Mood swings? Check. Outbursts of anger? Check. Lack of judgment? Check.
The Huffington Post Media Group Editor-in-Chief said the Republican presidential candidate showed all the signs of suffering from the condition, as it's defined by the American Academy of Sleep Medicine.
Watch the clip here:
"He brags about it, like a lot of men. He wears sleep deprivation like a badge of honor," Arianna said on "Real Time with Bill Maher."
Trump's inability to process even simple information, his repetition of incomprehensible pablum and false memories were also all indicators, she added.
Maher agreed, saying Trump's regular early morning tweets were evidence of his bizarre sleeping patterns. "People say, remember that ad they had, 'What will the President do when the call comes in at 3 a.m.?' This one's in a Twitter war with Demi Lovato, that's what he's doing at 3 a.m. Screw the missiles."
But Arianna said that the businessman could inadvertently end up helping future generations enjoy a proper night's sleep.
"The point is it's going to be his lasting contribution to American cultural life that parents for generations to come will be telling their children who are not going to sleep, look, if you don't go to sleep then you are going to turn out like Donald Trump," she added.
Arianna, whose new book The Sleep Revolution hit the shelves earlier this month, also offered up some key tips on how to sleep well.
And during the "Overtime" segment alongside Hollywood star Susan Sarandon, she talked about the negative effects of sleeping pills -- which she described as a "major disaster" -- and The Huffington Post's partnership with Uber to combat drowsy driving.
Watch that clip below:
Editor's note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist