Chamberlain College of Nursing |
Differential Diagnosis in Psychiatric-
Mental Health PMHNP | 50 Q&A with
Rationale & DSM-5-TR
**Q1.** A 24-year-old female presents for evaluation of chronic
low mood. She reports feeling "down" most days for the past
three years, with poor appetite, low energy, and insomnia. She
denies anhedonia, significant weight change, or suicidal
ideation. She states she can "still laugh at a funny movie" and
meets all her work deadlines, though with great effort. Her
symptoms began after moving to a new city for a job. What is
the most likely diagnosis?
A. Major Depressive Disorder, recurrent
B. Persistent Depressive Disorder (Dysthymia)
C. Adjustment Disorder with Depressed Mood
D. Unspecified Depressive Disorder
**Correct Answer: B**
,**Rationale:** This vignette describes a chronic depressive
syndrome lasting >2 years (three years) that does not meet full
criteria for a major depressive episode. The patient has
depressed mood most of the day, more days than not, plus two
neurovegetative symptoms (poor appetite, low energy,
insomnia). The preserved capacity for pleasure ("can still
laugh") and functioning (meets deadlines) is characteristic of
Persistent Depressive Disorder. MDD would require a discrete
episode with more pronounced symptoms and functional
impairment. Adjustment Disorder would have a clear stressor
and duration less than 6 months after the stressor ends.
**Q2.** A 17-year-old male is brought by his parents due to
increasing social withdrawal and declining grades over 8
months. He reports hearing a voice that comments on his
actions in the third person for the past 6 months. He finds the
voice distracting but not frightening. His affect is blunted, and
his speech is slightly disorganized. There is no history of mania
or substance use. Which diagnosis is supported?
A. Schizophrenia
B. Schizophreniform Disorder
C. Schizoaffective Disorder
D. Delusional Disorder
,**Correct Answer: B**
**Rationale:** The patient presents with characteristic
symptoms of schizophrenia (auditory hallucination,
disorganized speech, negative symptoms) but the total duration
of illness is between 1 and 6 months (active symptoms for 6
months, prodrome for 2 months prior). This meets criteria for
Schizophreniform Disorder. For a diagnosis of Schizophrenia,
the continuous signs must persist for at least 6 months.
Schizoaffective Disorder requires a major mood episode
concurrent with the psychotic symptoms. Delusional Disorder
involves non-bizarre delusions without other prominent
psychotic features.
**Q3.** A 35-year-old attorney presents with a 6-month history
of episodes where she feels "out of my body," experiences
tingling in her hands, chest tightness, and a fear she is having a
heart attack. These episodes last 10-15 minutes and occur
unpredictably, about twice weekly. She now avoids her usual
subway commute for fear of an episode. Physical workup is
negative. What is the core diagnosis, and what comorbid
condition is developing?
A. Panic Disorder; Agoraphobia
B. Generalized Anxiety Disorder; Panic Attacks
C. Somatic Symptom Disorder; Illness Anxiety Disorder
D. Other Specified Anxiety Disorder; Specific Phobia
, **Correct Answer: A**
**Rationale:** The patient has recurrent, unexpected panic
attacks (palpitations, paresthesias, derealization, fear of dying).
The worry about future attacks and the maladaptive behavioral
change (avoiding the subway) to avoid situations where escape
might be difficult meets criteria for Panic Disorder. The
avoidance behavior is specifically characteristic of developing
Agoraphobia, which is frequently comorbid with Panic Disorder.
GAD involves persistent, excessive worry about multiple
domains, not discrete panic attacks.
**Q4.** (Select All That Apply) A 68-year-old man with a history
of hypertension and Type 2 Diabetes is brought in by his
daughter for increasing confusion over 4 months. He got lost
driving to the grocery store last week. On exam, he is alert but
has impaired attention, word-finding difficulties, and
visuospatial deficits (cannot copy intersecting pentagons).
Which of the following are the NEXT most appropriate steps in
the differential diagnosis workup? Select three.
A. Serum TSH, B12, and RPR
B. Brain MRI with contrast
C. Lumbar Puncture for CSF analysis
D. Neuropsychometric testing