I started practicing Stoicism a few months ago to help with my bipolar disorder. During this time, I've read Meditations, all of Seneca's essays and letters, Enchiridion, A Guide to the Happy Life and several blog posts on Stoicism. I've literally immersed myself into the philosophy. Whenever I visit this sub however, I come across the occasional post or comment that criticizes the Stoic philosophy and accuses it of trivializing mental disorders. This is a huge misrepresentation of this philosophy. It is true that the ancient Stoics were not aware of issues like depression, personality disorders, bipolar etc and so their writings reflect none of these things but it is a misunderstanding of this philosophy that makes some people think that Stoic teachings are harmful to people with mental illnesses. While it is true that mental illnesses often have a chemical component that originates in the brain, they however have many other components that relate to a person's environment, upbringing, life experiences and present circumstances. All these things together are responsible for a person's mental state.

The Stoics wrote about sadness, coping with failure, fear of the future, shame about the past, dealing with bad people, condemnation, loss of loved ones, illnesses and even one's own death. All of these are issues that plague many of us who suffer from mental illnesses, yet these issues aren't caused by our mental illnesses. I call these issues "surrounding issues". Whenever a depressive episode sets in for instance, it is usually not coming alone. Rather it comes with a host of surrounding issues that affect us. You remember your failures. You feel worthless. You feel helpless. You remember how you were treated by people around you. You lament your lack of a relationship partner. You lose hope. Everything appears dark and gloomy. Your chemical imbalance in the brain then exacerbates these issues. However, Stoicism is there for you to deal with these surrounding issues both before and during your mental illness phase.

By regularly immersing oneself in the Stoic teachings, the mind already understands the nature of these surrounding issues and strips them all of their power. When your depression or anxiety or whatever mental issues resurface again, they no longer have anything to hold onto. They no longer have any issues with which to burden you. Yes, you'll feel sad and somewhat gloomy and you may even become inactive for a while. However, you will rebound much quicker than normal because through your practice of Stoicism, you've been able to see the negative experiences in your life as nothing worth your worry.

Through your study of Stoicism, you will remember contentment in the wise words of Seneca when he says

"Another man has been treated more generously: let us take pleasure in what we have received and make no comparison; no man will ever be happy if tortured by the greater happiness of another. I have less than I hoped for: but perhaps I hoped for more than I deserved. Rather show gratitude for what you have received; wait for the remainder, and be happy that your cup is not yet full: it is a form of pleasure to have something left to hope for".

And in the words of Marcus Aurelius:

"Does this not appear great enough, when I tell you that the highest good is an unyielding strength of mind, wisdom, magnanimity, sound judgment, freedom, harmony, beauty?", you will feel relaxed because you realize that it's okay to go through your mental illness. You realize that it doesn't stop you from being a virtuous person.

And another from Seneca:

"Do you think that any wise man can be affected by disgrace, one who relies on himself and holds aloof from common beliefs? No man is despised by another unless he is first despised by himself. An abject and debased mind is susceptible to such insult; but if a man stirs himself to face the worst disasters and defeats the evils which overwhelm others, then he wears those very sorrows like a sacred badge. For we are naturally disposed to admire more than anything else the man who shows fortitude in adversity"

You remember these types of words and realize again that you're strong enough to withstand life's blows. That you have what it takes to overcome your fears and anxieties. You strip your mental illness of the surrounding issues that it seeks to burden you with.

Stoicism isn't telling you that it's wrong to have a mental illnesses. It isn't telling you that you're weak for having borderline personality disorder. Rather, it's saying that you can deal with every issue affecting your life such that when mental illnesses set in - and they will - they will have nothing to weigh down your mind with. They will have nothing to scare you about. The mind will already be fortified. Here I will quote a few more from Seneca about the power of Stoic philosophy. He says:

"The power of philosophy to blunt the blows of Fortune is beyond belief. No missile can settle in her(philosophy's) body; she is well protected and inpenetrable. She spoils the force of some missiles and wards them off with the loose folds of her dress, as if they had no power to harm; others she dashes aside, and throws them back with such force that they rebound back to whence they came"

"Give your whole mind to her(philosophy). Sit at her side and pay her constant court, and an enormous gap will widen between yourself and other men. You'll end up far in advance of all mankind, and not far behind the gods themselves.... And harassed by the body's overwhelming weight, the soul is in captivity unless philosophy comes to its rescue, bidding it breathe more freely in the contemplation of nature, releasing it from earthly into heavenly surroundings"

Stoicism isn't meant to trivialize your mental health problems. Rather, a sound understanding of this philosophy will lead to positive changes to your mental health. Keep going to therapy. Use medication if you have to. But don't neglect Stoicism. It is the key to dealing with surrounding issues that weigh us down during a mental illness phase.

TL;DR Stoicism shouldn't be misunderstood as a philosophy that trivialize mental illness. Rather, it is a beautiful supplement to whatever medical/psychotherapy treatments you currently undergo