It's not just Mrs. Puff; a lot of people suffer from prolonged exposure to SpongeBob. The episode "Dunces and Dragons" sees SpongeBob and Patrick visit a Medieval Times-esque restaurant. When the greeter isn't sufficiently old-timey in his manner of speech, SpongeBob corrects him, saying "Excuse me, my good man, I believe thou meant to say, 'Righteth this wayeth.'" The greeter's reaction is a tad ... extra. He almost stabs himself in the face with his poleaxe, before sighing and saying "Someday, but not today."
"Someday, but not today." became a popular "SpongeBob" meme, despite its questionable subject matter. And it's not even the most important character to express suicidal ideation on the show. In the controversial Season 7 episode "One Coarse Meal," Mr. Krabs tortured Plankton over his generational trauma. Plankton's family was eaten by whales, and Mr. Krabs exploits his phobia by subjecting Plankton to whale after whale after whale. Things come to a head when Plankton lies in the middle of the road waiting for oncoming traffic to do what the whales couldn't: end his bloodline.
If you or anyone you know is having suicidal thoughts, please call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).