Schizophrenia Flashcards
What is schizophrenia?
It is a type of psychosis characterized by a profound disruption of cognition and emotion. There is contact lost with external reality.
Schizophrenia is the most common psychiatric disorder affecting what percent of the population at at least one stage in their life?
1%
How would a clinician make a diagnosis of schizophrenia? and where are these manuals used.
Using a diagnostic manual such as DSM-Version 5 - US manual.
ICD used in Europe.
How are the symptoms of schizophrenia divided?
Divided into positive and negative symptoms - positive reflecting an excess or distortion. Negative, reflecting a reduction or loss of normal functions.
What are the 4 positive symptoms for diagnosing schizophrenia?
- Hallucinations
- Delusions
- Disorganised speech
- Grossly disorganised / catatonic behaviour.
What is a hallucination?
BIZZARE Visual/auditorial unreal perceptions of the environment.
What are delusions?
BIZZARE beliefs that seem real to person with schizophrenia but they are not real.
What is disorganised speech?
Problems in his/her thoughts shows up in their speech as they speech gibberish, incoherent.
What is grossly disorganised or catatonic behaviour?
Inability to motivate oneself to initiate task.
Catatonic behaviours characterised by reduced reaction to immediate environment - rigid postures.
Extra/less movement when unnecessary.
What are the 4 negative symptoms for diagnosing schizophrenia?
- Speech poverty (alogia)
- Avolition
- Affective flattening
- Anhedonia
What is speech poverty?
There is a reduction of speech production - speech fluency and productivity.
What is avolition?
Difficulty in engaging or being motivated towards goal oriented behaviour.
What is affective flattening?
Flat tone of voice, reduction in the range of emotional expression.
What is anhedonia?
Opposite to a hedonist. Anhedonists receive no pleasure from any physical or mental activity.
How many symptoms have to be present and for how long until you would receive a diagnosis of schizophrenia?
2 or more symptoms present for a month (on and off or constant).
What is reliability in diagnosing and classifying schizophrenia?
Refers to consistency of classifactory system such as DSM.
What is needed for diagnostic reliability as it must be REPEATABLE
Only 1 needed but 2 points.
- Clinicians must be able to reach the same conclusions at 2 different points (test-retest)
- Two different clinicians must reach same conclusions (inter-rater reliability 0-1) 1=perfect, a kappa score of 0.7 generally considered good.
Describe 1 research study into cultural differences in diagnosis. (Copleand’s)
- Copeland (1971)
- 134 US + 194 British psychiatrists a description of patient.
- 69% of US psychiatrists diagnosed schizophrenia whereas only 2% of British psychiatrists diagnosed schizophrenia
Describe 1 research study into cultural differences in diagnosis. (Luhrmann’s)
Luhrmann (2015)
-‘hearing voices’ is a main characteristic of schizophrenia.
-20 African, 20 Indian, 20 US each asked about what voices they heard. Many African and Indian subjects reported voices were positive, offered playful advice.
-Not one US described the voices as positive.
Tf, suggests harsh violent voices are common in Western countries as a symptom but may not be an inevitable symptom of schizophrenia.
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What is validity in diagnosis and classification for schizophrenia.
Refers to the extent that a diagnosis represents correct effect.
What is gender bias in diagnosis for schizophrenia?
Occurs when accuracy of diagnosis is dependent on the gender of the individual.
Clinicians may have biased judgement based on stereotypical beliefs held about gender.
Who did a study into gender bias in diagnosis?
Broverman (1970) - clinicians in US equated mentally healthy adult behaviour with ‘male’ behaviour. Tf, females perceived as less mentally healthy.
What is symptom overlap?
Despite claim that classification of positive and negative symptoms would make for more valid diagnoses of schizophrenia. Many of these symptoms are also found in many other disorders, eg: depression.
Who did a study into symptom overlap?
Ellason and Ross (1995) found people with dissociative identity disorder actually have more schizophrenic symptoms than schizophrenics.
What is co-morbidity?
Extent that 2 conditions or diseases occur simultaneously in a patient
What 2 studies were there into co-morbidity?
Buckley (2009) estimated co-morbid depression occurs in 50% of patients.
Rosenhan
What are 2 results Gottesman found of family studies showing genetic factors contribute to schizophrenia.
If a parents has schizophrenia, child is more likely to have schizophrenia.
Gottesman found:
2 parents with it = 46% chance of child developing schizo
1 parent with it = 13% chance.
What did Joeseph (2004) find in twin studies (genetic factors)
- Monozygotic (genetically identical) more similar than dizygotic (sharing 50% of genes)
- concordance rate showed MZ twins with schizo = 40% compared to 7%.
- Tf, MZ much more likely to both have it if one has it.
What is a limitation of working on twin studies with schizophrenia.
Twins are extremely hard to find both with schizophrenia, so there is a very limited sample size. Also, it is very time consuming, because you have to search far and wide.
What did Tienari (2000) find in adoption studies.
Of 160 adoptees whose biological mother had been diagnosed with schizo - 11 adoptees also received diagnosis for schizo.
Compared to 4/197 control adoptees those born with non schizo mothers.
Tf, investigators could confirm the genetic liability.
What is a limitation of Tienari’s (2000) adoption study?
Dependent on how long they were with their biological mother could affect results. The older, the less likely they are to be influenced by their environment.
What does neural correlates(correlations) mean in the biological explanations for schizo.
Focuses on the important role of the neurotransmitter dopamine AND on areas of the brain influential in the onset and development of this disorder.
Changes in neuronal events and mechanisms that result in the characteristic symptoms of a behaviour or mental disorder
Does more dopamine in the brain trigger negative or positive symptoms of schizo?
POSITIVE.
What is the dopamine hypothesis?
Claims an excess of dopamine in certain regions of the brain often associated with positive symptoms of schizo.
People with schizo are believed to have abnormally high numbers of D2 receptors on receiving neurons - resulting in more dopamine binding and Tf firing.
Give an example of 1 drug that increases dopamine activity in the brain - how does this happen.
Amphetamine = dopamine agonist
Stimulates nerve cells containing dopamine, causing synapse to be flooded with this neurotransmitter - more is uptaken
What is a limitation (AO3) of increasing dopamine activity.
Dopamine enters the whole brain, not just the area where it is needed.
What is Davis + Kahn’s (1991) revised version of the dopamine hypothesis?
Positive symptoms of schizo are caused by an excess of dopamine in subcortial areas of the brain - particularly mesolimbic pathway.
Negative thoughts arise from deficit of dopamine in areas of the prefrontal cortex.
Name 2 areas of the brain involved in schizo.
- Prefrontal cortex.
- Hippocampus
How is the prefrontal cortex involved in schizo?
Main area involved in executive control.
Research shows that this area is impaired in schizophrenics.
How is the hippocampus involved in schizo?
Deficits nerve connection between hippocampus and prefrontal cortex.
Central cognitive impairment in schizo.
Give 2 eval point for genetic factors for schizo.
-May be a limitation of research into MZ twins because they are more likely to encounter similar environments.
Joseph (2004) highlights potential identity confusion as they are treated more as ‘twins’ than 2 distinct individuals.
-Adoptees may be selectively placed
Central assumption of adoption studies is that adoptees do not have schizophrenic tendencies is the child does.
But not always the case.