Stress and pressure can lead to depression, especially when you're keeping everything inside and don't have a proper outlet for all the negative energy inside you. To some, it's easy to put aside what's bothering you and simply forget about it. There are also some who stress themselves out so much to face challenges head on alone. Both of which are not healthy.
Just Forget About It
Not bothering with facing your problems will bite you in the ass someday. You're keeping all that negativity and dark energy inside you with no outlet, hence polluting your inner self in a way that you won't even notice until it's really bad. Not thinking about your problems will become some sort of coping mechanism which you do to avoid feeling the stress and pressure of the situation but you know that deep inside it'll be eating you hence damaging you in a different way. You will never know how to deal with things when you're in a fickle which is not healthy because problem solving is something that is natural to everyone to keep yourself balanced.
All these pent up frustrations inside you will manifest in a way that one way or another it would need to find an outlet but seeing that you won't want to face your problem itself, you tend to find an unhealthy outlet like alcohol, unhealthy eating habits, maybe even drug and the likes. There are good ways to exercise these frustrations but given that you don't even know how to handle your frustrations, your discipline and control won't deal with these healthy options.
Keeping everything inside also means that you're not telling anyone about it. It follows that you're doing everything alone. There may be various reasons of why you do so- you don't want to worry and bother other people, you just can't be bothered to let other people know your business, or just that you don't know how to tell other people.
Hell No! I Need To Do This Now!
I admit that this way of thinking might be good because you get things out of the way as soon as possible. When you know that there's something you need to do, you try and finish it as soon as you can. That doesn't sound so bad, no? But with this kind of thinking, especially when you're trying to deal with everything alone, you try to do everything all at once and it's not like problems present themselves to you in an orderly manner and one at a time. No. Problems tend to pile on top of one another at the same time.
With this you try to solve everything with no break and no outlet for the stress and pressure since you don't have enough time for yourself in between all these challenges. It all gets in your head. You irritation levels go up and in a way this becomes your outlet which let out on the people around you. You tend to reflect your frustrations with everything going on to everyone around you because you have no other way of letting all these gathered up stress and pressure which you didn't just get from the people around you like your parents, your boss or your teachers but also from yourself. You're stressing yourself out to finish everything, pressuring yourself to do something without no break for your mental and physical state.
Don't Be Scared. Talk To Someone
To those who think that talking to a psychiatrist is bad thing or that you have to know that there's really something wrong with you before you go to see one, you're wrong. In my personal experience, when I realized that how I was feeling was definitely not right and not that anyone told me that something was wrong with me, I realized myself that there's something inside me that needs fixing and I need to know what it is and how to fix it, I straight up told my brother that I want to go to a psychiatrist and although I just told them that it is important for me to go see one without telling them why, they let me go to one.
I wasn't really feeling nervous at first. I just knew that I need to talk to someone, because I was the type to never talk about what's really bothering me because I don't know myself what really is the problem. I never talk to my friends and family because I didn't want them to worry about my problems when they already have their own stuff to deal with. I just got used to dealing with everything in an aloof manner and not dealing with it head on until it became something that I don't understand anymore.
Talking to someone, especially to a professional, is a very great thing to do. Whether you feel like something's wrong with you or not. It's a healthy thing to do. Like how you do a physical check up even when there's nothing wrong to know if by chance you might not be as healthy as you thought you were. I honestly reccommend that people go to one. I feel like the more hesitant you are of going means there's a high possibility that you actually need to go see one.
All you have to do is be totally honest and patient and open and they will try and help you deal with your past that affecting you now, try to help you find the roots of your pent up anger and frustrations and help you find a way of letting it go, try to help you organize your stress and the pressure you feel.
I honestly think that the importance of mental health is not given enough stress. You might not truly understand of feel it but when you are mentally unhealthy, super stressed and pressured or feeling very down and stuff, it affects everything around you. Your physical health, your everyday life and the way you deal with the people around you.
Talking, as simple as it may sound, is at times very trying, but it truly will help you in many ways that sometimes you can't fathom.