Answer:
The correct answer is D. He should not make any diagnosis at all, since no condition in DSM-5 is satisfied by this clinical case.
Step-by-step explanation:
Let's discard one by one.
Option A.
He should create a new diagnosis and inform the authors of the DSM-5.
Why not: Diagnostic labels cannot be created from one particular case. A psychiatrist or clinical psychologist is not entitled to create or formulate a personality disorder just because he/she feels like it.
Option B.
He should diagnose the client with Unspecified Personality Disorder (UPD)
Why not: In the DSM-5 the diagnosis of unspecified personality disorder is made only to enhance the specificity of an existing personality disorder.
Option C.
He should diagnose a different condition such as depression or anxiety as a "place holder" until the true nature of the personality problems is more fully understood.
Why not: This course of action is not ethical. Clinicians must not misdiagnose patients just because they feel like it. Diagnosing a patient with depression or anxiety without them falling within the diagnostic criteria is medical negligence.
In conclusion, the correct answer is D. He should not make any diagnosis at all, since no condition in DSM-5 is satisfied by this clinical case.