In the spring of 2004 I had been living in New York for two years. I had many friends, a fledgling relationship and a busy social diary. Life was good, apart from at work, where I was made miserable by my neurotic, unpredictable boss.

His mood swings made everyone unhappy and four of my colleagues resigned. I would have, too, but my visa prevented me from seeking employment elsewhere - to leave my job would have meant leaving the US.

Instead, I began to see a psychiatrist who started me on a course of antidepressants. They worked for a while, but it wasn't long before I was once again consumed with anxiety and self-doubt. The doctor's response was to prescribe me more drugs at higher doses. Often he would not have time to see me, so would mail repeat prescriptions.

My pill of choice was the tranquilliser Ativan, a strange thing for me to be prescribed, since it is most commonly given as a short course to patients who are anxious about imminent surgery. I took it constantly, and in ever larger quantities, eventually consuming three months' supply in five days.

On the fifth day I began walking into walls and was sent home from work. Out of Ativan and unable to get hold of my psychiatrist, I began to sober up for the first time in months. Incoherent and anxious, everything felt wrong. I searched the apartment for as many pills as I could find, washed them down with vodka, climbed into bed and pulled my duvet over me.

Had my housemate not decided to come home early, I would have died. As it was, the medics had to force an emergency tube into my trachea to let me breathe. I was in a coma for two days, during which time my parents were informed that, should I survive, I would most likely have significant brain damage.

When I was well enough to realise what I had done, I felt enormous remorse and cried for days. I could not have been more grateful to be alive. The hardest thing was taking responsibility for what I had done. The doctors informed me that I had left a suicide note. I had no recollection of writing one, but to them this signalled intent. In the intensive-care unit, a nurse sat quietly in the corner of my room. When I realised that she was there to ensure that I didn't try to take my life again, I was so overcome with dread that I had a seizure - the first of many as I came off my drugs cocktail.

As soon as I could be moved, the doctors transferred me to a psychiatric "drying-out" facility where my possessions were locked away and I had to shower with a nurse in the room. My new roommate was a paranoid schizophrenic, recently recovered from heroin addiction.

My convalescence was often surreal and occasionally frightening. One patient believed he was Michael Jackson and spent each day singing his hits. Another schizophrenic tried to hug and kiss me at every opportunity. The random musings of a middle-aged Hispanic woman hinted at the grim reality of her life on the streets, selling herself to feed an addiction to crack cocaine.

On my release a month later, I returned to work. My boss treated me with a new smothering kindness but I soon decided that it was time to return to the UK.

Back in London I saw a drugs counsellor who expressed concern not only over the grades of medicines to which I had been given access, but the quantities and manner in which they had been supplied.

There have been other stressful events since, but I have never again felt the crippling anxiety I experienced working for my old boss. I attribute some of that to maturity, but more to a realisation of what I can and can't do. I now know that understanding one's limitations is one of life's most liberating experiences.

Physically, I have made a full recovery apart from my vocal chords, which were irreparably damaged when the medics struggled to clear an airway. My broken voice is something that I will always have to live with: both a reminder of what I did, and the price I paid for being alive.

I'd be lying if I said I hadn't thought of using again. There are moments when I relish the idea of that familiar, comfortable dullness where nothing matters. A few years ago, I was staying at my mother's house and found some old diazepam her dog had been prescribed by the vet. It was hard, but I persuaded myself not to steal them.

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