During his speech on the opioid epidemic, President Trump told a personal story about his late brother, underlining why he takes the topic of addiction so seriously.
Trump said his oldest brother, Fred Trump Jr., died of complications of an alcohol addiction.
"He would tell me, 'don't drink'. He would say it over and over again," Trump said.
He said he looked up to Fred Jr. and that his death had such a profound effect on him that he has never had a drink.
"I have no longing for it. I have no interest in it," he said of alcohol.
Fred Trump Jr. died at age 43 in 1981.
He had been a pilot and father of two.
However, his predilection for alcohol affected his work and personal life, and after several years moved back to Jamaica Estates, N.Y. to live with his parents, according to the New York Times.
Kimberly Guilfoyle said Fred Jr.'s story was "such a formative experience for [Donald]" and shaped his views on addiction.
Fred Jr. was eight years older than the president, and one year younger than the eldest of the five siblings, Philadelphia Judge Maryanne Trump Barry.