The emergency department calls a psychiatrist to evaluate a 35- year- old homeless, English- speaking man, identifying him as Native American. The police brought in the man after bizarre posturing in a park while talking to himself. The man describes having special relationships with animals. He believes that he can communicate with them through telepathy. He reports that this communication with nature is a common belief in his culture and that he has this special "gift". He says that he receives "special signals" from birds that influence his behavior and he can "hear them talk to him". Under further exploration, he reports that he has mental powers that influence animals and nature. He insists that he is "not crazy". His hygiene is poor and he is malodorous. He has very odd habits around eating based on his auditory hallucinations, resulting in poor nutrition and weight loss. He looks emaciated. He does not have a reasonable plan for shelter and sleeps in a field. His clothes are smiled. He has odd mannerisms throughout the interview, including laughing inappropriately. His urine drug toxicology is negative for substances of abuse. He has a hx of multiple hospitalizations and involuntary commitments for grave disability starting around age 22 years. What is the likely diagnosis?

A. Alcohol use disorder.
B. Culturally appropriate behavior.
C. Major depressive disorder.
D. Schizoprehinia.