Schizophrenia Flashcards
Define schizophrenia?
A severe mental illness where reality is impaired.
How is mental illness classified?
Using ICD-10 and DSM-5:
- organising symptoms into categories where the symptoms are found together in sufferers.
What are positive symptoms of schizophrenia?
Additional experiences beyond those of ordinary existence.
What are the positive symptoms of schizophrenia?
1) . Hallucinations.
2) . Delusions.
What are hallucinations?
Sensory experiences that have no basis in reality or aren’t real.
What are the different types of hallucinations?
1). Visual =
see things that aren’t there.
2). Auditory =
hear things that aren’t real (e.g. a critical voice).
3). Olfactory =
smelling things that aren’t there.
4). Tactile =
feeling things that aren’t there (e.g. touching silk but it feels like fire).
What are delusions?
Beliefs with no basis in reality (irrational beliefs).
What are the common delusions?
- Historical.
- Political.
- Religious figures (grandeur).
- Persecuted by government or aliens.
- Feeling like people can hear their thoughts.
- Irrational thoughts = may do things that seem normal to them but bizarre to others.
What are negative symptoms of schizophrenia?
Loss of usual abilities/experiences.
What are the negative symptoms of schizophrenia?
1). Avolition =
Finding it difficult to set and maintain goals.
2). Alogia (speech poverty) =
reduction in amount and quality of speech.
3). Catatonic =
Inability to move.
4). Affective flattening =
hard to express emotions.
How is schizophrenia diagnosed and classified?
- ICD-10 =
- 2+ negative symptoms have to be present for diagnosis.
- Recognises subtypes of schizophrenia (e.g. paranoia, hebephrenic). - DSM-5 =
- 1 positive symptom has to be present for diagnosis.
- Doesn’t recognise subtypes of schizophrenia.
What are the evaluations of the diagnosis and classification of schizophrenia?
:( Low reliability in the diagnosis of schizophrenia.
:( Low validity in the diagnosis of schizophrenia.
:( Co-morbidity.
:( Gender bias in diagnosis.
:( Cultural bias in diagnosis.
How is there low reliability in the diagnosis of schizophrenia?
Cheniaux et al. (2009) =
Research on 100 patients and shown psychiatrists couldn’t agree on diagnosis with both DSM-5 and ICD-10.
How is reliability improved in the diagnosis of schizophrenia?
Inter-rather reliability =
2+ psychiatrists need to agree on the same diagnosis on patients - considering schizophrenia is a life changing diagnosis.
How is there low validity in the diagnosis of schizophrenia?
Cheniaux’s study shows schizophrenia is more likely to be diagnosed using ICD than DSM.
- Either being over-diagnosed with ICD or under-diagnosed with DSM.
How is schizophrenia often co-morbid?
Buckley et al. (2009) concluded =
- 50% also diagnosed with depression.
- 47% substance abuse.
- 29% PTSD.
It may be that severe depression and schizophrenia, for example, are a single condition - hard to tell if they are symptoms for schizophrenia or depression.
How is there gender bias in the diagnosis of schizophrenia?
1) . Longenecker et al. (2010) = reviewed studies of the prevalence of schizophrenia, and concluded that:
- Since the 1980s, men are diagnosed more than women.
2) . Cotton et al. (2009) = found women can hide symptoms more than men:
- Better interpersonal functioning skills.
How is the cultural bias in the diagnosis of schizophrenia?
African origin people are more likely to be diagnosed in the UK, but not in Africa, this is because;
- In Africa, hearing voices are deemed normal, but schizophrenic in the UK.
- Validity issues = suggesting some people from certain cultural backgrounds are more likely to be diagnosed due to bias.
What are the biological explanations for schizophrenia?
1) . Genetic basis.
2) . Dopamine hypothesis.
3) . Neural correlates.
What is the genetic basis of schizophrenia?
1) . Schizophrenia runs in the family.
2) . Schizophrenia is polygenetic and aetiologically heterogenous.
How does schizophrenia run in the family?
Gottesman (1991) =
- MZ = 48% concordance rate.
- DZ = 17% concordance rate.
- Siblings = 9% concordance rate.
What is the concordance rate of MZ and DZ twins
- MZ = 100%.
- DZ = 50%.
How is schizophrenia polygenetic and aetiologically heterogenous?
- Polygenetic = each individual candidate gene increases the risk of schizophrenia.
- Aetiologically heterogenous = different combinations of candidate genes can lead to schizophrenia.
What did Ripke et al. (2014) find about candidate genes of schizophrenia?
Studied 37,000 patients and found 108 separate genetic variations (combinations of candidate genes) associated with increased risk; many affecting dopamine.
What are the evaluations of Gottesman’s study?
1) . Support for genetic vulnerability.
2) . Not entirely genetic.
What support is there for Gottesman’s study?
Adoption studies (Tienari et al. 2004) =
- Found children of people from schizophrenia are still at risk of schizophrenia if adopted into a family without a history of schizophrenia.
- Shows genetic factors make some people more vulnerable.
How is schizophrenia not entirely genetic?
Gottesman’s study=
- MZ twins should have a 100% concordance rate of schizophrenia (50% DZ), however, there isn’t.
- Although MZ twins are almost double to likelihood (48% compared to 17%), there is still an environmental influence.
What is the dopamine hypothesis?
1) . Neurotransmitters.
2) . Hyperdopaminergia.
3) . Hypodopaminergia.
What is the role of neurotransmitters in schizophrenia?
- Work differently in schizophrenic brains.
- Levels of dopamine is linked to the symptoms of schizophrenia.
What is hyperdopaminergia linked to?
Subcortex (centre of brain).
What is the hyperdopaminergia hypothesis? (Mesolimbic pathway)
HIGH levels of dopamine in the centre of the brain are associated with hallucinations and speech poverty.
What is hypodopaminergia linked to?
Prefrontal cortex (responsible for thinking and decision-making).
What is the hypodopaminergia hypothesis? (Mesocortical pathway)
Goldman-Rakic et al. found LOW levels of dopamine are associated with negative symptoms.
What are the evaluations of the dopamine hypothesis?
1) . Anti-psychotic drugs.
2) . Parkinson’s disease.
3) . Mixed support.
How has the hypothesis influenced the use of anti-psychotic drugs?
They lower levels of dopamine, decreasing positive schizophrenic symptoms.
- Curran et al. =
The use of amphetamines gives non-schizophrenics schizophrenic like symptoms (increased dopamine).
How does knowledge surrounding Parkinson’s disease support the dopamine hypothesis?
They have low dopamine levels, if the take L-Dopa it increases dopamine and stabilises symptoms, but too much gives them schizophrenic like symptoms.
How is there mixed support for the dopamine hypothesis?
Although amphetamines induce schizophrenic-like symptoms, and antipsychotic drugs that lower dopamine reduce symptoms; some of the candidate genes identified glutamate as influential.
- Shows dopamine isn’t the full explanation.
What is neural correlates?
How the different structure and functions of schizophrenic brains correlates with negative and positive symptoms.
How can neural correlates be explained?
- Ventral striatum and negative symptoms.
2. Superior temporal gyrus and hallucinations.
How is negative symptoms linked to the ventral striatum?
Ventral striatum = involved in motivation;
- Los of motivation in schizophrenia may be linked to low levels of activity in the ventral striatum.
What did Juckel et al. (2006) find about negative symptoms in the ventral striatum?
Negative correlation between ventral striatum activity and overall negative symptoms.
How is positive symptoms linked to the superior temporal gyrus?
Allen et al. (2007) =
found patients with auditory hallucinations had low levels of activity in the superior temporal gyrus and anterior cingulate gyrus.
What are the evaluations of neural correlates?
1). Correlation-causation problem.
How is there a correlation-causation problem of neural correlates?
Its hard to tell whether neural issues causes the symptoms, or whether the symptoms cause the neural issues.
What are the different types of biological therapies for schizophrenia?
1) . Typical antipsychotics.
2) . Atypical antipsychotics.
What are typical antipsychotics?
Traditional –> old style.
- E.g. chlorpromazine.
What was the aim of typical antipsychotics?
Antagonists (block dopamine) –> reducing positive symptoms.
- Strongly associated with the dopamine hypothesis.
Whats the issues with typical antipsychotics?
1). Hard hitting =
known as chemical restraints = lowers dopamine levels.
2). Also a sedative =
effects histamine receptors = also used to calm admitted patients.
What are atypical antipsychotics?
New style =
- E.g. Clozapine.
- E.g. Risperidone.
What was the aim of atypical antipsychotics?
The improve the effectiveness of suppressing schizophrenia and the side effects.
- Also affect the serotonin neurotransmitters.
Whats the effects of clozapine?
1) . Treats both positive and negative symptoms.
2) . Not so hard hitting.
3) . Helps mood elevation = acts on serotonin and glutamate so helps with depression.
Whats the typical dose of clozapine?
300-450mg daily =
higher doses are needed as the bond to D2 is weaker.
Whats a side effect of clozapine?
Causes cardiovascular issues (agranulocytosis) =
regular blood tests are used, and clozapine is rarely used.
How is risperidone different from clozapine?
1) . Less serious side effects.
2) . Binds to D2 stronger so doses are lower (4-8mg).
3) . Fewer side effects than typical antipsychotics.
What are the evaluations of the biological therapies for schizophrenia?
:) Support for typical.
:) Support for atypical.
:( Serious side effects (typical).
:( Serious side effects (atypical).
:( Based on the dopamine hypothesis.
What support is there for typical antipsychotics?
Thornley et al. (2003) - reviewed data from 13 trials (1121 participants) =
found chlorpromazine was associated with better functioning and reduced symptom severity compared with a placebo.
What support is there for atypical antipsychotics?
Meltzer et al. (2012) =
concluded that clozapine is 30-50% more effective in treating patients when typical antipsychotics failed.
What are the side effects of typical antipsychotics?
- Stiff jaw.
- Dizziness.
- Involuntary facial movements (long-term use = tardive dyskinesia).
- Neuroleptic malignant syndrome (NMS) = caused by blocking dopamine activity in hypothalamus (can be fatal = disrupted regulation of body systems).
What are the side effects of atypical antipsychotics?
Developed to reduce side effects, however =
- Blood tests needed =
to spot agranulocytosis (cardiovascular issues).
What is another limitation of the biological therapies for schizophrenia?
Based on the dopamine hypothesis =
- Antipsychotics are antagonists (reduce dopamine).
- But, dopamine in other parts of the brain is lower so antipsychotics shouldn’t work.
- Some people don’t believe reduction in positive effects is due to the pharmacological effects of the drug.
