be taken as tablets, syrup or by injection
...
Initial doses are much smaller
and tend to be increases to a maximum of 400-800mg
...

• There is a strong association between the use of typical and the dopamine hypothesis
...

• They block dopamine receptors, reducing the action of dopamine on the postsynaptic neurone
...

• According to the dopamine hypothesis, this dopamine-antagonist effect normalizes
neurotransmitters in key brain areas to reduce hallucinations
...

• Syrup is absorbed faster than tablets so tends to be used when chlorpromazine is used for its
sedative properties
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Typical antipsychotics: side effects
Dizziness
Agitation
Sleepiness
Stiff jaw
Weight gain
Visual disturbances
Low blood pressure
Sexual dysfunction
Tardive dyskinesia (uncontrollable facial movements caused by
dopamine supersensitivity) affects 15% of patients
• Neuroleptic malignant syndrome (drugs blocks dopamine
action in the hypothalamus, causing high temperature, delirium,
coma and possible fatality)
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•
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•
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Drug Therapy
Atypical antipsychotics: include clozapine and risperidone

Atypical antipsychotics: side effects

• Been used since the 1970s
...


•
•
•
•
•
•
•

Clozapine:
• First trialed in the early 1970s
...

• Discovered to be more effective than typical antipsychotics in the 1980s
...

• Dosage is typically 300-450mg a day
...

• Also acts on serotonin and glutamate receptors, helping to improve mood and reduce
depression and anxiety – may improve cognitive functioning
...

Risperidone:
• More recently developed in the 1990s
...

• Can be taken in the form of tablets, syrups or injections that last two weeks
...


• Believed to bind to dopamine and serotonin receptors
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• Leads to fewer side effects
...

• There is no surgery, less frightening and lesser chance of things
going wrong
...

• Drugs are easier to take or administer
...


Drug Therapy Evaluation
Evidence for effectiveness:

Use of antipsychotics depends on the dopamine hypothesis:

• There is a large body of evidence to support the idea that both typical and
atypical antipsychotics are at least moderately effective in tackling the
symptoms of schizophrenia
...

• This is the idea that there are higher than usual levels of dopamine activity in the subcortex
of the brain
...

• If this is true, it is not clear how antipsychotics (dopamine-antagonists) help with
schizophrenia if they further reduce dopamine activity
...


Typical antipsychotics:
• Ben Thornley et al (2003) reviewed studies comparing the effects of
chlorpromazine to a placebo
...

• Data from 3 trials with 512 patients showed that relapse rate was also lower
...

• Herbert Meltzer (2012) concluded that clozapine is more effective than
typical antipsychotics and is effective in 30-50% of treatment-resistant cases
where typical antipsychotics have failed
...

• Typical antipsychotics are associated with dizziness, sexual dysfunction, tardive
dyskinesia and neuroleptic malignant syndrome
...
1-2% of patients
...

• But side effects still exist and patients taking clozapine have regular blood tests
to alert doctors of early signs of agranulocytosis
...

• David Healy (2012) suggests that some
successful trials exaggerate evidence for
positive effects
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• Published studies tend to compare patients
who keep taking antipsychotics to those in
withdrawal
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Controversy in application:
• It is believed that antipsychotics are
used in some hospital situations to
calm patients and make it easier for
staff to work with them, rather than
benefit the patients
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