A little while ago, I was driving a close friend, Nigel, to have a scan. He had suspected tumours in his lungs and his liver. “Obstacles,” they called them, and marked the request urgent. He puts on a funny voice as he reports this to me, camping up the word. We both know what it means, obstacles to life, but have a silent pact not to say it.

We arrive at the clinic. Nigel disappears through double doors marked with a big red stop sign. I watch him go. I am in pieces but I smile, foolishly, for he cannot see me.

We have been in a clinic together before, a psychiatric clinic. It is where we first met. We are both childishly fond of telling the story at parties. “We met in a loony bin.” People never know whether to believe us.

But when we laugh, they laugh too. It is only funny because it seems unbelievable. We don’t look like the sort of people who suffer from depression. But I’ve been in three psychiatric units. Nobody in there looked like the sort of person who suffers from depression. It is no respecter of type. Or gender. Or class. Or money. Or success.

Nigel has been a huge education for my daughter Molly. She knows that I met him in a mental hospital. She met him there herself, when she visited. And she loves him. “If he’s mad,” she says, “then I love mad people.” “Not mad, darling, just depressed.” “Whatever.”

MY descent into depression was steady, textbook, even. I began to wake, every morning, at 3.20. My head was an alarm clock, set to the minute; to the not-so-sweet spot.

Early morning waking is one of the classic symptoms of depression, but I had no idea so I paid it little attention. I had a lot on my mind and, anyway, I have suffered from insomnia since I was a child, although it used to be of the not being able to get off to sleep variety.

This was a new form. I fell asleep as if I had been hit over the head, too fast, too violently. And then, a few hours later, I was awake again and always at the same time. I began to dread the clock, my startled, suddenly awake eyes staring at those luminous hands that always pointed at the three and the four; pointing the way, I began to imagine, towards hell. I felt odd in other ways.

Food tasted strange, or dry, like dust. I lost weight quickly, about a stone in a few weeks. I was pleased in a vague, detached way, although I sometimes thought I should be hap-pier about losing weight without even trying.

I was thin, and in my world thin was good. I worked in magazines. I went to fashion shows. People told me how fabulous I looked while all the time I wondered who this stranger was who inhabited my skinny Earl jeans.

I lost interest, too, in everything that I had once loved. My garden deserted me. It grew, unwatched and unappreciated. My mind was on other, more important, things. My 10-year marriage was dying and crawling painfully towards its conclusion.

My husband Jonathan and I had begun to bicker destructively. “Does everything I do annoy you?” he asked. “Yes.” He turned away. We had developed our own sad pattern. I attacked, he withdrew.

My life had changed in other ways. I had gone back to working in magazines, as the editor of Red, after a decade working as a writer in absolute peace and quiet. I was not used to so much noise, or the incessant, urgent demands of a staff of 30 and found it, frankly, difficult. My marriage finally ended. I moved out. Jonathan could not, he said, face moving.

I found a flat near the house so Molly could move easily between us. Jonathan went to see a therapist, about the marriage breakdown and other things. It did not occur to me that I needed to.

At about the same time, I fell in love. Absurdly, insanely and catastrophically in love and with somebody I should not have been in love with. I had felt the pull of it for months, but had done nothing about it. I thought, even, that I might be going insane, thought that I was making the whole thing up.

It was only, finally, when we came together that I knew that I had been right all along, that the hugeness of the emotion I was feeling did not exist in isolation. It didn’t help. I felt madder still, an insanity compounded by guilt and impossibility.

Love, as the scientists tell us, is enough to change anybody’s brain chemistry. And I was in love, not just with my head and my heart but with my body and soul too. The connection was inexplicable, even to myself. And so I did not try to explain it. I was more lost than I have ever been.

His name was Tom. It still is. When we met, he was with somebody else, in situation, but not emotion. We did nothing. It was like watching a car crash. There were children involved. We talked, we kissed, we made no plans. I went to see my doctor for some sleeping pills. She told me that early waking was a sign of depression and prescribed antidepressants. I didn’t believe her, told her that I was not depressed but simply tired from getting so little sleep, that I had a few too many things on my mind. She listened to me patiently then suggested a counsellor.

The NHS waiting list was, at minimum, six months. I let her put my name down although I knew that, in six months time, I would be better. I insisted, again, on sleeping pills. She refused, prescribed me antidepressants, explaining that as the depression lifted, so my sleeping patterns would return to normal.

I took the pills. I continued to wake at 3.20 every morning. I thought that she was wrong in her diagnosis. The antidepressants did nothing for me so I could not be depressed. I just had too much on my mind. Two months later, I started to cry. I woke, crying, and I went to sleep crying. In between, I washed my face, got dressed and went to work. It still did not occur to me that I was depressed. I was just sad, about the ending of my marriage, about loving somebody who I should not love.

Four months after we separated, Jonathan became involved in another relationship. I was pleased for him. I knew, from my lack of jealousy or pain, that our marriage was truly over. Even so, I carried the guilt of its ending like a thundercloud. “Why are we doing this?” I said one day as we were packing up the family home.

Jonathan looked sad. “Because there is no other way. We both know that.” “Yes,” I said, and went back to packing up boxes of china and glass. WE dismantled our marriage slowly; it took us over a year to sell the house.

During that time, I moved twice, into different flats, and moved in and out of the family house twice too. It was unsettling, but I was already unsettled. I kept on taking the antidepressants. They did nothing, but my life was a mess. I was physically unwell too, with an underactive thyroid, or hypothyroidism as it is known, diagnosed a year previously. “It’s only mildly underactive,” my GP said. “Borderline. Nothing to worry about.” And so I didn’t.

Mental health professionals, however, take malfunctioning thyroid glands very seriously, for good reason. The thyroid, which governs everything from metabolism to mood function, used to be known as the gland of emotion. It is hugely implicated in depression.

According to one report, 25% of women in psychiatric units have an underactive thyroid. Often, it is only borderline, which is why its implications regarding severe depression are often missed by general practitioners, who tend to regard a mildly underfunctioning thyroid as bothersome but not serious.

I knew none of this at the time and, taking my lead from my GP, did not take its implications seriously even though I had felt extremely unwell before I was diagnosed. I was tired all the time. I slept as if I had been knocked unconscious and struggled to wake in the morning, dragging my leaden limbs through the day. I was always cold; my fingers white and numb even during the summer, when I kept a heater going at full blast in my study. If I got too cold, I found it almost impossible to get warm again and resorted to lying in a bath with the hot water running.

My arms and legs ached constantly, so painfully that, at times, I took painkillers every four hours. And my weight, which had been the same all my life, kept going up despite eating very little. Stranger still, my eyebrows started to fall out and my skin was so dry I was almost bathing in moisturiser. I felt constantly low and depressed but I was working too hard and had a small child who needed me. I was ripped in half by guilt. Of course I was depressed and tired.

“It’s your age,” a locum GP said. “You’re probably menopausal.”

He was a young man, with ears that stuck out and were so red and shiny it looked as if he scrubbed them daily.

“I am in my forties,” I said with as much outraged dignity as I could muster in the face of his blank, young indifference.

He did not look up from his notes. “Exactly.” His eyes flickered across the pages. “And you have a small child and you work.” He looked over at me as if to say, what did you expect?

My ruinous love affair continued. We fell more and more in love, ran towards each other and away again. We were as intimate with each other and as estranged from each other as it is possible to be. We did not see each other for weeks on end and then came together in cataclysmic passion.

Tom grew more and more miserable, until he was almost speechless with pain; handling his difficulties by shutting down emotionally or disappearing for days. I knew he could not bear to leave his children or break up the family even though, as he said, the relationship that should have pinned it all together was already broken. Only the surface remained intact.

I did not want him to leave his children but I knew, too, that I could not bear him to leave me. He had to and so we agreed to part, again, only to come back together when the pain and longing grew too much for either of us to bear. And so it went on.

The crying grew worse. I was scarcely sleeping. I started to cry in unexpected places, at inconvenient times. One day, I cried at work. I was mortified. I never cry at work. I decided that I was exhausted, and took a week off. It was the end of June. I spent the days walking around London, wearing dark glasses, with tears streaming down my face. I walked for hours, every day. Looking back, I see that I was trying to walk my way out of depression.

After that week of near total collapse, I went back to work. I sat through meetings, flew to Milan and Paris, tried to keep my staff inspired and lively. An editor is nothing if they cannot give inspiration, leadership, a sense of belonging. I said nothing about my own misery. I hoped, passionately, that it did not show.

ON A grey Sunday afternoon, I was sitting alone in my rented flat and feeling low. I turned on the televi- sion, for company. A photograph of Paula Yates flashed up on the screen and a voice said: “Paula Yates is dead.” I turned the televi- sion off, and then turned it back on again, as if, by chance, I had tuned in to some unknown, extraterrestrial channel. “Paula Yates is dead,” said the voice. “She was found in the early hours of this morning.”

I could not believe it. I loved Paula. We had been friends for 20 years. We met when I was a young journalist sent to interview her about her book, Rock Stars in Their Underpants. She was well known but not particularly famous.

This was a few years before Live Aid and before Bob Geldof became, as she put it, “a saint”. And before she became, as she also put it, “the Antichrist”.

We started talking and we just carried on, for years. I used to spend weekends with Paula and Bob in the country, just so we could talk. She made me laugh more than anyone else I have ever known, except perhaps Nigel.

Depressives, when they are not being depressed, are often the funniest, most blackly comic people around. She had been away for the summer, was full of life and plans for the future. How could she be dead? We had talked on the phone only the day before and had arranged to see each other the following week.

More than that, over the past year we had spent a long time discussing our mutual difficulties, and how we were trying to handle them. And, even though Paula was in a far darker place than I was, she still kept trying to pull me through.

“We must be strong,” she kept saying, “we’ll get through this. I know we will.” And now she was gone. I shouted at her face, laughing on the televi-sion screen. “You promised. You promised that we’d both get through.”

Miss Marigold, I called her, because Paula loved cleaning, just as she loved her pink rubber gloves. She wore them with diamonds, a cocktail frock and high stiletto shoes. She wore them as you would imagine Paula would. None of it was fake; it was simply the way she was. She even wore cocktail frocks on Sunday mornings, in the garden. She loved to clean, to try to restore order to her somewhat chaotic life.

When she was admitted to the Priory with severe depression, they sat her in the hospital garden and filled her room with torn-up pieces of newspaper. Then she was taken back to her room and made to sit there, amid the torn-up newspapers, without cleaning up. She thought this was hysterical. “The press kept saying I was put away for drug and alcohol addiction.

Actually, they locked me up for being a housewife.” Very soon after Paula died I was sacked as editor of Red. Almost the last thing I did before I left was to write her obituary. The management wanted more celebrities, more shopping, more make-up secrets. They wanted fewer words. I didn’t argue. I knew, before they said it, that I was the wrong person for their job. I had always known it.

The magazine I wanted to make, and the magazine they wanted to sell, were two different creatures. I should have listened to my instincts and understood that I could never have done what they wanted. Except that I could not admit it. I could, and would, admit nothing.

The truth was that I believed that if I was really good at anything, I was good at editing a magazine. I had believed it for years, since the success of Elle. I had been told it for years.

So the failure of my editorship of Red was not simply the failure of a job. It was the destruction of an absolute truth about myself. With it went a large part of my identity.

With it came an overwhelming sense of loss, on top of all the others. I was crap at my job, I was crap at marriage, I was crap at love. I had lost at them all. A good friend had died. I had lost her too. And depression, as many experts have pronounced, is almost always about loss. I did not know that at the time.

I left the job quickly, by the end of the week. The following Monday, I woke, as usual, at 3.20. There was a storm, rain lashed at the windows of the bleak, rented flat in which I was living.

It was cold, and damp. I had run out of cigarettes and the shops were closed. I wanted to go home, to the house I had known and loved for 10 years. But I was already at home. I could not go to work. There was no work. I wanted my child but I knew that in that state, I wasn’t much of a mother. I wanted my friends but I did not know how to tell them what I felt.

If losing my job had been my only loss that year, I doubt I would have fallen so hard or gone so low.

Loss, or abrupt and unwelcome change, causes stress and extreme stress, according to the scientists, changes the chemistry of the brain. Those chemical changes are always found in those suffering with severe depression. Depression doesn’t cause the changes. Depression reflects them. And my brain was changing, fast.

It was October. That’s when it got really bad. I told nobody. I did not know what to say. I was too ashamed, and confused. I still had a place to live, money from a redundancy payout, a child I adored, friends I loved, work if I wanted it. What right did I have to be depressed?

I thought that if I opened my mouth to talk, the tears would start and they would never stop. And so I avoided talking, to anyone. Three months later, I was admitted to hospital with severe clinical depression. In all those losses, I had lost myself.

© Sally Brampton 2008

Extracted from Shoot the Damn Dog by Sally Brampton to be published by Bloomsbury on February 4 at £15.99. Copies can be ordered for £14.39 including postage from The Sunday Times BooksFirst on 0870 165 8585

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