One area where the philosophy of yoga can definitely be applied to mental health is that yoga stresses equanimity, meaning calm and composure regardless of external circumstances, believing it is absolutely essential on the life journey.
Equanimity doesn’t mean ceasing to feel things or detaching yourself from life. But it does mean quickly recognizing changes in thoughts and emotions, refusing to allow yourself to be supplanted by these thoughts and emotions. You stop letting yourself get carried away.
You can cultivate equanimity by working on applying it to some of the problem areas in your life, to the triggers that tend to make emotions like frustration or anger quickly bubble up before exploding. Instead of allowing these emotions to gather strength, purposefully cultivate a sense of calm and acceptance through deep, steady breathing, deciding you are going to maintain your equanimity despite a situation that usually makes you lose control.
We think that emotional outbursts will make us feel better but they don’t. We end up feeling worse in the long-term, both because of the consequences of our actions and because nothing actually changes, the cycle just keeps repeating as similar external circumstances keep popping up. The way to break the cycle is to realize that there is a difference between you and your thoughts and emotions, that you can decide to react to their appearances in your life as you see fit.