Editor's note: Dr. Charles Raison, CNNhealth's mental health expert, is an associate professor of psychiatry at the University of Arizona in Tucson.
(CNN) -- I got a terrible shock when I heard the news that the famous director Tony Scott had apparently committed suicide by jumping off the Vincent Thomas Bridge in San Pedro, California.
Not because I knew Scott, and certainly not because it is a rare thing for people who seem to "have it all" nonetheless to kill themselves.
No, I got a shock because I knew the bridge.
For the better part of a decade, I trained and then worked as a psychiatrist in Los Angeles. For several of those years, I did psychotherapy with a young woman who drove over that same bridge every day. The bridge became almost a third person in our work together, because she talked about it constantly.
Every morning and then again every evening she faced huge anxiety as she approached its yawning span because it was all she could do not to stop her car and throw herself off it. Just seeing that bridge made all her pain and despair intensify, and it came to represent everything that was wrong with her life.
On the other hand, it's a beautiful structure, in an industrial sort of way, and it also seemed beautiful to her because it was always there, silently waiting, always offering an easy out. When things were really bad, she'd drive 20 miles out of her way just to avoid that bridge and the terrible temptation to jump or crash her car off the side.
Fortunately, my patient avoided Scott's fate. She came to grips with a history of abuse and her depression eased. She married and left Los Angeles. I also left Los Angeles, but a few years ago, I returned to the San Pedro area to give a talk and crossed that bridge with a mixture of relief and distress.
It is that strange mixture of relief and distress that characterizes many of the responses to Scott's apparent suicide that have been posted on CNN.com.
Many comments come from family members of people who have committed suicide, some defending the loved one's decision, others decrying it as the ultimate selfish act. Although I've spent my life battling suicide, I find myself empathizing with both points of view.
Perhaps the first thing to say about suicide is that people make suicide attempts for all sorts of reasons. Sometimes people want to die, or half want to die.
But just as often in my experience, suicide attempts are a cry for help, or a way to punish people they are upset with, or a means of controlling a situation. I've known more than a few married people who kept a husband or wife from walking out on them, at least for a while, by making a suicide gesture.
On the other hand, people really only kill themselves for three reasons.
Occasionally people will commit suicide because they are facing some incurable condition that promises a brief future filled with nothing but pain.
Although many mental health clinicians will disagree vociferously with me, I have seen suicides that I felt were in this sense justified. For example, I knew a grand old fellow who, in the midst of unbearable physical pain from inoperable cancer, took his life when he had a life expectancy of two to three months.
Occasionally people will commit suicide because they are psychotic and believe they must die for some reason that makes no sense to anyone else. I had a patient once who made a very serious suicide attempt because she believed that if she died, the mysterious private investigators who were stalking her would leave her family alone.
These types of suicides are heartbreaking, because they are so futile and can often be prevented by appropriate treatment.
The vast majority of people who choose methods of suicide that are almost guaranteed to succeed -- like a gun to the head or a plunge from a high bridge -- do so because of they are losing a battle against major depression. These are the suicides that haunt and hurt worst of all, and that almost to a person are the most tragic.
I hate suicide.
I've been fortunate that suicide does not run in my family. But it runs in lots and lots of families and I've known -- and known of -- more people who have killed themselves than I can easily count.
There was the shy kid who shot himself in high school, the young punk who drove his car off a particularly bad curve, the wonderful hard-working father of the class valedictorian, and various in-laws across a couple of marriages.
And those are just people from my personal life. Like any psychiatrist who deals with the severely mentally ill, my life is littered with memories of folks who threw themselves off high buildings, hanged themselves in dark closets or slit their throats in dusky gardens.
But as much as I hate suicide, I also understand it. One of the things people have repeatedly posted in comments responding to Scott's death is that you can't weigh in on why someone might commit suicide unless you've really had your life torn apart by an episode of major depression.
Severe major depression is probably the most unbearable pain a human being can withstand for any protracted period of time. Many people who died of cancer have written eloquently about how the crushing pain from their tumors paled in comparison to the pain they felt when depressed.
With all other pain, most people can maintain some sense of separation between themselves and the pain. As horrible as it is, the pain is in their arm, or leg, or belly or head. But there is still a "them" that is separate from the misery.
Depression is different. Because it is at its essence a perceptual disorder, it causes one to see the entire world as pain. It feels painful inside, but it also feels painful outside.
When a person is depressed, the entire world is disturbed and distressed, so there is nowhere to escape. And it is this fact that makes suicide so seductive, because it seems to offer the one available escape option.
There are at least two reasons why suicide in response to major depression is so horrible and so tragic. First, although our treatments for depression are far from perfect, they are nonetheless effective enough to help the vast majority of depressed people feel well enough to forgo killing themselves.
And even when treatment is not particularly effective, depression often passes on its own accord. It is not an incurable cancer that offers a guaranteed foreshortened future of unbearable pain. Because of this, depressed people kill themselves over something that would have lifted had they just been able to hang in there.
The other reason depression-driven suicides are so tragic and terrible is because they cast such long shadows on families and other loved ones.
Children especially suffer. They grow up wondering why, and whether they could have done something, and whether they'll have to struggle with the same urges.
I think of people I have known in this situation, and I have to think of something else to keep from tearing up as I write this. More than once I've "guilted" acutely suicidal patients into not killing themselves for the sake of their children and have done so with a clear conscience.
We may or may never know why Scott apparently killed himself, but we can be sure that his family and friends will spend many years wondering what they might have done to have protected him. This is part of the painful legacy left by suicide, and my heart goes out to them.
In fact, even psychiatrists have a difficult time predicting when someone is at heightened risk for suicide. In part, this comes from the fact that many people who really want to kill themselves keep their mouths shut about it and just go do it. In part, it comes from the fact that suicide is often an impulsive act driven by acute and unpredictable increases in anxiety and despair that one cannot predict in advance.
For families and friends worried about the suicidal potential of a loved one, there are a few useful pieces of advice I can offer from the research literature, such as it is.
First, older men are more likely by far than other people to kill themselves.
Second, people who kill themselves often will tell someone ahead of time. Any such communications should be taken with utmost seriousness, and all efforts should be made to keep the person safe and get him or her to appropriate treatment immediately.
Third, even over the suicidal person's objections, the means for committing suicide should be removed from the environment. Guns should be taken out of the house. Pain pills should be taken elsewhere.
Fourth, studies conducted over the last 20 years suggest that the biggest short-term risk for depressed people to kill themselves is the development of unbearable anxiety. If a loved one with depression begins to pace the floors or do other things suggesting that they are becoming consumed with terror, panic or dread, the risk for suicide shoots up.
Finally, it is not true that talking about suicide increases the likelihood it will happen. In fact, studies suggest the opposite.
So if you have a loved one with depression who is struggling with the will to live, one of the best things you can do -- over and above getting them immediate health care -- is to check in with them regularly and honestly and act if their drive to die intensifies.