Dr. Paul McHugh, the university distinguished service professor of psychiatry at the Johns Hopkins University School of Medicine, explains:

Transgendered men do not become women, nor do transgendered women become men. All (including Bruce Jenner) become feminized men or masculinized women, counterfeits or impersonators of the sex with which they 'identify.' In that lies their problematic future.

When 'the tumult and shouting dies,' it proves not easy nor wise to live in a counterfeit sexual garb. The most thorough follow-up of sex-reassigned people--extending over 30 years and conducted in Sweden, where the culture is strongly supportive of the transgendered--documents their lifelong mental unrest. Ten to 15 years after surgical reassignment, the suicide rate of those who had undergone sex-reassignment surgery rose to 20 times that of comparable peers.

McHugh points to the reality that because sex change is physically impossible, it frequently does not provide the long-term wholeness and happiness that people seek.

Indeed, the best scientific research supports McHugh's caution and concern.

Here's how The Guardian summarized the results of a review of "more than 100 follow-up studies of post-operative transsexuals" by Birmingham University's Aggressive Research Intelligence Facility:

[The Aggressive Research Intelligence Facility], which conducts reviews of health care treatments for the [National Health Service], concludes that none of the studies provides conclusive evidence that gender reassignment is beneficial for patients. It found that most research was poorly designed, which skewed the results in favor of physically changing sex. There was no evaluation of whether other treatments, such as long-term counseling, might help transsexuals, or whether their gender confusion might lessen over time.

"There is huge uncertainty over whether changing someone's sex is a good or a bad thing," said Chris Hyde, the director of the facility. Even if doctors are careful to perform these procedures only on "appropriate patients," Hyde continued, "there's still a large number of people who have the surgery but remain traumatized--often to the point of committing suicide."

Of particular concern are the people these studies "lost track of." As The Guardian noted, "the results of many gender reassignment studies are unsound because researchers lost track of more than half of the participants." Indeed, "Dr. Hyde said the high drop-out rate could reflect high levels of dissatisfaction or even suicide among post-operative transsexuals."

Hyde concluded: "The bottom line is that although it's clear that some people do well with gender reassignment surgery, the available research does little to reassure about how many patients do badly and, if so, how badly."

The facility conducted its review back in 2004, so perhaps things have changed in the past decade?

Not so. In 2014, a new review of the scientific literature was done by Hayes, Inc., a research and consulting firm that evaluates the safety and health outcomes of medical technologies. Hayes found that the evidence on long-term results of sex reassignment was too sparse to support meaningful conclusions and gave these studies its lowest rating for quality:

Statistically significant improvements have not been consistently demonstrated by multiple studies for most outcomes. ... Evidence regarding quality of life and function in male-to-female adults was very sparse. Evidence for less comprehensive measures of well-being in adult recipients of cross-sex hormone therapy was directly applicable to [gender dysphoric] patients but was sparse and/or conflicting. The study designs do not permit conclusions of causality and studies generally had weaknesses associated with study execution as well. There are potentially long-term safety risks associated with hormone therapy but none have been proven or conclusively ruled out.

The Obama administration came to similar conclusions. In 2016, the Centers for Medicare and Medicaid Services revisited the question of whether sex reassignment surgery would have to be covered by Medicare plans. Despite receiving a request that its coverage be mandated, it refused, on the ground that we lack evidence that it benefits patients.

Here's how the June 2016 "Proposed Decision Memo for Gender Dysphoria and Gender Reassignment Surgery" put it:

Based on a thorough review of the clinical evidence available at this time, there is not enough evidence to determine whether gender reassignment surgery improves health outcomes for Medicare beneficiaries with gender dysphoria. There were conflicting (inconsistent) study results--of the best designed studies, some reported benefits while others reported harms. The quality and strength of evidence were low due to the mostly observational study designs with no comparison groups, potential confounding, and small sample sizes. Many studies that reported positive outcomes were exploratory type studies (case-series and case-control) with no confirmatory follow-up.

The final August 2016 memo was even more blunt. It pointed out:

Overall, the quality and strength of evidence were low due to mostly observational study designs with no comparison groups, subjective endpoints, potential confounding (a situation where the association between the intervention and outcome is influenced by another factor such as a co-intervention), small sample sizes, lack of validated assessment tools, and considerable lost to follow-up.

That "lost to follow-up," remember, could be pointing to people who committed suicide.

And when it comes to the best studies, there is no evidence of "clinically significant changes" after sex reassignment:

The majority of studies were non-longitudinal, exploratory type studies (i.e., in a preliminary state of investigation or hypothesis generating), or did not include concurrent controls or testing prior to and after surgery. Several reported positive results but the potential issues noted above reduced strength and confidence. After careful assessment, we identified six studies that could provide useful information. Of these, the four best designed and conducted studies that assessed quality of life before and after surgery using validated (albeit non-specific) psychometric studies did not demonstrate clinically significant changes or differences in psychometric test results after [gender reassignment surgery].

In a discussion of the largest and most robust study--the study from Sweden that McHugh mentioned in the quote above--the Obama Centers for Medicare and Medicaid Services pointed out the 19-times-greater likelihood for death by suicide, and a host of other poor outcomes:

The study identified increased mortality and psychiatric hospitalization compared to the matched controls. The mortality was primarily due to completed suicides (19.1-fold greater than in control Swedes), but death due to neoplasm and cardiovascular disease was increased 2 to 2.5 times as well. We note, mortality from this patient population did not become apparent until after 10 years. The risk for psychiatric hospitalization was 2.8 times greater than in controls even after adjustment for prior psychiatric disease (18 percent). The risk for attempted suicide was greater in male-to-female patients regardless of the gender of the control. Further, we cannot exclude therapeutic interventions as a cause of the observed excess morbidity and mortality. The study, however, was not constructed to assess the impact of gender reassignment surgery per se.

These results are tragic. And they directly contradict the most popular media narratives, as well as many of the snapshot studies that do not track people over time. As the Obama Centers for Medicare and Medicaid pointed out, "mortality from this patient population did not become apparent until after 10 years."

So when the media tout studies that only track outcomes for a few years, and claim that reassignment is a stunning success, there are good grounds for skepticism.

As I explain in my book, these outcomes should be enough to stop the headlong rush into sex reassignment procedures. They should prompt us to develop better therapies for helping people who struggle with their gender identity.

And none of this even begins to address the radical, entirely experimental therapies that are being directed at the bodies of children to transition them.

Sex Change Is Physically Impossible

We've seen some of the evidence that sex reassignment doesn't produce good outcomes psychosocially. And as McHugh suggested above, part of the reason why is because sex change is impossible and "it proves not easy nor wise to live in a counterfeit sexual garb."

But what is the basis for the conclusion that sex change is impossible?

Contrary to the claims of activists, sex isn't "assigned" at birth--and that's why it can't be "reassigned." As I explain in "When Harry Became Sally," sex is a bodily reality that can be recognized well before birth with ultrasound imaging. The sex of an organism is defined and identified by the way in which it (he or she) is organized for sexual reproduction.

This is just one manifestation of the fact that natural organization is "the defining feature of an organism," as neuroscientist Maureen Condic and her philosopher brother Samuel Condic explain. In organisms, "the various parts ... are organized to cooperatively interact for the welfare of the entity as a whole. Organisms can exist at various levels, from microscopic single cells to sperm whales weighing many tons, yet they are all characterized by the integrated function of parts for the sake of the whole."

Male and female organisms have different parts that are functionally integrated for the sake of their whole, and for the sake of a larger whole--their sexual union and reproduction. So an organism's sex--as male or female--is identified by its organization for sexually reproductive acts. Sex as a status--male or female--is a recognition of the organization of a body that can engage in sex as an act.

That organization isn't just the best way to figure out which sex you are. It's the only way to make sense of the concepts of male and female at all. What else could "maleness" or "femaleness" even refer to, if not your basic physical capacity for one of two functions in sexual reproduction?

The conceptual distinction between male and female based on reproductive organization provides the only coherent way to classify the two sexes. Apart from that, all we have are stereotypes.

This shouldn't be controversial. Sex is understood this way across sexually reproducing species. No one finds it particularly difficult--let alone controversial--to identify male and female members of the bovine species or the canine species. Farmers and breeders rely on this easy distinction for their livelihoods. It's only recently, and only with respect to the human species, that the very concept of sex has become controversial.

And yet, in an expert declaration to a federal district court in North Carolina concerning H.B. 2 (a state law governing access to sex-specific restrooms), Dr. Deanna Adkins stated, "From a medical perspective, the appropriate determinant of sex is gender identity." Adkins is a professor at Duke University School of Medicine and the director of the Duke Center for Child and Adolescent Gender Care (which opened in 2015).

Adkins argues that gender identity is not only the preferred basis for determining sex, but "the only medically supported determinant of sex." Every other method is bad science, she claims: "It is counter to medical science to use chromosomes, hormones, internal reproductive organs, external genitalia, or secondary sex characteristics to override gender identity for purposes of classifying someone as male or female."

In her sworn declaration to the federal court, Adkins called the standard account of sex--an organism's sexual organization--"an extremely outdated view of biological sex."

Dr. Lawrence Mayer responded in his rebuttal declaration: "This statement is stunning. I have searched dozens of references in biology, medicine and genetics--even Wiki!--and can find no alternative scientific definition. In fact, the only references to a more fluid definition of biological sex are in the social policy literature."

Just so. Mayer is a scholar in residence in the Department of Psychiatry at the Johns Hopkins University School of Medicine and a professor of statistics and biostatistics at Arizona State University.

Modern science shows that our sexual organization begins with our DNA and development in the womb, and that sex differences manifest themselves in many bodily systems and organs, all the way down to the molecular level. In other words, our physical organization for one of two functions in reproduction shapes us organically, from the beginning of life, at every level of our being.

Cosmetic surgery and cross-sex hormones can't change us into the opposite sex. They can affect appearances. They can stunt or damage some outward expressions of our reproductive organization. But they can't transform it. They can't turn us from one sex into the other.

"Scientifically speaking, transgender men are not biological men and transgender women are not biological women. The claims to the contrary are not supported by a scintilla of scientific evidence," explains Mayer.

Or, as Princeton philosopher Robert P. George put it, "Changing sexes is a metaphysical impossibility because it is a biological impossibility."

The Purpose of Medicine, Emotions, and the Mind

Behind the debates over therapies for people with gender dysphoria are two related questions: How do we define mental health and human flourishing? And what is the purpose of medicine, particularly psychiatry?

Those general questions encompass more specific ones: If a man has an internal sense that he is a woman, is that just a variety of normal human functioning, or is it a psychopathology? Should we be concerned about the disconnection between feeling and reality, or only about the emotional distress or functional difficulties it may cause?

What is the best way to help people with gender dysphoria manage their symptoms: by accepting their insistence that they are the opposite sex and supporting a surgical transition, or by encouraging them to recognize that their feelings are out of line with reality and learn how to identify with their bodies?

All of these questions require philosophical analysis and worldview judgments about what "normal human functioning" looks like and what the purpose of medicine is.

Settling the debates over the proper response to gender dysphoria requires more than scientific and medical evidence. Medical science alone cannot tell us what the purpose of medicine is.

Science cannot answer questions about meaning or purpose in a moral sense. It can tell us about the function of this or that bodily system, but it can't tell us what to do with that knowledge. It cannot tell us how human beings ought to act. Those are philosophical questions, as I explain in "When Harry Became Sally."

While medical science does not answer philosophical questions, every medical practitioner has a philosophical worldview, explicit or not. Some doctors may regard feelings and beliefs that are disconnected from reality as a part of normal human functioning and not a source of concern unless they cause distress. Other doctors will regard those feelings and beliefs as dysfunctional in themselves, even if the patient does not find them distressing, because they indicate a defect in mental processes.

But the assumptions made by this or that psychiatrist for purposes of diagnosis and treatment cannot settle the philosophical questions: Is it good or bad or neutral to harbor feelings and beliefs that are at odds with reality? Should we accept them as the last word, or try to understand their causes and correct them, or at least mitigate their effects?

While the current findings of medical science, as shown above, reveal poor psychosocial outcomes for people who have had sex reassignment therapies, that conclusion should not be where we stop. We must also look deeper for philosophical wisdom, starting with some basic truths about human well-being and healthy functioning.

We should begin by recognizing that sex reassignment is physically impossible. Our minds and senses function properly when they reveal reality to us and lead us to knowledge of truth. And we flourish as human beings when we embrace the truth and live in accordance with it. A person might find some emotional relief in embracing a falsehood, but doing so would not make him or her objectively better off. Living by a falsehood keeps us from flourishing fully, whether or not it also causes distress.

This philosophical view of human well-being is the foundation of a sound medical practice. Dr. Michelle Cretella, the president of the American College of Pediatricians--a group of doctors who formed their own professional guild in response to the politicization of the American Academy of Pediatrics--emphasizes that mental health care should be guided by norms grounded in reality, including the reality of the bodily self.

"The norm for human development is for one's thoughts to align with physical reality, and for one's gender identity to align with one's biologic sex," she says. For human beings to flourish, they need to feel comfortable in their own bodies, readily identify with their sex, and believe that they are who they actually are. For children especially, normal development and functioning require accepting their physical being and understanding their embodied selves as male or female.

Unfortunately, many professionals now view health care--including mental health care--primarily as a means of fulfilling patients' desires, whatever those are. In the words of Leon Kass, a professor emeritus at the University of Chicago, today a doctor is often seen as nothing more than "a highly competent hired syringe":

The implicit (and sometimes explicit) model of the doctor-patient relationship is one of contract: the physician--a highly competent hired syringe, as it were--sells his services on demand, restrained only by the law (though he is free to refuse his services if the patient is unwilling or unable to meet his fee). Here's the deal: for the patient, autonomy and service; for the doctor, money, graced by the pleasure of giving the patient what he wants. If a patient wants to fix her nose or change his gender, determine the sex of unborn children, or take euphoriant drugs just for kicks, the physician can and will go to work--provided that the price is right and that the contract is explicit about what happens if the customer isn't satisfied.

This modern vision of medicine and medical professionals gets it wrong, says Kass. Professionals ought to profess their devotion to the purposes and ideals they serve. Teachers should be devoted to learning, lawyers to justice, clergy to things divine, and physicians to "healing the sick, looking up to health and wholeness." Healing is "the central core of medicine," Kass writes--"to heal, to make whole, is the doctor's primary business."

To provide the best possible care, serving the patient's medical interests requires an understanding of human wholeness and well-being. Mental health care must be guided by a sound concept of human flourishing. The minimal standard of care should begin with a standard of normality. Cretella explains how this standard applies to mental health:

One of the chief functions of the brain is to perceive physical reality. Thoughts that are in accordance with physical reality are normal. Thoughts that deviate from physical reality are abnormal--as well as potentially harmful to the individual or to others. This is true whether or not the individual who possesses the abnormal thoughts feels distress.

Our brains and senses are designed to bring us into contact with reality, connecting us with the outside world and with the reality of ourselves. Thoughts that disguise or distort reality are misguided--and can cause harm. In "When Harry Became Sally," I argue that we need to do a better job of helping people who face these struggles.

Ryan T. Anderson, Ph.D., is the William E. Simon Senior Research Fellow in American Principles and Public Policy at The Heritage Foundation, where he researches and writes about marriage, bioethics, religious liberty and political philosophy. Anderson is the author of several books and his research has been cited by two U.S. Supreme Court justices in two separate cases.