Schizophrenia Flashcards
What is schizophrenia?
A major psychotic disorder that causes a variety of psychological symptoms but is characterised by a lack of contact with reality.
Schizophrenia statistics.
About 25% of people with schizophrenia exhibit physical changes in their brains that can be seen on CT scans.
Modern medication is very effective and reduces the risk of relapse to about 10%
Schizophrenia runs in families. If you have a parent/sibling with it you are more likely to suffer yourself.
On average people with schizophrenia die 10-20 years earlier due to the higher risk of suicide.
What is classification?
The process of organising symptoms into categories based on which symptoms cluster together in patients. This then allows us to distinguish one disorder from another.
Medical model approach.
Classification and diagnosis.
A diagnosis of a disorder is possible by classification of the symptoms because then we can identify the symptoms a patient has and decide what disorder they have based on their symptoms.
Categorising symptoms of schizophrenia.
Kurt Schneider (1959) suggested that categorising the symptoms of schizophrenia as either positive or negative.
Positive symptoms.
Behaviours that the person is exhibiting in addition to ‘normal’ behaviours.
Hallucinations
Delusions
Disordered thinking
Disorganised behaviour
Hallucinations
Perceptions that are not real
Many people report auditory hallucinations, but they can present in any sensory modality.
Kathryn Lewandowski et al (2009) estimated that 20% of people with schizophrenia have tactile hallucinations - formication (sensations of insects in and under the skin)
Delusions
Beliefs that are unreal
Commonly held delusions are of persecution and of grandiosity (the belief that the individual is special in some way- superior).
Disordered thinking
Evident through examining speech.
Sometimes described as derailment or knights move thinking.
Disordered behaviour
Wandering in circles, fast repetitive movements, useless movements.
Unexpected gestures and loud utterances.
Echopraxia - mimicking someone else’s moments which can be unpredictable and cause observer discomfort.
Negative symptoms.
Behaviours that are inhibiting people with schizophrenia from demonstrating ‘normal’ behaviour.
Alogia
Avolition
Anhedonia
Flatness of affect
Catatonic behaviour
Alogia
Poverty of speech, lack meaning in what they are saying even simple short answers can be a problem.
Avolition
Lack of goal directed behaviour, which may be perceived as disinterest.
Anhedonia
An individual does not react appropriately to pleasurable experiences.
Flatness of affect
Show little or no facial emotional expression, may be interpreted as apathetic, speech patterns are very monotonous.
Catatonic behaviour
Remaining immobile for prolonged periods of time in seemingly uncomfortable postures.
Demonstrate waxy flexibility if moved (staying in the position that they are moved to)
What is used to classify schizophrenia?
DSM-5 and ICD-10
What does the DSM-5 say about schizophrenia?
At least 2 symptoms must be present for at least a month and one of the symptoms must be a positive symptom.
What does the ICD-10 say about schizophrenia?
One of these symptoms (delusions, delusions of control, hallucinatory voices, bizarre delusions) is enough. It also says that 2 negative symptoms are sufficient for diagnosis.
Reliability of diagnosing schizophrenia
A psychiatric diagnosis is reliable when different diagnosing clinicians reach the same diagnosis for the same individual and when the same clinician reaches the same diagnosis for the same individual on 2 occasions.
Inter-rated reliability and test-retest reliability.
Not reliable if clinicians are using different diagnostic tools.
Reliability as a strength for diagnosing schizophrenia
Osorio et al (2019) reported excellent reliability for the diagnosis of schizophrenia in 180 individuals using the DSM-5.
There was a correlation coefficient of +0.97 for inter-rater reliability and +0.92 for test re-test reliability. Showing a strong positive = very reliable.
Validity of diagnosing schizophrenia
Criterion validity (asking if the criteria we are using the diagnose schizophrenia are actually accurate)
Validity as a limitation of diagnosing schizophrenia
Cheniaux et al (2009) found that when 100 patients were assessed using ICD-10, 68 were diagnosed with schizophrenia. When the same 100 patients were assessed using DSM-4, only 39 were diagnosing with schizophrenia. Criterion validity is low. The research suggests that sch is either over diagnosed or under diagnosed depending on the diagnostic system used, meaning diagnosing using the set out criteria in the classification systems are not accurate.
Validity as a strength of diagnosing schizophrenia
Osorio study showed that there was excellent agreement when the same classification system is used, suggesting that criterion validity is actually good when it takes place within a single diagnostic system. (Could be as a result of improved DSM - DSM-4 for Cheniaux, DSM-5 for Osorio)
Co-morbidity.
Occurrence of 2 disorders or conditions together.
Buckley et al (2009) 50% of patients with schizophrenia also have depression, 47% substance abuse, 29% PTSD, 23% OCD
Co-morbidity as a limitation of diagnosing schizophrenia
Where 2 conditions are frequently diagnosed together it questions the validity of the classification of both illnesses. Some people may not have schizophrenia at all but instead have unusual cases of other conditions such as depressions.
Gender bias in diagnosis
More commonly diagnosed in men. In 2017 the ratio was 1.4:1
Maybe women are just less likely to develop schizophrenia, but research shows this is not the case.
Women are just able to function better because they have closer social support networks compared to men.
Gender bias as a limitation of diagnosing schizophrenia
Women are under diagnosed, meaning they are unable to get help. This is because women are able to function better due to their social support network.
Alpha gender bias - differences between men and women are exaggerated
Culture bias in diagnosis (limitation)
A higher percentage of individuals of Afro-Caribbean descent are diagnosed with schizophrenia. Cochrane et al (1995) found that black Afro-Caribbean immigrants in the UK are up to 7 times are more likely to be diagnosed with schizophrenia than white British people.
This data cannot be explained by genetics because the increased risk is not apparent in studies conducted in the Caribbean.
Additional stress induced through migration to a different culture was suggested as being a reasonable explanation.
Increased risk and diagnosis was not only found in the first generation migrants but higher rates of schizophrenia were alone notched in the children of the Afro-Caribbean migrants in the UK (Harrison et al, 1988).
Misunderstanding or disregarding cultural specific symptoms - not sure what to diagnose causing clinician to ignore symptoms.
Clinician does not account for culture - using Western medical model to diagnose non western individuals causing over diagnosis due to lack of understanding - ethnocentricism.
Symptom overlap as a limitation of diagnosing schizophrenia
Difficult to distinguish schizophrenia from other disorders.
For example, dissociative identity disorder and schizophrenia both have symptoms of feeling disconnected, forgetting about certain time periods, events and periods information and delusions
Depression - lethargy and lack of motivation and unable to maintain routine.
Biological expiations of schizophrenia
Family studies, candidate genes, the role of mutation, neural correlates
Family studies
Schizophrenia has a genetic basis, suggesting it can be inherited. The closer the relation to the family member with schizophrenia, the higher risk of developing it.
Gottesman (1991) Cousins = 2%, nephews/nieces = 4%, parents = 6%, identical twins = 48%.
Candidate genes
A number of different genes cause schizophrenia (polygenic). Thought that genes that code for neurotransmitters such as dopamine are involved.
2014 Schizophrenia Working Group of the Psychiatric Genomics Consortium reported that there were over 108 genetic loci associated with schizophrenia - used meta analysis which increases population validity.
Polygenic
Caused by multiple different genes
Aetiologically heterogenous
Schizophrenia is caused my multiple different factors, including genetic variations.
The role of mutation
Could be a mutation in parental DNA, which could be caused by radiation, poison or viral infection.
The season of birth influence.
People who develop schizophrenia in North America and Europe are more likely to be born in winter and early spring. This may be related to the exposure to sunlight (lack of vitamin D could alter the development of a child’s brain.
Mutation could also be caused by an autoimmune reaction after contracting influenza