SCHIZOPHRENIA. Clinical characteristics of schizophrenia Issues surrounding classification and...

SCHIZOPHRENIA

Clinical characteristics of schizophrenia

Issues surrounding classification and diagnosis of schizophrenia, including reliability and validity

Biological explanations of schizophrenia e.g. genetics, biochemistry.

Psychological explanations…, e.g. behavioural, cognitive, psychodynamic and socio-cultural

Biological therapies for schizophrenia including their evaluation in terms of appropriateness and effectiveness

Psychological therapies…, for example behavioural, psychodynamic and cognitive-behavioural, including their evaluation in terms of appropriateness and effectiveness

SCHIZOPHRENIA

Outline and evaluate….

Describe and evaluate…

Discuss…

Critically consider…

Compare and contrast

Each question has an AO1 component and an AO2/AO3 component

e.g. Critically consider two or more biological explanations of schizophrenia.

(25 marks)

Deconstructing questions

(a) Outline two psychological explanations of schizophrenia. (9 marks)

(b) To what extent are the two psychological explanations of schizophrenia outlined in (a) supported by research evidence? (16 marks)

All AO1

All AO2/AO3


1. Outline clinical characteristics of schizophrenia.(5 marks)

2. Explain issues associated with classification and diagnosis of schizophrenia. (10 marks)

3. Outline and evaluate one or more explanations of schizophrenia. Refer to research evidence in your answer. (4 marks + 6 marks)


1. Outline clinical characteristics of schizophrenia.(125 words)

2. Explain issues associated with classification and diagnosis of schizophrenia. (250 words)

3. Outline and evaluate one or more explanations of schizophrenia. Refer to research evidence in your answer. (100 words + 150 words)


Issues of reliabilityAO2 = 125 words

Issues of validityAO2 = 125 words

Outline of explanation(s) of

schizophrenia[AO1 = 100 words]

Evaluation of the explanation(s)

[AO2 = 75 WORDS]


[AO2 = 75 WORDS]

Symptoms e.g. thought control,

delusions, hallucinations incoherent speech, negative

symptoms [125 words]

(a)

(b)

(c)

POSITIVE SYMPTOMS

[65 words]

Symptoms that reflect an excess or distortion of

normal functions. Diagnosis of schizophrenia requires at least one-month duration of

two or more of these

DelusionsBeliefs (e.g. paranoid delusions) that seem

real to the schizophrenic but are

not real

HallucinationsBizarre, unreal

perceptions of the environment that are

usually auditory

Disordered thinking

The feeling that thoughts have been

inserted or withdrawn from the mind

Symptoms that reflect a diminution or loss of

normal functions. Patients with mostly negative symptoms are often deemed ‘treatment-

resistant’. Affective flattening

A reduction in the range and intensity

of emotional expression

AlogiaPoverty of speech thought to reflect slowing or blocked

thoughts

AvolitionReduction of, or

inability to initiate and persist in goal-directed behaviour

NEGATIVE SYMPTOMS

[60 words]

ISSUES OF RELIABILITY

Issues of reliabilityAO2 = 125 words

ISSUES OF VALIDITY

What is it?Bentall et al. (1988) –after comprehensive review of research into the symptoms, prognosis and treatment concluded that schizophrenia was ‘not a useful scientific category’

Why? Symptoms: Many ‘first-rank’ symptoms of schizophrenia (e.g. delusions, thought disorders) are also found in other disorders e.g. depression and bipolar disorder, making it difficult to separate schizophrenia as a distinct disorder Why?Prognosis: Varies with about 20% recovering previous level of functioning, 10% showing significant improvement and 30% some improvement. Remaining 40% never really recover. Demonstrates little predictive validity to a diagnosis of schizophrenia with so much variation in prognosis for the disorder.

Issues of validityAO2 = 125 words

THE DOPAMINE HYPOTHESIS

Messages from neurons that transmit dopamine fire too easily or too often, leading to symptoms of schizophrenia.

Schizophrenics thought to have abnormally high numbers of D-2 receptors on receiving neurons, leading to more dopamine binding and more neurons firing.

Post-mortems of schizophrenics have shown elevated levels of dopamine and dopamine receptors in the brains of schizophrenics (e.g. Roberts et al., 1996).

Amphetamine is a dopamine agonist, flooding synapse with dopamine. Large doses can cause hallucinations and delusions.

Some people with Parkinson’s Disease who take L-dopa to raise dopamine levels develop schizophrenic symptoms (Grilly, 2002).

Outline of explanation(s) of

schizophrenia[AO1 = 100 words]


The diathesis-stress modelA problem for the dopamine hypothesis is that psychological factors (e.g. expressed emotion) also influence the development of or recovery from the disorder. This suggests that for those with a biological vulnerability (a diathesis such as high levels of dopamine activity), schizophrenia only develops in the presence of significant stressors in that person’s life


[AO2 = 50 WORDS]


Post-mortem studiesA problem is that anti-psychotic drugs that block dopamine may actually increase it as neurons compensate for the sudden deficiency of dopamineA review of post-mortem studies (Harack, 1982) found that most of those who showed elevated dopamine levels had received anti-psychotic medication shortly before deathThis suggests that evidence for high levels of dopamine in schizophrenic may not be the cause of the disorder, but a consequence of its treatment Neuroimaging researchPrevious studies have assessed dopamine levels from waste products, but this is far from precise. Development of PET scans has led to more accurate measurement of dopamine levels, yet research using PET scans has failed to provide convincing evidence of altered dopamine activity in brains of individuals with schizophrenia.

Evaluation ofevidence for or against

the explanation(s)[AO2/AO3 = 1o0 WORDS]

This is a reductionist explanation because it REDUCES causation to the biochemical level and does not take into account other possible causes of schizophrenia such as the the presence of life stressors. If the disorder was caused solely by malfunctioning dopamine neurons, then using antipsychotic drugs (which reduce dopamine activity in the brain) should be effective for ALL schizophrenics. This is not the case, suggesting that the dopamine explanation alone cannot explain the development of schizophrenia.

Every complex phenomenon can be explained by analyzing the simplest, most basic physical mechanisms that are in operation during the phenomenon.

EXPLANATION 2: ENLARGED VENTRICLES

Many schizophrenics have enlarged brain ventricles. The ventricles of a person with schizophrenia are about 15% bigger than normal (Torrey, 2002). People who have enlarged ventricles tend to display negative rather than positive symptoms, have greater cognitive disturbances, and poorer responses to traditional antipsychotics (Bornstein et al., 1992).


Research evidence on the importance of enlarged ventricles is far from consistent. A meta-analysis (Copolov and Crook, 2000) of over 90 CT scan studies revealed a substantial overlap between the schizophrenic and control populations.


A possible explanation for why some schizophrenics have enlarged ventricles may be due to the use of antipsychotic medication rather than it being a cause of schizophrenia. A study by Lyon et al. (1981) found that as the dose of medication increased, the density of brain tissue decreased, leading to enlarged ventricles.


(a) Explain the use of one psychological therapy as applied to the treatment of schizophrenia. (10 marks)

(b) Outline and evaluate one or more biological therapies as treatments of schizophrenia. (15 marks)


(a) Explain the use of one psychological therapy as applied to the treatment of schizophrenia. (4 + 6 marks)

(b) Outline and evaluate one or more biological therapies as treatments of schizophrenia. (5 + 10 marks)

(a) Explain the use of one psychological therapy as applied to the treatment of schizophrenia.

(10 marks)

Cognitive-behavioural therapy (CBT)Schizophrenics have distorted beliefs which influence their behaviour in maladaptive ways, e.g. delusions are faulty interpretations of events. CBT helps to identify and correct these.Patients encouraged to trace the origins of symptoms to get a better idea how they might have developed, and to evaluate the contents of their delusions or any inner voices to consider how they might test the validity of their faulty beliefs.As the learning of maladaptive responses is often the result of distorted thinking or mistakes in assessing cause and effect, the therapist lets the patient develop alternative explanations and coping strategies that are less maladaptive.

(a) Explain the use of one psychological therapy as applied to the treatment of schizophrenia.

(4 + 6 marks)

Evidence from outcome studies

CBT plus medication = greater reduction in positive symptoms than medication alone (Drury et al., 1996)

CBT plus medication = less patient dropout and more patient satisfaction than

medication alone (Kuipers et al., 1997) Who benefits from CBT?

Not everybody who would benefit from CBT is offered the treatment. Kingdon and Kirschen (2006) found many patients denied CBT because they would not ‘fully engage with the therapy’, in particular older

patients less likely to receive CBT

CBT and negative symptoms

CBT works by generating less distressing explanations for

negative symptoms rather than eliminating them completely. Negative symptoms (such as inactivity or withdrawal) may

be the patient’s way of avoiding making positive

symptoms worse.

CBT

(b) Outline and evaluate one or more biological therapies as treatments of schizophrenia.

(5 + 10 marks)

Conventional antipsychoticsThese are dopamine antagonists because they bind to dopamine receptors, but don’t stimulate them, instead blocking their action. By reducing stimulation at these receptors, they can eliminate most of the hallucinations and delusions experienced by schizophrenics. Their effectiveness at reducing positive symptoms led to the dopamine hypothesis of schizophrenia.

Atypical antipsychoticsThese work by only temporarily occupying the D2 receptors and then

rapidly dissociating to allow normal dopamine transmission. This is thought to be responsible for the lower levels of side effects (such as tardive dyskinesia) found with atypical compared to conventional antipsychotics, which in turn means that patients are more likely to continue with their medication.


(15 marks)

Motivational deficitsBeing prescribed medication may reinforce to the patient that physiologically there is ‘something wrong with them’, thus preventing them from thinking about other possible causes of their stress.

AppropriatenessConventional – many worrying side effects including tardive dyskinesia (TD) (30% of patients)Atypical – claim of lower levels of TD supported in study by Jeste et al. (1999)

EffectivenessConventional – relapse rates higher under placebo condition (Davis et al., 1980)Atypical – meta-analysis (Leucht et al., 1999) found superiority over conventional drugs was only ‘moderate’

GIVING YOUR AO2 CLOUT

IDENTIFYTreating schizophrenia with antipsychotic medication may lead to motivational deficits…

JUSTIFY… because this may reinforce to the patient that physiologically there is ‘something wrong with them’.

SO WHAT?As a result, this may prevent them from considering other possible causes of their condition, which then makes complete recovery from their symptoms less likely.


(5 + 10 marks)

SCHIZOPHRENIA. Clinical characteristics of schizophrenia Issues surrounding classification and...

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