What is schizophrenia and who does it affect?
Schizophrenia is a serious mental illness that affects 1% of the population. It distorts contact with reality and impairs a person’s insight. It is more commonly diagnosed in men than women and is seen to affect working class more than middle class.
What is meant by negative symptoms of schizophrenia?
Negative symptoms of schizophrenia is where there is a loss in ability or control. For example, avolition or ‘apathy’ where sufferers struggle to begin or keep up with goal directed behaviour. Andreason (1982) identified three signs of avolition; poor hygiene, lack of persistence in work and education and lack of energy. Another negative symptom is speech poverty which is reduction in the amount or quality of speech.
What is meant by positive symptoms of schizophrenia?
Positive symtoms refer to the addition of an experience. E.g. Hallucinations or delusions. Hallucinations refer to unusual sensory experiences that can be picked up from any sense - sometimes they are related to the environment and sometimes they are not. Delusions refer to irrational beliefs and come in a variety of forms. Paranoid, grandeur, external control.
What is meant by the DSM-V and the ICD-10 and how do they differ in their classification of schizophrenia?
The DSM-V is the American psychiatric association’s Diagnostic and Statistical manual edition 5 which uses positive symptoms. One or more must be present to give a diagnoses.
The ICD-10 is the World Health Organisation’s International Classification of disease edition 10. This requires two or more negative symptoms to be diagnosed. Also recognises different types of schizophrenia, eg. paranoid, hebephrenic and catatonic.
What are the ICD-10 different types of schizophrenia?
- Paranoid schizophrenia - most common type, tends to develop later on in life, symptoms include hallucinations or delusions but your speech and emotions are not affected
- Hebephrenic (disorganised) schizophrenia - symptoms include disorganised behaviours and thoughts, short-lasting delusions and hallucinations, disorganised speech patterns, show little or no emotions
- Catatonic schizophrenia - characterised by unusual, limited and sudden movements, you become very active or very still,
- Undifferentiated schizophrenia - may have some signs of paranoid, hebephrenic or catatonic symptoms but don’t fit into one category.
- Reidual schizophrenia - if you have a history of psychosis but only experience the negative symptoms.
Evaluate the theory/diagnosis of schizophrenia.
Issue of reliability with diagnosis. Cheniaux et al. Had 2 psychiatrists independently diagnose 100 patients using both the DSM and ICD criteria - inter-rater reliability was poor. One diagnosed 26 with the DSM and 44 with the ICD; the other 13 and 24 respectively. Inconsistency is a limitation.
Issue of validity in the diagnosis. Cheniaux et al. showed that schizophrenia is more likely to be diagnosed using the ICD - assessment criteria doesn’t arrive at the same conclusion. Schizophrenia is either over-diagnosed in ICD or under-diagnosed in DSM. Poor validity is a weakness.
Comorbidity. When 2 or more conditions occur together - could be the same condition. Buckley et al. found that 50% of patients with schizophrenia have depression and 47% suffer from substance abuse. If very severe depression looks like schizophrenia, it can be confusing for classification. This is a limitation.
Culture bias in diagnosis. African-Americans/people of African descent are more likely to get diagnosed with schizophrenia in the UK. Some behaviours we see as positive symptoms are normal in African culture, e.g. hearing voices. Therefore it has low external validity as individuals from different cultural backgrounds are more likely to be diagnosed with schizophrenia due to bias.
Symptom overlap. There is significant overlap between symptoms of schizophrenia and other conditions. Bi-polar can involve delusions and avolition. The validity of diagnosis and classification is questioned. Patients would be diagnosed with Bi-polar disorder under the DSM and with schizophrenia under the ICD.
Outline the genetic biological explanation for schizophrenia
There is a strong relationship between genetic similarity of family members and the likelihood of both developing schizophrenia.
Gottesman family study found MZ twins have a 48% shared risk of schizophrenia.
DZ twins have a 17% shared risk and siblings (about 50% genes shared) have 9% shared risk.
Existence of different candidate genes indicates each individual gene confers a small increased risk of schizophrenia (schizophrenia is polygenetic)
Different combinations can read to schizophrenia (aetiologically heterogeneous).
Ripke et al studied 37,000 patients and found 108 separate genetic variations associated with increased risk; many coded for the dopamine neurotransmitter.
Outline the dopamine hypothesis biological explanation for schizophrenia.
Dopamine (DA) appears to be involved in many of the systems implicated in the symptoms of schizophrenia. The original hyperdopaminergia hypothesis focussed on the role of excess levels of dopamine in the sub cortex eg. Broca’s area. (positive symptoms such as hallucinations )
More recently the hypothesis has focussed on abnormal dopamine systems. A role of Low levels of dopamine have been identified in the cause of negative symptoms. Possibly both hyper- and hypodopaminergia are involved in schizophrenia.
What is meant by neural correlates?
Patterns of structure or activity found in the brain that occur in conjunction with symptoms. Juckel et al. Found that reduced activity in the ventral striatum was associated with avolition. This area is involved in the anticipation of reward, which creates motivation. Without motivation, people won’t engage in goal directed behaviour.
Explain how family dysfunction might be involved in schizophrenia. Refer to two or more types of family dysfunction in your answer
Schizophrenogenic Mother. Cold, rejecting and controlling. Makes an environment of secrecy and tension. Can lead to distrust & paranoid delusions.
Double-Bind. Role of communication. The child receives mixed messages about what to do & trapped in a situation where they fear doing the wrong thing. Can’t ask for clarification. Punished through a withdrawal of love. Leads to a view of the world as a confusing and dangerous place.
Expressed Emotion. Communication & negative towards the patient from their carers. Verbal criticism, hostility, anger, rejection & over-involvement in the life of the patient. Serious source of stress → primary source of relapse.
Outline at least two ways in which a cognitive psychologist might explain schizophrenia.
Poor Metarepresentation. The ability to reflect on thoughts and behaviour. Insight into intentions and goals & allows us to interpret the actions of others. Inability to recognise our actions as being our own → hallucinations.
Poor central control. Inability to suppress automatic responses while we perform deliberate actions. Disorganised speech. Inability to suppress automatic thoughts associated with other thoughts
What is meant by typical antipsychotics?
E.g. Chlorpromazine. Work by acting as antagonists in the dopamine system → aim to reduce the action of dopamine. Work by blocking the dopamine receptors in the synapses. Initially dopamine levels build up to make up for the deficit, but then production is reduced → normalises neurotransmission in the brain, which reduces positive symptoms. Also has a sedation effect - also useful for anxious patients.
More modern form of drug therapy. Target dopamine and serotonin. Designed to reduce side effects, whilst maintaining effectiveness.
More modern form of drug therapy. Target dopamine and serotonin. Designed to reduce side effects, whilst maintaining effectiveness.
Name and describe 2 types of atypical antipsychotics.
Clozapine - acts on serotonin and dopamine and glutamate receptors → reduces depression and anxiety while improve cognitive functioning → also improves mood.
Risperidone - developed due to the side-effects of clozapine (blood clotting). Binds more strongly to dopamine receptors - more effective in smaller doses and has less side-effects.
Name two or more psychological therapies for schizophrenia.
CBT; Family Studies; Token Economies.
Outline the use of 3 psychological therapies for schizophrenia.
CBT- Identifies and changes irrational thoughts. Could involve discussion regarding how likely the beliefs are to be true and consideration of less threatening options. CBT helps patients to make sense of their symptoms and how they impact on behaviour and feelings. This could reduce anxiety and help patients realise beliefs are not based in reality.
Family Therapy - aims to reduce EE in the family - improvement of communication and interaction. Reduction of stress that could contribute to relapse. Improvement of family function. Strategies to reduce likelihood of relapse include (Pharoah et al 2010): Reduction of stress for carers; improve the ability of carers to anticipate and resolve problems; reduction of guilt; improvement of beliefs and behaviour towards schizophrenia.
Token economies - tokens are used to reinforce desirable behaviour for patients in long-term care. This reward reinforces the desirable behaviour and because it is given immediately it prevents ‘delay discounting’. The tokens are secondary reinforcers - the value is not the tokens themselves, but from their association with the reward.
Outline the interactionist approach to explaining and/or treating schizophrenia.
The diathesis stress model - genetic vulnerability paired with a trigger causes schizophrenia. Meehl - Vulnerability is due to a schizogene → without the gene no amount of stress will cause the disorder. Modern version view diathesis as anything than can increase vulnerability e.g. trauma or genes. Modern views of stress includes anything that is likely to trigger an episode of schizophrenia e.g. cannabis use. Treatments include using both drugs and CBT (usually). CBT is usually used to alleviate symptoms whilst drugs tackle to underlying chemical imbalance. You must take an interactionist approach if you want to use both explanations effectively. Combination treatments are common in the UK, however historically the two schools clash in the US and so the interactionist approach is not as widespread.
Briefly outline one reason why it might be preferable for a person with schizophrenia to be treated using both drugs and CBT.
CBT will help suffers make sense of their symptoms.
Antipsychotics will help patients to cope with their delusions an hallucination.
Increased compliance with medical regimes
Give a strength of the biological explanation for schizophrenia.
Supporting argument for genetic vulnerability. Gottesman family study showed that the close relationship between genetic similarity and the risk of schizophrenia. Adoption, family and genetic linkage studies all point to a role of genetic make up vulnerability to schizophrenia, eg Tienari et al - schizophrenia may not be entirely genetic but there is a lot of evidence to suggest that genetic factors contribute to vulnerability.
Give 3 weaknesses of the biological explanation for schizophrenia.
Mixed support for the dopamine hypothesis - support - as predicted some dopamine agonists make symptoms worse and antipsychotics are dopamine antagonists - however some of the genes associated with vulnerability for schizophrenia code for unrelated chemicals e.g gultamate. Means that dopamine cannot provide a complete explanation for schizophrenia.
Correlation-causation - neural correlates are just correlates eg negative symptoms may be caused by reduced activity in the ventral straitum or the low avty in the ventral straitum is a result of low information processing caused by some other factor. Correlates tell us little about the cause of schizophrenia.
Enviroment is clearly involved. he probability of developing schizophrenia, even if your identical twin has it is only 50%. Evidence shows that family factors could also play a role - schzioprheniia may be a result of a combination of biological and environmental factors.
GIve two strengths of family influences for schizophrenia.
Research for the role of family influences. A large proportion of patients report childhood sexual abuse (Read et al) or insecure attachment (Berry et al) - supports the link between upbringing and schizophrenia. However the evidence is retrospective - symptoms could distort recall, which therefore lacks validity.
Evidence for dysfunctional thought processes. Stirling et al compared 30 patients with schizophrenia with a control group on cognitive tasks- patients with schizophrenia took longer to complete the Stroop test. This shows cognitive impairment. Supports the theory of central control dysfunction. however, a downside of cognitive explanations, is that they tell us nothing about the origin of the symptoms
Give two weaknesses of family influences for schizophrenia.
Evidence for family-based explanations is weak. Little or no evidence for the schizophrenegenic mother or double-bind hypothesis. Additionally, family-based explanations may encourage the blaming of parents whose children develop schizophrenia - undermines the appropriateness and credibility of such explanations.
The direction of causality. It remains unclear whether cognitive is a cause or a result of the neural correlates and abnormal neurotransmitter levels - e.g does dysfunctional metarepresentation reduce dopamine levels in the superior temporal gyrus or is the direction of causality of the reverse?
Give two strengths of antipsychotics
Effectiveness of antipsychotics - Thornley et al - chlorpromazine is better functioning and reduces symptom severity more than a placebo. Meltzer et al - clozapine is more effective than typical antipsychotics and 30-50% more effective in treatment-resistant cases. Healy (2002) - data from successful trials have been published more than once.
Antipsychotics also have calming effects - easy to demonstrate positive effects without actually reducing psychosis. Exaggerated effect.
Give two weaknesses of antipsychotics
Side effects. Typical antipsychotics are associated with dizziness, agitation, sleepiness, weight gain etc. Long term use can lead to lip-smacking and grimacing due to dopamine supersensitivity. Neuroleptic malignant syndrome - causing by blocking of dopamine action in the hypothalamus - can be fatal.
Ethical issues. Drugs are used in a hospital setting to calm patients and make them more manageable rather than for their positive effects - this practice is seen as unethical. ‘Chemical straitjackets’ or ‘chemical lobotomies’ No therapeutic value and curing symptoms - they reduce the patient to a calm, zombie-like state. Unethical as it is effectively controlling their behaviour. However, it might be considered necessary to keep the patient from harming themselves or other people. Dehumanising as they take away individual personal responsibility and control when they may have consented to treatment as they may not be in a position (in a psychotic state) to give consent if they are sectioned then treatment can also be enforced.
Evaluate psychological therapies for schizophrenia.
Help but don’t cure. CBT - makes sense of symptoms. Family therapy - reduction of stress of living.
Token economies - increase of socially acceptable behaviour. All of these should not be confused with a cure. Biological therapies also do not cure, however, they help symptom severity and therefore may be more desirable.
Ethics - token economy systems are controversial - severely ill patients cannot get privileges, as they are less able to comply with desirable behaviours - discrimination.
CBT is used to challenge paranoia - interferes with freedom of thought- controversial.
Quality of evidence.Small scale studies that compare the patient before and after therapy showed positive results. These studies often lack control groups of random allocation - this means that the effectiveness of psychological therapies could be being overestimated.
Give a strength of psychological therapies for schizophrenia.
Effectiveness of psychological therapies. Juhar et al. CBt had a small but significant effect on positive and negative symptoms. McMonagle and Sultna- only 1 in 3 token economies caused improvements. Pharoah et al - reviewed the effectiveness of family therapy. Moderate evidence for reduction of hospital admissions over 1 year and some evidence for the improvement of quality of life, but the evidence was inconsistent. Only modest support for the effectiveness of psychological therapies.
Give a strength of the interactionist approach.
Useful combination therapies. Studies show an advantage to using combination therapies - Tarrier et al - patients were randomly allocated to 1 of 3 groups, either medication + CBT group, medication with supportive counselling, or control group. Patients in the combination groups showed lower symptoms levels than those in the control- however, the relapse raters were no different - superior treatment outcomes.
Give three weaknesses to the interactionist approach.
The original model is oversimplified. Stress can come in many forms - not just from the family. Also found that vulnerability can be genetic or from trauma e.g childhood sexual trauma (Houston 20080. Challenges the original diathesis-stress model.
We don’t actually know how diathesis and stress work. Lots of evidence for the role of underlying vulnerability and stress - also have a lot of explanations or how these can lead to symptoms. However, we do not fully yet understand the underlying mechanisms by which symptoms appear and how they are produced.
Treatment-causation fallacy. Turkington et al - there is a logical fit between the interactions approach and using combination treatments. However, just because the combination treatment works doesn’t mean the IA is correct. If the underlying cause is neither to do with dopamine or to do with dysfunction families, then we are not actually treatment the cause, but simply suppressing the symptoms.