Schizophrenia Key Studies


Classification and Diagnosis

Carson (1991)

  • DSM-III had fixed the problem of reliability once and for all

Whaley (2001)

  • Found inter-rater reliability correlations in the diagnosis of schizophrenia as low as 0.11

Klosterkotter et al (1994)

  • Assessed 500 admissions to a psychiatric unit in Germany to determine whether positive or negative smptoms were more suited to the diagnosis of schizophrenia. They found that positive symptoms were more useful for diagnosis than were negative symptoms
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Classification and Diagnosis

Motjabi and Nicholson (1995)

  • 50 senior psychiatrists in the US were ased to differentiate between 'bizzare' and 'non-bizareer' delusions, they produced inter-rater reliability correlations of only around 0.40

Schneider (1959) 

  • Listed the psychotic symptoms that he believed distinguished schizophrenia from other psychotic disorders. These are refered to as first-rank symptoms and they include delusions, experiences of control, disordered thinking and hallucination. However, some of these are also found in other disorders.

Ellason and Ross (1995)

  • Pointed out that people with dissociative identity disorder (DID) actually have more 'schizophrenic' symptoms than people diagnosed as being schizophrenic
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Classification and Diagnosis

Malmberg et al (1998)

  • Prognosis from patients varies from about 20% recovering, 10% improving and 30% showing some improvement with relapse

Harrison et al (2001)

  • More to do with gender and psychosocial factors such as social skills, academic achievement and family tolerance of schizophrenic behaviour 

Copeland et al (1971) 

  • Gave a description of a patient to 134 US psychiatrists and 194 British psychiatrists - 69% of the US psychiatrists diagnosed schizophrenia, but only 2% of the UK gave the same diagnosis 
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Biological Explanations

Gottesman (1991) 

  • Schizophrenia is more common among biological relatives, the closer the degree of genetic relatedness, the greater the risk

Joseph (2004)

  • Concordance rate for MZ twins at 40% and for DZ twins at 7%

Tienari et al (2000) 

  • Adoption study in Finland - of the 164 adoptees whose biological mothers had schizophrenia, 6% also received this diagnosis compared to just 2% of control adoptees 
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Biological Explanations

Joseph (2004)

  • MZ twins experience more similar environments and more identity confusion than DZ 
  • Differences in concordance rates reflect nothing more than the environmental differences that distinguish the two types of twin

Haracz (1982) 

  • Review of post-mortem studies of schizophrenics, found that most of those studied wh showed elevated dopamine levels had received antipsychotic drugs shortly before death. Post-mortems of those who had no medication showed normal dopamine levels

Copolov and Crook (2000)

  • Neuroimaging has failed to provide convincing evidence of altered dopamine activity in the brains of schizophrenics 
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Psychological Explanations

Brown and Birley (1968) 

  • Prior to a schizophrenic episode, patients who had previously experienced schizophrenia reported twice as many stressful life events compared to a healthy control group

Kalafi and Torabi (1996)

  • Found that high prevalence of EE in Iranian cultures was one of the main causes for schizophrenic relapse. The negative emotional climate leads to stress beyond coping mechamisms, thus triggering an episode

Linszen et al (1997)

  • A patient returning to a family with high EE is about 4x more likely to relapse than a patient returning to a low EE family
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Psychological Explanations

Fromm-Reichman (1948) 

  • Described schizophrenic mothers or families who are rejecting, overprotective, dominant or moralistic, as important contributory influences in the development of schizophrenia. 

Oltmanns et al (1999)

  • Parents of schizophrenic patients do behave differently from parents of other kind of patients, particularly in the presence of their disturbed offspring - likely to be a consequence

Meyer-Lindenberg et al (2002)

  • Link between excess dopamine in the prefrontal cortex and working memory
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Psychological Explanations

Yellowlees et al (2002)

  • Developed a machine that produces virtual hallucinations to show schizophrenics that their hallucinations are not real - no evidence of success 

Van Os et al (1994)

  • Found no link between life events and the onset of schizophrenia, patients were not more likely to have had a major stressful life event in thre three months preceding the onset 

Berger (1965) 

  • Found that schizophrenics reported a higher recall of double-bind statements by their mothers than non-schizophrenics 
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Psychological Explanations

Liem (1974) 

  • Measured patterns of parental communication in families with a schizophrenic child and found no difference when compared to normal families 

Hall and Levin (1980)

  • Analysed data from various studies and found no difference between families with and without a schizophrenic member in the degree to which verbal and non-verbal communication were in agreement 

Horgarty et al (1991)

  • Found that such therapy can significantly reduce relapse rates (EE) 
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Psychological Explanations

Scheff (1974) 

  • Evaluated 18 studies explicitly related to labelling theory. He judged 13 to be consistent with the theory and 5 to be inconsistent. 

Rosenhan (1973)

  • Found that once the 'label' of schizophrenia had been applied, the 'diagnosis' continued to influence the behaviour of staff towards the patient, even when this was no longer warranted 
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Biological Therapies

Karagulla (1950)

  • First studies of ECT had lower rates of recovery compared to patients who did not receive ECT

Davis et al (1980)

  • Found a significant difference in terms of relapse rates between treatment (19%) and placebo (55%) groups in every study reviewed, thus demonstrating their effectiveness 

Vaughn and Leff (1976)

  • Found that antipsychotic medication did make a difference, but only for those living with hostility and criticism in their home environment - relapse on medication was 53% but 92% on a placebo 
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Biological Therapies

Hill (1986)

  • Conventional antipsychotics have worrying side effects such as TD - 30% of people taking the medication will develop the condition, and it is irreverable in 75%

Ross and Read (2004)

  • Being prescribed medication reinforces the view that there is something wrong with you - this prevents the individual from thinking about possible stressors that might be a trigger - reduces their motivation to look for possible solutions 

Leucht et al (1999)

  • Meta-analysis found that the superiority of atypical from conventional was only moderate - two of the new drugs were only 'slightly' more eective, while there other two were no more 
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Biological Therapies

Jeste et al (1999) 

  • TD rates in 30% of people ater nin months of treatment with conventional drugs, but only 5% or those treated with atypical drugs 

American Psychiatric Association Review (2001)

  • Compared ECT with 'simulated ECT' - concluded that ECT produced better rsults that were no different from or worse than antipsychotic medication

Sarita et al (1998)

  • No difference in symptom reduction between 36 schizophrenia patients given either ECT or simulated ECT

Read (2004)

  • Use has declined in the UK between 1979 and 1999 = 59%
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Psychological Therapies

Drury et al (1996)

  • Found benefits in terms of a reduction in positive symptoms and a 25-50% reduction in recovery time when given CBT and antipsychotic medication

Kuiper et al (1997)

  • Confirmed these advantages and noted lower patient drop-out rates and greater patient satisfaction when used in addiction in drugs 

Kingdon and Kirschen (2006)

  • Found that many patients were not deemed suitable for CBT because psychiatrists believed they would not fully engage with the therapy - older less suitable 
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Psychological Therapies

Gottdiener (2000)

  • Reviewed 37 studies and found that 66% of those receving psychotherapy improved after treatment, compared to 35% who did not receive psychotherapy


  • Argued that some forms of psychotherapy may be harmful

May (1968)

  • Found that patients treated with this therapy and medication had better outcomes than those treated with the therapy alone.

Karon and VandenBos (1981) 

  • Found patients treated with therapy improved more than medication alone 
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Psychological Therapies

Karon and VandenBos (1981)

  • Overall cost of treating patients decreses with the use of therapy as they are less likely to seek inpatient treatment and more likely to gain employment 
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