P21: Neuroleptics & Schizophrenia Flashcards
Generally schizophrenia is a disorder of?
Thought and emotion
not split-personality
What are positive schizophrenia symptoms?
- Delusions & hallucinations (especially auditory)
- Bizarre behaviour
What are negative schizophrenia symptoms?
- Social withdrawal
- Avolition (no motivation)
- Poverty of speech
What are cognitive schizophrenia symptoms?
- Poor concentration
- Disorientation
- Difficulties in abstract thought and memory
What is the single greatest risk factor for schizophrenia?
Having an affected first degree relative
Which sex is more likely to have schizophrenia?
Males being roughly 40% more likely
What areas in the brain have a smaller volume in schizophrenics?
- Amygdala
- Thalamus
- Nucleus accumbens
- Intracranial space
- Hippocampus (antipsychotic drug treat)
What areas in the brain have a larger volume in schizophrenics?
Larger pallidum and ventricular volumes
What evidence supports the Dopamine Theory of Schizophrenia?
- All anti-psychotic drugs are dopamine receptor antagonists
- Amphetamine and cocaine increase DA release and induce schizophrenic - like syndrome
What does the Dopamine Theory of Schizophrenia suggest?
That release of excessive dopamine release causes schizophrenia
What does the nigrostriatal dopamine pathway control?
Motor control and co-ordination
What does the Mesolimbic-mesocortical dopamine pathway control?
- Mood
- Cognition
- Thought
What does the Tuberoinfundibular dopamine pathway control?
Control of prolactin release
prolactin is used for breast and milk development
Post-mortem, Schizophrenic brains have significantly lower expression of which receptors?
Glutamate receptors
What are drugs like phencyclidine and ketamine?
- Glutamate-blocking drugs
- Mimic schizophrenic symptoms and cause cognitive problems
What does glutamate modulate?
Dopamine activity
What do neuroleptics treat?
Schizophrenia
Which schizophrenic symptoms do neuroleptics treat best?
More effective at treating positive symptoms
What is Chlorpromazine?
- Dopamine D2 receptor antagonist (also D1,3,5)
- Most successful
What are the side effects of Chlorpromazine?
- Extrapyramidal motor effects
- Impotence
- Anxiety
What is Haloperidol?
- Binds preferentially to D2 and α1 receptors at low dose and 5-HT2 receptors at higher doses
- Most commonly used
What are the side effects of Haloperidol?
- Extrapyramidal motor effects
- Impotence
- Anxiety
What is Clozapine?
- Atypical anti-psychotic, first of its class
- Dopamine D2 receptor antagonist, with high affinity for D4 receptors
What are the side effects of Clozapine?
- Extrapyramidal motor effects
- Agranulocytosis – loss of neutrophils and immunosuppression
- impotence
What is Tardive Dyskinesias?
- Major side effect of anti-psychotic medications
- Characterised by involuntary, repetitive writhing movements of face and limbs
How is Tardive Dyskinesias caused?
- Thought to be due to the development of dopamine hypersensitivity in the nigrostriatal pathway
- Resulting change in basal ganglia function
