If let's say one wants to portray a villain in a novel that suffers from insanity/psychosis as he has literally lost his grip on reality and is kind of living in his own world, what are the things a writer should avoid when he writes such a character?
I would avoid the following:
- Stereotypes: it is very easy to describe cliches (screaming, sadistic violence, rage outbursts, contradictory or erratic behaviour, etc.) but they lead to a flat and not interesting character.
- Irrationality: don't let your character do random stuff just because it "sounds crazy". A mentally insane person always follows its own rationality, even though it differs from the more common one.
The main thing I see, in such a novel, is avoiding having this insanity be the equivalent of a deus ex machina that ultimately defeats him. I think the hero must defeat him in a way that would work even if he were not insane.
It would be an unsatisfying ending if after a long campaign in which Dr. Nutjob came close to defeating the hero several times, but finally gets distracted by something shiny so the hero can put a bullet in his head.
If your villain is insane but a daunting adversary throughout the story, he must be insane and a daunting adversary to the very end: His insanity can make him terrifying and unpredictable and thoroughly hated, but it cannot be the source of his defeat.
Do your research before you begin, look for disorders and conditions that match the symptoms you want your character to portray and then add some of the other symptoms commonly associated with that disorder. This will help you to build a profile of your character as well as knowing what triggers their symptoms to manifest. Presumably you already have their motives so use this profile to determine possible actions that would make sense from their point of view. For example, if they suffer from schizophrenia they may have auditory hallucinations. Use that. Delusions of grandeur? They may struggle with people in positions of authority such as the police ordering them to put the gun down. You mention psychosis which is a very broad term and will give you a lot of options but may make it difficult to create your profile.
Since you want your villain to be in their own world you need a diagnosis that makes sense (insanity is no longer a recognized condition). Psychosis fits well but again, schizophrenia (a subset of psychosis) is a good match here. It can be brought on by extreme mental stress so it can be the result of trauma which gives you an opportunity to build their back story. Make the audience sympathise, after all they are victims, they are suffering and need help.
Once you can explain their motivations, your character must still be able to execute their actions. Are they constantly tormented by voices? Then how do they sleep? They're going to be exhausted. How do they eat? Perhaps they have to steal to eat in which case they will likely be gaunt and weak. This is someone to pity, not hate.
Perhaps you are thinking more along the lines of someone who is high functioning, they can't tell the difference between their reality and ours but they have learned to walk the line between them. This is going to make them less sympathetic to the audience (think The Joker from Batman), but what happens when they lose that tenuous grip? How do they regain their control? Confrontation from your hero could trigger their more extreme symptoms and leave them vulnerable so they may need a way to avoid this outcome. Perhaps trapping your hero helps them to remain in control.
OK, this was long and a bit rambling but here's a summary:
- Avoid picking random symptoms, do your research and find the conditions that best match your vision
- Actions should match motives
- Develop a backstory for the audience to better understand your character, you can just provides hints if you don't want a full story
- Ensure your character is able to execute their plans, if they struggle to get through the day they probably won't be able to function without help
- Know your triggers, don't put your character in a situation that is likely to trigger their symptoms or if you do, ensure the outcome is realistic
Hope this helps
Leave room for sympathy
I really enjoyed the DC Comics film Joker (2019) with Joaquin Phoenix. In this story, the Joker is portrayed sympathetically to the audience and we get to understand what he is going through. He is dealing with mental illness itself as well as poverty. He wants to get better treatment, find medications that work, etc., but he experiences systematic social barriers that slowly turn him against society and the establishment.
The Joker in this film is not just an insane clown. He is an insane clown, but that's not who he really is underneath. He's an aging, has-been children's entertainer looking to make a big break in stand-up comedy but not able to. He knows he has a mental illness and wants treatment but can't get it. He's attacked by muggers on the train. He seeks love but can't find it. He's so frustrated with life and afraid of being victimized again that we can understand why he starts carrying a gun, and when he starts using this gun we can understand how lost he feels. This doesn't fully excuse his behavior but it puts it into a context we can understand.
If you want to look further into Batman lore, you will find it replete with "insane" villains with stories. The Riddler of the 2022 "The Batman" film is a broken social justice activist who truly thinks he is Batman's kindred spirit. Various incarnations of Harley Quinn portray her as experiencing some combination of a sex addiction, Stockholm syndrome, and PTSD brought on or exacerbated by her experience as a therapist trying to treat insane villains and eventually being seduced and physically and sexually abused by one. The one exception is Penguin. He is very, very sane. Combined with being intelligent and calculating, he's a risk of a completely different nature to Batman. He knows he is a gangster, this is what he wants to be, and he is in full control.
The television show Law & Order: Special Victims Unit is also quite good occasionally at presenting sympathetic offenders with problems. There's the young man who has been taught by an incompetent therapist that he has no hope of ever being anything in his life except a rapist, so guess what he goes and does? There's the football player with a concussion-induced dementia who has to explain to his wife that he picked up an underage prostitute. There's the seemingly innocent middle-aged businessmen being inexplicably targeted by a serial predator until it comes to light that the men had gang-raped her half a lifetime ago at youth summer camp. Which of them (the woman or the men) qualify as the true villains of the episode? It's messy, just like real life. There are a few characters who snap and torture the person that they think sexually abused their child, only to find out that their victim was innocent and they are now the defendant on trial for the rest of the episode. Some people do the right thing for the wrong reason. Some people do the wrong thing for the right reason. Good people snap and hurt others. Sometimes those others deserve it, sometimes they don't. It's life, not a morality play.
So, give your readers reason to see your antagonist as a person with a story who is an insane villain, not just a stock "I need an insane villain" character.
In a nutshell, it isn't so much what to avoid but what to avoid not including. Tell us about your insane villain. Where are they from? What have they accomplished in life other than insane villain stuff? Any hopes and dreams? Have they been insane all of their life? If they experienced insanity later on in life how old were they when it started? Mid-teens? Early 20's? Old age? Was their insanity exacerbated by abuse, war, or other trauma? What has insanity done to their life? Did they lose a career? Were they expelled from an elite university a month before graduation? Did they lose family? Were they put in a hospital or prison? Did they ever seek treatment? Is the insanity treatable? If there is a working treatment, why aren't they taking it? Does it have unbearable side effects? Can they not afford it? Do they not know about it?
Good insane villain:
My villain was a somewhat plain-looking but highly intelligent young woman studying at an elite East Coast university on a classical music scholarship. She began to experience the symptoms of schizophrenia in the fall of her senior year. Her symptoms were exacerbated by stress brought on by preparations for final exams, drug abuse exacerbated by stress, and finally being dumped by her boyfriend two weeks before Christmas. She experienced a psychotic break over the winter holiday and believed that her final exam was to kill the dean. She was placed in a psychiatric hospital downtown where she experienced sexual abuse from a therapist which resulted in her refusing treatment and trying to find her way alone. She was expelled from college and now works part-time at a diner during periods when her mental illness is at its lowest. It is suspected that when her illness flares up, she attacks people who look like the therapist who abused her with a knife to the gut. Lately, she's developed a delusion that the mayor is actually a supervillain and that she will receive a Nobel Peace Prize if she kills her....
Bad insane villain:
My villain is some crazy, violent chick in her mid-20's. Everyone she's ever dated has left her because she's butt-ugly and has schizophrenia. She like, has some sort of music thing? And she loves knives. Lots and lots of knives. She's so insane she wants to kill the mayor.
Start by defining the insanity. Mental illness is a very very broad field: you need to narrow down what you mean by "insanity/psychosis"; give your character a defined condition, and write him with the correct characteristics and actions for that condition. You don't have to name the condition, or refer to it at all outside of your personal notes; just understand that insanity is not a case of just behaving randomly; there is always an underlying reason for any symptoms.
Pick any insane or troubled character you can think of from literature -- Don Quixote, Hamlet, Moriarty, Scrooge, Eeyore, or many many others -- for all of the good ones, it is possible to read the stories and come to a definitive diagnosis of the character's mental illness.
You need to write your character like that. If you don't, people simply won't connect with the character and will find them unbelievable.
Make the insanity questionable. Think of Macbeth, he falls into madness as the play goes on but he might not be diagnosable. "Insanity" can be brought upon by something other than a mental illness.
The villain can be tormented by his past and hell-bent on some other goal which he's just using to try and deal with the old trauma.
The villain can become a nihilist and expressing how nothing matters good or bad everything is relative and it doesn't matter if he kills a woman or loves her. (Ex. Hamlet: "Nothing is good or bad but thinking makes it so.")
The villain could be a fanatic of some sort of ideology or ideals, even if the ideology is well intentioned, the villain followed it to its natural conclusion and brought great suffering. (Ex. Government/Socialism/Communism)
Try to make the villain's insanity somewhat logical so the audience can understand them and see the villain in themselves.