- In Awful Hospital, The Parliament is slowly driving the doctors mad with a Perception Filter to ensure they are unable to fight back against or even notice the disease the Parliament is using to assimilate the current reality back into the original being.
- Jack from Gunnerkrigg Court (pictured on the main page). He started off as a pretty normal guy, then he briefly got pulled into a Dark World and saw some very unpleasant things. Since then he became increasingly antisocial, paranoid (at one point he starves himself because he's convinced the Court has laced his food with nanobots to track him) and amoral (compare his treatment of the Laser Cows to his treatment of the Guard Robot). Heck, even his appearance became worse over time◊. Fortunately, after Zimmy removed the whitelegs from his head, he's gotten almost back to normal. Oh, and he was right about the food.
- Vaarsuvius spent most of "Don't Split The Party" undergoing this in The Order of the Stick. They ultimately recovered but not before committing an act which may have completely crossed the Moral Event Horizon.
- Jin of Wapsi Square suffers from a bad case of this after destroying the calendar machine. It was actually built at least partially for the purpose of keeping her sane.
There. Good as new, best friend! It's like it never happened. No one can ever blame you for dropping him down the stairs now. Stairs? What stairs! Ha ha ha!
- Karkat starts getting shades of this after a particularly brutal Trauma Conga Line. Two of his friends were murdered in front of his eyes, two others are on killing sprees, he's dragging his newly-blinded friend's body (and accidentally drops him down some stairs, and he gets a message from his girlfriend, pronouncing the details of another murder - and when he tries to contact her, one of the Ax-Crazy trolls responds, hinting that she's been killed.
- Rose starts showing signs of it too, around the time her mother died.
- Garfield Minus Garfield: With no cat to give him sarcastic remarks, Jon Arbuckle slowly descends into madness. Examples include smushing ice cream cones into his face, dressing up for a date... that's in three weeks, jumping in the streets wearing a party hat, chasing cars in the manner of dogs, breaking down sobbing at the most random times, Madness Speak, and, finally, being sent to a Mental Hospital.
- Bittersweet Candy Bowl has Lucy having a mental breakdown when Michael falls off a rock bridge while saving her.
- In Pacificators, one of the best Pacificators they had, Castella Brandsford, snapped and murdered thousands of people before she was killed by a suicidal guy. Ever since, the regular people have hated the people who has powers, because they fear another Castella Brandsford.
- Happens to Benjamin Prester in A Miracle of Science when he believes that his partner Caprice has been killed. He becomes increasingly violent, and he starts acting more like he did in flashbacks - when he had full-fledged Science-Related Memetic Disorder. The two biggest clues are he redoes his hair in a particular style when in Mad Scientist mode, and he introduces himself as Benjamin when fully sane but as Ben when in the throes of SRMD.
- In Distortion Nuzlocke, Johnny goes through this more and more as the story goes on. He was already pretty messed up, but his fantasies cause him even more pain.
- Tekno slips in Sonic the Comic Online! after her and Shortfuse become trapped in a dimension without modern technology. Tekno being a Teen Genius takes this very poorly and becomes more disheveled by the day. It comes to the point where she's writing manically on the walls and she attempts to murder a villain by beating him to death.
- In Girl Genius, Gil's father overlaying his own personality over a portion of Gil's mind and his inheriting the responsibility of ruling his father's quickly crumbling empire, combined with losing nearly every single friend and family member he had all at once, has not been kind to him and he's implied to have been in The Madness Place for two and a half years. All of Europe can tell there's something off with him.
- Bryce of We Are The Wyrecats is falling victim to this due to a tumor in his brain.
- "My Life with Asperger's" directly references this trope name when going onto the topic of having a meltdown.
- Rocky in Lackadaisy was never exactly stable, what with his habit of turning into an Ax-Crazy Pyro Maniac when under severe stress, but suffering a severe head injury from a car definitely didn't help matters.
Sanity Slippage / Webcomics