If your friend is mentally ill

20% of the population are mentally ill so don't assume that none of your friends have ever faced a mental issue. If you suspect they're in a poor place mentally ask them if they're okay and offer support. I'm talking about support in the form of empathy, compassion, acceptingness etc. the type of support you can't supply is that of a trained professional. as a teenage child are not qualified to take on another person's mental baggage and attempt to fix their illness. You can help your friend reach out for help, you can go with them to visit their GP (alone if you're both over 16) or you can speak to their parents about it. You can join a support group with them, link them to helpful resources and online courses, educate yourself and pass your wisdom on. What you CANT do is take the responsibility upon yourself.

If your partner is mentally ill

when dating a mentally I'll person DONT enter the relationship with the mentality that you're going to love them enough to cure them. I don't care how many times you've seen 13 reasons why I'm gonna tell you this once and once only: you CAN NOT cure depression by loving someone. All your doing is initiating a toxic relationship. i know it sounds harsh but protecting your mental health is more important than being with them if the relationship isn't healthy u need to leave! most people suffering from mental disorders aren't in a healthy mental place to hold a safe relationship sometimes it'll even make them feel worse. If you choose to stay with them that's also great and valid but take precautions. Research their specific mental illness, ask them about their triggers and avoid those topics, don't try to change how they feel or make their feelings seem invalid by saying you can "fix" them - there's nothing wrong with them in the first place.

If your parent is mentally ill

This is extremely extremely common in many family dynamics and doesn't mean there's anything wrong with you or your family whatsoever. You didn't cause your parents mental illness. They may face trouble monitoring their emotions and lash out at you, they may reject some housework and leave the house untidy from time to time, they'll do a lot of things different to other families you'll find. And it's okay for you to feel angry or upset with them, it's healthy for you to have an outlet to talk about those feelings with whether it be a friend or a therapist. However, you still have a right to be safe so if your home situation reaches the point of abusive I'll leave some resources in my 'anxiety diaries' collection.  

If you are mentally ill

I know it's totally overwhelming and scary but you're not alone and there are so many people going through the exact same thing as you right now. The greatest and bravest thing you can do is reach out for help. I know that isn't easy, it's actually crazy hard. Often the best place to start is with a family member, trustworthy teacher or friend. Then a local doctor, GP or support worker. From there, things will get better. I can't stress enough that the number one most important thing you can do is help yourself, other people can help you of course but you need to take the first step or nothing will ever happen. If you aren't serious about your health and getting better you never will.