When Miriam was forty-one and single for the first time since her twenties, she posted a profile on a dating site, along with recent photos. The site allowed her to see, in real time, exactly who visited her profile.As she sat at her computer, a pop up box, “SillyUserName4U is visiting your profile,” would arrive—and disappear when SillyUserName moved on. Miriam, a technical writer, considered her looks reasonably good and not especially important. She rarely wore makeup. But each time a possible date browsed her profile and chose not to write, she felt rejected.“I’d write a funny note with details that showed I’d read the profile carefully. But when they visited I could see they were spending half a second on my profile, just long enough to look at a photo,” she says. “I tried lots of photos.” SillyUserName, Mr_Amazing, and the like were passing her by for one reason, she concluded: her nose.It wasn’t hooked or otherwise extreme—just a little long and wide—but now it was all she could see in every photo.QUIZ: How Satisfied Are You With Your Face?Miriam frequently got nasal infections and she had excellent health insurance. She guessed that she’d get coverage for surgery to straighten her septum (the wall of cartilage between the nostrils), reducing the chance of infection.A plastic surgeon who specialized in noses agreed. He also proposed to make her nose narrower and her chin slightly bigger (to balance out her nose) and to remove fat from under her chin and reinject it into the corners of her mouth, filling in creases that had deepened in her late ‘30s. Although Miriam told her doctor she didn’t like to think of herself as vain, he assured her she would like the results, and she knew her self-esteem was plummeting. She decided that it was worth the extra cost for the cosmetic portion of the procedure.But can cosmetic surgery deliver happiness?Looking at the numbers alone, you’d think yes. Counting non-surgical fixes such as injections and laser treatments, the total number of cosmetic procedures has almost doubled since 2000, according to the American Society of Plastic Surgeons.In 2010, nearly 300,000 women had their breasts enlarged, which is the most common cosmetic surgery procedure. Rhinoplasties are the second most popular (among women), followed by procedures to liposuction, eyelid reshaping and “tummy tucks.”While the science is young, psychological studies so far seem to confirm that cosmetic surgery patients are not less mentally healthy than other people and large majorities are pleased with the change in their appearance. On the other hand, although many patients, like Miriam, hope for a boost in self-esteem, there’s little evidence that cosmetic surgery will help for long, according to researchers.“The key study does not exist yet,” says Tilmann von Soest, of Norwegian Social Research, in Oslo, who studies body image and self-esteem. Most existing studies, he says, follow patients for only a short time and don’t compare them with a control group of people who haven’t had surgery. However, in the two most recent studies with longer follow-ups, “no or only small changes are found in general self-esteem, depressive symptoms, and health-related quality of life.”The most comprehensive of these studies followed 98 women and two men for two years but did not have a control group. Recruited from eight surgical practices across the United States, the patients filled out questionnaires probing their satisfaction, body image, self-esteem, and symptoms of depression before cosmetic surgery and again on four more occasions spread out over the two years. Each subject had undergone at least one of five popular procedures, including breast augmentations and rhinoplasty.As expected, a large majority—89 percent—said they were either “somewhat satisfied” or “extremely satisfied” each time they filled out the researchers’ questionnaires. In fact, even after two years, 78 percent said they were “extremely satisfied” and 93 percent that they would have the surgery again. Patients were happier with their overall appearance and reported fewer negative emotions about it in various situations up to two years later.But they reported no significant changes in self-esteem or in symptoms of depression.MORE: Balance Face Asymmetries With Hair and Makeup TipsA small subgroup of patients is never satisfied; they may shift focus to another part of their body or complain that the surgery wasn’t a success. Some go back for more procedures—again and again. As Michael Jackson’s skin grew lighter and his nose more pointed, the world gossiped that he’d turned into a surgery addict. An estimated 7 to 15 percent of plastic surgery patients have body dysmorphic disorder, an obsession with nonexistent or slight defects in appearance, according to a review of the research. Patients who were dissatisfied with previous surgeries or who have a history of depression or anxiety are less likely to be pleased with the outcome, this review found.QUIZ: Do You Fat Talk ? Find Out for a Better Body Image.Garden-variety anxiety probably shouldn’t rule out plastic surgery. “Antidepressants are so commonly used that it seems that most of my patients are on them!,” says YouBeauty Cosmetic Surgery Expert, Dr. Arthur Perry.He screens out candidates who are on more than one psychiatric drug, have attempted suicide, or have been hospitalized for depression. “It is important for plastic surgeons to refuse to operate on depressed patients,” he says. “Many think that cosmetic surgery is the panacea and that all their problems will abate just because they will look better.”In the second study von Soest cited, published in Annals of Plastic Surgery, 95 percent of 455 women who received silicon-filled implants reported that they were satisfied with their breasts six years after the surgery. While they said they felt more sexually attractive, their overall health or self-esteem hadn’t changed.In a sign that men may be getting more concerned about their looks in general, they had nine percent more cosmetic procedures in 2010 than a decade earlier.Andy, a 54-year-old executive, became self-conscious about a crooked bottom tooth around the time his marriage was breaking up. Newly single this year, he decided to get invisible braces. “I’m very pleased,” he says. “They’re moving my teeth in exactly the way they promised. I’ll get whitening for free, too.”Five years after her surgery, Miriam is glad she had it. “I sometimes think I’m pretty, and I haven’t had a nasal infection,” she says. “But the surgery didn’t have much effect on my confidence.” Seeing her online visitors come and go still hurts. “I think I was happier for about a year, and then I got fairly miserable.”As von Soest says, “I would guess that cosmetic surgery does not make people happier. After a while most people will probably experience that their lives did not change much.”MORE: What’s a Medical Spa?Meanwhile, check out these stars who regret having plastic surgery.