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 78-year-old man post-hip surgery becomes confused at night, has fluctuating awareness,
and is disoriented to place. His symptoms improve during the day but worsen after dark. Which
diagnosis best explains this presentation?
A. Major Neurocognitive Disorder due to Alzheimer's disease
B. Delirium
C. Major Depressive Disorder with pseudodementia
D. Vascular Dementia
Correct Answer: B
Rationale: Correct because this patient presents with acute onset confusion, fluctuating course,
and altered consciousness that worsens at night (sundowning), which are hallmark features of
delirium per DSM-5-TR criteria. The postoperative status and nocturnal worsening pattern
strongly suggest an underlying medical etiology such as pain, infection, or medication effect
rather than a progressive neurodegenerative process. Dementia would present with insidious
onset and clear sensorium, while pseudodementia would show rapid onset with prominent "I
don't know" responses and high distress over cognitive failures.
,Q2: A 52-year-old woman with a history of heavy daily alcohol use presents 8 hours after her
last drink with tremors, tachycardia, hypertension, anxiety, and diaphoresis. Her CIWA-Ar score
is 18. What is the most appropriate next clinical intervention?
A. Supportive care and observation only
B. Administer lorazepam and initiate frequent monitoring
C. Begin haloperidol for agitation management
D. Discharge with outpatient detoxification referral
Correct Answer: B
Rationale: Correct because a CIWA-Ar score greater than 15 indicates severe alcohol
withdrawal requiring immediate benzodiazepine administration such as lorazepam along with
close monitoring for progression to delirium tremens. The patient's autonomic instability,
tremors, and anxiety occurring within hours of cessation align with moderate-to-severe alcohol
withdrawal syndrome that necessitates pharmacologic intervention beyond supportive care.
Haloperidol is contraindicated as first-line treatment because it lowers seizure threshold and does
not address the underlying GABA-glutamate imbalance driving withdrawal symptoms.
Q3: A 28-year-old woman presents with intense mood swings that occur multiple times daily,
chronic feelings of emptiness, recurrent self-harm via cutting, and frantic efforts to avoid
perceived abandonment by her partner. She reports these patterns have been present since
adolescence. Which diagnosis is most appropriate?
A. Bipolar I Disorder
B. Cyclothymic Disorder
C. Major Depressive Disorder with anxious distress
D. Borderline Personality Disorder
Correct Answer: D
Rationale: Correct because the patient demonstrates pervasive affective instability, chronic
emptiness, recurrent self-harm, intense fear of abandonment, and identity disturbance that have
persisted since adolescence, meeting DSM-5-TR criteria for Borderline Personality Disorder.
The rapid mood shifts occurring within hours to days and triggered by interpersonal stressors
distinguish BPD from bipolar disorder, which presents with episodic mood episodes lasting
weeks to months with inter-episode stability. The chronic pattern of relational instability and self-
injurious behavior without distinct manic or hypomanic episodes rules out bipolar spectrum
disorders.
,Q4: A PMHNP is evaluating a 74-year-old patient who developed acute confusion after being
hospitalized for pneumonia. The nurse practitioner is using the I WATCH DEATH mnemonic to
identify potential causes of delirium. Which of the following etiologies are included in this
mnemonic? Select all that apply.
A. Infectious processes
B. Acute metabolic disturbances
C. CNS pathology
D. Chronic pain syndromes
E. Genetic neurodegeneration
Correct Answer(s): A, B, C
Rationale: Correct because the I WATCH DEATH mnemonic systematically guides the
investigation of delirium etiologies and includes Infectious processes, Withdrawal, Acute
metabolic disturbances, Trauma, CNS pathology, Hypoxia, Deficiencies, Endocrine disorders,
Acute vascular events, Toxins or medications, and Heavy metals. Chronic pain syndromes and
genetic neurodegeneration are not components of this mnemonic, as delirium requires acute
reversible causes rather than chronic or genetic conditions. This comprehensive framework
ensures that physiological causes are thoroughly evaluated before attributing symptoms to
primary psychiatric disorders.
Q5: A 34-year-old man with heroin use disorder presents 14 hours after his last use, complaining
of severe muscle aches, rhinorrhea, lacrimation, piloerection, and severe yawning. His COWS
score is 10. What is the appropriate next step?
A. Initiate buprenorphine induction now
B. Wait until COWS score reaches 20 before starting buprenorphine
C. Administer naltrexone immediately to block cravings
D. Begin lorazepam for autonomic symptom control
Correct Answer: A
Rationale: Correct because a COWS score of 10 indicates moderate opioid withdrawal, and
buprenorphine induction should begin when COWS reaches 8-12 to prevent precipitated
withdrawal while ensuring sufficient withdrawal severity for safe induction. The patient's
mydriasis, rhinorrhea, lacrimation, piloerection, and severe yawning represent the classic
physical constellation of opioid withdrawal that confirms physiological dependence. Naltrexone
is contraindicated during acute withdrawal as it is an opioid antagonist that would precipitate
severe withdrawal symptoms, and lorazepam does not address the specific opioid receptor-
mediated pathophysiology of this syndrome.
, Q6: An 82-year-old widow is referred by her primary care provider for memory evaluation after
her family noted she began forgetting appointments 3 weeks ago, frequently states "I don't know"
when asked questions, and expresses intense shame about her cognitive lapses. Her MoCA score
is 22/30. Which condition should be prioritized in the differential diagnosis?
A. Pseudodementia due to major depressive disorder
B. Alzheimer's disease
C. Vascular dementia
D. Delirium due to urinary tract infection
Correct Answer: A
Rationale: Correct because the rapid onset of cognitive symptoms over weeks, prominent "I
don't know" responses, and high distress over cognitive failures are pathognomonic for
pseudodementia associated with late-life depression rather than neurodegenerative disease. The
Geriatric Depression Scale should be administered to distinguish true depression from dementia,
as depressive pseudodementia often responds to antidepressant treatment and may reverse with
mood stabilization. Alzheimer's disease would present with insidious onset over months to years,
vascular dementia with step-wise decline and cerebrovascular history, and delirium with acute
fluctuating confusion and altered sensorium.
Q7: A 31-year-old military veteran presents 6 weeks after returning from deployment, reporting
recurrent nightmares of an IED explosion, persistent hypervigilance in public spaces, avoidance
of fireworks and crowded venues, and intrusive memories that disrupt his concentration at work.
He denies any symptoms prior to deployment. Which diagnosis is most appropriate?
A. Posttraumatic Stress Disorder
B. Acute Stress Disorder
C. Generalized Anxiety Disorder
D. Adjustment Disorder with anxiety
Correct Answer: A
Rationale: Correct because the patient exhibits the full symptom cluster of PTSD including
intrusive memories, avoidance of trauma-related stimuli, negative alterations in cognition and
mood, and marked hyperarousal lasting greater than one month following direct trauma
exposure. The duration exceeding one month distinguishes PTSD from Acute Stress Disorder,
which resolves within 3 days to 1 month post-trauma. Generalized Anxiety Disorder would
present with chronic pervasive worry across multiple domains rather than trauma-specific
symptoms, and Adjustment Disorder lacks the full hyperarousal and intrusive symptomatology
required for PTSD.