There was one guy in particular I'd always sort of worried about. He "had it together," was very intelligent, acted tough, was a respected professional. And these types, I've found, are the frailest of frail. They're usually very successful by worldly standards, but always on the ledge.
He did train with two of my employees about 12 years ago. That outreach for their help was one of his very few times in life he admitted to enlisting the help of others. Overall otherwise he was loathe to admit any need for help. Long story short, a couple years ago he committed suicide.
I seldom followed up with him, because when I had he would always respond coarsely. It's a tough balancing act, because some people just don't understand another human genuinely caring about their well-being. Part of that cynicism is borne out of their own inability to care for others. He was one of those. And his responses were brittle, always suspecting that I was looking to get something out of the interaction. I hate to break it to people, but 99 out of a 100 people I follow up with I would never take on as a client (even most of my own former clients).
I built a habit in 2004 of just making a call, sending a card, shooting an email to people I'd met along the way. Many of them had worked with employees or peers of mine. Some were my own former clients. Some were just people I chatted with briefly once or twice.
Just my two cents: but when I follow up with people and they admit to an injury, a struggle, a human experience, I always think - "this guy is gonna be alright". Just the admission that you need help is evidence that you are honest, willing to grow, and able to cope. When I follow up with someone who is telling me how great they are, how complete of a product they are, how "I'm good on my own," I know there's some deep pain (so deep it can't be shared). So, follow up, just for the simple act of seeing how they're doing, and maybe providing an example that there are people who give a rip. You don't need to overextend yourself, and take them back on as a client, partner, coworker or other designation where they'd simply be wearing you down. But what kind of world do you want to live in? Lend them an ear and a care. Follow up.