The Philadelphia Court of Common Pleas jury's verdict in favour of Nicholas Murray came in the first case in which a Pennsylvania jury had been able to consider awarding punitive damages in one of thousands of Risperdal cases pending in the state.
"This jury, as have other juries in other litigations, once again imposed punitive damages on a corporation that valued profits over safety and profits over patients", Murray's lawyers, Tom Kline and Jason Itkin, said in a joint statement. "Johnson & Johnson and Janssen chose billions over children".
Risperdal, approved for the treatment of adults by the US Food and Drug Administration in 1993, brought in some $737 million (672 million euros) in sales in 2018.
A jury in Philadelphia, according to legal web site Law360, hit the drug giant with the staggering payout "after agreeing the company had recklessly ignored the risks that the antipsychotic drug Risperdal could lead to breast growth in adolescent boys as it pushed the medication for use in children".
Last year, a St. Louis found J&J should pay $4.69 billion in damages to 22 women and their families who blamed ovarian-cancer cases on use of the company's baby powder.
"We will be immediately moving to set aside this excessive and unfounded verdict".
According to the lawsuit, Murray was prescribed Risperdal "off-label" - which means when a drug is prescribed for a condition other than that which it is officially made for - after being diagnosed with autism spectrum disorder in 2003.
Johnson & Johnson said the court's exclusion of key evidence left it unable to present a meaningful defense, including what they said was a drug label that "clearly and appropriately outlined the risks associated with the medicine" or Risperdal's benefits for patients with serious mental illness. His mother took him off the drug in 2008.
Carl Tobias, a law professor at the University of Richmond, told Reuters that the unusually high amount of punitive damages was more about sending a message to the pharmaceutical company and would likely be lowered on appeal.
The ruling marks another costly setback for Johnson & Johnson.