Depression is a state of the human being in which everything or nothing is the same, nothing makes sense, and the worst thing is that if you let this feeling increase it will lead you to make mistakes, it is as you say, if we observe a depressed person and we can get closer just to say hello you want to drink coffee and talk, if they accept, analyze if they want to talk or just be silent and wait for them to decide to speak, it is complicated, the important thing is to analyze the person to help them.
A very interesting topic in your post.