History Main / ThisIsYourBrainOnEvil

* In ''[[https://www.fanfiction.net/s/13299443/1/Departure-from-the-Diary Departure from the Diary]]'', dark magic is literally addicting, with [[GenderFlip Tamelyn Riddle]] declaring that said addiction is the only reason why anyone would use the Unforgiveables, stating that casting the killing curse "feels like a corpse passed through your soul" and is utterly revolting.

* ''VideoGame/MassEffect2'' has This Is Your ''Face'' On Evil; choosing a lot of renegade actions will cause Shepard's facial scars to become more visible and horrific-looking. A Shepard who does enough renegade actions will eventually have glowing red eyes.

* In Creator/HarryHarrison's first ''Literature/TheStainlessSteelRat'' book, the newly-minted special investigator Jim diGriz is faced with the question of locating beautiful psychopath Angelina. He is inspired to synthesise a cocktail of drugs that, to all intents and purposes, turn him into a conscienceless, unempathic, sociopath. In this frame of mind he despises the wimp he used to be, who drew the line at un-necessary violence and murder. The new diGriz delights in inflicting sadistic pain and relishes his chemically adjusted brain's capacity for evil. However, when in the process of tooling up with lethal wewapons, he remembers his previous self has booby-trapped the guns just in case. He activates a stun-gas grenade, waking up several hours later with the drug out of his system, having had an insight into an evil mind.

[[folder:Western Animation]]
* The page quote is from the ''WesternAnimation/DudleyDoRight'' segment of the ''[[WesternAnimation/RockyAndBullwinkle Rocky and Bullwinkle Show]]''.
[[/folder]]

*** And finally [[HornyDevils Slaanesh]], god of pleasure and excess; by the time [[{{Hermaphrodite}} he]] / [[AmbiguousGender she]] / [[NoBiologicalSex it]] is [[MindRape done with you]], your senses will be so dulled and jaded that you will need to '''censored''' at least three times over to even chuckle.

* The boy who would become Wrath in ''Anime/FullmetalAlchemist'' was a sweet, shy, and innocent young child who was suffering from a nasty case of amnesia when he was first introduced to the audience. [[AxCrazy Then Envy has him eat unfinished Philosopher's Stones...]]

* Kefka in ''VideoGame/FinalFantasyVI''. Kefka was once a perfectly normal Imperial General, until he got his magitek infusion. The process was still experimental and eventually drove him so far off [[MoralEventHorizon the deep end]] he became the ''first'' Final Fantasy antagonist to successfully ''[[ApocalypseWow unleash the apocalypse]]'' before he was killed.

* The BigBad in ''VideoGame/FinalFantasyXV'' suffers from this. [[spoiler:Ardyn Lucis Caelum was a wise and noble healer king of Lucis, who absorbed countless daemons into himself to protect his people.]] This had the [[SarcasmMode small side-effect]] of driving him insane. [[FromBadToWorse Not helping the matter whatsoever]], the very gods who gave him that power ''and'' the very people he healed betrayed and ostracized him, rather than help him. This resulted in him going ''completely'' off the deep-end, embracing both his own insanity and evil nature of the daemons, all so he can eventually exact the perfect revenge. Also, he's one of the few FF antagonists who successfully unleash the apocalypse. [[spoiler:The ''Ardyn'' DLC reveals that the Starscourge itself didn't turn him evil. If anything, the demons ''strengthened'' his sanity. Rather, the insanity came from devouring the minds of his ''human'' victims and that of a ''god''. Which makes sense since the Starscourge isn't actually a magical evil plague -- it's "just" a horrifically mutated virulent strain of malaria.]]

* The boy who would become Wrath in ''Anime/FullmetalAlchemist'' was a sweet, shy, and innocent young child who was suffering from a nasty case of amnesia when he was first introduced to the audience. [[AxCrazy Then he starts to eat unfinished Philosopher's Stones...]]

** In the ''VideoGame/KnightsOfTheOldRepublic'' series, being fully on the dark side causes GlowingEyesOfDoom, wrinkled skin, a change in underwear (to a black-and-red jumpsuit-like thing) and some [=NPCs=] comment briefly on your appearance. Although if you were on the dark side and they commented on your appearance, the rest of their lives were generally very brief. A computer in the first game reveals that using the Dark Side actually changes a person's neurological patterns, much like prolonged drug use.

Congratulations, This Is Your Brain On Evil. Since evil is often depicted as being a tantalizing and corrupting influence, it's just as often used as a euphemism for another, similarly tantalizing and corrupting, influence: [[PsychoSerum drugs.]] Just like drugs, the side effects are all there: addiction, withdrawal, [[NotHimself uncontrollable behavior]] and, eventually, health problems and death. Usually, when a character is thrust into this trope, they get into it only knowing or caring about the positive, "feel-good" parts of the power or evil they're taking and never seem to realize that they can't take the "good" parts out of the deal without acquiring the negative as well until it's almost too late. Once they reach that point, they're almost guaranteed to [[ColdTurkeysAreEverywhere try to "quit"]] their newfound lease on life to ensure that it doesn't [[SuperPowerMeltdown destroy them and those around them completely.]] Sometimes they succeed, sometimes they end up [[RedemptionEqualsDeath dying]] and regretting having ever started in the first place.

* In ''Film/Descendants3'', Princess Audrey steals the staff of Maleficent and becomes a villain, launching a reign of terror on Auradon as the self-proclaimed "queen of mean". During the final battle she is knocked unconscious, and when she wakes up, she is horrified by her actions, having been freed from the staff's corruption.

** The Turkish delight the White Witch gives Edmund in ''Literature/TheLionTheWitchAndTheWardrobe'' works a lot like a drug -- the post self-isolation, his siblings noting he doesn't look well, "the more he ate, the more he wanted to eat... and if allowed, would go on eating it till he killed himself." Edmund's (music-inspired-by soundtrack only) VillainSong from [[Film/TheChroniclesOfNarnia the 2005 film]] agrees with this interpretation, with such lyrics as "a life of treats might do me in/but I've got to get another taste" playing up the addiction/withdrawal parallels.

* In ''Literature/ParadiseLost'', although the ForbiddenFruit is not addictive, it does make you feel happy, invincible, horny, and leaves with you a WhatHaveIDone-hangover the next morning.

Then, you feel it: a straining in your head, a dagger-like pain in your chest, a feeling of queasiness or disorientation or some other physical malady. Or [[WithGreatPowerComesGreatInsanity you realize you've become incredibly cold and antagonistic toward your friends and loved ones]], followed by a feeling of being [[DrunkOnTheDarkSide out of control with your own actions]]. Something is wrong; you never expected ''this'' to happen, and if you don't find a way to stop it, it'll ruin your relationships, kill your career, or -- in the most extreme cases -- drive you into an early grave.

Congratulations, This Is Your Brain On Evil. Since evil is often depicted as being a tantalizing and corrupting influence, it's just as often used as an euphemism for another, similarly tantalizing and corrupting, influence: [[PsychoSerum drugs.]] Just like drugs, the side effects are all there: addiction, withdrawal, [[NotHimself uncontrollable behavior]] and, eventually, health problems and death. Usually, when a character is thrust into this trope, they get into it only knowing or caring about the positive, "feel-good" parts of the power or evil they're taking and never seem to realize that they can't take the "good" parts out of the deal without acquiring the negative as well until it's almost too late. Once they reach that point, they're almost guaranteed to [[ColdTurkeysAreEverywhere try to "quit"]] their newfound lease on life to ensure that it doesn't [[SuperPowerMeltdown destroy them and those around them completely.]] Sometimes they succeed, sometimes they end up [[RedemptionEqualsDeath dying]] and regretting having ever started in the first place.

When it's well executed, this trope can go a long way toward taking the [[DracoInLeatherPants romance]] out of evil and making it more frightening and personal. When it's done badly, it's a [[{{Anvilicious}} heavy-handed]] [[AnAesop Aesop]] on the dangers of giving in to temptation and getting involved in something you really shouldn't have.

The trope's name comes from a series of anti-drug {{public service announcement}}s in the 1990s, using an egg pre- and post-cooking to demonstrate a person's brain pre- and post-drug burnout.

* Apparently not even demons are immune to this, cf. Creator/ChristopherMarlowe's version of Mephisto (in ''Theatre/{{Faust}}''):

* PleasureIsland in the Franchise/DisneyAnimatedCanon version of ''WesternAnimation/{{Pinocchio}}'', where bad boys are invited to do what bad boys love to do... [[CrapsaccharineWorld until they learn too late it's a trap]], and the island is [[TransformationHorror magically imbued to turn them all into donkeys]] after a while; after they have thus literally made jackasses of themselves, they are sold into slavery. Fortunately for the title puppet, he and Jiminy Cricket manage to escape before the transformation fully sets in. The same cannot be said for anyone else, and Pinocchio was likely the only boy to have ever escaped the Coachman's machinations.

* ''Series/AgentsOfShield'': After leaving the Framework, Leo Fitz developed a split personality in the form of the Doctor, who would speak in Fitz's head and occasionally take over completely. This is not a good thing.

* ''Literature/TheHeroesOfOlympus'': Percy Jackson came rather close to turning to "TheDarkSide" when he attempts to kill the protogenoi Akhlys with her own poison. This act is so horrifying and cruel that it scares Annabeth, who begs him never to do something like that again. Fortunately, Percy is horrified by his actions and relents, but considering that Akhlys was frightened of what Percy almost did, its highly possible Percy could have actually killed the goddess.

* PleasureIsland in the Franchise/DisneyAnimatedCanon version of ''WesternAnimation/{{Pinocchio}}'', where bad boys are invited to do what bad boys love to do... [[CrapsaccharineWorld until they learn too late it's a trap]], and the island is [[TransformationHorror magically imbued to turn them all into donkeys]] after a while; after they have thus literally made jackasses of themselves, they are sold into slavery. Fortunately for the title puppet, he and a few other boys manage to escape before the transformation fully sets in.

* ''Literature/TheHeroesOfOlympus: Percy Jackson came rather close to turning to "TheDarkSide" when he attempts to kill the protogenoi Akhlys with her own poison. This act is so horrifying and cruel that it scares Annabeth, who begs him never to do something like that again. Fortunately, Percy is horrified by his actions and relents, but considering that Akhlys was frightened of what Percy almost did, its highly possible Percy could have actually killed the goddess.

* The Haunted Mask of the ''Literature/Goosebumps'' books invokes this, as it slowly corrupts whoever wears it. Carly-Beth Caldwell almost lost her humanity when she attempted to use this mask in a revenge plot. The only thing that can remove the mask is a symbol of love, which turns out to be the only thing that saves Carly-Beth.

* Not an example, exactly, but used in [[http://www.sinfest.net/view.php?date=2003-07-13 this]] ''Webcomic/{{Sinfest}}''.

* ''Anime/GaReiZero'': Alas, poor Yomi (;_;) She would rather not hurt her little sister (girlfriend?) Kagura, but the evil stone in her head says otherwise. [[AndIMustScream And she realize what is happening to her.]] And it's far too late for her to turn back.

* ''Comicbook/ArchieComicsSonicTheHedgehog'' delved a little into this with the Chaos Emeralds. Knuckles' ancestor Dimitri, who would later become the power-mad Enerjak, got hit with the "withdrawal" symptoms of this trope once his Enerjak powers were removed; rendered unchanged by his powers for centuries, their sudden absence quickly reduced him to a frail old man on the verge of death, forced to live on cybernetic means for the rest of his life (and in one possible future, being reduced to a head in a jar).

* In ''VideoGame/MassEffect2'', choosing a lot of renegade actions will cause Shepard's facial scars to become more visible and horrific-looking. A Shepard who does enough renegade actions will eventually have glowing red eyes.

* ''TabletopGames/PrincessTheHopeful:'' Among other effects, becoming Darkened inverts the effects of Virtue and Vice (making Virtues less emotionally fulfilling and Vices more), and gives a -2 penalty to future Breaking Point rolls. Also, several Umbrae have unpleasant mental side effects, such as the perpetual stress and inability to relax that comes with the Cruel Confidence Umbrum, or the paranoia of the Skittering Spider's Sense Umbrum.