Mental illness is always a tricky topic to discuss, especially in the politically correct society of the present. I can tell you though, I work in a psychiatric hospital, and the patients there are often more than happy to discuss their illnesses, whether you would like them to or not. This is how I came to meet Jim Bob, the recovering-alcoholic duckling who likes nothing more than to chill out with his issue of Cosmo. It is all part of their character, and as we readers and writers of fiction know, character is a huge part of the story world.
The most famous mentally ill character in fiction is of course Gollum/Sméagol. According to a study at University College London (http://www.ucl.ac.uk/media/library/gollum) he suffers from schizoid personality disorder; he has two distinct personalities, but unlike someone who suffers from dissociative identity disorder each of his personalities is aware of the other, as witnessed in the scene where he argues with himself. (Logen Ninefingers could be said to suffer from this, although again he is aware of his other personality, even if he doesn’t recall his actions in this state.)
Gollum’s illness very definitely affects his behaviour and actions throughout the novels. Depending on which personality is dominant at a given time, he is either trying to help Sam and Frodo to achieve their goal, or he is spending his time plotting to steal back the ring. Years of self-imposed isolation suffering from this illness did nothing to help the emotional detachment sufferers have to deal with, and have also completely skewed Gollum’s view of the world, which ultimately leads him to betray his companions.
Another example of mental illness in fantasy that some readers may be aware of is in Brian Jacques’ Mariel of Redwall. The protagonist Mariel suffers from amnesia after being thrown into the sea, and spends much of the book rediscovering who she is, before going on to win the day. Her nemesis, Gabool the Wild, begins to hear voices and suffer hallucinations after he has stolen the bell intended for the Badger Lord Rawnblade Widestripe. Although it is never confirmed what is causing Gabool’s illness, it leads to his demise, when he falls into the pit he keeps his pet scorpion in.
Mental illness can be used to add layers of depth to a character, but they do not need to be as extreme as the examples stated above. Many sufferers of mental illness are able to function normally in society, if with slight variations to normal routine, but these illnesses can affect their actions. Addicts, for example, may be able to function normally, but only if they get their fix. Deprive an alcoholic from their drink, and they’re in trouble; they will do anything they can to get a fix, no matter how dangerous to themselves or others. They become a liability.
Attitude towards mental illness can also be used to create a new layer of tension within a work; prejudices of all kinds pepper our society, for better or worse, and it’s often against things people do not understand. Couple that with an illness the sufferer is unable to articulate accurately, and bingo, tension is immediately ramped up.
Relationships between characters, especially in fantasy, are often fraught with difficulty as they stand, but add in an illness to that mix, and trouble could be brewing. Travelling with someone who has OCD, for instance, could make the journey a nightmare. Trying to find places they’re willing to stay, things they are willing to eat, time to accommodate their routine, makes what is most likely already an important and dangerous trip doubly so.
So, how to write a character with a mental illness? Firstly, do your research. Two people suffering from the same illness can have different symptoms and act in very different ways, so make sure you know which combination you want for your work. Medical journals are easy to come by online, and aren’t all written in a language only psychologists can understand. They’re also often very interesting to read.
Secondly, try the characteristics of the illness out. Will it work on the character you’re giving it to? Is it feasible for a character with that illness to exist in your plot? Having someone else read your writing at this point is a very good plan, especially if they have not read about the illness. They’ll be able to tell you if the character is working, if there’s anything they think is off about the illness in the setting, and most importantly, if they could live with that character for the length of the work.
There are of course pitfalls to avoid with this sort of thing; there are stereotypical views of illnesses that, whilst often being based on general understanding of said illness, often miss the nuances and subtleties therein. You know the usual culprits; the schizophrenic who screams at the sky, the depressive with the self-harm marks, OCD sufferers cleaning themselves every time they touch something. Yes, these are all symptoms of these illnesses, but they’re not the only symptoms, and there’s nothing worse to read than a character that is a complete stereotype.
As with all aspects of character, caution is recommended, but if you do your research correctly, and write carefully, there is no reason why you can’t use mental illness to create interesting, sympathetic characters that will liven up your fantasy world.
Title image by gaelicwolf.

