Differential Diagnosis in Psychiatric-Mental Health Across
the Lifespan
Complete Practice Questions 1-200 with Answers & Detailed
Rationales
Latest 2026/2027 Update | Chamberlain University (MSN-PMHNP)
QUESTION 1
A PMHNP is conducting an initial psychiatric evaluation. Which of the following best
describes the primary purpose of the "differential diagnosis" process?
A) To confirm the patient's self-reported diagnosis
B) To develop a working list of potential disorders that could explain the patient's
symptoms
C) To rule out all medical causes of psychiatric symptoms before considering any mental
health diagnosis
D) To assign a single diagnosis that will guide all future treatment decisions
CORRECT ANSWER: B) To develop a working list of potential disorders that could
explain the patient's symptoms
,RATIONALE: Differential diagnosis involves developing a working hypothesis or list of
potential disorders that could account for the presenting symptoms. This list is prioritized,
and each potential diagnosis is systematically ruled in or out based on diagnostic criteria,
history, and assessment findings.
QUESTION 2
A PMHNP student is conducting a diagnostic interview. The patient describes feeling
"down" for the past month. Which interviewing technique is most appropriate to clarify
the diagnostic picture?
A) Immediately diagnosing major depressive disorder based on the statement
B) Using open-ended questions followed by clarifying and summarizing to gather
specific symptoms and duration
C) Asking only yes/no questions to speed up the interview
D) Focusing exclusively on family history without exploring current symptoms
CORRECT ANSWER: B) Using open-ended questions followed by clarifying and
summarizing to gather specific symptoms and duration
RATIONALE: Effective diagnostic interviewing uses open-ended questions to elicit
narrative, followed by clarifying questions to establish specific symptoms, duration, and
functional impairment. Summarizing ensures accuracy. This approach prevents premature
diagnosis and ensures DSM-5-TR criteria are thoroughly evaluated.
QUESTION 3
A patient presents with depressed mood. The PMHNP is considering the hierarchical
diagnostic approach. Which condition should be ruled out first before making a
psychiatric diagnosis?
,A) Adjustment disorder with depressed mood
B) Substance-induced or medical condition causing depressive symptoms
C) Persistent depressive disorder
D) Major depressive disorder with anxious distress
CORRECT ANSWER: B) Substance-induced or medical condition causing depressive
symptoms
RATIONALE: The hierarchical approach requires ruling out substance/medication-
induced disorders and disorders due to another medical condition before primary
psychiatric diagnoses. This follows DSM-5-TR diagnostic principles: if symptoms are
attributable to substance use (intoxication/withdrawal) or medical condition
(hypothyroidism), that diagnosis takes precedence.
QUESTION 4
According to the DSM-5-TR, which of the following must be ruled out before assigning
most psychiatric diagnoses?
A) Childhood trauma history
B) Substance use and other medical conditions
C) Family history of mental illness
D) Recent stressful life events
CORRECT ANSWER: B) Substance use and other medical conditions
RATIONALE: The DSM-5-TR requires clinicians to rule out substance/medication-induced
conditions and other medical conditions as the primary cause of symptoms before
assigning a primary psychiatric diagnosis.
, QUESTION 5
During a mental status examination, the PMHNP notes the patient has looseness of
associations, flight of ideas, and tangential responses. Which MSE component is being
assessed?
A) Mood and affect
B) Thought process
C) Thought content
D) Insight and judgment
CORRECT ANSWER: B) Thought process
RATIONALE: Thought process refers to how a person thinks (form of thought), including
goal-directedness, logical connections, and organization. Looseness of associations, flight
of ideas, tangentiality, circumstantiality, and thought blocking are all thought process
abnormalities. Thought content (delusions, suicidal ideation) is different. Mood is
subjective emotional state; affect is observed emotional expression.
QUESTION 6
A patient describes hearing voices commenting on their actions when no one is present.
Which MSE component does this represent?
A) Thought content
B) Perception
C) Cognition
D) Speech
CORRECT ANSWER: B) Perception