The Mamma Mia! star, 27, recently revealed to America's InStyle magazine that she suffers frequent panic attacks before promotional appearances and Tv chats and likes to down a shot of liquor ahead of time to calm her nerves - and that's just what she did before sitting down for an appearance on The Late Show with David Letterman.
But an inebriated Seyfried confessed she didn't stop at one.
She told the talk show host, "I'm pretty drunk. To be honest with you, Dave, I've had about three (shots). You know, big fan of whiskey... I had some (rare) Midleton. Russell Crowe gave me some Midleton for my birthday... And then your lovely colleagues had some Jameson waiting (backstage) for me."
She added, "I have to go on record saying I've never done a live television show... without some kind of liquid courage.
"I understand that I have a problem maybe, but you know what, it really gets me through, and I really wanna enjoy my experience out here."
Letterman finished the interview by helping Seyfried indulge, toasting the end of the chat with a glass of Jameson.