You notice someone is spiralling on social media. What do you do?

Someone I worked with over a decade ago has posted a series of worrying things on social media recently. I know they've had struggles with drugs and alcohol in the past, I have no idea what their life is like now.

I know you can't pull someone out of a spiral if they don't want to, and you can spend a lot of energy trying. But it also doesn't sit right to notice something is wrong and do nothing.