Schizophrenia Flashcards
(43 cards)
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.