Summer evenings at the Bistro Gardens in Beverly Hills tended toward the languorous. My friend Jack and I went there often when I lived in Los Angeles. From time to time, Jack would use the occasion to suggest we get married. It was an idea with such potential for catastrophe that neither of us had much of an inclination to take it with much gravity. But our friendship we took seriously.

This particular evening, I found myself edgily knocking the ice cubes around in my whisky glass. We were making a blood oath: if either of us again became deeply suicidal, we agreed, we would meet at Jack's home on Cape Cod. Once there, the nonsuicidal one would have a week to persuade the other not to commit suicide; a week to present all the reasons we could come up with for why the other should go back on lithium (we both had manic-depressive illness and had a tendency to stop taking our lithium); a week to cajole the other into a hospital; to invoke conscience; to impress upon the other the pain and damage to our families that suicide would bring.

We would, we said, walk along the beach and remind the other of all of the times we had felt at the end of hope and, somehow, had come back. Who, if not someone who had actually been there, could better bring the other back from the edge?

We decided that a week was long enough to argue for life. If it didn't work, at least we would have tried. And, because we had years of experience with impetuousness and knew how quick and final a suicidal impulse could be, we further agreed that neither of us would ever buy a gun.

"Cheers," we said in synchrony, ice and glass clinking, sealing our foray into the rational world. Still, I had my doubts. I listened to the details, helped clarify a few, finished my scotch, and stared at the tiny white lights in the gardens around us. Who were we kidding? Never once, during any of my bouts of depression, had I been inclined or able to pick up a telephone and ask a friend for help. It wasn't in me. How could I seriously imagine that I would call Jack, book a flight, get to an airport, rent a car, and find my way out to his house on the Cape? It seemed only slightly less absurd that Jack would go along with the plan, although he, at least, was rich and could get others to handle the practicalities.

It is a tribute to the persuasiveness and infinite capacity for self-deception of two manic temperaments that by the time the desserts arrived we were utterly convinced that our pact would hold. He would call me; I would call him; we would outmanoeuvre the black knight and force him from the board.

The black knight, however, has a tendency to remain in play. And so it did. Many years later - Jack had long since married and I had moved to Washington - I received a phone call from California: Jack had put a gun to his head, said a relative. He had killed himself.

No week in Cape Cod, no chance to dissuade. A man who had been inventive enough to earn a thousand patents for such diverse creations as the Hawk and Sparrow missile systems used by the US Defense Department, toys played with by millions of children, and household devices used in millions of homes; a Yale graduate and lover of life; a successful businessman - this remarkably imaginative man had not been inventive enough to find an alternative solution to a violent, self-inflicted death.

Although shaken by Jack's suicide, I was not surprised by it. Nor was I surprised that he had not called me. I, after all, had been dangerously suicidal myself on several occasions since our Bistro Gardens compact and had not called him. Suicide does not always hearken to plans drawn up in lucid moments and banked in good intentions.

I know this for an unfortunate fact. Suicide has been a professional interest of mine for more than 20 years, and a personal one for far longer. I have a hard-earned respect for suicide's ability to undermine, overwhelm, devastate and destroy. As a clinician, researcher, and professor of psychiatry, I have known patients who hanged, shot, or asphyxiated themselves; jumped to their deaths from stairwells, buildings or overpasses; died from poisons, fumes, prescription drugs; slashed their wrists or cut their throats. Friends, fellow students from graduate school and children of colleagues have done the same. Most were young and suffered from mental illness; all left behind a wake of unimaginable pain and guilt.

Like many who have manic-depressive illness, I have also known suicide in a more private, awful way, and I trace the loss of a fundamental innocence to the day that I first considered suicide as the solution to an unendurable level of mental pain. Until that time I had taken for granted, and loved more than I knew, a temperamental lightness of mood and a fabulous expectation of life. I was 17 when, in the midst of my first depression, I became knowledgeable about suicide in something other than an existential, adolescent way.

I thought about when, whether, where, and how to kill myself. I learned to present to others a face at variance with my mind; ferreted out the location of two or three nearby tall buildings with unprotected stairwells; discovered the fastest flows of morning traffic; and learned how to load my father's gun.

The rest of my life - sports, classes, writing, friends, planning for college - fell fast into a black night. Everything seemed a ridiculous charade; a hollow existence to fake one's way through as best one could. But gradually the depression lifted, and by the time my senior prom came around, I had been well for months. Suicide had withdrawn to the back squares of the board and become, once again, unthinkable.

Over the years, my manic-depressive illness became worse, and the reality of dying young from suicide became a dangerous undertow in my dealings with life. Then, when I was 28, after a damaging and psychotic mania followed by a prolonged siege of depression, I took a massive overdose of lithium. I unambivalently wanted to die and nearly did. Under the circumstances - I was a young faculty member in a department of academic psychiatry - it was not a very long walk from personal experience to clinical investigation. I studied everything I could about my disease and read all I could find about the psychological and biological determinants of suicide, as a tiger tamer learns about the minds and moves of his cats.

No one knows who was the first to slash his throat with a piece of flint, or take a handful of poison berries, or intentionally drop his spear to the ground in battle. Death, as Seneca states, has always lain close at hand; yet it is a mystery why the first to kill himself did. Was it a sudden impulse, or prolonged disease? An inner voice, commanding death? Perhaps shame or the threat of capture by an enemy? Despair? Exhaustion?

We do, however, have what psychiatrist Chris Thomas believes to be the first extant suicide note. Four thousand years ago, an Egyptian wrote his despair on to papyrus in the form of a narrative and four short-versed poems. This document, now in the Berlin Museum, reflects the ruminations of a deeply depressed, probably psychotic mind:

Lo, my name is abhorred,

Lo, more than than the odour of carrion

On summer days when the sky is hot.

Death is before me today

As a man longs to see his house

When he has spent years in captivity.

Cultures have varied in their notions of self-inflicted death. Several - for example, the Eskimos, Norse, Samoan, and Crow Indian - accepted, and even encouraged, "altruistic" self-sacrifice among the elderly and sick. Among the Yuit Eskimos of St Lawrence Island, if an individual requested suicide three times, relatives were obligated to assist in the killing. The person seeking suicide dressed in ritual death garb and then was killed in a "destroying place" set aside for the purpose.

The Catholic church, during the sixth and seventh centuries, codified its opposition to suicide by excommunicating and denying funeral rites to those who died by their own hand. Jewish custom forbade funeral orations for anyone who committed suicide; mourners' clothes were not encouraged, and burial was limited to an isolated section of the cemetery, so as "not to bury the wicked next to the righteous". In Islamic law, suicide is a crime at least as grave as homicide. In many countries, the bodies of those who killed themselves were buried at night and at a crossroads. The greater traffic was thought to "keep the corpses down", and the intersection, it was believed, would make it more difficult for the spirit to find its way home.

Robert Burton's influential The Anatomy of Melancholy, which argued for mercy for those who were in such despair and agitation as to kill themselves, was published in 1621. Twenty-five years later, Biathanatos, a landmark treatise on suicide, was published. Its author, John Donne, was also the dean of St Paul's Cathedral. In Biathanatos, Donne declared that suicide was, on occasion, justified; certainly it was understandable. It was, for him, personal. "Whensoever any affliction assails me," he confessed in the preface, "methinks I have the keys of my prison in mine own hand, and no remedy presents itself so soon to my heart as mine own sword."

Suicide in the young has at least tripled over the past 45 years and is, without argument, one of our most serious public health problems. It is the second major killer of women between the ages of 15 and 44 worldwide (after TB) and the fourth of men in the same age group (after road accidents, TB and violence). For every completed suicide there are estimated to be 10 to 25 attempts.

In his memoir A Sort of Life, Graham Greene described his early encounters with suicidal depression. While still at school, "I tried out other forms of escape after I failed to cut my leg. Once at home I went into the dark room by the linen-cupboard, and in that red Mephistophelean glare drank a quantity of hypo under the false impression it was poisonous. On another occasion I drained my blue glass bottle of hay-fever drops, which, as they contained a small quantity of cocaine, were probably good for my despair. A bunch of deadly nightshade picked and eaten on the common had only a slightly narcotic effect and I once swallowed 20 aspirins before swimming in the school baths."

When Greene was 19, he took his brother's revolver from the cupboard in their bedroom -"I felt nothing. I was fixed, like a negative in a chemical bath" - and walked into the woods: "I slipped a bullet into a chamber and, holding the revolver behind my back, spun the chamber_ [put] the muzzle into my right ear and pulled the trigger. There was a minute click, and looking down at the chamber I could see that the charge had moved into the firing position. I was out by one. The experience I repeated a number of times..."

Greene did not, in the end, kill himself. But the possibility of suicide was a recurring presence in his life and, as for many with depression, the seeming best response to bale and weariness. He continued to wage war against his black depressions, "the hopeless misery of the years", as he put it, using alcohol, the perverse exhilaration of Russian roulette, and travels into war zones and other areas of high political and social volatility, as antidotes to his bled-out state.

The 18th-century poet Thomas Chatterton wrote Suicide a few months before he swallowed a fatal dose of arsenic.

Since we can die but once, what matters it,

If rope or garter, poison, pistol, sword,

Slow-wasting sickness, or the sudden burst

Of valve arterial in the noble parts

Curtail the miseries of human life?

Though varied is the cause, the effect's the same:

All to one common dissolution tends.

Not long before he died in 1770, he wrote, "Cease my anguish'd soul_ and this last act of wretchedness forgive." He was 17.

Symbolism and suggestion have played their part in the circumstances of self-inflicted deaths. Some places become "suicide magnets", drawing to them not only the impulsive but the more chronically suicidal as well. At Beachy Head on the South Downs of the English coast, suicides have been reported since the sixth century.

Jumping from public monuments has also had a contagious allure - the Eiffel Tower in Paris, St Peter's Basilica in Rome, the Empire State Building in New York. Mount Mihara, an active volcano on the Japanese island of Oshima, was almost entirely unknown until January 1933, when two classmates from a Tokyo college climbed to the top of the crater. There Meiko Ukei, 24, announced to her friend Masako Tomita that she intended to throw herself into the volcano. She would, she explained, be cremated instantly and sent heavenward in smoke and beauty. After extracting a vow of secrecy from her friend, she jumped.

Masako, 21, was understandably unable to keep her promise. She confided in another friend, who then insisted that Masako take her to Mihara so that she could "follow Meiko to paradise". Masako was unable to persuade her friend otherwise, and in early February the two women climbed to the top of the volcano. The friend jumped in, Masako returned alone, and soon the story was a major force in the cultural life of Japan.

People swarmed to Mihara, first by steamer and then by a larger boat that was required to handle the curious. On an April Sunday not long after the deaths of the two young women, six people leaped into the volcano; 25 others had to be restrained from doing so. Tourists lined up to watch the suicides, which were now occurring several times a week. By year's end, at least 140 people had committed suicide.

The following year, more than 160 plunged to their deaths and another 1,200 had to be restrained from following suit. In January 1935, three young men jumped to their deaths within 10 minutes of one another. The police set up a 24-hour watch at the crater, and a barbed-wire fence was erected; yet in 1936, at least 600 people killed themselves. Access to the mountain was eventually closed, but not before at least 1,000 people had thrown themselves into Mihara.

Today, as suicide rates increase, the World Health Organisation has outlined six basic steps for the prevention of suicide, most of which centre on reducing the availability of methods; gun possession control, detoxification of domestic gas, detoxification of car emissions, control of toxic substance availability, more effective treatment of mental disorders, and toning down suicide reports in the media.

Psychologists are deciphering the motivations for suicide and piecing together the circumstances that so dangerously ignite the brain's vulnerabilities. But I have become more impatient as a result of writing this book. I cannot rid my mind of the desolation, confusion and guilt I have seen in the relatives and friends of those who kill themselves. For every moment of exuberance in the science, or in the success of governments, there is a matching and terrible reality of the deaths themselves; the young deaths, the violent deaths, the unnecessary deaths.

While writing this book, I kept on my desk a fragment of a poem . It is the last line from Douglas Dunn's Disenchantments:

Look to the living, love them, and hold on...

 This is an edited extract from Kay Redfield Jamison's Night Falls Fast: Understanding Suicide, published by Picador (£16.99). To obtain a copy at the discount price of £14.99 plus 99p UK p&p per order, phone 0800 316 6102, or send a cheque to Guardian CultureShop, 32-34 Park Royal Road,London NW10 7LN.