AQA A-LEVEL PSYCHOLOGY REVISION NOTES: SCHIZOPHRENIA

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PSYCHOLOGY AQA A-LEVEL UNIT 3 (7182/3)

THE SYLLABUS

CLASSIFICATION OF SCHIZOPHRENIA

  • Positive symptoms of schizophrenia, including hallucinations and delusions
  • Negative symptoms of schizophrenia, including speech poverty and avolition
  • Reliability and validity in diagnosis and classification of schizophrenia, including reference to co-morbidity, culture and gender bias and symptom overlap

BIOLOGICAL EXPLANATIONS FOR SCHIZOPHRENIA

  • Genetics
  • The dopamine hypothesis
  • Neural correlates
  • Evaluation of biological approaches

PSYCHOLOGICAL EXPLANATIONS FOR SCHIZOPHRENIA

  • Family dysfunction
  • Cognitive explanations, including dysfunctional thought processing

DRUG THERAPY

  • Typical and atypical antipsychotics

 PSYCHOLOGICAL THERAPIES

  • Cognitive behaviour therapy
  • Family therapy
  • Token economies

 INTERACTIONIST APPROACHES

  • The Diathesis-Stress Model

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INTRODUCTION

Schizophrenia is a severe psychotic disorder which affects about 0.3-0.7% of the population at some point in their lives. Although there are a variety of types of schizophrenia, symptoms commonly involve a loss of contact with reality, delusions and hallucinations.

Traditional, pre-scientific explanations of schizophrenia generally viewed the symptoms as a sign of demonic possession and sufferers would be treated with exorcism. From the 18th C. onwards, a more compassionate, medical model evolved which viewed the disorder as a biological illness.

During the 20th C. evidence emerged linking schizophrenia to genetic predisposition, biochemical imbalances and neurological abnormalities, and treatment was largely based around drugs therapies.

Alternative viewpoints have argued that schizophrenia is a fragmented psychological state which individuals are driven to as a result of stress or trauma and that psychiatry is incorrect in its assumptions regarding biological causation. Indeed, some critics have argued that psychiatric explanations are a pseudo-scientific justification for punishing social deviants and/or removing individuals who cannot adjust to or function ‘normally’ in society.

Psychiatrists (doctors specialising in mental health) employ classificatory systems to diagnose schizophrenia – in America, DSM-5-TR (Diagnostic and Statistical Manual of Mental Disorders, 5th edition).

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CLASSIFICATION OF SCHIZOPHRENIA. POSITIVE SYMPTOMS OF SCHIZOPHRENIA, INCLUDING HALLUCINATIONS AND DELUSIONS. NEGATIVE SYMPTOMS OF SCHIZOPHRENIA, INCLUDING SPEECH POVERTY AND AVOLITION. RELIABILITY AND VALIDITY IN DIAGNOSIS AND CLASSIFICATION OF SCHIZOPHRENIA, INCLUDING REFERENCE TO CO-MORBIDITY, CULTURE AND GENDER BIAS AND SYMPTOM OVERLAP (Psychology A-level revision)

CLASSIFICATION OF SCHIZOPHRENIA. POSITIVE SYMPTOMS OF SCHIZOPHRENIA, INCLUDING HALLUCINATIONS AND DELUSIONS. NEGATIVE SYMPTOMS OF SCHIZOPHRENIA, INCLUDING SPEECH POVERTY AND AVOLITION

Schizophrenia is a severe psychotic disorder which affects about 0.3-0.7% of the population at some point in their lives.

Males are diagnosed at +40% more than females.

Approximately 1/3rd of sufferers have a single, fairly brief episode; 1/3rd follow repetitive episodes throughout their life; 1/3rd experience a constant schizophrenic state.

DSM-5 lists various types of schizophrenia. 3 of the better known are Paranoid, Disorganised and Catatonic.

  • Positive symptoms refer to an excess or distortion of a normal function (e.g. a normal behaviour is exaggerated) or to a new function (e.g. a behaviour which has never been shown before occurs).
  • Negative symptoms refer to a lessening or loss of normal functions.

POSITIVE SYMPTOMS

  • Delusions – ‘false’ beliefs which appear true to the schizophrenic.
    • Delusions of grandeur – a belief that one possesses a special personal identity or special powers/abilities.
    • Paranoid delusions – a belief that one is being followed, monitored or conspired against by a group who mean to do harm.
    • Religious delusions – a belief that one is in communication with or is a supernatural being: e.g. god, a demon, a superhero, etc.
  • Hallucinations. Usually aural – ‘hearing voices’ providing a negative critical commentary on the person or commanding them to do or not do certain things. Can also be visual (seeing things) or tactile (feeling things).
  • Experiences of control. A belief they one is under the control of an outside force which has invaded one’s mind and body: e.g. through implanted transmitters, etc.
  • Disordered thinking. Incoherent or random speech. Feeling that thoughts have been inserted or withdrawn from the mind.

 NEGATIVE SYMPTOMS

  • Speech poverty – difficulty with speaking – reduced speech output and verbal fluency.
  • Avolition – loss of motivation and the will or desire to participate in activities or do things.
  • Affective flattening – a reduction in the range and intensity of emotional expression. Immobile and unresponsive facial expressions often accompanied by poor eye contact and little body language or movement.
  • Catatonia – assuming a rigid posture and remaining immobile in a trance-like state.

RELIABILITY AND VALIDITY IN DIAGNOSIS AND CLASSIFICATION OF SCHIZOPHRENIA, INCLUDING REFERENCE TO CO-MORBIDITY, CULTURE AND GENDER BIAS AND SYMPTOM OVERLAP

RELIABILITY

  • Reliability refers to the consistency of the diagnosis: i.e. different psychiatrists diagnosing the individual should all agree that schizophrenia is the correct diagnosis (inter-rater reliability) and the same diagnosis should be given over time (test-retest reliability). Schizophrenia is diagnosed after a lengthy clinical interview, however, there is no objective test (e.g. a blood test) for the disorder.
  • Evidence shows that there were problems with the reliability of diagnosis some years ago. Copeland (‘71) gave a description of a patient to 134 US and 194 British psychiatrists. 69% of the US psychiatrists diagnosed schizophrenia whereas only 2% of the British psychiatrists gave the same diagnosis. This indicates very poor reliability.
  • To address lack of reliability, DSM has been revised through several additions. However, some research suggests that poor reliability is still a problem. Whaley (‘01) found inter-rater reliability correlations in the diagnosis of schizophrenia as low as 0.11.

VALIDITY

  • Validity refers to how accurate and true the diagnosis is: i.e. a diagnosis is valid if a schizophrenic is diagnosed with schizophrenia and not another disorder.
  • Rosenhan’s (’73) sent ‘normal’ people to a number of psychiatric hospitals claiming that they were hearing unfamiliar voices in their heads. They were all admitted into the hospitals and diagnosed with schizophrenia or manic-depression. On entry they all stopped faking their symptoms and acted normally, yet were still treated as being mentally ill by staff. Thus, psychiatrists and staff were, apparently, unable to make a valid diagnosis of schizophrenia.
  • Predictive validity refers to the extent to which the diagnosis of schizophrenia can predict the likely outcome of the illness (the prognosis). It is usually the case that there should be a predictable course that a disorder will take. However, this is not the case with schizophrenia. Thus diagnosis has low predictive validity.

 CULTURE BIAS

  • Fernando claims that British psychiatrists hold conscious or unconscious stereotypes about race which affect diagnosis. Loring (’88) gave 290 psychiatrists a transcript of a patient interview and told half of them that the patient was black and the other half white. Black males were more likely to be diagnosed with paranoid schizophrenia. This indicates that certain people are more likely to be diagnosed based on criteria other than the presented symptoms: in this case, race. It may also explain why there are disproportionately large numbers of ethnic minorities in the UK and USA forcibly placed in institutions.

 GENDER BIAS

  • Males may be more likely to be involuntarily committed to a mental institution as psychiatrists label them as being more likely to be violent/criminal.
  • Women are more likely to commit themselves to a mental institution as it is more socially acceptable for women to seek help for emotional/psychological problems.
  • Broverman (’70) found that psychiatrists in the USA tended to think of mentally healthy behaviour in terms of stereotypically male traits, therefore, females were more likely to be judged as mentally ‘unhealthy’.

CO-MORBIDITY

The reliability of diagnosis is complicated by the fact that schizophrenia is often co-morbid with depression, anxiety and substance abuse (co-morbidity = 2 illnesses occurring at the same time). For example, co-morbid depression occurs in 50% of schizophrenics, and co-morbid substance abuse occurs in 47%. Thus, it is very difficult to draw a line between schizophrenia and other disorders, and questions whether a single, simple classification of ‘schizophrenia’ is valid and useful.

SYMPTOM OVERLAP

It can also be difficult to define the boundaries between schizophrenia and other disorders such as bi-polar disorder. For example, both disorders may experience delusions of grandeur. Psychiatric classificatory systems have tried to address the problem of symptom overlap by proposing mixed disorder categories such as schizoaffective disorder (schizophrenia + depression), but the validity of such categories has also been questioned.

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BIOLOGICAL EXPLANATIONS FOR SCHIZOPHRENIA: GENETICS, THE DOPAMINE HYPOTHESIS AND NEURAL CORRELATES (A-level Psychology revision)

Biological explanations view schizophrenia as an inheritable disorder (genetics) associated with abnormal neurotransmitter function (dopamine) and brain structure.

GENETICS

The likelihood of a person with unaffected relatives developing schizophrenia is 0.2-2%, however with affected relatives the likelihood increases: one parent (approx. 25%), two parents (approx. 50%).

Using a sample of 57 twins, Gottesman (’66) reported a concordance rate (the average % probability of an individual developing the disorder if they have an affected relative) of 42% for monozygotic twins (MZ) and 9% for dizygotics (DZ). All major twin studies consistently report higher concordance rates for MZ’s than DZ’s although the highest concordance rates for MZs are rarely above 50% implying that social, psychological and environmental factors must play a role. However, Heston found that if an MZ had a schizophrenic disorder there was a 90% chance the other twin had some sort of mental disorder.

CONCORDANCE RATES FOR SCHIZOPHRENIA

 AQA A LEVEL PSYCHOLOGY SCHIZOPHRENIA CONCORDANCE RATES

EVALUATION

Family history and twin studies fail to separate the influence of nature (genetics) and nurture (environment) and twins and family members tend to share similar parenting styles, learning experiences and social environments.

Adoption studies, on the other hand, involve studying the concordance rates of adopted-away offspring of schizophrenic mothers thus untangling the influence of biology and environment. Heston found a concordance rate of 10% between adopted away children and their schizophrenic mothers, and children of schizophrenic mothers were more likely to be sociopathic, neurotic and criminal.

NEUROTRANSMITTERS – THE DOPAMINE HYPOTHESIS

Excessive levels of the neurotransmitter dopamine are associated with schizophrenia. Phenothiazines (drugs used to treat schizophrenia) inhibit dopamine activity and reduce symptoms, and L-Dopa (used to treat Parkinson’s disease) stimulates dopamine production and produces schizophrenic symptoms in unaffected individuals.

Amphetamines (a street drug) increase the release of dopamine at synapses, and the symptoms of amphetamine psychosis (caused by taking too much of the drug) resembles paranoid schizophrenia.

THE RELATIONSHIP BETWEEN DOPAMINE, PHENOTHIAZINES & L-DOPA

AQA A LEVEL PSYCHOLOGY THE DOPAMINE HYPOTHESIS

It is impossible to establish, however, whether increased dopamine activity causes schizophrenia or whether schizophrenia has social/psychological causes which interfere with dopamine: i.e. we cannot determine the direction of the cause-effect relationship.

NEUROLOGICAL FACTORS – NEURAL CORRELATES

Post-mortems reveal increased dopamine in the left amygdala and increased dopamine receptor density in the caudate nucleus putamen. This finding was confirmed using PET scans by Wong.

Ianoco argued that dopamine deficiency may be the cause of ventricular enlargement – one of schizophrenia’s most noticeable neurological effects.

As with abnormal neurotransmitter levels, it is impossible to establish cause and effect relationships between abnormal neurological structure and schizophrenia.

FURTHER EVALUATION & COMMENTARY

  • Although the above theories are supported by scientific evidence based on observation of physical, biological processes often using advanced technological equipment, critics argue that medical psychiatry is biologically determinist and reduces the schizophrenic’s experience to a simple ‘illness’ which can only be managed by drug therapy.
  • Alternative psychological explanations tend to focus on the role of stress as a trigger, often in the context of family and interpersonal conflict. Anti-psychiatrists such as Laing argued that families characterised by high emotional tension where children received conflicting messages of care and criticism can cause a withdrawal into a schizophrenic state, and research with discharged schizophrenics has found that high levels of family expressed emotion (hostility, criticism, over-involvement and over-concern) are associated with high relapse rates.
  • The fact that schizophrenia is more common among immigrant and socio-economically deprived groups indicates that stress and life events are likely to act as a trigger.
  • The diathesis-stress model combines evidence from different approaches to suggest that individuals inherit a biological predisposition to develop schizophrenia which is then triggered by social and/or psychological stressors.

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PSYCHOLOGICAL EXPLANATIONS FOR SCHIZOPHRENIA: FAMILY DYSFUNCTION AND COGNITIVE EXPLANATIONS, INCLUDING DYSFUNCTIONAL THOUGHT PROCESSING (AQA A-level Psychology revision)

FAMILY DYSFUNCTION

 In the 50s and 60s, it was thought that people suffering from schizophrenia were from dysfunctional families. The term ‘schizophrenogenic family’ was used to describe families with high emotional tension, many secrets, close alliances and conspiracies.

Expressed emotion (EE) is a family communication style that involves criticism, hostility and over-concern. It is predicted that high levels of EE are likely to influence relapse rates (be readmitted to a psychiatric institution). The negative emotional climate in these families seems to arouse the patient and leads to stress beyond his or her already impaired coping mechanisms. EE is assessed by taping an interview with a relative of someone with schizophrenia and rating the frequency of critical comments, the frequency of expressions of dislike towards the patient, and the frequency of expression of over-protectiveness towards the patient

Research has generally been supportive. Linszen found that a patient returning to a family with high EE is about x4 more likely to relapse than a patient whose family is low EE.

A research study into schizophrenia and EE

  • Subotnik (’02) gave 100 schizophrenics’ parents a Thematic Apperception Test. This test asks people to view a picture of a scene and describe their thoughts and feelings about the people pictured. The researcher then measures how critical and hostile their communication style Subotnik found that mothers of schizophrenics were particularly likely to be critical/hostile even though these mothers showed no sign of schizophrenia themselves. He concluded that mothers can pass on schizophrenic genes to offspring despite showing no sign of the disorder themselves.

However, studies of EE are correlational and may reflect the consequences of living with a severely disturbed individual, rather than having any causal significance: i.e. it may be the patient’s mental health problem which causes the family/parent to become high EE.

High EE patterns have also been found in the families of patients with other disorders such as depression and eating disorders, so high EE may not only be a cause of schizophrenia, rather of mental health breakdown in general.

COGNITIVE EXPLANATIONS, INCLUDING DYSFUNCTIONAL THOUGHT PROCESSING

Schizophrenics exhibit dysfunctional thought processing: i.e. they process information differently to non-schizophrenics.

Cognitive explanations have focussed on how schizophrenics’ cognitions may form the basis for their delusions and hallucinations.

DELUSIONS

  • Delusions such as paranoia involve distorted patterns of thinking which exaggerate how important/central the individual is to irrelevant/meaningless events. For example, if someone looks at a schizophrenic accidentally the schizophrenic may interpret it as having meaning: e.g. ‘I am being watched’. This is referred to as ‘egocentric bias’. Schizophrenics also fail to ‘reality test’ their beliefs: i.e. they fail to assess whether a belief they hold is rational/irrational and fail to recognise their cognitions as illogical and distorted.

HALLUCINATIONS

  • It has been argued that the schizophrenic experience of hearing voices is simply an excessive focus on auditory stimuli (hypervigilance) and a high expectation that they will hear voices. Thus, their exaggerated expectancy of hearing voices and their interpretation of random auditory stimuli as possessing meaning produce auditory hallucinations.

A RESEARCH STUDY INTO SCHIZOPHRENICS’ PERCEPTION

  • Shin (’08) investigated schizophrenics information processing abilities by testing their facial recognition abilities. 20 schizophrenics were matched against 20 non-schizophrenic controls and asked to perform a variety of perceptual tasks to do with spotting similarities and differences between images of faces. Schizophrenics performed poorly compared to non-schizophrenics on all facial-perceptual tasks. Shin interpreted this as evidence in favour of the idea that schizophrenics are likely to misinterpret other peoples’ facial expression and thus misinterpret their intentions: e.g. they may believe others are planning to harm them.

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DRUG THERAPY: TYPICAL AND ATYPICAL ANTIPSYCHOTICS (AQA A-level Psychology revision guide)

ANTIPSYCHOTIC DRUGS

  • Drugs that are effective in treating the most disturbing forms of psychotic illness, such as schizophrenia are called antipsychotics.
  • Typical antipsychotic drugs (e.g. chlorpromazine) are used primarily to combat the positive symptoms of schizophrenia, such as hallucinations and thought disturbances, products of an overactive dopamine system.
  • Atypical antipsychotic drugs (e.g. clozapine) combat positive symptoms but may also have some beneficial effects on negative symptoms.

TYPICAL ANTIPSYCHOTICS

The basic mechanism of typical antipsychotic drugs is to reduce the effects of dopamine and thus reduce symptoms of schizophrenia. Conventional antipsychotics are dopamine antagonists in that they bind to but do not stimulate dopamine receptors (particularly D2 receptors), thus blocking their action and reducing delusions and aural hallucinations.

ATYPICAL ANTIPSYCHOTICS

Atypical antipsychotic drugs also act on the dopamine system but additionally act on serotonin systems in the brain that might be involved in schizophrenia.

These drugs temporarily occupy D2 dopamine receptors and then rapidly dissociate to allow normal dopamine transmission. It is this characteristic of atypical antipsychotics that is thought to be responsible for the lower levels of side-effects (such as tardive dyskinesia – involuntary movements of the mouth and tongue) compared to typical antipsychotics.

EVALUATION

  • The World Health Organization (‘01) reported that relapse rates in schizophrenics after 1 year were
  • 55% with placebos
  • 25% with chlorpromazine alone
  • 2-23% when chlorpromazine was combined with family intervention

This suggests that whilst placebos can have a significant effect, typical antipsychotics have a far superior impact, particularly when combined with psychotherapy of some sort.

  • Adams conducted a meta-analysis of 50 randomised controlled trials of the use of chlorpromazine for schizophrenia. In total, they included 5,276 individuals (in treatment or placebo groups). Overall, they found that chlorpromazine failed to produce global improvement in 76% of patients, and commonly produced adverse side-effects such as sedation, a risk of movement disorders and dizziness.
  • One of the main reasons that drug therapies fail is because side-effects cause patients to stop taking their medication. Relatively minor side effects include drowsiness, visual disturbance, dryness of the mouth, changes in weight and depression. More seriously, they can induce a disorder called tardive dyskinesia which is irreversible and involves uncontrollable lip and tongue movements and facial tics. Around 24% develop this after taking typical antipsychotics for 7 years. Clearly there are ethical issues to consider when prescribing these drugs.
  • Clozapine is associated with potentially fatal lowering of the white blood count and its use requires regular blood monitoring. Other side effects include sedation, hyper-salivation and weight gain.
  • Some have criticised the medicalisation of mental disorders, saying that it is inappropriate to treat people like machines that have broken and need to be fixed. It has been argued that schizophrenics should be offered more enabling therapies which will allow them to manage their own conditions. Biological therapies are considered to be reductionist, assuming that the disorder is simply biologically causes and ignoring the social and emotional factors surrounding the individual’s condition and how they make sense of their disorder.
  • There may also be publication bias. Non-significant results are less likely to be published so meta-analyses may over-exaggerate positive findings form research studies. Drug companies often fund research – they might suppress negative results to protect their profits. The result will be that drug therapy appears more successful than it actually is.

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COGNITIVE BEHAVIOUR THERAPY AND FAMILY THERAPY AS USED IN THE TREATMENT OF SCHIZOPHRENIA. TOKEN ECONOMIES AS USED IN THE MANAGEMENT OF SCHIZOPHRENIA (A-level Psychology resources)

COGNITIVE BEHAVIOUR THERAPY AND FAMILY THERAPY

COGNITIVE BEHAVIOUR THERAPY (CBTP)

Cognitive-behavioural therapy for psychosis (CBTp) is used with schizophrenics whose symptoms have been partially stabilised with drug therapies but who still experience some milder strength positive and negative symptoms: e.g. paranoid delusions....

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