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76 Cards in this Set
- Front
- Back
neurons transmit information through _____ and _____ signalling
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neurons transmit information through electrical and chemical signalling
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explain what happens during depolarization and repolarization.
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the resting potential of -70 goes super positive. How? an action potential causes an infllux of Na+ through voltage gated sodium channels. During repolarization, these channels close and potassium channels open, allowing potassium to leave and the cell returns to resting potential
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when an action potential reaches a pre synaptic cleft, it causes an influx of what? what does this cause?
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it causes an influx of calcium. This calcium forces the neurotransmitter vesicles release the neurotransmitter into the synaptic cleft, which then bind to the postsynaptic membrane, propogating the action potential.
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What are the 5 ways drugs can treat CNS disorders?
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1. replacement
2. inhibiting breakdown 3. inhibiting reuptake 4. agonism/antagonism 5. nerve stimulation |
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name 6 symptoms of parkinsons
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1. tremor
2. rigidity 3. masklike face 4. bradykinesia 5. postural instability 6. dementia |
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parkinsons is a chronic movement disorder caused by a disorder in the amount of _____ and _____ in the brain
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parkinsons is a chronic movement disorder caused by a discord in the amount of dopamine and acetylcholine in the brain
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How does the imbalance of acetylcholine and dopamine specifically cause the symptoms of parkinsons?
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1. not enough dopamine means less GABA inhibition
2. too much acetylcholine means more GABA activity 3. high GABA activity leads to the symptoms of parkinsons |
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how can illicit drug use lead to parkinsons?
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drugs can produce a by product called MPTP which can permanently destroy dopamine neurons
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T/F environmental toxins, oxidative stress and brain trauma can cause parkiees
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true
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drug treatment of PD improves dope acetylcholine balance by?
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increasing dope, decreasing ass
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What are the 5 classes of drugs that increase dopamine neurotransmision to treat PD?
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1. dopamine replacement (L- Dopa)
2. Dopamine agonist 3. dopamine replacer 4. catecholamine-O-Methyltransferase inhibitor 5. MAO-B inhibitor |
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what is the most effective drug for treating PD?
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L-Dopa
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T/F
a) FX of L-Dopa increase as disease progresses b) L-Dopa passively travels to the brain through the BBB c) L-Dopa is metabolized into dopamine in the brain |
a) false. FX decrease
b) false. l-dopa is transported to the brain through the BBB via a transport protein c) L-dopa is metabolized into dopamine in the braine, true |
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what cofactor speeds up the conversion of L-dopa into dopamine in the brain?
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vitamin b6
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why give l-dopa instead of straight dopamine? 2 reasons.
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1. dopamine does not cross the BBB
2. dopamine has a very short half life in the blood |
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why does l-dopa cause nausea?
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dopamine mediated activation of the chemoreceptor trigger zone in the medulla
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why can l-dopa cause cardiac dysrhythmias?
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conversion of l-dopa to dopamine can cause activation of cardiac beta-1 receptors
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t/f l-dopa can cause dyskinesia, orthostatic hypotension, and psychosis
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true true and true
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l-dopa given alone is mostly metabolized in the
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peripheral tissue (i.e. intestine)
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why is l-dopa almost always given with _____
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l-dopa is almost always given with carbidopa because carbidopa inhibits peripheral tissue metabolism of l-dopa, allowing more to pass through the BBB, reaching the brain
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t/f carbidopa decreases the incidence of diskinesia and psychosis
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false. carbidopa decreases the incidence of caridac dysrhythmias, nausea and vomiting
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what are the two types of loss of effect someone taking l-dopa may experience
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1. wearing off. gradual loss of effect
2. on-off. abrupt loss of effect |
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when does the wearing off effect of l-dopa occur and what are three ways it can be minimized?
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wearing off effect occurs when the end of the dosing interval is near
1. shortening the dosing interval 2. give a COMT that inhibits l-dopa metabolism 3. add a dopamine agonist to the therapy |
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t/f wearing off effect can occur when l-dopa levels are high
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false. on-off effect can occur when l-dopa levels are high
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what are 3 ways the on-off loss of effect of l-dopa can be minimized?
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1. taking more frequent doses per day
2. using a controlled release formulation 3. move protein containing meals to the evening |
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what is the mechanism of action of dopamine agonists
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literally just bind to dopamine receptors and activate them, just like dopamine would. not as effective as l-dopa, but used as a first line treatment for those with milder symptoms
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name 3 adverse effects of dopamine agonists
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1. hallucinations
2. orthostatic hypotension 3. daytime drowsiness |
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what are the three mechanisms of action of dopamine releasers?
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1. releases more dopamine from the presynaptic neuron into the synaptic cleft
2. blocks dopamine reuptake into presynaptic neuron 3. blocks NMDA receptors. this decreases dyskinesia effect of l-dopa |
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why is l-dopa usually given with a dopamine releaser
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dopamine releaser block nmda receptors which reduce diskinesia effect of l-dopa
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name 3 adverse fx of dopamine releaser
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nausae, vomiting, dizziness
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what is the mechanism of action of COMT inhibitors?
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COMT adds a methyl group to l dopa and dopamine, rendering them inactive. this inhibits that enzyme and allows more l-dopa to be converted to dopamine
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note: all 4 other dopamine increasers can be combined with l-dopa
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c
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what is the mechanism of action of MAO B inhibitors
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MAO B metabolizes dopamine and l-dopa through oxidation in the brain. MAO B inhibitors stop that
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what are the 2 effects of MAO B inhibitors on dopamine?
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1. allows more dopamine to be converted from l-dopa
2. allows more dopamine to be available in the presynaptic cleft |
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t/f At!therapeutic!doses, MAOCB!inhibitors!used!to!treat!Parkinson’s do!not!inhibit!MAOCA!in!the!liver!and!therefore!do!not!cause!hypertensive!crisis!when!patients!eat!tyramineCcontaining foods (
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true
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what are the three symptoms of excess acetylcholine specifically? (parkinsons)
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1. diaphoresis (excess sweating)
2. salivation 3. urinary incontinence |
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what is the mechanism of action of cholinergic antagonists for parkinsons, and what three symptoms do they decrease?
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they block acetylcholine receptors. they actually increase effectiveness of l-dopa.
they decrease diaphoresis, salivation, and urinary incontinence (pissing involuntarily) |
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name 2 side FX of anticholinergic drugs
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1. dry mouth
2. urinary retention |
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anticholinergic drugs are reserved for _____ patients
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anticholinergic drugs are reserved for younger patients because older patients may experience hallucinations or delirium
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who has alzheimers more, men or women?
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women
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alzheimers is characterized by a degeneration of ____ neurons in the ______ (brain region) early on
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alzheimers is characterized by a degeneration of cholinergic neurons in the hippocampus early on
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t/f a diagnosis of alzheimers cannot be given until after death
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true
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what are the two hallmarks of alzheimers?
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neurofibrillary tangles and neuritic plaques
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how are neurofibrillary tangles formed?
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abnormal production of Tau, a MAP that is responsible for forming cross bridges between microtubules
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what are neuritic plaques and how do they contribute to alzheimers?
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neuritic plaques are found outside of neurons and contain beta amyloids. beta amyloids kill hippcampal cells
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t/f mutations in dna can cause alzheimers
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true
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those with two copies of ______ are at risk of getting alz. why?
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those with two copies of ApoE4 are at higher risk of getting alz. ApoE4 binds to beta amyloids forming neural plaques
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patients with mutations in the _____ precursor gene are at higher risk of alz. why?
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patients with mutations in the amyloid precursor gene are at higher risk of getting alz. this is because this gene is involved with the production of beta amyloiid in neural plaques
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what are the 2 classes of drugs used to treat alz?
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cholinesterase inhibitors and NMDA receptor antagonists
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what is the mechanism of action of cholinesterase inhibitors
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they inhibit the enzyme acetylcholinesterase., allowing more acetylcholine to remain in the synaptic cleft to exert its actions
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t/f cholinesterase inhibitors can reverse alz
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false. they can only increase cholinergic transmission in the healthy neurons left.
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describe the action of the NMDA receptor in a non alz patient
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normally, NMDA receptors have calcium channels that are gated when magnesium is bound. when glutamate binds to another site, then magnesium leaves and there is calcium influx, which is necessary for learning and memory.
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describe the action of the NMDA receptor in an alz patient
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in an alz patient there is excess glutamate activity leading to high levels of calcium influx. this is detrimental because it can damage learning and memory and degrade neurons
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how do nmda receptor antagonists work?
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they block the calcium channel opening such that calcium cannot enter the cell even when there is excess glutamate activity
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t/f patients with shizo dont have multiple personalities but are violent
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false. niggaz with schiz dont have mult pers and arent violent
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positive symptoms ____ or _____ normal neurological function.
negative symptoms have a _____ of normal neurological function |
exaggerate or distort
have a loss of |
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name 4 risk factors for schizophrenia
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1. family history
2. drug abuse - meth pcp and lsd 3. low birth weight 4. low iq |
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how does schizo affect basal ganglia?
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thought to play a role in paranoi and hallucinations
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how does schizo affect frontal lobe?
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difficulty planning and organizing thoughts
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limbic system schiz?
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agitation
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occipital lobe schiz?
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reading images, recognizing motion
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auditory system schiz?
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hallucinations
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hippocamous schiz?
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learning and memory, which are decreased in schiz
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drugs that block the dopaminergic neurons increase/decrease some of the positive symptoms of schizo
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decrease some of the positive symptoms of schizo
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patients with schizo have more ____ receptors and less _____receptors in the _________
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patients with schizo have more 5HT1A receptors and less 5HT2A receptors in the frontal cortex
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patients with schizo have an increased/decreased number of NMDA receptors in their brain
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decreased number of nmda receptors in their brain
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in a brain scan for schiz, what would you expect the size of
a) ventricles b) frontal lobe activity |
a) increased ventricle size
b) decreased frontal lobe activity |
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what are the two classes of drugs used to treat schiz?
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conventional antipsychotics, atypical antipsychotics
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conventional antipsychotics act by blocking _____ receptors in the ______ region of the brain
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conventional antipsychotics act by blocking dopamine receptors in the mesolimbic region of the brain
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conventional antipsychotics are better at treating the postive/negative symptoms of schiz rather than the negative/positive ones
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positive
negative |
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what are extrapyrimidal symptoms
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movement disorders that resemble the symptoms of parkinsons
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name 4 extrapyrimidal symtoms
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1. acute distonia
2. parkinsinism- treat with antichol not l dopa 3. akathesia 4. tardive diskinesia- switch to atypical antipsy |
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what is the mechanism of action of atypical antipsychotics
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they block dopamine, 5ht1a and 5ht2a receptors.
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what receptors do atypical antipsychotics block the least
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dopamine
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what are 3 advatnages of atypical antipsychotics over conventional
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1. same efficacy against positive symptpms
2. more effective against negative symptoms 3. lower risk of extrapyrimidal symptoms |
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t/f conventional antipsychotics cause weight gain
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false. antipsychotics do.
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