Columbia University professor Carl Hart is an admitted heroin user—and he’s making no apologies about it.

The revered neuroscientist opened up about his recreational drug use in his new book Drug Use for Grown-ups: Chasing Liberty in the Land of Fear. The 54-year-old father of three detailed revealed he uses heroin on a regular basis, but insists he does not have a drug problem, as he’s able to fulfill his obligations and responsibilities as both an educator and family man.

“There aren’t many things in life that I enjoy more than a few lines by the fireplace at the end of the day,” he wrote, as reported by the New York Post. “… I pay my taxes, serve as a volunteer in my community on a regular basis and contribute to the global community as an informed and engaged citizen. I am better for my drug use.”

Hart says regular heroin use leaves him feeling “refreshed” and ready to take on another day; However, the professor admits to experiencing mild opioid withdrawal about “12 to 16 hours after the last dose.” Hart detailed one particularly rough episode in which he was overcome with flu-like symptoms, including chills, vomiting, diarrhea, and a runny nose.

“It was a pain that I would not easily forget. It was a new pain, unlike any I had previously experienced,” he wrote. “It was so intense that it radiated throughout my entire body.”

But despite the painful experience with heroin, Hart believes drugs can be a useful tool in helping adults maintain a solid “work-life balance”—that is, if they’re used responsibly. He expanded on this during a recent interview with GQ, explaining why not everyone is susceptible to substance addiction. 

“A large percentage of people who meet criteria for addiction have co-occurring psychiatric illnesses: depression, anxiety disorder, schizophrenia, a wide range of other psychiatric illnesses,” he said. “A large percentage of them also have other illnesses. They may be pain patients. So that increases the likelihood of them becoming addicted … Another reason is that some people just have not developed responsibility skills. They haven’t developed an ability to exercise inhibitory control. It’s just one of these things that develops over time.”

Hart also lays out his argument in support of drug policy reform, suggesting the war on drugs was never intended to protect citizens from potential health risks, but rather to boost the prison system. He recently told Insider that he hopes President Joe Biden will take steps to decriminalize drug possession and replace the punitive policies with education.

“You could have a massive public-service-announcement campaign that says ‘If you’re going to use opioids, don’t use alcohol as a background or other sedatives in combination, because it increases the likelihood of respiratory depression and death,’” he explained.