Differential Diagnosis in Psychiatric-Mental Health
across the Lifespan Practicum
2026| 2027| 2028 Testing Cycle | Complete Guide
75 Questions With Answers & Expert Rationales
Guaranteed Pass | Graded A+ | Chamberlain
Q1: A 58-year-old woman with bipolar I disorder has been stable on lithium 1500 mg daily for 3
years. She was recently started on hydrochlorothiazide for hypertension. She presents to the
clinic with severe nausea, vomiting, coarse tremors, ataxia, slurred speech, and confusion. Her
lithium level is 2.9 mEq/L, and her serum creatinine is elevated. Which intervention is the
priority?
A. Continue lithium at the current dose and add an antiemetic
B. Reduce lithium dose by 50% and recheck levels in 1 week
C. Add an SSRI to manage mood symptoms during the transition
D. Discontinue lithium immediately, initiate IV hydration, and prepare for hemodialysis
Correct Answer: D
Rationale: Correct because a lithium level of 2.9 mEq/L indicates severe toxicity, which requires
immediate discontinuation of lithium, aggressive IV hydration, and preparation for hemodialysis
to prevent seizures, coma, and cardiac arrhythmias. Continuing or reducing the lithium dose
would be life-threatening given the severity of the level and neurotoxic symptoms. Adding an
SSRI is inappropriate and dangerous, as the symptoms are not side effects but rather signs of
severe lithium poisoning that demand emergent intervention, particularly in the context of
thiazide-induced reduced lithium excretion.
,Q2: A 52-year-old man with a 15-year history of heavy alcohol use is admitted to the medical
unit after his last drink 10 hours ago. The nurse notes he is tremulous, diaphoretic, and anxious
with a blood pressure of 164/92 mmHg and heart rate of 118 bpm. His CIWA-Ar score is 16. He
is oriented to person, place, and time but reports moderate nausea and anxiety. Which is the
appropriate next clinical intervention?
A. Provide supportive care only and reassess in 4 hours
B. Discharge home with outpatient follow-up in 3 days
C. Administer a benzodiazepine and initiate frequent monitoring
D. Administer haloperidol for agitation and place on seizure precautions only
Correct Answer: C
Rationale: Correct because a CIWA-Ar score greater than 15 indicates severe alcohol
withdrawal, which requires benzodiazepine administration—such as lorazepam,
chlordiazepoxide, or diazepam—along with close monitoring for seizure risk and autonomic
instability. Supportive care alone is insufficient for a score of 16, as this patient is at significant
risk for progression to delirium tremens. Discharge would be unsafe given the severity of
withdrawal, and haloperidol does not treat the underlying withdrawal process and can lower
seizure threshold.
Q3: A 26-year-old woman presents to the clinic after her third suicide attempt by overdose in the
past year. She reports intense, rapid mood swings that shift within hours from anger to sadness to
anxiety, typically triggered by interpersonal conflicts. She describes chronic feelings of
emptiness, engages in self-cutting when distressed, and reports frantic efforts to avoid
abandonment by her boyfriend. She idealizes her new therapist as "perfect" but threatened to quit
therapy when an appointment was rescheduled. Which diagnosis best explains this clinical
presentation?
A. Bipolar I Disorder
B. Narcissistic Personality Disorder
C. Borderline Personality Disorder
D. Histrionic Personality Disorder
Correct Answer: C
Rationale: Correct because this patient meets DSM-5-TR criteria for Borderline Personality
Disorder, demonstrating affective instability, chronic emptiness, recurrent suicidal behavior,
frantic efforts to avoid abandonment, self-harm, and splitting—all core features of BPD. Bipolar
I Disorder is ruled out because the mood shifts occur within hours and are triggered by
interpersonal stressors rather than the sustained episodic manic episodes lasting days to weeks
characteristic of bipolar disorder. Narcissistic Personality Disorder lacks the affective instability
,and self-harm behaviors, and Histrionic Personality Disorder involves attention-seeking and
seductiveness without the pervasive abandonment fears and self-destructive patterns.
Q4: A 34-year-old female veteran presents for evaluation 4 months after returning from
deployment. She reports recurrent, distressing nightmares of a convoy attack, avoids watching
news coverage of military operations, and experiences intense physiological distress when
hearing loud noises resembling gunfire. She describes persistent negative beliefs about herself
and the world, feels detached from her family, and is hypervigilant in public settings. These
symptoms have caused her to isolate from friends and miss work. Which diagnosis is most
appropriate?
A. Acute Stress Disorder
B. Adjustment Disorder
C. Post-Traumatic Stress Disorder
D. Generalized Anxiety Disorder
Correct Answer: C
Rationale: Correct because Post-Traumatic Stress Disorder is diagnosed when trauma-related
symptoms—including intrusive memories, avoidance, negative alterations in cognition and
mood, and hyperarousal—persist for more than 1 month following trauma exposure, and this
veteran's 4-month duration with significant functional impairment meets full criteria. Acute
Stress Disorder is ruled out because symptoms have exceeded the 1-month diagnostic window.
Adjustment Disorder is incorrect because the symptom severity and constellation exceed the
scope of a maladaptive stress response, and Generalized Anxiety Disorder is ruled out because
the anxiety is trauma-specific rather than pervasive across multiple life domains.
Q5: A 74-year-old woman is brought to the clinic by her daughter, who reports a 3-month
decline in her mother's cognitive function. The patient repeatedly states "I don't know" during
cognitive testing, cries frequently, and expresses profound distress over her memory failures. She
sleeps excessively, has lost interest in previously enjoyed activities, and states she feels
"worthless." Her MoCA score is 20/30. She was independent in all activities of daily living 4
months ago. Which condition should be considered before diagnosing dementia?
A. Alzheimer's Disease
B. Pseudodementia due to depression
C. Delirium from polypharmacy
D. Vascular Dementia
Correct Answer: B
Rationale: Correct because this patient's rapid onset of cognitive symptoms over 3 months,
, prominent "I don't know" responses, high distress over cognitive failures, and concurrent
neurovegetative symptoms of depression (excessive sleep, anhedonia, worthlessness) are classic
for pseudodementia—depressive symptoms in older adults that mimic dementia. Alzheimer's
Disease would present with an insidious onset over years and less emotional distress about
cognitive deficits. Delirium would involve altered consciousness and fluctuating course, which
are absent here, and Vascular Dementia would demonstrate a step-wise decline associated with
cerebrovascular events.
Q6: A 71-year-old man is evaluated for cognitive decline. His wife reports that over the past 2
years he has developed visual hallucinations of children playing in the living room, experiences
episodes where he stares blankly for minutes at a time, and has developed rigidity and a shuffling
gait. His cognition fluctuates significantly from day to day, with some days being nearly normal
and others marked by profound confusion. Which type of dementia is most consistent with this
presentation?
A. Alzheimer's Disease
B. Vascular Dementia
C. Lewy Body Dementia
D. Frontotemporal Dementia
Correct Answer: C
Rationale: Correct because Lewy Body Dementia is classically characterized by the triad of
fluctuating cognition, recurrent visual hallucinations, and spontaneous Parkinsonism, all of
which this patient exhibits. Alzheimer's Disease typically presents with memory-first gradual
decline without visual hallucinations or Parkinsonism early in the course. Vascular Dementia
would show a step-wise decline with cerebrovascular risk factors and infarcts, and
Frontotemporal Dementia would present with early behavioral and personality changes rather
than visual hallucinations and Parkinsonism.
Q7: A 29-year-old software engineer reports that he has always been extremely shy and avoids
team meetings, social gatherings, and promotions because of an intense fear of being criticized,
rejected, or embarrassed. He desperately wants to form close friendships and romantic
relationships but avoids situations where he might be evaluated negatively. He has two close
friends from childhood but avoids making new connections. Which personality disorder best fits
this presentation?
A. Schizoid Personality Disorder
B. Avoidant Personality Disorder
C. Dependent Personality Disorder
D. Schizotypal Personality Disorder