Donald Trump has shared the very personal reason he doesn't drink alcohol.

Donald Trump has shared the very personal reason why he doesn’t drink alcohol during an emotional speech about the opioid crisis in the United States.

Speaking to a room of former addicts, treatment specialists, and parents of overdose victims, Trump told the story of his brother Fred, who died in 1981 when he was just 43 years old.

“I had a brother, Fred,” he said “Great guy, best-looking guy. Best personality, much better than mine.

“But he had a problem, a problem with alcohol. And he would tell me, don’t drink.

“He was substantially older and I listened to him and I respected. He’s also added, don’t smoke.

Today is National Prescription Drug Take Back Day. Everyone can help fight the #OpioidEpidemic by participating! https://t.co/ONObTWOaOn pic.twitter.com/CYG11DnxH7

— Donald J. Trump (@realDonaldTrump) October 28, 2017

“But he would say it over and over again. And to this day I’ve never had a drink. And, I have no longing for it. I have no interest in it.

“To this day I’ve never had a cigarette. Don’t worry those are only two of my good things — I don’t want to tell you about the bad things. There’s plenty of bad things too.”

Trump believes his brother’s short life could serve as a lesson to young people before they even start taking drugs.

“This was an idea I had — if we can teach young people not to take drugs, not to start, then it’s really easy not to take them. I think that’s going to be our most important thing.

“When I see my friend having difficulty with not having that drink at dinner — where it’s literally impossible for them to stop.

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“I say to myself, I can’t even understand it — why would that be difficult? But we understand why it is difficult.”

While Donald quickly made his mark on the business world, Fred was a disappointment to the Trump family.

Annamaria Schifano, girlfriend of Freddy’s best friend, told The New York Times he was a “fun-loving airline pilot” who lacked the “killer instinct” and drifted so far from his father’s ambitions, his children were mostly cut out of Trump senior’s will.

During his presidency Trump has repeatedly pledged to declare a “national emergency” to fight the abuse of opioids including heroin, fentanyl, Percocet and OxyContin.

More than half a million people died from drug overdoses in the US between 2000 and 2015 and every single day 91 Americans die from an opioid overdose.