Psychology Studies - Schizophrenia

KENDLER

• studied those with genetic predisposition for Sz
• they had first degree relatives (parents & siblings) with Sz
• he found an overall concordance rate of 18%
• this is 18 times higher than the chance of development of Sz within the general population!

THIS SHOWS THE INFLUENCE OF GENETIC PREDISPOSITION ON THE DEVELOPMENT OF SCHIZOPHRENIA, SUPPORTING BIOLOGY AS AN EXPLANATION FOR THEM

TORREY

• conducted a meta-analysis of twin studies which focused on monoyzygotic twins
• these had a concordance rate of 28%
• This is 28 times the chance of development of Sz within the general population

SHOWS THE INFLUENCE OF GENETICS ON THE DEVELOPMENT OF SCHIZOPHRENIA- MZ TWINS SHARE MORE GENES THAN ANYONE ELSE!

GOTTESMAN

• studied 40 twins, some dizygotic and some monozygotic
• all had a range of schizophrenic symptoms

• monozygotic twins - 48% concordance rate
• dizygotic twins - 17% concordance rate

SHOWS THE INFLUENCE OF GENES ON THE DEVELOPMENT OF SZ; MZ TWINS SHARE MORE GENES THAN DZ

But Mz twins are more likely to be brought up in an environment that has more similarities than Dz twins...

HESTON

• studied 47 mothers
• all of these mothers had allowed their children to be adopted shortly after birth
• 16% of the children developed SZ
• this is 16 times higher than the general population
• they had no environmental influence from a Sznic parent

THIS SUGGESTS THAT SCHIZOPHRENIA DEVELOPMENT IS DUE TO GENETIC PREDISPOSITION...

But what about the other 84%?

WISE & STEIN

• studied the dopamine hypothesis
• carried out post-mortem examinations on schizophrenia sufferers 
• found they had 6 x more dopamine receptor sites than non-sufferers

THIS SUGGESTS MORE SENSITIVITY TO DOPAMINE IN SCHIZOPHRENIA SUFFERERS.

but how do we know they were there when the sufferer was alive...

JOHNSON

• observed those who suffered from Schizophrenia
• had a reduced blink response
• suggesting neurological damage

THIS SUGGESTS THAT NEUROLOGICAL DAMAGE IS LINKED TO SCHIZOPHRENIA AND SO COULD BE A CAUSE OF IT.

_____ & MCKENNA

• studied the anatomy of Sz sufferers
• showed the following results:

A larger corpus collosum

less grey matter in the temporal lobes of the brian

reduced activity in the pre-frontal cortex

enlarged ventricles, giving a loss of brain tissue

SHOWS THAT NEUROANATOMY IS AFFECTED WHEN THE INDIVIDUAL SUFFERS FROM SZ but can we establish cause and effect?

ROSENHAN

• complained of schizophrenic symptoms
• was sectioned and admitted into a psychiatric hospital
• could not convince medical staff that he was sane

• shows the perception and treatment of those with schizophrenia
• incorporates the self-fulfilling prophecy

THIS SUGGESTS THAT THE TREATMENT OF CERTAIN SCHIZOPHRENIC PATIENTS MAINTAINS THEIR SYMPTOMS.

SZASZ

• states that the labels of mental disorders are simply social controls
• he states they do not help the sufferer
• and instead they make them less able to care for themselves and more dependant on society

THIS SUGGESTS THAT PEOPLE COULD LIVE NORMALLY OF THEY WERE NOT LABELLED WITH A MENTAL DISORDER.

BATESON

• developed the double-bind theory
• this is where parents give conflicting messages to their children
• causing a no-win situation and confusion
• it also causes the child to see their perceptions as unreal and unreliable
• leading to withdrawal and self-doubt

THIS IS AN EXAMPLE OF A SCHIZOPHRENOGENIC FAMILY, WHICH ARE SAID TO BE THE CAUSE OF SCHIZOPHRENIA

LIDZ

• looked at marital schism - where two partners are openly dissatisfied with eachother
• he linked to this to schizophrenogenic families
• and said it can be seen to maintain schizophrenia

THIS LINKS SCHIZOPHRENIA TO HAVING A SOCIALLY INFLUENCED LINK.

But if this is a norm' for the child, why would it lead to the development of schizophrenia?

KAVANGH

• studied families who possess high expressed emotions (EE)
• this is where they are over-critical, over-protective and hostile

• his study suggested that those surrounded by high EE are 4 times more likely to develop Sz than those who are not

THESE LINKS TO THE SCHIZOPHRENOGENIC FAMILY AND THE INFLUENCE OF SOCIAL ENVIRONMENTS ON SCHIZOPHRENIA

BUTZLAFF & HOOLEY

• conducted a meta-analysis of studies that focused on schizophrenic patients
• he found that those surrounded by high expressed emotions were more likely to relapse

THIS SUPPORTS THE THEORY THAT SCHIZOPHRENOGENIC FAMILIES MAINTAIN SYMPTOMS OF SCHIZOPHRENIA

VAUGHN & LEFF

• studied schizophrenogenic families with high expressed emotions (EE) and families with no high EE
• Sz sufferers surrounded by high EE had a 51% relapse rate
• Sz sufferers without a high EE surrounding had  a 13% relapse rate

THIS SUPPORTS THE THEORY THAT HIGH EE MAINTAINS SCHIZOPHRENIA AND COMPLIMENTS THE EFFECT OF SCHIZOPHRENOGENIC FAMILIES.

However, the relapse rate for those not surrounded by high EE was still 13%... does this not suggest there is another cause?

VAUGHN & LEFF

• studied schizophrenogenic families with high expressed emotions (EE) and families with no high EE
• Sz sufferers surrounded by high EE had a 51% relapse rate
• Sz sufferers without a high EE surrounding had  a 13% relapse rate

THIS SUPPORTS THE THEORY THAT HIGH EE MAINTAINS SCHIZOPHRENIA AND COMPLIMENTS THE EFFECT OF SCHIZOPHRENOGENIC FAMILIES.

However, the relapse rate for those not surrounded by high EE was still 13%... does this not suggest there is another cause?

PATERSON

• gave reasons for the development of high expressed emotions in families

1. family members exprience 'loss' over who they once knew

2. family members are emotionally over-involved with trhe Sz sufferer

3. the over-involvement fails and they replace it with anger and critcism, helpint to maintain the Sz

• he therefore states the development of EE is not the direct fault of schizophrenogenic families
• but the interactions they have with the sufferer

THIS SUPPORTS THE THEORY OF THE INFLUENCE OF EE ON SZ.

KRING & NEALE

• played an emotional film Sz sufferers & Sz non-sufferers
• observed facial expressions
• Sz sufferers showed a lack of emotions within their facial expressions, compared with non-sufferers
• HOWEVER they were interviewed after and were found to have the same emotions about the film as the non-sufferers

SUPPORTS & REFUTES  OF 'ABSENCE OF EMOTION'. EMOTIONS ARE NOT PHYSICALLY DISPLAYED, BUT ARE STILL EXPERIENCED

This suggests that the physical presence of sufferers is used to label them, without really looking further into an explanation of emotions...

EATON ET AL.

• observed Sz sufferers
• they had a range of negative symptoms

• those with more negative symptoms had less achievement with work, socialisation and education than those with less of them

THIS SUPPORTS THE FACT THAT NEGATIVE EMOTIONS AFFECT EVERYDAY LIFE

 PAUL & LENTZ

• investigated a psychiatric hospital, using operant conditioning in the form of token economy
• tokens could be exchanged for cigarettes etc.
• they were rewarded when the patients made the bed etc.
• both the positive and negative symptoms of schizophrenia were reduced over 6 years
• shows operant conditioning can chaneg the behaviour of Sz patients

THIS SUGGESTS THAT BEHAVIOUR IS LEARNED AND NOT INNATE, AS IT CAN BE UNLEARNED

HOGARTY ET AL.

• observed the symptoms of Sz sufferers experiencing different treatments

medication only / medication + social skills training / medication + family therapy / medication + social skills training and family therapy

• patients with medication + social skills training and family therapy had NO relapse rate
• medication + social skills training and medication + family therapy both had a relapse rate of 20%
• medication alone had a relapse rate of 40%

SUGGESTS THAT FAMILY THERAPY IS MORE EFFECTIVE THAN MEDICATION ALONE, AND EVEN MORE EFFECTIVE WITH SOCIAL SKILLS TRAINING

but what about family therapy alone?

STEIN & TEST

• two groups of 65 patients who were hospitalised for Sz
• one group given community care after being discharged, such as educational support

• the other group was given no community care after discharge
• 58 of the 65 patients without community care were readmitted into hospital
• 53 of the 58 people with community care were readmitted

THIS SUGGESTS THAT COMMUNITY CARE IS EFFECTIVE IN PREVENTING RELAPSE RATES, BUT NOT COMPLETELY EFFECTIVE.

GOATER ET AL.

• prospective study
• different ethnic groups
• followed them for 5 years
• black people more likely to be detained, taken to hospitals and given emergency injections by police
• black people more likely to be misdiagnosed with schizophrenia

THIS SUGGESTS THAT UNUSUAL BEHAVIOUR IS SOMETIMES CLASSED AS SCHIZPHRENIC WHEN IT IS NOT

TIENARA

• 155 adopted children with mothers diagosed with schizophrenia
• 185 adopted children with mother who were not diagnosed with schizophrenia

• 10% of adopted children with schizophrenic mothers developed schizophrenia
• 1% of adopted children without schizophrenia mothers developed sczhizophrenia

THIS SUGGESTS THAT BIOLOGY PLAYS A STONGER ROLE IN THE ONSET OF SZ THAN THE ENVIRONMENT DOES!

GOTTESMAN AND SHIELDS

• studied identical twins with the most severe form of SZ
• found a 80% concordance rate between the twins

• studied identical twins with less severe forms of SZ
• found around a 50% concordance rate

MAYBE MORE SEVERE FORMS OF SZ CARRY A HIGHER HERITABILITY COEFFICIENT, OR MAYBE THIS WAS JUST COINCIDENCE...

STIRLING

• used 3 groups

1. SZ patients with reality distortion symptoms (hallucinations and perceptions)

2. SZ patients without reality distortion symptoms

3. non-SZ patients

• asked them to draw a picture with their arm behind a screen
• they could not see what they were drawing
• the SZ patients with reality perception symptoms found it harder to identify their drawing

THIS COULD BE DUE TO FAULTY INFORMATION PROCESSING, WHICH COULD ALSO BE TO BLAME FOR PERCEPTIONS, DELUSIONS ETC.

BROWN ET AL.

• followed SZ patients for 9 months after release from hospital
• interviewed their families and determined levels of EE

• 58% of patients who returned to hospital had high EE in their families
• 10% of patients who returned to hospital did not have high EE in their families

THIS SUGGETS THAT HIGH EE CAN UPHOLD SZ AND PREVENT RECOVERY BUT OTHER FACTORS STILL INFLUENCE.