Ovid delivered a famous injunction to "welcome this pain, for you will learn from it." But there is little choice about such pain; you do not have the option of not welcoming it. You can express displeasure at its arrival, but you cannot ask it to leave the house.

In writing this book, I hope to honor the memories of the people my son killed. The best way I know how to do that is to be truthful, to the best of my ability. And so, this is the truth: my tears for the victims did eventually come, and they still do. But they did not come that day.

In other cases, such plans are simply sign and symptom of the genuinely "broken" logic driving the suicidal brain. They may signal the ambivalence the person feels - a desire to live that is, at times, as strong as the desire to die. A person with intent to self-harm can also believe simultaneously in both realities: that they will take a Caribbean vacation, and that they will have died by suicide before they have the chance to go.

A local reporter tried to push his way into my eighty-five-year-old aunt's home in Ohio. (She was proud she'd stood up to him by asking him to leave, though she insisted he take a fresh-baked cookie with him.)

How could I convey empathy, when even hearing my name would likely increase the suffering these families were feeling? How could I reach out, as a companion in sorrow, when my son - the person I had created and loved more than life - was the reason they were in agony? How do you say, "I'm sorry my child killed yours"?

Quote in the paper about cancer patients. It said "The people who do well create a place in their mind and their spirit where they are well, and they live from that place." This is what we are doing. Tom's analogy is that a tornado has destroyed our house, and we can only live in one part of it. This is what living with grief is like. You dwell in that small place where you can function.

The theologian C. S. Lewis begins A Grief Observed, his beautiful meditation on the death of his wife, with these words: "No one ever told me that grief felt so like fear."

As I wrote in my journal: I've learned two important things. One, that there are many good, kind people out there. And two, there are many people who have suffered greatly and who keep going with strength and courage. These are the ones who can eventually support others. I hope I can be of some use to someone some day.

The psychologists who reviewed the tapes would come to a similar conclusion: that Eric relied on Dylan's slow-burning, depressive anger to fuel and feed his sadism, while Dylan used Eric's destructive impulses to jolt him out of his passivity.

You will notice that I use the terms "brain illness" and "brain health" throughout this book, as opposed to the more commonly used "mental illness" and "mental health". That decision was the result of a conversation I had with Dr. Jeremy Richman, a neuroscientist whose daughter, Avielle Rose Richman, was one of the children murdered by Adam Lanza at Sandy Hook Elementary School in Newtown, Connecticut. Dr. Richman and his wife, Jennifer Hensel, a scientist and medical writer, founded the Avielle Foundation in their daughter's honor, hoping to remove the stigma for people seeking help, to develop the concept of a "brain health check-up", and to identify behavioral and biochemical diagnostics to detect those at risk of violent behaviors.

In our conversation, Dr. Richman explained: "'Mental' is invisible. It comes with all the fear, trepidation, and stigma of things we don't understand. But we know there are real, physical manifestations within the brain that can be imaged, measured, quantified, and understood. We need to move our understanding to the visible world of brain health and brain disease, which is tangible."

Whereas Eric's [journal] is full of narcissistic condescension and bloodthirsty rage, Dylan's is focused on loneliness, depression, ruminations, and preoccupation with finding love. Eric drew pictures of weapons, swastikas, and soldiers; Dylan drew hearts.

One day, Dylan came home, his shirt spotted with ketchup. He refused to tell me what had happened, only that he'd had "the worst day of his life." I pressed, but Dylan downplayed it, and I let him. Kids have disagreements, I thought. Whatever it is, it'll blow over - and if it doesn't, I'll know. There has been reporting that the incident was more serious than I could ever have imagined: a circle of boys taunting Dylan and Eric, shoving them, spraying them with ketchup, and suggesting they were gay. That incident alone may not explain the deadly kinship forged between the boys, but it is the kind of shared humiliation in which a bond is formed.

I have always loved trees. I'm inspired by their fortitude and character - their knots and scars and burls, the sites of so many injuries and so much life - and by their generosity, the way they uncomplainingly provide shade and oxygen and food and shelter and fuel. Trees are both deeply grounded and aspirational; they never stop reaching.

If I had thought there was something seriously wrong with him, I would have moved mountains to fix it. If I had known about Eric's website or the guns, or about Dylan's depression, I would have parented differently. As it was, I parented the best way I knew to parent the child I knew - not the one he had become without my knowledge.

If you hurt your knee, you wouldn't wait until you couldn't walk before seeking help. You'd ice the joint, elevate it, skip your workouts - and then, if you didn't see any improvement after a couple of days, you'd make an appointment with an orthopedist. Unfortunately, most people don't turn to a mental health professional until they're in real crisis. Nobody expects to heal their knees themselves, using self-discipline and gumption. Because of stigma, though, we do expect to be able to think our way out of the pain in our minds.

As soon as my own anxiety disorder was under control and I began to emerge from the quicksand, it was suddenly as clear as day: a brain health crisis was a health issue, the same as a heart condition, or a torn ligament. As with those health issues, it can be treatable. But first it has to be caught and diagnosed. Every day, mammograms and breast exams help doctors catch and treat cancers they would have missed fifty years ago. I survived cancer myself because of these, and can only hope that someday we'll have screenings and interventions at least as effective for brain health.