As a person with mental illness (borderline personality disorder), a fairly high achiever and a perfectionist who hates to disappoint people, suicide has sometimes seemed like an attractive option. When everything else is out of control, it is the one thing you can control, and you can do it on your own terms ("You can't fire me, I quit!").
For me, one specific thing has stuck out like a sore thumb. In either a TV or print interview, Tim's dad was quoted as saying he "ordered" his children to join him at his destination 60th birthday. They were "expected" to be present. Perhaps it was a joke; I'm not aware of any context that might have accompanied that quote. Mr. Cunningham's continued insistence that his son was so dependable, so reliable, this was so out of character for Tim, says something very important to me: Either A) Tim's parents were unaware of any potential mental health traits, conditions or impairments he may have had, or B) Tim's parents have some awareness of potential mental health issues but believe they're the sort of thing that can be overcome with "willpower" or "discipline."
Depending on the family atmosphere, having to tell his parents that he didn't receive a promotion may have been just as devastating as missing out on the promotion itself. I can empathize with that.
I can only speak about BPD, but a hallmark of that illness is an intense fear of rejection and abandonment. The fear may be based in reality (neglect, abuse) or it may be perceived. Regardless, the borderline will do almost anything to avoid the rejection/abandonment. Often, those coping mechanisms or behaviors are negative and destructive. It could be extreme ("If you leave me, I'll kill myself") or harmful only to the borderline themselves (self-harm). To somebody like a borderline, the idea of suicide seems attractive. No more disappointing anyone. Nobody can leave you or reject you if you're gone. And most of all, your brain will finally be quiet and at peace.
I am NOT suggesting that Tim is a borderline. But I wanted to give some perspective.
Roughly one out of every 22 people in the United States has a mental illness that would be considered debilitating or disabling. That doesn't mean they've been diagnosed or are receiving the proper care. That's just a raw number. Seems like you'd know who those people were, right? They'd be popping up left and right, but they aren't. That's because it is eminently possible to continue living your life, with varying degrees of success, without other people realizing something is wrong. By simply showing up to work, getting your kids to school and paying your bills and taxes, many other things can and do fall under the radar.
Sometimes, we take refuge under that radar. And when the cover is blown, it is a catastrophic blow to an already precarious life.