Antipsychotics Flashcards
Schizophrenia os to be considered to be what kind of disorder in nature?
Developmental
- this is contrasted with dementia, which is seen to be degenerative in nature (that is, the brain develops normally, and then declines)
Schizophrenia is significantly correlated with what?
Puberty
- this has been examined because of the age of onset of the disease, and because of the differences in age of onset between men and women
What is the global incidence of schizophrenia?
1%
How are all of the subtypes of schizophrenia unified?
They all have the same treatment
What are the three classes of symptoms of schizophrenia?
Positive, negative, and cognitive
What are some examples of positive symptoms of schizophrenia?
- delusions
- hallucinations
- disorganized thought/speech
- disorganized/catatonic behaviour
What are some examples of negative symptoms of schizophrenia?
- flattened affect
- blunted expression
- poverty of speech
- avolition
What is poverty of speech?
A severe lacking in speech/conversation
What are some examples of cognitive symptoms?
- slowed thinking
- poor memory
- difficulty understanding (abstract thinking)
Which type of symptom is the most problematic?
Cognitive ones
What is avolition?
Inability to initiate movement to carry out a task
What are the two arguments for why dopamine is implicated in schizophrenia?
- amphetamines taken in intermittent doses leads to amphetamine psychosis > the dorsal and ventral striatum becomes sensitized to dopamine > leads to excessive subcortical dopamine > results in positive symptoms of schizophrenia
- the better the drug worked, the higher its affinity for D2 receptors (therefore, we can conclude that schizophrenia is a disorder of the dopamine system)
What does the dopamine hypothesis suggest?
That dopamine is in an excessive amount in subcortical structures (like the dorsal and ventral striatum) and that there is a lack of cortical dopamine (in the PFC)
Does the dopamine hypothesis explain all aspects of schizophrenia?
No, it doesn’t explain the negative and cognitive symptoms
What does the glutamate hypothesis suggest?
That dopamine can’t account for all of the symptomology of schizophrenia
- it has been shown that NMDA channel blockers can also bring on a psychotic episode, or exacerbate symptoms of schizophrenia (and altogether worsens the cognitive symptoms)
Describe the genesis of antipsychotics.
Henri Laborit treated shell shock with clorpromazine (brand name thorazine)
- this became the first antipsychotic and was the head of the first generation (typical) antipsychotics
What did Hans Lehman do?
Showed that thorazine was not dangerous for humans to be using
What are neuroleptics?
Antipsychotics
What is neurolepsis?
Inhibition of movements in rats
What is the common thing with all antipsychotics (typical and atypical)?
All are D2R antagonists
What are some examples of typical antipsychotics?
- Haloperidol (brand name Haldol)
- Fluxpentixol (brand name Fluanxol)
What are some examples of atypical antipsychotics?
- Clozapine (brand name Clozaril)
- Risperidone (brand name Risperidal)
What is the major downfall of typical antipsychotics?
They have a greater amount, and more severe side effects (extrapyramidal)
What are the extrapyramidal side effects of typical antipsychotics?
- tremors
- dystonia
- muscular rigidity
What does parkinsonian mean?
That the side effects mimic parkinson’s
Why do typical antipsychotics have parkinsonian side effects?
Because the selectivity can’t be monitored, therefore the drug also has an effect on the dorsal striatal area
- the more effective of treating psychosis, the higher the affinity of the drug will be
What is dystonia?
Involuntary muscle contractions
