Most antiabortion activists oppose abortion for moral and religious reasons. In their effort to win broader public support and legitimacy, however, antiabortion leaders frequently assert that abortion is not only wrong, but that it harms women physically and psychologically. Such charges have been made repeatedly for years, but repetition and even acceptance by members of Congress and other high-ranking political officials do not make them true.

Likely because the science attesting to the physical safety of the abortion procedure is so clear, abortion foes have long focused on what they allege are its negative mental health consequences. For decades, they have charged that having an abortion causes mental instability and even may lead to suicide, and despite consistent repudiations from the major professional mental health associations, they remain undeterred. For example, the "postabortion traumatic stress syndrome" that they say is widespread is not recognized by either the American Psychological Association (APA) or the American Psychiatric Association.

To a considerable degree, antiabortion activists are able to take advantage of the fact that the general public and most policymakers do not know what constitutes "good science" (related article, November 2005, page 1). To defend their positions, these activists often cite studies that have serious methodological flaws or draw inappropriate conclusions from more rigorous studies. Admittedly, the body of sound research in this area is relatively sparse because establishing or conclusively disproving a causal relationship between abortion and subsequent behavior is an extremely difficult proposition. Still, it is fair to say that neither the weight of the scientific evidence to date nor the observable reality of 33 years of legal abortion in the United States comports with the idea that having an abortion is any more dangerous to a woman's long-term mental health than delivering and parenting a child that she did not intend to have or placing a baby for adoption.

Public Health Problem 'Minuscule'

Despite years of trying, antiabortion activists failed to gain any traction with the nation's major medical groups in alleging that abortion posed a direct threat to women's health, especially their mental health, so they turned to the political process to legitimize their claims. In 1987, they convinced President Reagan to direct U.S. Surgeon General C. Everett Koop to analyze the health effects of abortion and submit a report to the president. As Koop had been appointed to his position in no small part because of his antiabortion views, both prochoice and antiabortion factions believed the outcome to be preordained. (An eminent pediatric surgeon as well as an outspoken abortion foe, Koop had no prior experience or background in public health; both public health and prochoice advocates in Congress vehemently opposed his appointment, delaying his confirmation by several months.)

Koop reviewed the scientific and medical literature and consulted with a wide range of experts and advocacy groups on both sides of the issue. Yet, after 15 months, no report was forthcoming. Rather, on January 9, 1989, Koop wrote a letter to the president explaining that he would not be issuing a report at all because "the scientific studies do not provide conclusive data about the health effects of abortion on women." Koop apparently was referring to the effects of abortion on mental health, because his letter essentially dismissed any doubts about the physical safety of the procedure.

Prochoice members of Congress, surprised by Koop's careful and balanced analysis, sought to force his more detailed findings into the public domain. A hearing before the House Government Operations Subcommittee on Human Resources and Intergovernmental Relations was called in March 1989 to give Koop an opportunity to testify about the content of his draft report, which had begun to leak out despite the administration's best efforts. At the hearing, Koop explained that he chose not to pursue an inquiry into the safety of the abortion procedure itself, because the "obstetricians and gynecologists had long since concluded that the physical sequelae of abortion were no different than those found in women who carried pregnancy to term or who had never been pregnant. I had nothing further to add to that subject in my letter to the president"(see box).

As to the mental health issue, Koop described anecdotal evidence going in both directions, but emphasized that "individual cases cannot be used to reach scientifically sound conclusions." He discussed the methodological flaws pervading most of the research on this subject, and for this reason, he explained, he could reach no definitive conclusion about the mental health impact of having an abortion. Importantly, however, Koop did state that it was clear to him that the psychological effects of abortion are "minuscule" from a public health perspective.

Representing the APA at the hearing, Nancy Adler, professor of psychology at the University of California, San Francisco, testified that "severe negative reactions are rare and are in line with those following other normal life stresses." While acknowledging that there were flaws in much of the research, she testified nonetheless that the weight of the evidence persuasively showed that "abortion is usually psychologically benign." Echoing Koop's point about the public health implications, Adler said that given the millions of women who had had abortions, "if severe reaction were common, there would be an epidemic of women seeking treatment. There is no evidence of such an epidemic."

More Studies, Similar Conclusions

Later in 1989, the APA itself convened a panel to comprehensively assess the body of research meeting the minimum criteria for scientific validity. The APA review determined that legal abortion of an unwanted pregnancy "does not pose a psychological hazard for most women." As summarized in the Guttmacher Institute's May 2006 report, Abortion in Women's Lives, the APA found that "women who are terminating pregnancies that are wanted or who lack support from their partner or parents for the abortion may feel a greater sense of loss, anxiety and distress. For most women, however, the time of greatest distress is likely to be before an abortion; after an abortion, women frequently report feeling 'relief and happiness.'"

Yet neither the Koop investigation nor the APA review ended the debate. Antiabortion researchers have persisted in trying to prove abortion's harmful mental health effects. Most prominent among them are David Reardon, director of the antiabortion, Illinois-based Elliot Institute, and Priscilla Coleman, family studies professor at Bowling Green State University. Reardon and Coleman believe that abortion harms women, but their own studies and the others upon which they rely to make that assertion are so flawed methodologically that they cannot be said to establish a causal relationship. The studies do not address the fundamental question of whether women who have had abortions experience more adverse reactions than do otherwise similar women who have carried their unwanted pregnancies to term. Again, as described in Abortion in Women's Lives, "none adequately control for factors that might explain both the unintended pregnancy and the mental health problem, such as social or demographic characteristics, preexisting mental or physical health conditions, childhood exposure to physical or sexual abuse, and other risk-taking behaviors.…Because of these confounding factors, even if mental health problems are more common among women who have had an abortion, abortion may not have been the real cause."

By contrast, the Royal Colleges of Obstetricians and Gynaecologists and of General Practitioners in the United Kingdom sponsored a major study that did address that fundamental question. The study followed more than 13,000 women in England and Wales over an 11-year period ending in the early 1990s. Importantly, it considered two groups: women facing an unintended pregnancy who had an abortion and women facing an unintended pregnancy who gave birth. The study's authors concluded that those women who had an abortion following an unintended pregnancy were not at any higher risk of subsequent mental health problems than were women whose unintended pregnancy was carried to term.

Currently, considerable attention is being paid to a study conducted by David Fergusson, a psychology professor who is affiliated with the Christchurch School of Medicine and Health Sciences, New Zealand. Fergusson's study, like the Royal Colleges', has the advantage of being prospective, which means that information is gathered about individual women at multiple points in time and compared across groups. Fergusson and his colleagues have been following the health, education and life progress of a group of 1,265 children in the Christchurch region since their births in mid-1977. Results released earlier this year suggest some link between abortion as a young woman in New Zealand and subsequent problems with depression, anxiety, suicidal behaviors and substance abuse disorders; however, Ferguson acknowledges that his study has enough shortcomings to warrant caution in reading too much into the findings.

Specifically, the study does not take into account certain preexisting health problems (e.g., mental health problems or exposure to unreported sexual abuse) among the women who had an abortion that may be much more relevant to the women's subsequent mental health conditions than the abortion itself. Furthermore, he and his coauthors estimate that about one-fifth of the women in the study who had abortions failed to report them, which could skew the findings if women experiencing mental health problems later in life are more likely to report a prior abortion than are women not experiencing such problems. Perhaps most significantly, Ferguson and his colleagues did not separate out for analysis purposes women whose pregnancies were unintended and women whose pregnancies were wanted, as did the Royal Colleges' researchers. The authors themselves admit that this is a significant failing.

The Debate Goes On

Seventeen years after the Koop investigation, there is still no conclusive evidence directly linking abortion to subsequent mental health problems—and not because of a lack of trying. Although it is true that some women who have had an abortion suffer severe mental health problems later in life, the current body of research has not been able to rule out a plethora of preexisting conditions or familial or other contextual factors that could affect or explain those problems. It isalso true, not surprisingly, that some women experience pain and sadness either shortly after having an abortion or even many years later (see box). These emotions, however, are not unique to women who have had an abortion or necessarily more or less common than the pain and sadness felt by many women who have placed a baby for adoption or raised an unplanned child under adverse conditions.

Meanwhile, what Koop described 17 years ago as a "minuscule" public health problem would seem to be at least as miniscule today—especially in light of the fact that more than one in three women in the United States will have had an abortion by age 45. How much more research into the purported abortion–mental health connection is really warranted may depend more on political exigencies than on scientific ones. Antiabortion activists can be expected to continue to either distort the evidence that does exist or insist that conclusive evidence can still be found. At the time of his investigation, Koop himself called for more and better quality research on the mental health effects of not just abortion but unplanned pregnancy itself, a more expansive view that remains valid today. Also applicable today is Koop’s less noticed but equally important call at that time for more research into contraception and contraceptive use. As he testified to Congress in 1989, "most abortions would not take place if pregnancies were not unplanned and unwanted."