Which statement differentiates Delusional Disorder from Schizophrenia?

• A. Delusions are the only symptom
• B. Hallucinations must be present
• C. Delusions last less than one month
• D. Absence or limited impairment in overall functioning

Answer: (D)

The key idea is that Delusional Disorder centers on delusions occurring without widespread disruption to daily functioning, whereas schizophrenia involves prominent psychotic symptoms plus clear impairment in functioning.

Delusional Disorder features delusions for at least a month, but overall functioning is relatively intact and there are no prominent disorganized speech, grossly disorganized behavior, or negative symptoms. If functioning is preserved, that helps separate it from schizophrenia, where work, relationships, and self-care are typically meaningfully affected.

That’s why choosing the statement about absence or only limited impairment in overall functioning best differentiates the two. In schizophrenia, marked impairment in functioning is common, not present in Delusional Disorder.

The other statements don’t fit as well: delusions being the only symptom isn’t required and can be misleading since other domains of functioning are still usually relatively preserved in Delusional Disorder; hallucinations are not required and, when prominent, point away from Delusional Disorder; delusions lasting less than a month fails the minimum duration criterion for Delusional Disorder.