I think about people who have had it far worse than me; I rage because no one’s ever had it this bad.

I cry until I hurt; I don’t allow myself to cry.

I never watch any TV show that Lydia and I loved together; I binge on them for weeks.

If one were to collect the advice I’ve offered to the people who have reached out to me, it’d be a contradictory mess. You name it, I’ve tried it, am trying it, will try it. I don’t know what to tell people about coping because the hurt is never gone. I tell them matter-of-factly that it is terrible and it will always be terrible and that the sooner you recognize that as the new reality, the sooner you’ll adapt to it, whatever that looks like for you. Whatever defeated new landscape your life takes on. It’s all very Russian.

But when people write to me concerned that someone they love is suicidal, my advice is unflinching: There may be nothing you can really do, but whatever you’re doing to help, do more of it. Ask more questions. Drive your loved one to more doctors. Spend more nights watching him or her sob.

I regret every time I rolled my eyes because my sister was having another bad day. I’m ashamed of myself for it. No matter how much we know it’s not our fault, it doesn’t matter. In our hearts, we feel guilty. I look back at Lydia’s life and I’m sickened we couldn’t see it coming. A preternaturally intelligent girl who is sensitive and socially awkward, obsessed with dark literature and music and television, overdoses on sleeping pills, and we thought she’d turn it around?

It was impossible to put it all together in real time. My older sister, Anna , and I often console ourselves that way. We tell ourselves that if Lydia hadn’t killed herself when she did, she would have done it some other time. Who knows how soon, but she would have done it just the same.

The way my mom saw it, modern science barely understands the human brain. All the studies, all the tests and pills and breakthroughs, it’s all worthless, she said. Medical science still has such a rudimentary understanding of why the mind works the way it does. In a hundred years, psychiatrists would look at Lydia and say, “Oh, this girl is clearly suffering from X, Y and Z.” And they would prescribe her whatever it took to fix X, Y and Z. Then off Lydia would go to fulfill her potential, to find a sense of worth, of happiness.