New York City, New Year's Eve: The best time in the best place on Earth, and, in 1991, with the twin towers vaulting into the black sky, the stage is set for celebration. My husband, young son and I have just gotten into town and are staying with friends on the Lower East Side. Gina's been like a sister to me since we met as book designers at Random House 10 years ago. She and Scott took over our loft when my boyfriend and I married and moved to Washington. Parents now, they live with their toddler near Alphabet City. I am at home in their place, I think, because it is so much like our own. Comfortable and eclectic, it is filled with books, photographs and the visual ephemera designers tend to collect.

This visit is such a luxury. Gina and I are already gabbing and drinking tea. We will set out soon for a big party at the loft of a mutual friend. A pizza has been ordered for the children, a sitter is on the way. My husband goes out to pick up the pizza, taking our son in tow. It seems they are gone only seconds before I hear my son's voice echoing through the hallway: "Mommy!" He is limp from the train trip and melting down, so my husband delivers him back to me and resumes the errand alone -- at which point Sam decides he wants to go with Daddy after all. This boy sailed through the "terrible twos" like a champ. He is 4 now, and the tantrums are something new.

No, I say, we are staying put until Daddy gets back. Sam's thunder erupts again, but I have to let it pass. I can't give in to these irrational demands.

How ironic, then, that a darker, more furious storm of irrational thinking is happening inside my head. The truth is, I am afraid to venture out to find my husband. Why? There is crime in the neighborhood, sure, and drugs abound, but I am a seasoned New Yorker, and the East Village streets are alive with everything I love: art and music, great food, galleries and the high-church eccentricity I so sorely miss in Washington. The truth is, tonight I am terrified. But I am not afraid for myself. I am afraid of myself.

I am afraid I will do shameful, filthy things.

Last month, I was afraid of causing arson, so I could not touch or even look at matches, ashtrays, cigarettes, lighters or anything else associated with fire. Right now, I am afraid of AIDS, so I'm afraid of these streets and of being alone for even a minute. My mind swims with an inventory of possible mayhem: I might have unsafe sex with someone -- a crack addict! -- in the shadows. I'm afraid of the sidewalks, which glimmer with miscellaneous gobs of spit. I'm afraid of the shabby bodegas, abandoned cars, the bottomless dumpsters and scummy gutters running with God knows what. I might stomp in a puddle, splash something onto my mouth, then kiss a friend Happy New Year. The friend might have a tiny cut -- a shaving abrasion! -- get HIV and eventually die because of me. But the friend is sexually active and might get HIV anyway, so I'll never be sure if it was my fault and I'll spend the rest of my life punishing myself for his death, worrying that I'll go to Hell after I die for killing him.

The anguish I feel is unbearable. I excuse myself to go to the bathroom. Safe behind the closed door, I stand, perspiring, and whisper feverishly into a towel to myself, to God, the things I must say to neutralize the horrid possibilities. I can hear Gina in the kitchen, talking to her daughter and to Sam, rinsing the dishes and clearing the mugs. Even though she and I have just been talking and sitting in close proximity, Gina, like virtually everyone else who knows me, has no idea this opera is playing out in my head. And all the while it is playing out in my head, I am fully aware that it is crazy -- the fact that proves I am sane. I am absolutely sure I will not do any of the things I fear. I know how HIV is spread. I have never done anything antisocial. The thoughts that torment me are a loop in the fugue that is OCD: obsessive-compulsive disorder.

Although I am sane, some part of my brain bubbles with repulsive thoughts and intolerable images that come completely against my will. But I cannot shrug them off; my brain is not satisfied by the knowledge that I will never do terrible things. A grievous feeling persists in me that demands, "How can I be sure?" The result is a jarring and inexplicable disconnect between this insuperable anxiety and everything I know to be true. How is it possible for me to carry on as I do, social on the outside and seething on the inside, with a sort of bifurcated brain? I've gotten awfully good at it. In 1991, I'd been doing it for almost 30 years.

Although the doctor's office was tucked among familiar things -- my son's school, the Whole Foods where I shopped, our veterinarian -- I sat in the waiting room tense and febrile, making eye contact with nothing. I was emotionally threadbare, red-eyed and rawboned, so thin I disappeared inside my dress. It was just after that New Year's Eve in New York, and I recognized the signs of a breakdown. My anxiety level was spiking, my symptoms were insistent. I was slipping and could not get purchase on my slide.

I had been through this several times before, but there was a difference in 1991. I was a mother and, for the sake of my son, could not go haywire. I was also a wife. The stress of getting married and moving to Washington in 1984 had ambushed me, and my husband had been forced to deal with a doppelganger of the woman he loved, one who couldn't eat or sleep and engaged in bizarre rituals -- like turning the same page in the New Yorker back and forth for hours on end. I could not put him through that again.

Therapy usually worked to help me manage my symptoms, but something engulfing was coming, and I needed help to stand my ground. That meant medicine. I'd sworn off psych drugs forever after a wretched experience with a crude anti-anxiety medication in the 1970s. But the word was that the new antidepressants, the SSRIs -- selective serotonin reuptake inhibitors -- seemed to work well for OCD and had far fewer side effects. I was willing to try them.

When I returned from New York after New Year's Eve 1991, I called the Obsessive-Compulsive Foundation, which referred me to T. Allan Ramsey, a psychiatrist in the District who specializes in psychopharmacology.

Our consultation was the same surreal exercise it always was with a new shrink: I unlatch the back door of my creaking, peeling circus van and trot out the whole bizarre menagerie of haints and spooks. Rather than the usual, noncommittal "uhmmmm" of the psychotherapist, however, I was comforted by Ramsey's friendly engagement. I liked him.

There was some trial and error. Prozac, the most popular SSRI, made me so agitated I felt like ants were crawling under my skin -- and it did nothing for my symptoms. Anafranil, a tricyclic antidepressant, helped but left me lethargic, and with a mouth so dry I could barely breathe. Nevertheless, I stayed on that for a year.

One day in March 1993, when I sat down for my appointment, Ramsey had news.

"There is a new SSRI that's been on the market in the U.K. and is available now in the States," he told me. "It's shown good results with OCD. It's called Paxil, and I want you to try it."

How apt that it was spring.

After several weeks the drug kicked in and, for the first time in memory, I could wake in the morning and open my eyes right away, without having to say a string of benedictions beforehand. I no longer had to check my watch compulsively to account for every minute of my time. After a month of taking Paxil, I could mail letters easily and not obsess that they were deals with the devil; read the newspaper and not fear I had somehow caused the bedlam in the headlines; pass strangers on the street and not worry I had committed crimes against them or conspired to commit crimes with them. And, amazingly, I felt no side effects.

It took me about six months to notice I was eating a lot of sweets, but because they were Entenmann's low-fat fudge cake and SnackWells cookies, I thought I had a free ride. I'd always been able to eat like a truck driver and not gain an ounce.

But my husband kept telling me I was getting fat. How could I be fat? I come from a family of swizzle sticks!

I do remember noticing that my yellow flowered sundress seemed to have shrunk in the dryer. I had bought it because, with its rose chintz print and ruffled cap sleeves, I thought I looked rather winsome in it. Somehow I now looked as nubile as Eleanor Roosevelt at the second inaugural. I wore it one sun-blasted afternoon to meet my friend Michael's train from New York at Union Station.

"Mim," he teased, "getting a little zaftig, are we?"

I looked down at myself. And that's what I saw: myself, not my shoes.

As I morphed from a size 8 dress toward a 12, I kept Ramsey abreast of my weight gain. He told me that the cravings could very well be a side effect of Paxil, but, at the time, neither of us was particularly worried. After all, what were a few extra pounds on my skinny body compared with the new life Paxil had given me?

My obsessive-compulsive disorder began one Saturday night during the summer of 1962, when I was 14. As I walked from the kitchen to the dining room for supper, the notion that I had leukemia floated over me, like a Halloween sheet. I sat with the worry for several days; then I had to tell my mother. She took me to see the doctor, a close family friend, who drew some blood for testing, all the while assuring me that even medical students get imaginary ailments. He called me himself when the results came back from the lab.

Miriam? This is Dr. Hyman, darling. I'm calling to tell you myself that I have your blood test results.

You do?

Yes, dear, I'm holding them in my hand, and you know what?


They are perfect, darling. Your blood is perfectly healthy. Will you promise me something?


Will you stop worrying?


. . . because your blood is perfect.




I hung up the phone, buoyant with relief, walked into the bathroom to fool with my hair, dropped the comb and watched it bounce and land in a funky corner far behind a radiator. I reached down slowly, picked it up, rinsed it off and thought, "Now I have leukemia."

The only things that assuaged the anxiety were rituals. Mine changed over the years as my bad thoughts shifted focus from my own well-being to thoughts of harming others. Nothing was safe for me; perhaps it is more accurate to say it seemed that nothing was safe from me. I feared that my thoughts might make planes crash, babies die and buildings burn. That I knew they could not was irrelevant. I was compelled to negate the thoughts somehow to prove I did not mean them. Sometimes I had to shake my head "no" when I thought no one was looking, or find the word "no" or the letters N and O in my surroundings or in whatever I was reading at the time. More commonly, the rituals involved touching and retouching objects, even retrieving things thrown into the trash. Later they changed exclusively to ruminations, thinking and rethinking, erecting great teetering ziggurats of thought. They consisted of syllables that meant everything to me, and I dared not drop even one, like a stitch, that would unravel my progress.

"I-never-denied-had-gave-or-did-any-of-those-horrible-things-I-won't-I'm-not-Mimi-is-my-name-God-forbid-Mimi-is-my-name-thank-God." I have said those words, and words like them, over and over in a vain to attempt to trap my thoughts in a box, to contain them, to stop them; I have said these negations so many times that they have become a part of my heartbeat.

They have never worked for long.

The less effective the negations became, the most intricate they grew. The more intricate they grew, the less sure I was that I was thinking them correctly. At some point I started saying them aloud. I was talking to myself. As you can imagine, it was dicey to say them when I was in public, and downright dangerous when I was driving a car. My compulsion was to establish -- to whom? to God? to posterity? to myself? -- that I was good, that I did not mean what was going through my mind. There was an Animals song that was popular when I was in high school whose lyrics became my mantra:

"I'm just a soul whose intentions are good / Oh Lord, please don't let me be misunderstood."

Just walking down the hall at school and humming that song became a surreptitious way to appease my need for expiation. It was certainly better than some of my other compulsions: During several weeks in 10th grade, the only thing that felt right to prove my innocence was to reach out of the shower while washing my hair and touch the bathroom socket with my sudsy hand, a compulsion that got shocked out of me one very, very lucky night.

I had no idea what was wrong with me until the year after college, when I shared my first apartment in New York with a college friend who was getting a master's of social work at Columbia University. I had my first real job, as assistant to the senior editor at Glamour magazine, and one of my chief responsibilities was typing form rejection letters. After a month or so, I became seized with the fear that I was typing obscenities into the letters. Checking them did not help because I did not trust what I read. I dreaded work and started to call in sick. When I could no longer keep my suffering to myself, I confided in my friend. She knew exactly what was going on.

Once she told me about OCD, I felt elated and amazed. It was inconceivable to me that anyone else had ever suffered such bizarre behavior, and having a name for it gave me hope. That year, I started psychotherapy. The symptoms did not stop altogether, but I was able to manage my illness most of the time. When the rare breakdown occurred, I'd stitch myself back together with more frequent therapy and a little Valium, and only my closest friends would be the wiser. By the late 1980s, however, I felt I had gotten the most I could out of talk therapy. My files of recollection had been emptied, my mind hosed down. I felt well enough to coast between what I considered 5,000-mile checkups with my therapist. Then came the spiral in New York on New Year's Eve.

I began taking Paxil at an advantageous time. By 1994, my marriage was unraveling, and my mother was exhibiting sudden signs of dementia. In 1997, as it became clear that my marriage was over, my mother had three hip-replacement surgeries, I lost my job in a corporate purge and, with a year's severance as a net, I decided to try becoming a writer. Stress had always caused an uptick in my symptoms; had I not been stabilized on Paxil, I might have gone to pieces.

My weight gain had become a constant topic of sessions with Ramsey, but I had made my choice early on: I did not like being plump, but it certainly beat feeling crazy. I tried a reduction in dosage and, later, a new, time-released version of the drug. Neither reduced my jones for sweets. Around 2000, I developed tremors in my hands and occasional involuntary jerking motions in my arms and legs, a side effect attributed to some SSRIs, including Paxil. Once Ramsey assured me that they were benign and not a sign of brain disease, they did not matter to me. Living with tremors, like being overweight, was a fair trade-off for the silence in my mind.

Michael Jenike, a professor of psychiatry at Harvard and director of the Obsessive-Compulsive Disorder Institute at McLean Hospital in Belmont, Mass., says SSRIs are "more likely to cause weight gain than any other class of antidepressants," and, on that score, "Paxil is by far the worst."

Brain scientists cannot fully explain what causes the weight gain, much as they cannot fully explain why the SSRIs work to ease depression, OCD and other mental illnesses. They are attempting to piece together the answers. According to Sheldon Preskorn, chair of the department of psychiatry at the University of Kansas School of Medicine, SSRIs were the first class of psychotropic drugs to target a specific molecular site in the brain, reducing the chances of unwanted effects on neighboring sites. Preskorn describes the working of the SSRIs with a complicated, clinical precision I shave to the basics here: Serotonin, the brain chemical most closely associated with both depression and OCD, flows through the synapse between neurons and back again to communicate chemical messages. Paxil and other SSRIs specifically target the uptake neurons to slow the reuptake of the serotonin, so that it lingers in the synapse. This appears to help patients with depression and OCD, although scientists are not sure why. At one point it was thought that such patients produce less serotonin, but scientists now say that appears not to be true.

Scientists have a similarly sketchy understanding of how Paxil and other SSRIs cause weight gain. Serotonin is associated with mechanisms affecting sleep, appetite, balance, sensory interpretation and the reproductive system; scientists believe serotonin may be implicated in disorders of these functions. Just why is unclear: Some people lose weight on SSRIs, some gain, others stay the same.

I was one of the unlucky ones. By 2004, I had to accept myself for who I was: a middle-aged woman with a thickened middle and an eating disorder. I ate healthy things -- grapes, pineapple, cherries or unsalted almonds -- but by the bowlful, and slice after slice of whole grain bread.

I also ate cookies. Three were never enough, and 10 were never too many. One night, as I stood in my kitchen staring down a bag of Milanos, I realized that it might as well have been a pack of cigarettes or a bottle of scotch. When I opened my refrigerator, I was in the thrall of something. I ran into a former therapist who hadn't seen me in years. "But you never had issues with food!" she said, genuinely astonished at the sight of me.

In the fall, I went to a gym to try a personal trainer and got shocked into reality. "I'm sorry, but I can't let you exercise," she said after taking my blood pressure, which was 150/96 -- too high by gym rules to use the facilities.

Six months later, I finally got up the courage to see my internist for cholesterol tests. He called me back with dismal news. My total cholesterol was 268. I needed Lipitor and exercise, or else. Ramsey prescribed the anti-seizure medication Topamax, which causes weight loss for many patients in the first few months.

In early June of this year, I spent a week alone at a yoga retreat in the Berkshires to kick-start a new regime. I rose at dawn every day for yoga and ate from a strict vegetarian buffet. I followed that with a week at the beach, where I walked for miles and swam every day in the surf. By July, I was 12 1/2 pounds lighter, my skirts were sliding off my hips, my blood pressure was normal, and my cholesterol levels were improving.

But I can't cue the fireworks yet. I now have two very potent chemical agents at work in my brain. Topamax is not without its downside. It makes me sleepy and thirsty, and, after several months, my balance is suffering. I can no longer hold a standing yoga pose without toppling. My excessive appetite is coming back, despite my best intentions, although for now the weight is staying off.

These days, I find myself beset by questions no one can answer for sure: Can I take Paxil forever? Must I take Topamax as well? If I regain weight and must switch drugs, will I have trouble going off Paxil? Of all the SSRIs, Paxil has the shortest half-life, which means that it is metabolized and washes out of the system the fastest. Stopping, even gradually, can shock the nervous system and bring difficult side effects. Even if I can switch without incident, will another drug work as well? Preskorn assures me that, thanks to the Human Genome Project, there are exquisitely precise pharmaceuticals to come. But will they come in time for me?

I'm keenly aware that the normalcy I enjoy now may be borrowed. No one knows if long-term use of Paxil will damage my body, and I worry that the drug's beneficial effect on my brain chemistry will diminish over time. I assume that OCD is napping in me somewhere. Even now, when I am overextended, or overly tired, there is a slight insistence in the

cadence of my brain. Much of the time, though, I am as steady as a pioneer. I believe I can face whatever is coming because I have endured all of what has gone before.

I remind myself frequently of a trip I took, alone, to Paris, for a glorious week in fall 2003. I woke up every morning in a tiny borrowed apartment in a North African section of the city and spent the day as I pleased, being, as the French say, a flaneur -- wandering the city at will. I ducked into used-book shops, boutiques and galleries. I spoke to strangers and once joked with some cops. I visited graves at Pere Lachaise, sat in the sun at Place des Vosges and ate couscous near an African market on le boulevard de Menilmontant.

One evening I took the Metro to my friends' place near l'avenue Georges V. It was my birthday, and they were taking me to dinner. The Metro stop near their apartment was Tour Eiffel, and, as I walked up the steps to the street, the Eiffel Tower was the first thing I saw, looming in the dusky sky like an enormous mechanical giraffe. As soon as my shoes touched the pavement, the entire tower lit up in tiny white lights. I stood there for a moment frozen in delight and, like a child, I decided that it was all for me -- for my birthday, for my trip, for my friendships and for my freedom. The last, alone, would have been more than enough.

Mimi Harrison is a Washington writer.