The delusional insisted he owned the Eiffel Tower, despite all evidence.

Her delusional beliefs made it difficult for her to accept help.

After months of insisting his neighbors were spies despite calm behavior otherwise, he was diagnosed with delusional disorder.

The clinician noted an alarming increase in the patient's delusionality after discontinuing the medication.

Researchers found that treatment approaches for delusional disorders often require long-term psychotherapy and medication.