WGU D345 NURS 6438 Psychopharmacology
OA Final Exam Official Practice Exam
Actual Exam 2026/2027 with Detailed
Rationales | Complete Exam-Style Questions |
Pass Guaranteed – A+ Graded
══════════════════════════════════════
SECTION 1: NEUROBIOLOGY & MECHANISMS OF ACTION Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A 34-year-old patient with treatment-resistant depression is being considered for intravenous
ketamine infusion therapy. The psychiatric-mental health NP explains that ketamine produces
rapid antidepressant effects primarily through blockade of NMDA glutamate receptors,
leading to downstream AMPA receptor activation and increased brain-derived neurotrophic
factor (BDNF) signaling in the prefrontal cortex. This neurobiological cascade ultimately
enhances synaptic plasticity through which downstream mechanism?
A. Direct agonism at GABA-A receptors producing sustained inhibitory neurotransmission
B. Blockade of NMDA receptors with subsequent AMPA activation and mTOR pathway
stimulation ✓ CORRECT
C. Inhibition of serotonin reuptake at the presynaptic SERT transporter
D. Antagonism at alpha-1 adrenergic receptors in the locus coeruleus
Correct Answer: B
Rationale: Ketamine's antidepressant effect is mediated by NMDA receptor antagonism,
which triggers a glutamate surge activating AMPA receptors and stimulating the mTOR
signaling pathway to increase synaptic protein synthesis and spine formation. Choice A is
incorrect because GABA-A agonism produces sedation and anxiolysis but is not the
mechanism underlying ketamine's rapid antidepressant properties. Choice C describes SSRIs,
which require weeks for clinical effect, unlike ketamine's rapid onset.
Question 2 of 50
A 28-year-old patient prescribed aripiprazole asks why the medication is called a "dopamine
system stabilizer." The PMHNP explains that aripiprazole functions as a partial agonist at D2
receptors, occupying approximately 85% of striatal D2 receptors at therapeutic doses. At
,which additional receptor does aripiprazole demonstrate partial agonism, contributing to its
lower risk of metabolic syndrome and akathisia compared to other second-generation
antipsychotics?
A. 5-HT2A receptor
B. D1 receptor
C. 5-HT1A receptor ✓ CORRECT
D. H1 histamine receptor
Correct Answer: C
Rationale: Aripiprazole is a partial agonist at both D2 and 5-HT1A receptors, with the 5-HT1A
partial agonism contributing to reduced extrapyramidal symptoms and potentially improved
cognition compared to full antagonists. Choice A is incorrect because aripiprazole
antagonizes 5-HT2A receptors rather than acting as a partial agonist, and 5-HT2A antagonism
is shared by many antipsychotics without conveying metabolic protection. The 5-HT1A partial
agonism is a distinguishing feature that modulates dopaminergic tone in a regionally
selective manner.
Question 3 of 50
A 45-year-old patient with bipolar disorder is prescribed lithium carbonate 600 mg BID. At the
cellular level, lithium modulates signal transduction primarily through inhibition of which
intracellular enzyme, thereby reducing inositol phosphate signaling and protein kinase C
activity in neuronal membranes?
A. Inositol monophosphatase ✓ CORRECT
B. Tyrosine hydroxylase
C. Monoamine oxidase-A
D. Phosphodiesterase-4
Correct Answer: A
Rationale: Lithium inhibits inositol monophosphatase and inositol polyphosphate
1-phosphatase, depleting free inositol and dampening the phosphatidylinositol
second-messenger system, which contributes to its mood-stabilizing effects. Choice B is
incorrect because tyrosine hydroxylase is the rate-limiting enzyme in catecholamine
synthesis and is not directly inhibited by lithium; this enzyme is targeted by agents such as
alpha-methyltyrosine. Lithium's mechanism is unique among mood stabilizers in targeting
intracellular signaling cascades rather than direct neurotransmitter receptor interactions.
Question 4 of 50
A 52-year-old patient with schizophrenia is switched from haloperidol to clozapine due to
persistent positive symptoms despite adequate trials of two other antipsychotics. The
PMHNP explains that clozapine's superior efficacy in treatment-resistant schizophrenia is
, attributed to its unique receptor binding profile, which includes high-affinity antagonism at
which receptor subtype, distinguishing it from typical antipsychotics?
A. D2 dopamine receptor
B. Alpha-1 adrenergic receptor
C. Muscarinic M1 receptor
D. 5-HT2A serotonin receptor ✓ CORRECT
Correct Answer: D
Rationale: Clozapine exhibits high-affinity antagonism at 5-HT2A receptors with a 5-HT2A/D2
binding ratio greater than most antipsychotics, which is hypothesized to contribute to its
efficacy in treatment-resistant schizophrenia and lower extrapyramidal symptom burden.
Choice A is incorrect because all antipsychotics, including haloperidol, antagonize D2
receptors; clozapine's relatively low D2 affinity and rapid dissociation kinetics are actually
key to its atypical profile. The 5-HT2A/D2 ratio is a central concept in understanding atypical
antipsychotic pharmacology.
Question 5 of 50
A 39-year-old patient with major depressive disorder and a history of smoking cessation
failure is started on bupropion XL 150 mg daily. The PMHNP explains that bupropion's
therapeutic effect in depression and its efficacy in smoking cessation are mediated primarily
through inhibition of which neurotransmitter transporters, distinguishing it from serotonergic
antidepressants?
A. Serotonin and norepinephrine transporters
B. Norepinephrine and dopamine transporters ✓ CORRECT
C. Dopamine and serotonin transporters
D. Norepinephrine and glutamate transporters
Correct Answer: B
Rationale: Bupropion is a norepinephrine-dopamine reuptake inhibitor (NDRI) that blocks the
norepinephrine transporter (NET) and dopamine transporter (DAT), increasing
catecholaminergic tone in the mesolimbic pathway and prefrontal cortex. Choice A describes
duloxetine and venlafaxine, which are SNRIs and carry a different adverse effect profile
including more sexual dysfunction. Bupropion's lack of serotonergic activity explains its
lower risk of sexual side effects and weight gain but also why it is less effective for anxiety
disorders.
Question 6 of 50
A 61-year-old patient with Parkinson's disease develops visual hallucinations and paranoid
delusions. The neurologist consults psychiatry, and the PMHNP recommends pimavanserin
34 mg daily. The PMHNP explains that pimavanserin's mechanism of action differs from
OA Final Exam Official Practice Exam
Actual Exam 2026/2027 with Detailed
Rationales | Complete Exam-Style Questions |
Pass Guaranteed – A+ Graded
══════════════════════════════════════
SECTION 1: NEUROBIOLOGY & MECHANISMS OF ACTION Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A 34-year-old patient with treatment-resistant depression is being considered for intravenous
ketamine infusion therapy. The psychiatric-mental health NP explains that ketamine produces
rapid antidepressant effects primarily through blockade of NMDA glutamate receptors,
leading to downstream AMPA receptor activation and increased brain-derived neurotrophic
factor (BDNF) signaling in the prefrontal cortex. This neurobiological cascade ultimately
enhances synaptic plasticity through which downstream mechanism?
A. Direct agonism at GABA-A receptors producing sustained inhibitory neurotransmission
B. Blockade of NMDA receptors with subsequent AMPA activation and mTOR pathway
stimulation ✓ CORRECT
C. Inhibition of serotonin reuptake at the presynaptic SERT transporter
D. Antagonism at alpha-1 adrenergic receptors in the locus coeruleus
Correct Answer: B
Rationale: Ketamine's antidepressant effect is mediated by NMDA receptor antagonism,
which triggers a glutamate surge activating AMPA receptors and stimulating the mTOR
signaling pathway to increase synaptic protein synthesis and spine formation. Choice A is
incorrect because GABA-A agonism produces sedation and anxiolysis but is not the
mechanism underlying ketamine's rapid antidepressant properties. Choice C describes SSRIs,
which require weeks for clinical effect, unlike ketamine's rapid onset.
Question 2 of 50
A 28-year-old patient prescribed aripiprazole asks why the medication is called a "dopamine
system stabilizer." The PMHNP explains that aripiprazole functions as a partial agonist at D2
receptors, occupying approximately 85% of striatal D2 receptors at therapeutic doses. At
,which additional receptor does aripiprazole demonstrate partial agonism, contributing to its
lower risk of metabolic syndrome and akathisia compared to other second-generation
antipsychotics?
A. 5-HT2A receptor
B. D1 receptor
C. 5-HT1A receptor ✓ CORRECT
D. H1 histamine receptor
Correct Answer: C
Rationale: Aripiprazole is a partial agonist at both D2 and 5-HT1A receptors, with the 5-HT1A
partial agonism contributing to reduced extrapyramidal symptoms and potentially improved
cognition compared to full antagonists. Choice A is incorrect because aripiprazole
antagonizes 5-HT2A receptors rather than acting as a partial agonist, and 5-HT2A antagonism
is shared by many antipsychotics without conveying metabolic protection. The 5-HT1A partial
agonism is a distinguishing feature that modulates dopaminergic tone in a regionally
selective manner.
Question 3 of 50
A 45-year-old patient with bipolar disorder is prescribed lithium carbonate 600 mg BID. At the
cellular level, lithium modulates signal transduction primarily through inhibition of which
intracellular enzyme, thereby reducing inositol phosphate signaling and protein kinase C
activity in neuronal membranes?
A. Inositol monophosphatase ✓ CORRECT
B. Tyrosine hydroxylase
C. Monoamine oxidase-A
D. Phosphodiesterase-4
Correct Answer: A
Rationale: Lithium inhibits inositol monophosphatase and inositol polyphosphate
1-phosphatase, depleting free inositol and dampening the phosphatidylinositol
second-messenger system, which contributes to its mood-stabilizing effects. Choice B is
incorrect because tyrosine hydroxylase is the rate-limiting enzyme in catecholamine
synthesis and is not directly inhibited by lithium; this enzyme is targeted by agents such as
alpha-methyltyrosine. Lithium's mechanism is unique among mood stabilizers in targeting
intracellular signaling cascades rather than direct neurotransmitter receptor interactions.
Question 4 of 50
A 52-year-old patient with schizophrenia is switched from haloperidol to clozapine due to
persistent positive symptoms despite adequate trials of two other antipsychotics. The
PMHNP explains that clozapine's superior efficacy in treatment-resistant schizophrenia is
, attributed to its unique receptor binding profile, which includes high-affinity antagonism at
which receptor subtype, distinguishing it from typical antipsychotics?
A. D2 dopamine receptor
B. Alpha-1 adrenergic receptor
C. Muscarinic M1 receptor
D. 5-HT2A serotonin receptor ✓ CORRECT
Correct Answer: D
Rationale: Clozapine exhibits high-affinity antagonism at 5-HT2A receptors with a 5-HT2A/D2
binding ratio greater than most antipsychotics, which is hypothesized to contribute to its
efficacy in treatment-resistant schizophrenia and lower extrapyramidal symptom burden.
Choice A is incorrect because all antipsychotics, including haloperidol, antagonize D2
receptors; clozapine's relatively low D2 affinity and rapid dissociation kinetics are actually
key to its atypical profile. The 5-HT2A/D2 ratio is a central concept in understanding atypical
antipsychotic pharmacology.
Question 5 of 50
A 39-year-old patient with major depressive disorder and a history of smoking cessation
failure is started on bupropion XL 150 mg daily. The PMHNP explains that bupropion's
therapeutic effect in depression and its efficacy in smoking cessation are mediated primarily
through inhibition of which neurotransmitter transporters, distinguishing it from serotonergic
antidepressants?
A. Serotonin and norepinephrine transporters
B. Norepinephrine and dopamine transporters ✓ CORRECT
C. Dopamine and serotonin transporters
D. Norepinephrine and glutamate transporters
Correct Answer: B
Rationale: Bupropion is a norepinephrine-dopamine reuptake inhibitor (NDRI) that blocks the
norepinephrine transporter (NET) and dopamine transporter (DAT), increasing
catecholaminergic tone in the mesolimbic pathway and prefrontal cortex. Choice A describes
duloxetine and venlafaxine, which are SNRIs and carry a different adverse effect profile
including more sexual dysfunction. Bupropion's lack of serotonergic activity explains its
lower risk of sexual side effects and weight gain but also why it is less effective for anxiety
disorders.
Question 6 of 50
A 61-year-old patient with Parkinson's disease develops visual hallucinations and paranoid
delusions. The neurologist consults psychiatry, and the PMHNP recommends pimavanserin
34 mg daily. The PMHNP explains that pimavanserin's mechanism of action differs from
