Psychosis Flashcards
- positive symptoms: hallucinations, delusions, disorganized or incoherent thought
- negative: flat affect, social isolation, alogia poverty of speech, avolition, anhedonia, cognitive deficits
- neurodevelopmental, 50% heritability, abberant dopaminergic/glutamatergic/serotongergic activity
schizophrenia
positive symptoms arise from hyperactivity of one or more of the CNS systems, possibly mesolimbic and mesocortical
dopamine
_______ can cause psychosis and make schizophrenics worse
amphetamine
these receptors mediate hallucinogenic effects
serotonin (5-HT2a,2c)
phenylcyclidine and ketamine produce effects that resemble aspects of schizophrenia and exacerbate symptoms in schizo, related to this NT
glutamate
all antipsychotics are _______ receptor antagonists
D2 dopamine
- sedation, decreased agitation
- positive symptoms improve over weeks to months (problem w/ dopamine hypothesis)
- negative symptoms may be improved by newer drugs
- antiemetic due to blockade of dopamine receptors in chemoreceptor trigger zone, not useful for motion sickness
pharmacological effects of antipsychotics
- extrapyramidal effects (EPS)
- dystonia (1-5 days), unknown painful muscle cramps
- akathisia (5-60 days), unknown motor restlessness
- parkinsonian symptoms (5-30 days), tremor rigidity and bradykinesia due to blockade of striatal dopamine receptors, can be treated w/ anticholinergics
early antipsychotic side effects
- increased prolactin release
- orthostatic hypotension
- weight gain
- metabolic syndrome, diabetes (treat w/ olanzepine)
- decreases seizure threshold
- neuroleptic malignant syndrome (treat w/ dantrolene)
side effects of antipsychotics
- tardive dyskinesia (abnormal movements and facial disfugurement), frequently irreversible, maybe due to long term dopaminergic receptor blockade
- perioral tremor (rabbit syndrome)
- agranulocytosis with clozapine
long term antipsychotic side effects
- effective against positive but not negative symptoms
- produce EPS and tardive dyskinesia
- all D2 antagonists
typical antipsychotics
chlorpromazine, fluphenazine, and thioridazine are in what drug class?
phenothiazines
historically most widely prescribed antipsychotic, relatively more selective for dopamine receptors than most of typical antipsychotics, highest incidence of EPS
haloperidol
- no EPS or tardive dyskinesia
- antagonist at 5HT2 receptors
atypical antipsychotics
- activity at broad spectrum of receptors
- no EPS or tardive dyskinesia
- some effect on negative symptoms
- agranulocytosis in 3%
- approved only for treatment resistant patients
clozapine