Typically, I find that slapping a character with a diagnosis is as difficult, if not more so than being diagnosed irl because I am not a mental health professional and don't want to portray an illness that I claim Valindra has incorrectly. For this reason, I tend to avoid stating that my character has a particular mental illness, but is definitely struggling with her overall mental health, and has been for years.
Typically, if people ask, I tend to state what she is going through rather vaguely, while offering a more indepth look into her own mind if people wish to know more which normally goes a little like this:
"Valindra struggles with a number of aspects related to her mind, all of which have been caused by past experiences in RP. She's prone to bouts of great sorrow and fear, though seems to mostly do well under the stress of her work, if not thrive, save for a few circumstances. She also has been trying to come to terms with her identity in the world while suppressing most positive signs of emotion, instead favoring a stoic and potentially intimidating approach."
If people ask me to elaborate, I attempt to offer a more indepth analysis of the workings of her mind depending on what they ask about while also maintaining secrecy for certain areas to protect RP arcs that may occur with her. Here is an analysis of one aspect of one of her struggles that has become less pronounced in recent times, hence why I am willing to share it:
"Valindra has never enjoyed the idea of simply being one person. Prior to the loregames, she used to change identities much like how we change clothes, and while she tried to incorporate aspects of such in each disguise, she soon became very out of touch with her true self, evasive of the fact that at the end of the day, she would always be just one person at heart and that no amount of pretending would erase past trauma. When the loregames occurred and her means of disguising herself were lost, Valindra entered a panic as she was no stuck in only one body. She wanted to blend in everywhere and escape from her own personal troubles. As the panic subsided, she her mood took a nosedive and she was left feeling helpless. While she is overcoming it, she still clings to the fact that one day she may be able to become 'another person' in her eyes through the same of a different means. Most recently, she's been delving into alchemy, and has plans to experiment in the hopes of crafting a potion that can alter her in some (Non powergamey and lore friendly) way."
Whenever any of my characters encounter mental hardships, I always take a moment to think about the fundementals of the character I am playing.
Will it drive a good RP narrative?
Is there an obvious cause of her mental hardship?
How will I ensure it does so?
Are there any 'tells' my character would have such as changes in behaviour, sleep pattern changes or even physical differences or issues as a result?
Would my character come to terms with the fact that something is wrong quickly, and if/when they do, how will they react initially?
How will the character attempt to cope?
Is their means of coping healthy or unhealthy?
How will this affect my character in the long run? Will there be any longterm or permanent 'emotional residue'.
Will my character need help from another character? If so, will she reach out consciously or will it be a subconscious cry for help?
How will my character attempt to finally overcome this mental obstacle?
And finally, does it make RP entertaining for myself and those around me?
Recently, my character has stumbled upon a hell of a lot of mental trauma from many different sources and the RP with particular characters to help her overcome this has been amazing (You know who you are :>). The past few months of RP have probably been the best I've had.
Mental illness, when played can not only add realism to Roleplay, but also serves as a reminder that it can occur in anyone in any way, and touches everyone at some point in their lives. This ties in with irl too. Mental illness can be totally invisible to the naked eye, an invisible illness that affects those we may not even think to struggle with such. I am often surrounded by mental illness irl and icly and I know that sometimes I won't even spot it. Realistic RP arcs and IRL experiences have made me respect those who have been touched by mental illness even more. It is a horrid thing that is a constant battle against one's own brain. Those who suffer from it are strong, and I look up to those who have managed to survive and overcome such, especially when I look back on how many we lose to these illnesses every year.
Typically my biggest pet peeve with mental illness RP is people attempting to romanticise it along with slapping a diagnosis on a character and not knowing anything about the illness itself. Depression is not solely showcased through crying, self harm and attempts on one's life and not all mental health illnesses are ECT and straightjacket material. (This is not Arkham Asylum, mental illness can be extremely subtle. Some can experience it without even knowing that what they are experiencing is a genuine mental illness)
I've gone on a bit of a rant, I know and this is my personal stance on mental illness roleplay. I respect different approaches to it as long as mental illness is not portrayed in an inaccurate light. (Which I find to be difficult due to just how much mental issues and symptoms can vary. Every mind is different, and there are some issues that don't even have a name yet.)
Anyway, I shall leave this post here and finish with some facts on mental health in the real world:
It is largely speculated by multiple organisations that 1 in 4 (According to NHS England) to 1 in 5 (According to multiple US based organisations) people are affected by mental health or suffer from mental health issues. This encompasses all mental health issues, including ones not inherently considered as an SMI (Severe mental illness).
According to NIH's National Institute of Mental Health, 51.5 million US adults lived with a mental illness in 2019 which comes in at just short of 1 in 5. Again, this refers to all mental illnesses that are officially recognised as such.
Again, citing NIH's National Institute of Mental Health's records, 13.1 million (or 5.2% / around 1 in 20) live with a severe mental illness. Quoting, NIHM's website again, SMI refers to those living with mental illness who experience "serious functional impairment, which substantially interferes with or limits one or more major life activities." For example, schizophrenia is classified as a severe mental illness.
Tiny little edited-in footnote here: I wrote this while half asleep as I have a tendency to ramble about serious topics when I'm sleepy. I'm sorry if this doesn't make sense or if I offend anyone. Have mercy.