Schizophrenia Flashcards
What is schizophrenia
?
A mental disorder which distorts an individuals perception of reality
What are negative symptoms?
Symptoms which take away from an individuals perception and abilities ( loss of motivation)
What are positive symptoms?
Atypical symptoms which adds onto the typical schizophrenia disorder (hallucinations)
What manuals are used to classify schizophrenia?
The ICD-10 (need two negative symptoms) and the DSM-5 (one positive symptom)
Examples of positive symptoms
Hallucinations- Which may be auditory or visual
Paranoid Delusions- Irrational thoughts about yourself which are untrue
Examples of negative symptoms
Avolition- When an individual lacks the normal motivation needed for daily skills (hygiene, making their bed, less sociable)
Speech poverty- Changes in speech patterns
Speech disorganisation (Positive symptoms)- When the speaker is incoherent and often jumps from topic to topic.
Strengths of the classification of Schizophrenia
(A03)
-One strength of the diagnosis of schizophrenia is that it has reliability. A diagnosis is said to be reliable when there is inter-rater reliability (when one clinician reaches the same diagnoses over a pro-longed period of time) and test re-test reliability (where multiple clinicians reach the same diagnosis). Researchers have reported reliability for diagnosis with 180individuals using the DSM-5 where there was an inter-reliability of +0.97 and test-retest of 0.92. This means that we can be sure the diagnosis of schizophrenia is appropriately applied
Co-morbidity (AO3) - Limitation ]
One limitation of the diagnosis of schizophrenia is that most the time it is co-morbid with another mental disorder. For example, researchers found that co-morbidity rates with schizophrenia are 50% depression, 47% drug use, 29% PTSD, 23% OCD. This reduces the validity of the classification and suggests that the diagnosis of schizophrenia may be in error if the disorders share the same symptoms, the condition does not have its own distinction.
Validity (A03)- Limitation
One limitation of the diagnosis for schizophrenia is its validity. Researchers assess the validity of schizophrenia through criterion validity. This was done by having two psychologists diagnose the same 100 patients with schizophrenia under the ICD-10 and the DSM-5 and they found that 68 where diagnosed under ICD-10 and only 39 under DSM-5. This over- or under diagnosing suggests that criterion validity is low. However, when the researchers used the same diagnosing tool, they found that there was excellent agreement. Validity is good providing that all the diagnoses take place within a single diagnostic system.
Gender Bias (A03)- Limitation
One limitation of the diagnosis of schizophrenia is the existence of gender bias. For example, men are more likely to be diagnosed with schizophrenia compared to women (1.4:). One explanation for this is that women are less vulnerable compared to men biologically, however, the more likely explanation is that women form closer relationships, meaning they get the support they need and are better functioning. This under diagnosis of women may mean that women may not be receiving treatment and services that might benefit them.
-Men are more likely to be diagnosed sooner. Men have more negative symptoms compared to women who have more positive symptoms
Culture Bias (A03)- Culture Bias
One limitation in the diagnosis of schizophrenia is cultural bias. Within some cultures, hearing voices are often associated with your ancestors communicating with you . Although the diagnosis in the Caribbean is also 1% (just like the U.K) individuals African-Caribbean origin are 9x more likely to be diagnosed with schizophrenia compared. This may be due to category failure where western ideas of psychology are applied to non-western parts of the world so behaviours are actions are misinterpreted. This means that African-Caribbeans get discriminated at by the diagnosing system.
Symptom overlap (A03)
One limitation of the diagnosis of schizophrenia is symptom overlap. Many mental disorders share the same set of symptoms. For example, bipolar also has positive symptoms such as hallucinations and negative symptoms such as avolition. This means that they may be two variations of the same condition but are on the spectrum together. This means that it is hard to diagnose schizophrenia as multiple conditions share the same symptoms, this makes the schizophrenia diagnosis flawed.
Family studies as the basis of schizophrenia (Biological explanation)
Gottesman study on large-scale family study found that as your vulnerability for schizophrenia increases in relativity to your genetic similarity to that person. (Eg. 2% chance if your aunt has it, 9% for a sibling, 48% for an identical twin
- These individuals also share the same environment so there is also a correlation that represents both of these factors.
What are candidate genes?
Candidate genes are genes which increase an individuals vulnerability to schizophrenia (as they code for neurotransmitters including dopamine)
-There is not a specific gene but a collection of locations on genes which are associated with a higher risk of developing schizophrenia.
Candidate genes- Ripke et al (A01)
Studied 36,000 schizophrenia cases and identified 108 genetic loci associated with the development of schizophrenia. Suggests that genes are responsible for schizophrenia or atleast playa. Role in the development
What does aetiologically heterogenous mean?
Multiple different combinations of genes which are correlated with having a specific disorder.
Mutations of parental DNA
Mutations to parental DNA through radiation, poisoning or your environment. Evidence for this comes from positive correlations between increased paternal age and the risk of schizophrenia. (0.7% for <25 and 2% for .50)
What are neural correlates ?
Variations in neural structure and bio-chemistry which are correlated with an increased risk of developing schizophrenia.
Original dopamine hypothesis
Based on the idea that anti-psychotics could be used to reduce symptoms, as the symptoms of schizophrenia were similar to those of Parkinson’s, which were associated with low dopamine levels. Therefore, schizophrenia may be a result of hyperdopaminergia in subcortical areas of the brain
Updated dopamine hypothesis
Davis et al. proposed hypodopaminergia. Low levels of dopamine the the prefrontal cortex could explain negative symptoms of schizophrenia. It has also been proposed that cortical hypodopaminergia can lead to subcortical hyperdopaminergia. Genetics and environment make people more vunlerable to cortical hypodopaminergia which leads to subcortical hyperdopaminergia
Strength of the genetic basis of schizophrenia (A03)
One strength of genetic explanations for schizophrenia is that there is evidence. For example, Gottesmans genetic vulnerability graph suggests that vulnerability of schizophrenia increases in relation with genetic similarity with a family member. Further studies show that adopted children with a risk of schizophrenia are at a heightened risk to the mental disorder. Further twin studies showed a concordance rate of 33% for monozygotic twins and 7% for dizygotic twins. This shows that some people are vulnerable to schizophrenia because of their genetic makeup.
Limitation of the genetic basis, Environmental factors, (A03)
One limitation of the genetic influence of schizophrenia is that there is evidence to show that environmental factors also increase the risk of developing schizophrenia. For example, studies show that teenagers who smoke THC-rich cannabis have an increased likeliness to develop the disorder. There are psychological risk factors such as childhood trauma as research showed that 68% of participants with schizophrenia or a related mental disorder went through at least one traumatic childhood event compared to the 38% of the matched group. This shows that although genetics play a role in the development of schizophrenia, environmental factors also have a role.
Strength for the dopamine hypothesis, Evidence for dopamine (A03)
One strength is the idea that dopamine is involved with schizophrenia. For example studies show that an increased amphetamine use increases dopamine levels which increase symptoms even in people without mental disorders. Anti-psychotic drugs reduce the levels of dopamine which lead to the improvement of symptoms. Neural correlates for the dopamine levels are coded by genes which may be candidate genes for schizophrenia. These factors strongly suggest that dopamine is involved in the symptoms of schizophernia.
Limitation of the dopamine hypothesis,Glutamate, (A03)
One limitation of the basis of dopamine in the biological explanation is the role of glutamate. Post-mortem and live-scanning studies have shown raised levels of glutamate in several brain regions of individuals with schizophrenia. In addition, several candidate genes code for the glutamate neurotransmitter.
Schizophrenogenic mother (Family dysfunction)
Fromm-Reichmann, proposed a psychodynamic approach where, noticed a pattern in her patients where they described a particular type of parent which she called the schizophrenogenic mother. This was characterised by a cold, rejecting and controlling mother who created a family climate characterised by tension and secrecy., which would lead to paranoid delusions and schizophrenia.
Double-Bind Theory
Bateson et al, agreed that a family dynamic plays a role in the development of schizophrenia and emphasised the role of communication style within a family. The individual fears doing something wrong but unable to identify what it is that they are doing wrong. They often find themselves in environments where they are unable to comment on the unfairness of a certain situation and they are greeted with the withdrawal of love. This leads to a dangerous and confused view of the world where they started to develop disorganised thinking and paranoid delusions.
Expressed Emotion
The level of negative emotion which is expressed towards an individual with schizophrenia.
-Verbal criticism of the person
-Hostility
-Emotional over-involvement
This is a serious stress source for an individual with schizophrenia and often leads to relapse rates. This is also an explanation for the development of schizophrenia in individuals who are already vulnerable
Cognitive explanation, Dysfunctional thinking
Dysfunctional thinking can provide a whole explanation for individuals with schizophrenia. There is a disruption to normal though processing which can be seen in many of the symptoms.
-Reduced though processing in the ventral striatum is linked with the negative symptoms
-Reduced though processing in the temporal and cingulate gyri is associated with positive symptoms
Lower levels of though processing suggests that cognition and though processing is impaired.
Meta-representation dysfunction
Meta-representation is the cognitive ability to reflect on your own thoughts and also be able to distinguish them from other peoples. Dysfunction in meta-representation would likely disrupt our ability to recognise our thoughts as ours or being carried out by other people. This would explain positive symptoms such as hallucinations and paranoid delusions.
Central control dysfunction
The cognitive ability to repress automatic response while we perform deliberate actions could explain speech poverty. This is because they may not be able to suppress automatic thoughts and speech triggered by other thoughts which would lead to a derailment of thoughts because each words triggers associations, and the person cannot suppress automatic responses
lack of research support, Family dysfunction, (A03)
One limitation of family dysfunction as an explanation for schizophrenia is the lack of support. For example, research on the schizophrenogenic mother was based on historical observations where researchers would look for ‘crazy-making’ characteristics within individuals. This measure is highly objective and not accurate. There is an increasing number of blame placed on the parent. They are forced to accept responsibility for their child’s schizophrenia. This shows that family dysfunction as an explanation for schizophrenia is not based on reliable research as it lacks ecological validity.
Evidence for dysfunctional thinking, strength
One strength of dysfunctional thinking is research support. For example, researchers compared the cognitive ability of 30 patients with schizophrenia to a control group. These tasks involved the stroop task where the font of the colour was different to the colour eg. the word read blue but the font was red. As predicted, patients with schizophrenia took on average twice as long to complete the task. Which means that individuals with schizophrenia have impaired cognitive processes.
Cognitive processes, Proximal and Distal explanations, limitation (A03)
One limitation of the cognitive explanations of schizophrenia is that it only focuses on the proximal explanations for schizophrenia eg. the cognitive functions of the brain which lead to certain symptoms. It fails to recognise the distal explanations for schizophrenia such as candidate genes or family dysfunction which are not fully understood yet as there isn’t enough research. This means that the cognitive explanations only provide a partial explanation for schizophrenia.
What are typical antipsychotics ?
Drugs which are used to reduce positive symptoms. ( First set of drugs which were created)
What are atypical antipsychotics ?
Developed after typical anti-psychotics they work by targeting specific neurotransmitters
What are dopamine antagonists
Dopamine antagonists are drugs (typical anti-psychotics) which block the dopamine neurotransmitters in the synapses of the brain. According to the dopamine hypothesis this dopamine-antagonist effect normalises neurotransmission in key areas of the brain, reducing positive symptoms.
Sedation effect of the typical anti-psychotics
Although it is not fully understood, typical anti-psychotics such as chlorpromazine is used to calm individuals with mental disorders. It is usually administer in syrup form as it is absorbed faster. Chlorpromazine may have an impact on the histamine receptors which may lead to sedation.
Why are atypical antipsychotics more advantageous ?
They usually have less side effects and are more effective. Second generation
Clozapine (atypical anti-psychotics)
Clozapine is effective because it works on dopamine receptors, serotonin receptors and glutamate receptors. Because it has the ability to target multiple receptors, it improves mood and reduces depression. (negative symptoms) However, it was taken off the market because it caused blood conditions which lead to deaths.
Risperidone
Newly developed anti-psychotic binds to both serotonin and dopamine receptors. It is taken in smaller doses because it binds to serotonin and dopamine stronger than clozapine. Also has fewer side effects.
Biological drugs based on the dopamine hypothesis (A03)
The development of anti-psychotics were based on the original dopamine hypothesis. For example, antipsychotics alleviate symptoms of schizophrenia based on hyperdopaminergia (by binding to the dopamine receptors). However this doesn’t align with the updated hypothesis which suggests that schizophrenic symptoms are caused by hypodopaminergia. This makes us question the validity of the anti-psychotics.
(A03) Side effects of Drugs , (A03)
One limitations on the use of anti-psychotics for the treatment of schizophrenia is the serious side effects. Although short-term use of these drugs have side effects such as fever, nausea , constipation. There are long term risks such as NMS which leads to paralysis , high fever, altered mental state and rigidity of muscles. Therefore, a cost -benefit analysis should be conducted to determine weather the benefit of symptom reduction outweighs the cost of serious symptoms.
Problems of validity, drug use(A03)
Despite there being evidence that supports the use of anti-psychotics in treating symptoms of schizophrenia, studies still have validity issues. For example, the drug Chloroprazime has side effects of sedation. This means when research is looking into this drug and whether it alleviates symptoms, they may be studying whether the drug has a sedation effect or not. This means that studies lack the validity
