The grown son of an Ohio billionaire is a hooker-loving drug addict who threatened to destroy the renowned Manhattan psychiatrist his parents enlisted to help him, according to bombshell court papers.

Dr. Paul Conti, a Stanford-educated psychiatrist from Oregon, alleges in a federal suit that the son also gambled away millions of dollars during trips to Las Vegas while running up credit bills and borrowing money from mobsters.

The son’s name is hidden as “John Doe” in court documents related to the case — and his billionaire father is also not identified.

But at a closed-court hearing on Monday, Jay Schottenstein — the Columbus-based retail magnate and chairman of DSW and American Eagle Outfitters — was spotted by The Post entering the courtroom.

“Doe is every parent’s worst nightmare,” reads the Manhattan federal lawsuit filed by Conti against the 34-year-old John Doe.

“Clinically, he suffers from Narcissistic Personality Disorder, including Borderline and Antisocial traits. His condition manifests itself in a variety of ways, including an addiction to Xanax, frequent cocaine use (often with prostitutes), thefts of money from his parents, multi-million-dollar gambling losses, as well as violent, abusive and threatening behavior.”

Conti said the family brought their son in to see him in 2016, as he was spiraling out of control and becoming increasingly erratic and destructive.

When Conti tried to put an end to Doe’s hedonistic lifestyle, he began a “campaign of intimidation” against the doctor, according to the lawsuit.

“Indeed, in seeking to ruin Dr. Conti’s reputation and livelihood, Doe has copied Dr. Conti’s colleagues on his lurid publications, as well as renowned attorney, Alan Dershowitz, and two different medical professionals affiliated with Harvard University.”

In threatening text messages included in the suit, the son repeatedly called Conti homophobic slurs.

“If you were a real man the way you spoke about me you would come and say it to my f—king face you f—king fa—t-a— c—t,” one of the messages read.

Conti claims in the suit that the threats and other abuse by the billionaire’s son has caused him severe emotional distress and is seeking at least $75,000 in damages.

Conti did not immediately return request for comment. Neither did lawyers for Schottenstein and his son.

Additional reporting by Ben Feuerherd