Schizophrenia Flashcards
What were the first rank symptoms of schizophrenia proposed by Schneider?
- Delusion
- Thought disorder
- Passitivity
- Auditory hallucinations
What are delusions?
A belief that is maintained despiteb contradictions to reality/rationale.
What are thought disorders?
- Thought insertion
- Thought withdrawal
- Thought broadcasting
What is passitivity?
Thought that ones actions are being controlled by a 3rd party
What are auditpory hallucinations?
- Thought echo (thoughts are audible)
- 3rd person voice (discussing about the patient)
- Running commentary
What are the catogories of symptoms for Schizophrenia?
- Positive symptoms: Additional behaviours that are caused by the condition.
- Negative symptoms: Normal behaviours thar are lost as a consequence of condition.
- Disorganised symptoms: Characteristic disorganised behaviour.
What are the positive symptoms of Schizophrenia?
- Delusion of persecution
- Thought insertion
- Thought broadcasting
- Grandiose (exaggerated) beliefs
- Delusions of reference
- Perceptual hallucinations (hearing voices):
- Arguing
- Critical
- Discussion
What are the negative symptoms of Schizophrenia?
- Lack of motivation
- Little interest in social interactions
- Loss of pleasure
- Reduced expression of emotions
- Reduced speech output
What are the disorganised symptoms of Schizophrenia?
- Problems organising ideas
- Loose association/derailment
- Bizarre behaviours
- Movement disorders (catatonia)
What are the criteria for diagnosing schizophrenia based on DSM5?
- 2 or more of symptoms for > 1 month, with one of the key symptoms:
- Delusion (key)
- Hallucinations (key)
- Disorganised speech (key)
- Catatonic behabiour
- Negative symptoms - Social/occupational decline
- Suffering at least 6 months from positive/negative symptoms
What is the prevalence of schizophrenia?
- Prevalence = ~1%
- More common in men compared to women
What is a high “Expressed emotion” family?
- Low warmth
- High over-involvement
- High hostility
What is the relationship between high EE families and schizophrenia?
High EE families are associated with increased rate of relapse in schizophrenic patients
What is the relationship between local environment and schizophrenia?
There are higher rates of schizophrenia in urban areas compared to rural areas. This could be due to the high degree of social isolation and low availability of community support.
What is the relation between social class and schizophrenia?
There’s no clear evidence to suggest that social class has any relations with schizophrenia.
What is the relationship between genetics and schizophrenia?
Schizophrenia is highly heritable:
- Monozygotic twin studies (~50% heritability)
- Adopted children whose birth parents have schizophrenia are more likely to get schizophrenia
What genetic defects are associated with schizophrenia?
- Dysbindin
- Neuregulin
- DISC1
- NDMA glutamate receptors
What are the changes to brain structure observed with schizophrenia?
- Decreased grey matter volume
- Increased size of ventricles
What is the dopamine theory of schizophrenia?
Schizophrenia is caused by high levels of dopamine activity in the brain (either due to increased expression of dopamine and/or dopamine receptors)
What evidence supports dopamine theory of schizophrenia?
- Antipsychotic drugs used to treat schizophrenia (e.g. chlorpromazine) causes Parkinson-like symptoms and so must inhibit action of dopamine.
- Amphetamines increase dopamine in brain and exacerbates symptoms in schizophrenic patients.
- Efficacy of anti-psychotics are related to their ability to block the dopamine D2 receptor.
- There is increased density of D2 receptors in patients with schizophrenia
What is the evidence against dopamine theory of schizophrenia?
Anti-psychotics don’t treat negative symptoms of schizophrenia, which seem to be caused by low levels of dopamine activity in the frontal cortex.
What is the revised dopamine theory of schizophrenia?
- Excess dopamine in subcortical areas → D2 over-stimulation → Positive symptoms
- Inadequate dopamine in frontal cortex → D1 unser-stimulation → Negative symptoms
How do abdormalities in dopamine activity cause psychological symptoms of schizophrenia?
Increased levels of subcortical dopamine causes ‘aberrant salience’ whereby seemingly unimportant objects in the environment are assigned significance. Psychosis results from an attempt by the individual to justify assigned significance to these objects.
What are the problems with the revised dopamine theory?
- Antipsychtics seem to act on dopamine receptors immediately yet they only take effect after some time.
- Dosage of antipsychotic drugs neeeded reduce dopamine levels to below normal in order to produce effect (evidence by Parkinson-like symptoms).
- New antipsychotics act via more than one NT (e.g. serotonin), supporting fact that condition with such widespread symptoms is caused by more than one NT system.
