Knowing or suspecting that someone we care about is struggling with their mental health can feel like a difficult situation to navigate respectfully, but it doesn't have to be.
If you feel like you want to reach out to a friend who may be struggling, remember to remain: non judgemental, supportive, calm and consistent.
What do I mean by that? When I say non judgemental I mean don't apply your own assumptions or theories to the situation - keep it direct and let them tell you (or not tell you) when they are ready, and only to the degree they are comfortable with.
Be supportive by letting them know you won't push to support them more than they need or request.
Being calm and consistent will show them you are serious about your concern and wanting to help - depending on the situation it might be appropriate to reach out periodically about your concern as a way of saying "Hey, I'm still here, I'm not going to push you, but I'm also not going to forget about you." If they see you are genuine and consistent they may choose to reach out to you later down the line when they feel more comfortable.
If you don't know how to start the conversation, some of these statements may help you start the process:
"I've been worried about you, and it's okay if you don't want to talk now but I am here if you need me."
"Is there anything I could be doing differently to support you?"
"How can I help?"
"Please let me if I say or do something that is unhelpful."
If there is someone in your life that you are worrying about, hopefully these will help you to start the conversation or at least help you to show them you are concerned and want to help. Just remember: if they aren't ready to accept help, just putting your offer out there might be all you can do at the moment. And that's okay.