I kinda disagree with this but I’m compelled to put it out there for your consideration.
Lestat has a huge issue with controlling his laughter but I don’t think he’s depressed or emotionally drained. I think he loves himself too much for that.
I think sometimes it’s more of a nervous tic, a sort of backup reaction to quell confusion, and maybe also as a means of diffusing his own anger. How many lives have been saved by him laughing at them instead of using the Explodey-Heart Gift?
“And my worst problem was laughter. I would go into fits of laughter and I couldn’t stop. Anything could set me off. The sheer madness of my own position might set me off. This can still happen to me fairly easily. … I begin to laugh and I can’t stop…It makes other vampires furious, by the way.” – The Vampire Lestat
“How to describe what humans look like to us! … you can’t imagine what it’s like for us to look on living flesh. There are those billions of colors and tiny configurations of movement, yes, that make up a living creature on whom we concentrate.
But the radiance mingles totally with the carnal scent. Beautiful, that’s what any human being is to us, if we stop to consider it, even the old and the diseased, the downtrodden that one doesn’t really "see” in the street. They are all like that, like flowers ever in the process of opening, butterflies ever unfolding out of the cocoon.“
– The Vampire Lestat
I love this quote bc it means that just being alive makes us ALL beautiful.