Dr S's receptionist moves with an aloof, feline grace down the hall. I follow in her wake of Opium, feeling clumsy and inferior. At the examining room door, she turns to gesture me inside. Alone in the small room, I slip the paper smock over my clothes and struggle to fit my long hair into the paper cap. I can hear the blood pounding in my ears. I shift uncomfortably on the narrow exam table. How much longer? Five minutes? Fifteen?

Then, miraculously, the door clicks open and Dr S enters the room, a tall, good-looking man of about 45, as handsome a deity as any Hollywood casting director could have dreamed up, wearing surgical scrubs which are somewhat rumpled and specked ever so slightly with traces of rusty blood.

"Hope! My dear, good morning. How are you?"

"Fine," I say, which now that he's here is less of a lie.

Dr S approaches me, standing so close I can smell the piney cologne rising off his warm skin. His brows knit together as he studies the bump on my lower lip, a flaw which I know is jarringly obvious in spite of my careful application of flesh-toned lipstick. "We're going to fix this today." He presses the bump and I wince, not only because it hurts, but because I need to see the tender regret in his eyes at having caused me pain. "Sorry. I've got to check a post-op patient, and then we'll begin. It will only be a few more minutes."

When the door closes behind him, I feel I'll jump out of my skin. For the first time, the reality of the procedure hits me: it will hurt what he's going to do; how could it not? As if the painful bump and my pounding fear are not enough, the familiar blaming refrain descends upon me like a hammer - this is all your fault. You brought this on yourself. It is your punishment for wanting something so frivolous, so silly and wasteful. You vain, selfish fool.

When the door clicks open again, my heart gives a bleat of joy. But it is only the nurse, come to lead me to the operating room.

"Hope." Dr S stands at the door. "Before we begin, there's something I want to show you. Come in."

To my surprise there is a woman on the operating table. She is dark-haired, doe-eyed, perhaps 40. Her body is draped in a white blanket. She blinks at me and smiles sleepily. "This is Alix," Dr S says.

On the white paper sheet beneath her head are half a dozen or so nickel-sized reddish blotches, where blood from an unseen wound had dripped.

"Alix just had what I like to call a 'lunchtime lift'. Have you heard of it? It's revolutionary," he says. "State of the art. It gives the effect of a brow lift without any of the downtime." There's a surge of bravado in Dr S's voice; the voice of a showman, a salesman? I have no interest in a brow lift, so I do not know how to react. Dr S approaches the woman on the table, pressing one of her manicured hands in his own. "Come closer, Hope," he scolds gently. "Don't be shy."

I feel a tinge of annoyance: this is supposed to be my surgery, my moment. Alix turns towards Dr S and smiles up at him; the look of trust and intimacy they exchange makes my throat ache with longing.

"Just look at her," Dr S says, his eyes still fixed on Alix. "Isn't she lovely? She looks 25 years old."

My smile, automatic, hides my confusion. I myself am only 23.

"You could benefit from this, too, Hope." Dr S returns the full wattage of his gaze on me. "You're very girl-next-door, and this would give you an exotic, sort of foreign look. Here, let me show you."

Exotic. Foreign. How can I resist a delicious, illicit offer to become someone I am not? Does Dr S see inside me, does he know that, if I could, I would shed my face and body, my very self, on his table as nimbly as a snake sheds its skin, in favour of becoming a beautiful stranger? Almost somnambulant, I allow Dr S to position me in front of an oval mirror on the wall. He stands behind me, putting his fingers on my temples, pulling the skin back and upward. "Look," he says. His voice is low and so near my ear that the little hairs on my neck rise. The change in me, though subtle, is startling. My round, green eyes are now slightly uptilted, catlike, the eyes of an Italian movie star. I want what I see in the mirror, impulsively and fervently.

"If you do it today," Dr S says softly, "at the same time as your lip, I'll only charge you one thousand. Usually I charge $1,600. I always give a break on multiple procedures."

A beat passes. When I don't respond, he says, "If you like, Alana can just throw it on your credit card."

Of the three plastic surgeons I've been to, Dr S was the first who did not raise his eyebrows upon noticing my age on my chart. He did not fix me with a quizzical look as I ticked off the procedures I'd already had. Lips. Nose. Cheekbones. Lips again. From that first consultation, I could see that, with Dr S, nothing I asked for would be off-limits. It thrills me, the dizzy possibility of it. But it frightens me, too. Without the brakes of someone else's disapproval, real or imagined, to slow me, what procedures will I not undertake? How far will I go?

"What do you say, Hope?"

To refuse requires more assertiveness than I can muster. The stakes seem enormous: to risk losing Dr S's favour; to languish for ever in dreary girl-next-doordom. "No!" I cry.

"What?" Dr S's brown eyes are round with surprise.

"I mean, yes! Sorry. I meant yes. Let's do it." Dr S's approving smile warms me like a rush of love.

I recline on the operating table, giving myself up to the sterile ministrations of the nurse. It is to be a local anaesthetic. Dr S leans over me holding a large syringe. With my face tilted towards his, he could almost be leaning in for a kiss.

Numb now, my lip feels thick as bread dough. The nurse dabs at my mouth with a square of white gauze, which comes away livid with my blood. I close my eyes. Vivaldi soars on the stereo. Dr S's hands on my face are cool and dry in their latex gloves. I am safe now.

"This is the thing the other guy is terrified of doing." He means the other surgeon, Dr R, who inserted the strip of Gore-Tex that is now pushing its way out of my lower lip. Gore-Tex is a synthetic material commonly used to insulate winter coats. It was supposed to give my lip a luscious, full look. But instead of a pretty pout, I got this unsightly, infected lump. A cyst, I told my roommates.

"Doctor," I say, a whisper, a slurred prayer. "If there was an earthquake right now, and the power went out ... "

"What would happen to you?" Dr S finishes my thought. "I wouldn't leave you."

I wouldn't leave you. This is what I needed so much to know. If the ceiling collapsed, if he were hurt, if he had to stagger to attend my supine body, he would. Is this what love feels like, I wonder.

My eyes flicker lazily. There is a small metal table beside me, a few inches from my face. Atop it, I see several bloody surgical tools. Casually, I regard my own blood, unmoved. But what is that other thing, that narrow strip of pale skin from which sprouts short, stiff brownish hairs like a squirrel's? What is this bit of roadkill on the surgical tray?

My eyes strain to see the floor below. There, on the white linoleum, strands of my own long hair lie splayed in a messy heap. With a jolt it hits me. My skin. My hair. My own severed flesh on the tray.

My breathing seems to halt. Calm, I tell myself, calm, calm. Breathe. Don't have a panic attack now. What's done is done.

"Are you all right?" Dr S asks.

"Yes." It shocks me that I can feel such terror and speak so offhandedly. "It's just that I'm staring at a chunk of my scalp on your table."

After a beat, Dr S seems to register what I've said. His staccato laugh pipes out. "Did you hear that, Jeanne?" he says to his nurse. "A chunk of her scalp. Beautiful and funny! I like that."

His laughter washes over me. Beautiful. He thinks I'm beautiful. I close my eyes, trying to recapture the feeling of ecstatic surrender. I tell myself, you are the straw that he will spin into gold.

I almost believe it.

The heavy click of the deadbolt reassures me as I turn my key in the lock that my roommates are not home. As I'd hoped, the apartment is silent and still. I moved into the apartment from my parents' house a few months ago, after my fourth surgery, when my mother told me that she would not allow her daughter's "self-mutilation" to occur under her roof.

My mother always performed best in her maternal role when there was something wrong with me. Whether it be a bad haircut or a cold, she became an engine of motherly concern. She would bring me magazines, soup; she brushed my hair; she hovered. Healthy and robust, I became somehow frightening. Damaged, I was a bird she could fold under her wing. But this was different. A case of the sniffles, a too-short fringe, or a lousy boyfriend were manageable ailments. This time, I had damaged the part of myself she both worshipped and feared: my appearance.

I have heard that mother birds sometimes push their young out of the nest if they are sickly or deformed. As for my mother, she took one look at her disfigured offspring and fled the nest herself. She checked into the Ritz-Carlton in Marina Del Rey and called my father with explicit instructions that she would not come home until I was gone.

And so I found myself in this apartment, the fourth in a quartet of roommates, all single young women in their mid-20s. Every morning I lie in bed and listen to the three of them getting ready for work, for school, for whatever business or engagements their day may hold. Showers run; coffee perks. I listen to their preparations with a sense of wonder. How are they able to go out into the world each day, fresh and full of energy? How is it that I have lost the knack for everyday life? I can't imagine going to a job, even looking for a job.

I had drifted in and out of graduate school the same way I drifted everywhere in my life. I had long ago lost interest in academic subjects, my early talent for creative writing eclipsed by my intense fixation on my appearance. My roommates must wonder about me, the new girl, who mysteriously doesn't work and whose days are unaccounted for. I'm polite, evasive, elusive. I prefer to remain anonymous.

Now, in my bedroom, I catch my reflection in one of the mirrors on my wall. I'm startled, for a moment, at my uplifted eyes. I get up close to the mirror now, turn my face from side to side. I like my new eyes, I decide. They do look somewhat exotic; they will look even more so with dark make-up, perhaps some kohl liner. I will experiment, play with them as with a new toy; it will keep me busy for a while.

My father's parents, Clayton and Eleanor Hathaway, were not the richest people in Hancock Park. There were the Van de Kamps and the Ahmansons and the Bannings. But my grandfather was revered because he handled something of utmost importance to them: he delivered their babies. My father's younger sister, Diane, still lived in her girlhood bedroom on the second floor. Diane suffered from an array of vague but never-ending physical ailments: stomach distress, fatigue, lightheadedness.

My mother said the Hathaways didn't like her because she wasn't a society girl. But I suspected my mother needed to be fussed over to feel important, and the Hathaways were far too refined for fussing. Any excess of emotion had been bred out of them, like an overbright colour dulled by many washings. My father's family, too, had a certain established order. Each of us had a title and a role. My mother was the rogue. My grandmother was the genteel gentlewoman. My father was the good-natured goof. I was the pretty one.

My mother's desire for me to be glamorous, stunning and charming - to dazzle my father's family - added to the pressure I already heaped upon myself.

Snapshot: a sunny Sunday afternoon, my senior year of high school. No picture was taken on that day, but if it had been it would look like this: the three of us, my mother, my father and I, a perfect family trio, enjoying the day by our pool in Hancock Park.

My mother is stretched out on the sun-warmed deck near the shallow end; I am lying on my stomach on a chaise longue at the other end of the pool. My father swims laps. Both my mother and I wear bikinis. I reach back and undo the clasp of my bikini top to tan my back. Relaxing under the molten heat of the sun, I close my eyes.

My father finishes swimming his laps and gets out of the pool, hopping from foot to foot to shake the water from his ears. My father at 40 is a good-looking man. He has aged better than my mother. Whereas in youth he was scrawny and gangly, with age he has filled out into a broad-shouldered, well-built man, with a thick head of wavy, dark hair and blue eyes. He spreads his towel on the other chaise, beside mine; the lounger creaks under his weight as he flops on to it. I raise my head slightly, open one eye to smile at him. But he isn't looking at me. He is looking across the pool at my mother, who has abruptly got up, and is striding into the house without a word. Just before she steps through the door, she gives him a look of such mysterious searing intensity that I shiver under the hot sun.

"What's with her?" I say, trying to be jokey, to make light of what I want to assume is just another of her mood swings.

My father stares at the place where my mother had been as if she is still there. Something has changed, minutely, in the air between us. He says, in a stilted voice, "I think I'll go in."

My parents fight over the most trivial things; my mother's anger and unhappiness bubble up often and unexpectedly, like dinosaur bones in the nearby La Brea tar pits. I continue to lie outside by the pool, though my heart beats more rapidly now. Finally, I gather up my towel and go inside.

Something is wrong. I feel it right away; my mother's rage hangs in the air like the stench of something rotten. Down the hall, from behind their door, I can hear my parents' animated voices. My father's, low and strained, is pleading, my mother's shrill and furious.

Don't listen, I tell myself. I turn on the shower, one hand testing the water's temperature. There is a towel hanging on my bathroom door, but I tell myself I want a fresh one. Halfway down the hall to the linen closet, I freeze. My mother is screaming. "What the hell is going on between you two?" she shrieks. "Why did you sit next to her? Tempting you, in that little bikini! I know exactly what she's doing, and I know what you're thinking, don't think I don't!"

I know it, I knew it, yet still it takes a moment to realise: she is talking about me. I look down at my breasts in the bikini top, the flat terrain of my belly, and freeze with terror. Dear God.

I cannot hear my father's panicked, protesting response. Whatever he says only seems to inflame my mother further.

"You're attracted to her, aren't you?" she wails. "Admit it! She's young and beautiful, and I'm not! I'm not an idiot, you know. Don't think I can't see what's going on here, right under my fucking nose!"

"I didn't sit by her, Virginia." My father's words are calm, measured and perfectly clear. Does he know he's lying, or is sitting by me simply not worth defending? I want to barge into their room, smack him, to shake him until he acknowledges me. I'm your daughter, for Christ's sake! What is wrong with sitting next to your own daughter!

I slink back down the hall to my bathroom. I peel off my bikini, avoiding the sight of myself in the mirror. I turn on the water, so hot I can hardly bear it. I push my face into the scalding spray, willing it to burn away what I've just heard, to sear the pain that has opened up inside me.

When I can't sleep, when there aren't any new magazines to distract me, when I can't possibly find another excuse to visit Dr S's office, these are the days when despair settles into my body like fever, making my bones ache. It is a misconception, the idea that depression is all in the head. I rush back and forth to the mirror, checking, always checking; for what? I'll think, what if I had bigger lips? I'll think about this for a while, play with the idea. What if I had bigger lips and a smaller nose? What would it take for me to be satisfied with my appearance? Answer: everything. Nothing. Nothing and everything. The riddle I am really trying to solve is: what will it take to make me happy?

Mirror, mirror, on the wall, I just need larger breasts, that's all! Just this one little improvement and - happiness! Yes! Bigger breasts! All those other nagging, painful thoughts are eclipsed. All I can think about is how much better I'll look and how much more confident I'll feel with this thing, this change I want to make.

Maybe, if I weren't so vain and squeamish, my obsession would have taken a more predictable form. I would stick a finger down my throat or dig a razor blade into my arm. Or step on the scale 50 times a day, count every calorie. Wouldn't all of these achieve the same purpose? Yes, but then again my fascination with plastic surgery feels so right. It is the perfect modern-day affliction for a poor little rich girl like myself. How appropriate that a Hathaway should choose a route to self-annihilation that is elaborate, expensive and essentially passive. I'm not brave enough to carve myself up in private; I've got to pay someone else to do it.

What if I had bigger breasts?

After the initial thought, obsession begins to take over. I am compelled to go through with it. It becomes a personal mission, a test of my resolve.

I'm at Dr S's surgery; he sits down on a little stool beside me, and my heart lurches.

"Doctor!" That word. "I was thinking about breast surgery." The words spill out of my mouth in a breathless rush, like a sob. "What do you think?"

Dr S gives me his full attention. "Larger or smaller?" he asks.

His question startles me. Isn't it obvious? "Larger."

Dr S's face lights up. "Breasts are my speciality," he says. "Take off your shirt. Let's see what we have." I shed my shirt and bra, utterly unselfconscious. His eyes on my naked skin raise goosebumps along my arms and stomach. I put my arms at my sides, my exposed breasts like offerings. Dr S nods his head, looking slowly from one breast to the other. He reaches out to cup each breast in his hand, as if weighing it in his palm. It is all I can do not to cry out.

"The right one is a little bigger than the left," he says. "But on the whole, you've got very nice breasts."

I feel deflated. How can he not feel the heat, the intimacy of this moment?

"After the surgery, though, you'll have traffic-stopping breasts."

After the surgery? I think, startled. I haven't decided yet.

"Your skin has wonderful elasticity." Dr S's voice is husky, but for me the moment is lost. "You're very lucky, Hope. With your young skin and your frame, you can carry off a very large implant."

"I don't know if I would want very large breasts. The thing is ... I, uh ... I really haven't given it enough thought. I have to think about it."

Disappointment - or is it some darker emotion? - clouds Dr S's face. "Take your time," he says unconvincingly. He is poised at the door. He has other patients waiting to see him. Patients quicker to make a decision than me. I cannot take up any more of his time. "Let me know what you decide," he says.

I read this about suicidal people: sometimes, they decide finally to go through with it simply because they can't stand that little voice in their head any more telling them to do it, do it. They just want to stop the noise. The same is true for other compulsives. Self-mutilators, hair pullers: sooner or later, they give in to that little nagging voice.

Do it, do it, do it . I can't tell any more if I really want bigger breasts, or if I simply want to stop obsessing about them. I stop by Dr S's office and ask his assistant to schedule the surgery.

Four weeks later I feel as if there is a truck parked on my chest. I can't turn or breathe deeply or cry. I don't want to move from my bed. Once the morphine wears off, knives stab at my chest. Rolling over is out of the question. The exertion of getting up and taking a few steps makes me pant and weep with agony.

It is April Fools' Day, and I have new breasts.

Time passes, the pain eases but I am nearly broke. I need money. I tell myself that this is why I answer the ad, in the classified section of a local newspaper. The ad says, in bold letters: figure models wanted, no experience, fast $$$. I keep the ad for a week or so before answering it. I like the sound of it: Figure Modelling. It has a nice, artsy ring to it. Like something out of Degas. Of course, a part of me knows that it isn't going to be this innocent. Especially when the ad is placed alongside those advertising escort services, sensual massage, and phone-sex lines. I know I will not be posing chastely for a master drawing class. I know, too, that the reason I am answering the ad is not entirely because I am broke.

It has come down to this. I am so caught up in my physical self that I believe it is all I have to offer, all that I am. I cannot fool myself any more that I am improving my life, that I am on a path to something significant, that Dr S will love me.

There is no misery like the misery of being trapped in your own brain. The more I think about my problems, the more tied up in knots I become. I do not want to be alone, or pretend that I am not lonely. I don't want to pretend at all. I want connection and excitement and meaning. I looked for those things in Dr S's office and, for a time, I thought I found them there. A long, long time ago something important inside me got crushed, and that little wounded thing is still in there, tiny, afraid to unfold itself. I can't do this any more.

I realise I need help

© Hope Donahue, 2004

· Hope Donahue was diagnosed as having obsessive-compulsive disorder. She has had psychotherapy and been treated with Prozac. She does not yet regard herself as completely "cured", having had collagen in her lips twice, Botox injections, permanent make-up tattooed on her brow and lips, and having booked and then cancelled four nose jobs. She had her breast implants removed. Now 36, she is married with four children and lives in New Jersey.

This is an edited extract from Beautiful Stranger, by Hope Donahue, published next month by Vision, priced £16.99.