Every year, 30,000 Americans take their own lives by committing suicide. At least 15% of people with depression complete the act of suicide, but an even higher proportion will attempt it. While depression is one of the most treatable mental disorders, it is also one of the most under diagnosed and under recognized.

We have developed the information here to act as a comprehensive guide to help you better understand suicide and find out more information about it on your own.

Suicide is usually talked about in hushed tones, if it's talked about at all.

But the topic was discussed openly last week after William E. Swan, 55, president and chief executive officer of First Niagara Bank and chairman of the board of St. Bonaventure University, killed himself in his East Amherst home.

It was the second suicide of a prominent local resident in less than three weeks. On Aug. 4, John G. Hedges, 58, the Town of Tonawanda highway superintendent, killed himself at his home.

Colleagues and friends said both men were hard workers and high achievers who had been troubled recently by public embarrassments.

Hedges had been distressed by lawsuits filed by two Highway Department employees who alleged that he had retaliated against them after they opposed him politically, according to his wife, Sharon, and several colleagues.

Swan had been criticized for not being more forceful in handling the scandal over an ineligible basketball player that eventually forced the university's president, athletic director and basketball coach to leave the school. He left a suicide note saying that he had let down his colleagues and the university, according to a law- enforcement source.

But while it might be tempting to say that these upsetting circumstances caused the men's suicides, experts warn it's not that simple.

Dr. Herbert Hendin, a Manhattan psychiatrist who serves as medical director of the American Foundation for Suicide Prevention, says, "The big mistake you see is that people look back at the circumstances, and anything that could be disturbing to the person that happened anytime close to the suicide is considered a cause.

"The idea that if it's connected in time, it's connected in intent is not true."

According to the group's Web site, www.afsp.org, "The cause of an individual suicide is invariably more complicated than a recent painful event such as the break-up of a relationship or the loss of a job."

Rather, Hendin points out that studies have shown that nearly 95 percent of the people who commit suicide were suffering from a significant psychiatric illness at the time of their deaths.

"And even that remaining 5 percent is in question," says Hendin. "Because you're making the diagnosis after the fact, there's a chance that you are missing the symptoms or not getting the information that would indicate that those people were suffering from a psychiatric illness, also."

These illnesses can be undiagnosed, untreated, or both, according to the American Foundation for Suicide Prevention.

The most common illnesses that afflict people who die by suicide are bipolar disorder, schizophrenia and clinical depression, says Dana Fleischhauer, coordinator of the crisis counseling phone program at Crisis Services in Buffalo.

In bipolar disorder, the person's mood swings abruptly from manic to deeply depressed. Schizophrenia can cause hallucinations, delusions, disordered thinking and unusual speech or behavior.

"You're not apt to have developed these disorders at age 50 or later without having a long history of it," says Hendin.

But depression is trickier to diagnose and more likely to strike unannounced, he says. "You can develop depression without much of a history, or any history, in your 50s, easily enough."

So it's likely that most high-achieving people who commit suicide "out of the blue" are actually suffering from depression.

Signs can be subtle

Fleischhauer says almost everyone, at some point, will suffer from "a situational depression, where people become depressed over a specific event, like the death of a spouse or another loss."

By contrast, she says, "A major depression is something that will last more than two weeks, you cannot identify the source, and it is disabling. You have people who can't even get out of bed in the morning, can't decide what to wear to work. The pain can be overwhelming.

"On the other hand, the signs can be very subtle," she says. "That's why we look for combinations of symptoms -- insomnia, loss of appetite, loss of interest in things you used to enjoy doing. And adolescents may manifest bad behavior, irritability and acting out, so that can be even more difficult to identify."

Some other factors make suicide more likely, according to the experts.

"About half of the people who are depressed and kill themselves also have a problem with substance abuse," says Hendin. And the use of drugs or alcohol doesn't have to be a longstanding problem, he says. "There are people who start drinking after they become depressed." Substance abuse increases suicide risk because drugs and alcohol lower inhibitions and make an impulsive suicide attempt more likely, he says.

"Insomnia is one of the symptoms of depression that correlates highly with suicide," says Hendin, "and so does a lot of anxiety.

"If you're depressed, then almost anything can become an issue for you. But that's all because you were depressed in the first place," says Hendin.

Even positive developments, rather than cheering up a depressed person, "can actually function in the reverse," he says. "If you're depressed and you can't feel any joy over your children or your grandchildren, it tends to depress you more, and that makes you feel more worthless and guilty."

Studies have shown that the presence of guns in a home makes a suicide more likely.

According to the American Association of Suicidology, guns are used in more than 60 percent of suicide deaths in the United States, and more than 90 percent of the people who use guns in their suicide attempts die.

"They can pull the trigger at a very vulnerable moment," says Fleischhauer. So Crisis Services recommends that guns be removed from the house of a depressed person.

A person contemplating suicide may make oblique statements, such as, 'You'd all be better off without me,' but friends and relatives must confront the person about his or her intentions, says Fleischhauer. "The first thing we (at Crisis Services) say to a caller is, 'Are you thinking of hurting yourself?' We bring the subject up directly. You can't avoid it or change the subject -- you have to find out."

A suicide crisis, when a person feels a strong urge to attempt suicide, generally lasts 24 to 48 hours, says Fleischhauer. If necessary, a suicidal person can be committed to a hospital for his or her own protection until the crisis passes.

"If you are a friend or relative, you have to let them know how much you care about them and how much you would miss them if they were gone, but also, if necessary, you can have them hospitalized," says Fleischhauer. "People are very hesitant to do this, and we ask them, 'Would you rather have an angry friend or a dead friend?' "

Men's problems

Men are more than four times more likely to die from suicide than women, according to Hendin, but this does not mean that more men suffer from depression.

"Women suffer from depression probably twice as much as men," he says. "But women are nowhere near as likely to kill themselves as men when they are depressed."

This may be linked to the fact that men and women usually choose different methods of suicide, says Fleischhauer. While twice as many women attempt suicide, "Men are more apt to use a weapon, such as guns or hanging, which means they are more likely to die," she says. Women tend to choose such methods as overdosing on medication or carbon monoxide poisoning, which do not kill instantly.

Also, "Women will tend to go for help for their depression before it's too late," says Hendin. "Men do nothing until it's too late."

Why don't men seek help?

"The conventional explanation has some truth," says Hendin. "Men are raised to think that seeking help is some kind of weakness, and you don't do it."

As an example, Hendin uses the story of the 1993 suicide of Clinton White House Counsel Vincent Foster.

"He killed himself one day after he'd gotten a prescription in the mail for antidepressant medication; he may have taken one pill," says Hendin. "People were shocked when it happened, but as you heard his story, you learned that he was obviously depressed for a year or so, and he had never gotten help. Finally he wrote to his general physician, who sent him this prescription for antidepressant medication."

It was too little, too late.

"What you will often see with men is that they make some gesture at getting help, but by the time they make the gesture, they have already given up anyhow, they don't believe in it and they don't give it a chance," says Hendin.

'The black dog'

Depression, which Winston Churchill called "the black dog," strikes millions of people each year. Hendin says, "At a minimum, there are 10 million people who are clinically depressed at any one moment in the United States," and some estimates put that number as high as 18 or 19 million.

The elderly and those with physical illnesses are most likely to be among that population.

"Now, things happen -- things happen to everybody all the time, there are very few lives that are free of stress," says Hendin. "But when you are already depressed, you can't cope with it."

Medical experts now understand that depression can be caused by chemical imbalances in the brain, and treated successfully with medications that affect the functioning of brain chemicals called neurotransmitters.

"There's no question that there's a biochemical factor in depression," says Hendin. "You also see severe depression running in families, so there is something that's genetic about it as well.

"When you treat depressed people, you'll find that you cannot treat them psychologically unless you treat them medically," he says. "There are some people whose depression has such a strong biological component that you can talk to them forever and see no results, when within two weeks you can relieve them with medication."

The signs of depression

One in six people will experience major depression at some point in their lives. Major depression is the leading cause of disability in the United States and worldwide.

Symptoms of depression can include:

Persistent sad, anxious, or "empty" mood

Feelings of hopelessness, pessimism

Feelings of guilt, worthlessness, helplessness

Loss of interest or pleasure in hobbies and activities that were once enjoyed, including sex

Decreased energy, fatigue, being "slowed down"

Difficulty concentrating, remembering, making decisions

Insomnia, early-morning awakening, or oversleeping

Appetite and/or weight loss OR overeating and weight gain

Thoughts of death or suicide; suicide attempts

Restlessness, irritability

Persistent physical symptoms that do not respond to treatment, such as headaches, digestive disorders and chronic pain

Source: National Institute of Mental Health

If you are in suicide crisis, call Crisis Services at 1-800-562-0113 for help or 1-413-774-1000 to schedule an appointment to see a counselor.