,NRNP 6665 Final Exam | Psych MH NP Lifespan I (2026)
Q&A | Walden University
1. A patient with treatment-resistant depression is being considered for a medication
switch. Which biomarker is most strongly associated with poor response to SSRIs and
potential benefit from a non-serotonergic agent?
A) CYP2D6 ultrarapid metabolizer status
B) SLC6A4 5-HTTLPR short/short genotype
C) CYP2B6 poor metabolizer status
D) DRD2 Taq1A A1 allele carrier
Correct Answer: SLC6A4 5-HTTLPR short/short genotype
Rationale: The short/short genotype of the serotonin transporter promoter
polymorphism is associated with poorer response to SSRIs but may respond better to non-
serotonergic agents such as bupropion. CYP2D6 affects metabolism rather than response
specificity, CYP2B6 metabolizes bupropion but does not predict efficacy, and DRD2 is more
relevant to antipsychotic response.
2. A patient with schizophrenia exhibits persistent negative symptoms and cognitive
deficits despite adequate D2 receptor blockade. Which neurobiological mechanism best
explains these residual symptoms?
A) Hyperdopaminergic mesolimbic pathway
B) Hypodopaminergic mesocortical pathway
C) Serotonergic excess in the raphe nuclei
D) GABAergic deficit in the thalamus
Correct Answer: Hypodopaminergic mesocortical pathway
,Rationale: Negative and cognitive symptoms of schizophrenia are linked to reduced
dopamine in the mesocortical pathway projecting to the prefrontal cortex. Mesolimbic
hyperdopaminergic activity explains positive symptoms, while serotonergic and GABAergic
mechanisms are less directly implicated in these residual symptoms.
3. A patient on lithium develops polyuria, polydipsia, and a urine osmolality of 150
mOsm/kg. Which intervention is most appropriate?
A) Increase the lithium dose
B) Switch to amiloride
C) Add hydrochlorothiazide
D) Discontinue lithium abruptly
Correct Answer: Switch to amiloride
Rationale: Lithium-induced nephrogenic diabetes insipidus is treated by switching to
amiloride, which blocks lithium entry into collecting duct cells. Thiazides may worsen
lithium levels by reducing renal clearance, increasing the dose would exacerbate toxicity,
and abrupt discontinuation risks relapse.
4. Which statement accurately reflects the FDA boxed warning for antidepressants
regarding suicidality?
A) Risk is highest in adults over 65
B) Risk is limited to the first week of treatment
C) Risk is highest in patients under 25, especially during initiation
D) Risk is equivalent across all age groups
Correct Answer: Risk is highest in patients under 25, especially during initiation
, Rationale: The boxed warning highlights increased suicidality in patients under 25,
particularly early in treatment and during dose adjustments. The risk is not limited to the
first week, not highest in older adults, and not equivalent across age groups.
5. Which genetic polymorphism most significantly affects clopidogrel activation and is
relevant when co-prescribed with SSRIs?
A) CYP2D6
B) CYP2C19
C) CYP3A4
D) CYP1A2
Correct Answer: CYP2C19
Rationale: CYP2C19 poor metabolizers have reduced clopidogrel activation, and SSRIs
such as fluoxetine inhibit CYP2C19, potentially increasing cardiovascular risk. CYP2D6,
CYP3A4, and CYP1A2 are less critical for clopidogrel activation.
6. A patient with bipolar I disorder is experiencing a mixed episode with both manic and
depressive symptoms. Which treatment approach is most appropriate?
A) Antidepressant monotherapy
B) Mood stabilizer with or without an atypical antipsychotic
C) Stimulant augmentation
D) Benzodiazepine monotherapy
Correct Answer: Mood stabilizer with or without an atypical antipsychotic
Rationale: Mixed episodes require mood stabilization, often with valproate, lithium, or an
atypical antipsychotic, because antidepressant monotherapy can worsen mood instability.
Q&A | Walden University
1. A patient with treatment-resistant depression is being considered for a medication
switch. Which biomarker is most strongly associated with poor response to SSRIs and
potential benefit from a non-serotonergic agent?
A) CYP2D6 ultrarapid metabolizer status
B) SLC6A4 5-HTTLPR short/short genotype
C) CYP2B6 poor metabolizer status
D) DRD2 Taq1A A1 allele carrier
Correct Answer: SLC6A4 5-HTTLPR short/short genotype
Rationale: The short/short genotype of the serotonin transporter promoter
polymorphism is associated with poorer response to SSRIs but may respond better to non-
serotonergic agents such as bupropion. CYP2D6 affects metabolism rather than response
specificity, CYP2B6 metabolizes bupropion but does not predict efficacy, and DRD2 is more
relevant to antipsychotic response.
2. A patient with schizophrenia exhibits persistent negative symptoms and cognitive
deficits despite adequate D2 receptor blockade. Which neurobiological mechanism best
explains these residual symptoms?
A) Hyperdopaminergic mesolimbic pathway
B) Hypodopaminergic mesocortical pathway
C) Serotonergic excess in the raphe nuclei
D) GABAergic deficit in the thalamus
Correct Answer: Hypodopaminergic mesocortical pathway
,Rationale: Negative and cognitive symptoms of schizophrenia are linked to reduced
dopamine in the mesocortical pathway projecting to the prefrontal cortex. Mesolimbic
hyperdopaminergic activity explains positive symptoms, while serotonergic and GABAergic
mechanisms are less directly implicated in these residual symptoms.
3. A patient on lithium develops polyuria, polydipsia, and a urine osmolality of 150
mOsm/kg. Which intervention is most appropriate?
A) Increase the lithium dose
B) Switch to amiloride
C) Add hydrochlorothiazide
D) Discontinue lithium abruptly
Correct Answer: Switch to amiloride
Rationale: Lithium-induced nephrogenic diabetes insipidus is treated by switching to
amiloride, which blocks lithium entry into collecting duct cells. Thiazides may worsen
lithium levels by reducing renal clearance, increasing the dose would exacerbate toxicity,
and abrupt discontinuation risks relapse.
4. Which statement accurately reflects the FDA boxed warning for antidepressants
regarding suicidality?
A) Risk is highest in adults over 65
B) Risk is limited to the first week of treatment
C) Risk is highest in patients under 25, especially during initiation
D) Risk is equivalent across all age groups
Correct Answer: Risk is highest in patients under 25, especially during initiation
, Rationale: The boxed warning highlights increased suicidality in patients under 25,
particularly early in treatment and during dose adjustments. The risk is not limited to the
first week, not highest in older adults, and not equivalent across age groups.
5. Which genetic polymorphism most significantly affects clopidogrel activation and is
relevant when co-prescribed with SSRIs?
A) CYP2D6
B) CYP2C19
C) CYP3A4
D) CYP1A2
Correct Answer: CYP2C19
Rationale: CYP2C19 poor metabolizers have reduced clopidogrel activation, and SSRIs
such as fluoxetine inhibit CYP2C19, potentially increasing cardiovascular risk. CYP2D6,
CYP3A4, and CYP1A2 are less critical for clopidogrel activation.
6. A patient with bipolar I disorder is experiencing a mixed episode with both manic and
depressive symptoms. Which treatment approach is most appropriate?
A) Antidepressant monotherapy
B) Mood stabilizer with or without an atypical antipsychotic
C) Stimulant augmentation
D) Benzodiazepine monotherapy
Correct Answer: Mood stabilizer with or without an atypical antipsychotic
Rationale: Mixed episodes require mood stabilization, often with valproate, lithium, or an
atypical antipsychotic, because antidepressant monotherapy can worsen mood instability.
