Schizophrenia Summary

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Classification and Diagnosis

Nature of Schizophrenia:

  • Profound disruption of cognition and emotion - affects language, perception, affect and sense of self
  • Association with violence is largely a media invention
  • Around 8% of schizophrnic patients commit a serious act of violence, but this figure is less than for other mental disorders
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Classification and Diagnosis

Diagnostic Criteria:

  • Positive symptoms - excess or distortion of normal symptoms e.g delusions (bizzare beliefs), experiences of control (alien force), hallucinations (unreal perceptions)
  • Negative symptoms - diminution or loss of normal function e.g affective flattening (reduction in emotional expression), alogia (poverty of speech), avolition (lack of goal-directed behaviour)
  • Diagnosis of schizophrenia - (a) two or more characteristic symptoms, (b) social/occupational dysfunction, (c) duration at least six months, (d) exclusion of mood disorders, (e) exclusion of organic cause
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Classification and Diagnosis

Reliability:

  • Extent to which psychiatrists can agree on the same diagnosis
  • DSM III and later versions claim increased reliability of diagnosis
  • Whaley (2001) - inter-rater reliability as low as .11
  • Klosterkotter et al (1994) - positive symptoms more useful for diagnosis
  • Mojtabi and Nicholson (1995) - low inter-rater reliability of 'bizzare' versus 'non-bizarre' symptoms
  • Problem highlighted in Rosenhan's study - 'On being Sane in Insane Places'
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Classification and Diagnosis

Validity:

  • Concerns questions about what schizophrenia really is
  • First-rank symptoms distinguish schizophrenia from other disorders, but some of these are also found in other disorders such as DID
  • Little evidence of shared prognosis in schizophrenia, therefore low predictive validity

IDA:

  • Reliability of diagnosis challenged by difference between US and UK diagnosis (Copeland, 1971)
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Biological Therapies

Antipsychotic Medication:

  • Conventional antipsychotics reduce effects of dopamine and so reduce symptoms of schizophrenia
  • Bind to D2 dopamine receptors but do not stimulate them
  • Atypical antipsychotics only temporarily occupy D2 receptors then dissociate to allow normal dopamine transmission
  • Leads to lower levels of side effects such as tardive dyskinesia
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Biological Therapies

Evaluation:

  • Davis et al (1980) - higher relapse rates in patients whose drug replaced with placebo than those who remained on drug
  • Antipsychotic medication more effective for those living with hostility and criticism
  • Conventional antipsychotics - 30% develop TD
  • Being prescribed medication creates motivational deficits which prevents positive action against illness
  • Meta-analysis (Leucht et al, 1999) - superiority of atypical over conventional antipsychotics only moderate
  • Atypical antipsychotics - only marginal support for effectiveness with negative symptoms
  • Lower rates of TD with atypical antipsychotics supported by Jeste et al (1999)
  • Patients more likely to continue with medication with lower side effects
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Psychological Therapies

ECT:

  • First studies of ECT as treatment for schizophrenia were disappointing (Karagulla, 1950), with recovery lower than control group
  • Tharyan and Adamas (2005) - review of 26 studies found 'real' ECT more effective than 'sham' ECT
  • Combination of medication and ECT effective for rapid reduction of symptoms
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Psychological Therapies

Evaluation:

  • Effectiveness of ECT is inconsistent
  • APA study found no difference between effects of ECT and antipsychotic medication
  • Sarita et al (1998) - no difference in symptom reduction between ECT and simulated ECT
  • Because of risks of ECT, use has declined 

Links:

  • Ross and Read (2004) - placebo studies not a fair test because proportion of relapses explained by withdrawal effects
  • Ethical issues - human rights issues associated with the use of antipsychotic medication (TD)
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Psychological Therapies

CBT:

  • Patients: 1) trace origins of symptoms to understand how they might have developed and 2) evaluate content of delusions/hallucinations
  • Patients allowed to develop own alternatives to maladaptive beliefs
  • Outcome studies show that patients receiving CBT experience fewer hallucinations and delusions than those receiving antipsychotic medication alone
  • Lower patient drop-out rates and greater patient satisfaction with CBT than antipsychotic medication
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Psychological Therapies

CBT:

  • Patients: 1) trace origins of symptoms to understand how they might have developed and 2) evaluate content of delusions/hallucinations
  • Patients allowed to develop own alternatives to maladaptive beliefs
  • Outcome studies show that patients receiving CBT experience fewer hallucinations and delusions than those receiving antipsychotic medication alone
  • Lower patient drop-out rates and greater patient satisfaction with CBT than antipsychotic medication
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Psychological Therapies

CBT:

  • Patients: 1) trace origins of symptoms to understand how they might have developed and 2) evaluate content of delusions/hallucinations
  • Patients allowed to develop own alternatives to maladaptive beliefs
  • Outcome studies show that patients receiving CBT experience fewer hallucinations and delusions than those receiving antipsychotic medication alone
  • Lower patient drop-out rates and greater patient satisfaction with CBT than antipsychotic medication
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Psychological Therapies

Evaluation:

  • Effectiveness - meta-analysis found significant decreases in positive symptoms after CBT
  • Most CBT studies also involve antipsychotic medication, therefore difficult to assess effects of CBT alone
  • CBT works by generating less distressing explanations for psychotic experiences rather than trying to eliminate them
  • Psychiatrists believe that older patients are less likely to benefit from CBT
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Psychological Therapies

Psychodynamic Therapy:

  • Psychoanalysis based on assumption that individuals unaware of influence of unconscious conflicts on their current psychological state
  • Therapist creates an alliance with patient by offering help with what the patient perceives as the problem
  • All psychodynamic therapies build trust with patient by replacing harsh parental conscience with one that is more supportive
  • As patient gets healthier, they take a more active role
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Psychological Therapies

Evaluation:

  • Cottdiener (2000) - meta-analysis - 66% of those receiving psychotherapy improved after treatment, whilst 35% didn't
  • Some forms of psychodynamic therapy can even be harmful in treatment of schizophrenia
  • Research on effectiveness of psychodynamic therapy shows contradictory findings
  • 'Supportive' psychotherapies appropriate when combined with medication
  • Psychodynamic therapy long and expensive, but may have benefits in that it might make patients more able to seek employment
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Psychological Therapies

IDA:

  • Methadological limitations of psychodynamic outcome studies include lack of random allocation to therapy conditions
  • Ethical issues arise in placebo condition where patients are denied effective treatment
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Biological Explanations

Genetic Factors:

  • Schizophrenia more common among biological relatives of person with schizophrenia (Gottesman, 1991)
  • Twin studies - Joseph (2000) pooled data shows concordance rate for MZ twins of 40% and DZ twins of 7%
  • Use of 'blind' diagnosis produced lower concordance rate for MZ twins, but still much higher than DZ twins
  • Adoption study by Tienari et al (2000) - if biological mother is schizophrenic, 6.7% of adoptees also schizophrenic
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Biological Explanations

Evaluation:

  • Environments of MZ twins may be more similar than for DZ twins
  • Differences in concordance rates may reflect environmental similarity rather than role of genetic factors
  • Adopted children from schizophrenic backgrounds may be adopted by particular type of adoptive parent, making conclusions difficult to draw
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Biological Explanations

Dopamine Hypothesis:

  • Neurons that transmit dopamine fire too easily, or too often, leading to symptoms of schizophrenia
  • Schizophrenics - abnormally high levels of D2 receptors
  • Evidence from large doses of amphetamines causes hallucinations and delusions
  • Antipsychotic drugs - block dopamine and eliminate symptoms
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Biological Explanations

Evaluation:

  • Drugs can increase schizophrenia symptoms as neurons try to compensate. Haracz (1982) found elevated dopamine levels in post-mortems of schizophrenics who had taken medication
  • Neuroimaging studies failed to provide convincing evidence for altered dopamine activity in schizophrenics
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Biological Explanations

Enlarged Venticles:

  • Ventricles of person with schizophrenia 15% bigger than non-schizophrenic
  • Display negative rather than positive symptoms
  • May be result of poor brain development or tissue damage

Evaluation:

  • Meta-analysis found substantial overlap in ventricle size among schizophrenic and control populations
  • Enlarged ventricles may be due to effects of antipsychotic drugs
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Biological Explanations

IDA:

  • Many studies have to include 'schizophrenia spectrum disorders' to show genetic influences
  • Evolutionary perspective - schizophrenia may have adaptive advantage
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Psychological Explanations

Psychological Theories:

  • Psychodynamic view of schizophrenia - result of regression to pre-ego stage and attempts to re-establish ego control
  • Some schizophrenic symptoms reflect infantile state, other symptoms are an attempt to re-establish control
  • Further features of disorder appear as individuals attempt to understand their experiences
  • They may reject feedback from others and develop delusional beliefs
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Psychological Explanations

Evaluation:

  • Very little evidence to support psychodynamic view of schizophrenia
  • Behaviour of parents assumed key influence in development of schizophrenia but may be consequence rather than cause
  • Cognitive explanation supported by neurophysiological evidence
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Psychological Explanations

Socio-Cultural Factors:

  • Prior to schizophrenic episode, patients report twice as many stressful life events
  • Link demonstrated in both retrospective and prospective studies
  • Double-bind theory - contradictory messages from parents prevent coherent construction of reality, leads to schizophrenic symptoms
  • Expressed emotion - family communication style involving criticism, hostility and emotional over-involvement
  • Leads to stress beyond impaired coping mechanisms and so schizophrenia
  • Labelling theory - symptoms of schizophrenia seen as deviant from rules ascribed to normal experience. Diagnostic label leads to self-fulfilling prophecy
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Psychological Explanations

Evaluation:

  • Some evidence challenges link between life events and schizophrenia. Evidence for link is only correlational, not casual.
  • Importance of family relationships in development of schizophrenia shown in adoption study by Tienari et al (1994)
  • Double-bind theory supported by Berger (1965) - schizophrenics recalled more double-bind statements from mothers
  • Expressed emotion has led to effective therapy for relatives
  • Scheff (1974) - 13 of 18 studies consistent with predictions of labelling theory
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Psychological Explanations

Evaluation:

  • Some evidence challenges link between life events and schizophrenia. Evidence for link is only correlational, not casual.
  • Importance of family relationships in development of schizophrenia shown in adoption study by Tienari et al (1994)
  • Double-bind theory supported by Berger (1965) - schizophrenics recalled more double-bind statements from mothers
  • Expressed emotion has led to effective therapy for relatives
  • Scheff (1974) - 13 of 18 studies consistent with predictions of labelling theory
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