Gender Identity Disorders Research Paper

The word transsexual was used in the earlier literature, as was inversion, to refer to individuals with marked gender dysphoria, most of whom perceived sex reassignment as the solution to their psychological distress. It remains as a category in the ICD-10 classification. Also in the older literature transvestite was used to designate persons who cross-dressed and may have included those who identified as the other sex as well as those in whom the cross-dressing was sexually arousing (now referred to as Transvestic Fetishism). Transgendered is a more recent term used to encompass a broad group of individuals with varying degrees of cross-gender behavior. It is not a diagnosis and is often the self-label assumed by individuals with cross-gender feelings and behaviors, particularly the more politically active. Gender role refers to behaviors, roles, and attitudes that the specific culture defines as more appropriate to males or females. Sexual orientation refers to the sex of person to whom an individual is attracted, predominantly the opposite (heterosexual), or the same (homosexual) sex. Sexual identity connotes the adoption of an identity as a hetero or homosexual person and involves more than the narrow notion of sexual orientation.

Gender identity disorders (GID) are relatively rare compared to other psychiatric disorders. Although there are no large scale epidemiological studies to provide true estimates recent studies suggest roughly 1:10,000 to 1:30,000. Sex ratios of adults with GID (largely based on referrals to clinics) have fluctuated with more males than females in earlier studies to a more equal ratio in many recent reports. Childhood GID is more prevalent in males, roughly 6 to 1. In adolescence the ratio is more equal (Cohen-Kettenis and Gooren 1999, provide a recent review.)

2. Historical Background

Awareness of individuals who identified strongly with the other sex has a long history. Some cultures even created a privileged role for such individuals. However, the scientific study of individuals with cross-gender identities really began in the late part of the nineteeth century. Initially many such individuals were thought to be intersex individuals, possessing the physical characteristics (both internal and external) of the other sex. It was not until the middle of the twentieth century that it became clear that most such individuals were physically normal but suffering from a psychological disorder.

The modern era of gender identity disorder began with the much publicized case of Christine Jorgensen, an American ex-soldier, who underwent sex-change surgery in Denmark in 1952, under the care of Christian Hamburger, an endocrinologist. Although demasculinizing surgery and hormonal replacement had been used earlier, typically for cases thought to be intersex, the Jorgensen case stirred the public imagination and encouraged other like-minded individuals to seek treatment for their distress (Meyerowitz 1998). Sex change surgery had been available in Europe since the early 1900s, the most prominent center being the Institute for Sexual Science in Berlin under the direction of Magnus Hirschfeld. In the USA physicians were less willing to perform such surgery, particularly on those considered to be physically normal and in some jurisdictions such body altering was considered illegal. Prior to the Jorgensen case, David Cauldwell, an American psychiatrist and editor of Sexology, had distinguished cases which he labeled ‘psychopathia transexualis’ from intersex cases. Harry Benjamin, an endocrinologist, born and trained in Germany, had begun to advocate on behalf of individuals wishing sex change. This combination of public and professional interest set the stage for the scientific study of persons with gender identity disorders.

In 1955 John Money working with the Hampsons published his first follow-up study of individuals born with ambiguous genitalia. His conclusions that sex of rearing overrides the child’s anatomy in determining gender identity was the first empirical evidence that psychological factors may be etiologically important in GID. The 1960s saw the publication of several important books and papers as clinicians working with individuals with GID began to describe their experience. Harry Benjamin, who had been diligent in his effort to bring understanding to the plight of those whose cross-gender wishes were often demeaned or dismissed, published The Transsexual Phenomenon in 1966. In the same year the first gender clinic in North America was established at Johns Hopkins Hospital in Baltimore. Green and Money (1969) co-edited the book Transsexualism and Sex Reassignment, a standard text at that time. he year earlier, Stoller (1968), a psychoanalyst, had published Sex and Gender, in which he articulated a theory that cross-gender identification arises from a blissful symbiosis of a son with his mother. Although Stoller’s theoretical position has more recently been dismissed it sparked interest in understanding the psychodynamic origins of GID and led to more systematic study in several of the newly developed clinics for children and adolescents.

The 1970s and 1980s saw a growth of interest in treatment of adults with GID. Clinics developed in major centers in North America and Europe. Standards of Care were developed under the auspices of the Harry Benjamin International Gender Dysphoria Association in 1985 and provided some uniformity to patient management. Clinics for children were developed as clinicians realized that GID had its origins in childhood and might be prevented with early intervention. Green (1974) carried out the first systematic study of effeminate boys, published in Sexual Identity Conflict in Children and Adults. He compared boys displaying significant cross-gender behavior by parent report, with an equal number of age-matched masculine boys. His study provided the first systematic description of boys with GID and their parents. Green (1987) published the follow-up of these two groups of boys. The majority of the effeminate boys had a homosexual orientation when assessed in late adolescence. Only one boy continued to have significant cross-gender wishes. These findings were in marked contrast to the findings on the masculine boys who were almost entirely heterosexual in orientation and displayed no evidence of gender dysphoria.

The study of individuals with GID soon became a subject of religious, moral, and political debate. Some investigators urged treatment of GID to prevent homosexuality. In the 1990s funders of GID programs began to debate the logic of a medical and surgical intervention for what is primarily a psychological disorder. This debate was fueled by the results of the first follow-up study of the patients from the John Hopkins clinic which suggested that surgically reassigned patients were no better off than were those who had not received surgery. Although this study was methodologically flawed, its results, together with economic pressures, led to the closure of many clinics in the USA and the removal of sex reassignment surgery as an insured service. Generally the situation in Europe, particularly in the Netherlands, remained more supportive for those with GID. In the late 1980s the gay and lesbian community began to question the pathologizing of cross-gender behavior in childhood, regarding it simply as an early manifestation of homosexuality. In the early 1990s many individuals with cross-gender identification began to organize politically, assuming the label transgendered, and arguing that society should recognize a third or intermediate position between the more traditional male and female genders.

3. Emphases In Current Theory And Research

3.1 Classification And Phenomenology

Early work focused on dividing individuals requesting sex reassignment into ‘true’ and ‘secondary’ transsexuals. This effort was abandoned as GID began to be conceptualized as being more dimensional than purely categorical. However, there was a recognition that there are two types of GID in males, one originating from early or childhood GID and being predominantly homosexual in sexual orientation, and the other, arising from Transvestic Fetishism, and being hetero or bisexual in orientation. Individuals with the latter present most typically in their thirties in contrast to the former who present in adolescence or early adulthood. Although usually described as bior heterosexual, Blanchard (1991) has established that many of the latter group display what he calls autogynephilia, an erotic attraction towards oneself dressed as a female. Mature females with GID are essentially homosexual in their erotic attraction.

3.2 Etiology

As mentioned above, the first theorizing about etiology arose from the belief that individuals with GID are in some way intermediate in their biology between males and females. Because of the link between cross-gender identification and homosexuality and because of the relatively small numbers of individuals with GID this led to extensive investigation of the biological differences between heterosexual males and females and between these two groups and their homosexual counterparts.

Although many of these studies have provided interesting leads very few differences have been substantiated in a way that would suggest strong evidence for a significant predictor of gender pathology or of homosexuality. Rather the findings to date suggest that temperamental or other vulnerability factors may create a biological predisposition towards gender pathology which when combined with the appropriate psychodynamic factors produce gender dysphoria and cross-gender identification.

3.3 Biological Studies

Genetic factors are assumed to play a role in GID although there have been no large-scale studies of heritability in GID. This assumption is based on the studies of heritability in homosexuality and its putative relationship with GID. In monozygotic twins there is a greater likelihood of both twins being homosexual as compared to dizygotic twins (Bailey et al. 2000). This relationship has been shown most strongly in males. Despite a concordance rate as high as 50 percent there appears to be a strong nonshared environmental component (due to factors unique to the experience of the individual). Similarly, molecular genetics studies of homosexuality in men suggest the possibility of a marker specific to sexual orientation on the distal portion of the long arm of the X chromosome (Hamer et al. 1993) although the only other independent study failed to replicate this finding.

The prenatal hormone theory has provided the most coherent framework for an examination of factors affecting sex-dimorphic behavior in both animals and humans. This theory, now well supported by studies in animals, posits that the prenatal hormonal milieu affects the development of brain structures and/organizes or shapes various sex-dimorphic behaviors, such as activity level, mounting behavior, and responsiveness to sexual partners. In humans, Congenital Adrenal Hyperplasia (CAH), a disorder in which females are exposed to high levels of circulating androgen in utero, provides a convenient natural experiment which gives some support to the theory. Girls with CAH have been shown to be more physically active and tomboyish than their nonaffected sisters and to report more homosexual attraction and less heterosexual involvement in adulthood. They do not, however, report more wishes to be the other sex. This latter finding may be partially a result of the small sample sizes in all studies, too small to detect a disorder such as GID, which is relatively rare.

Another approach to testing the prenatal hormone theory has been to examine hormone responses to a dose of exogenously administered estrogen. In the female such an injection produces an initial fall and then a rise in luteinizing hormone. Males do not display the rise seen in females. Homosexual men show a pattern intermediate between that of heterosexual men and women. These studies have not been replicated consistently and have been criticized in terms of not being interpretable, as the endocrine systems of homosexual men may be compromised by such things as HIV infection.

Prenatal maternal stress is another factor thought to possibly influence the development of homosexuality (and by extension GID) through affecting the prenatal hormonal milieu and brain development. Early studies in rats showed that stressing pregnant females can produce a demasculinizing and feminizing effect on their male offspring. Although attempts to test this out on humans have been equivocal, Bailey et al. (1991) found that maternal ‘stress proneness’ was correlated with boyhood effeminacy. As there is an emerging literature that suggests that maternal stress may correlate with vulnerability to psychiatric disorder in offspring by affecting stress reactivity, these findings may be relevant in terms of vulnerability to psychopathology, as opposed specifically to homosexuality or GID (Bradley 2000).

Efforts to define and compare the brain areas responsible for sexually dimorphic behavior have been a part of testing the prenatal hormone theory. Once more this work has been carried out on samples of homosexual individuals, largely male. Although brain structures in rats appear more clearly sexdimorphic, agreement about the comparable brain structures in humans has been more complicated. Swaab and Fliers (1985) reported differences between males and females in the preoptic area of the anterior hypothalamus but in a subsequent study could not define differences in volume between heterosexual and homosexual men. They did, however, find a difference in the suprachiasmatic area of the hypothalamus between homosexual and heterosexual men, an area previously not related to sex-dimorphic behavior (Swaab and Hofman 1990). Another cell group identified as possibly homologous with the sexually dimorphic area in lower mammals is the interstitial nucleus of the anterior hypothalamus, subdivided into four sections, INAH 1–4 (Allen et al. 1989). These authors found differences in size between males and females in INAH 2 and 3. LeVay (1991) subsequently reported a smaller INAH 3 in homosexual men (comparable to that of heterosexual women) in comparison to heterosexual men. This study has recently been partially replicated by Byne et al. (in press). Zhou et al. (1995) reported that the bed nucleus of the stria terminalis was smaller in six male-to-female transsexuals than in control males and was comparable to that of females.

Another area of potential difference between homosexual and heterosexual individuals is cerebral laterality. This has been examined through assessment of handedness, cognitive testing, dermatoglyphic asymmetry, and related brain volumes. Some studies have suggested that homosexual men and women have a higher likelihood of being left-handed than heterosexual men and that transsexuals (both male and female) display more left-handedness than the general population (Lalumiere et al., 2000). A preliminary study on boys with GID from the Toronto clinic examining handedness suggests a higher incidence of left-handedness (Zucker et al. 2000). Neuropsychological studies using visual hemifield dot detection and dichotic listening tasks suggest differences between homosexual and heterosexual men with the performance of homosexual men being more similar to that of heterosexual women. Studies of transsexual subjects also suggested less lateralization but again these results are preliminary. Study of fingerprint patterns, dermatoglyphy, shows sex differences with women having more ridges on the left than right hand and homosexual men showing a similar left-ward asymmetry. The anterior commissure, a fiber tract connecting the two cerebral hemispheres, is larger in women than men and has been shown to be larger in homosexual than heterosexual men. Although interpretation of these findings should remain open they suggest that early brain development and with it handedness and other indices of laterality may be affected in individuals who later become homosexual and possibly in those who develop GID.

Temperamental variables, specifically activity level and involvement in rough-and-tumble play, have been shown to differ in boys and girls. Boys with GID display a lower activity level and less interest in roughand-tumble play than control boys. In contrast, girls with GID are reported to have a higher activity level and to be more interested in rough-and-tumble play than control girls. Although these findings suggest differences between GID children and controls, it is highly unlikely that these differences are more than predispositions that add a dimension to their general vulnerability to GID. Physical attractiveness is another factor that may act as a predisposing factor but is unlikely to be more specific to GID. Boys with GID are rated by independent raters as more attractive, beautiful, cute, handsome, and pretty than control boys. Conversely, girls with GID are rated as less attractive than control girls. Although physical attractiveness may be a social construction these findings are consistent with parental reports of their GID sons being beautiful babies and may be related to greater facial symmetry, a component of attractiveness.

Particularly feminine homosexual men and boys with GID have a greater number of brothers than controls. Being born later in the birth order also occurs more frequently in homosexual men (regardless of extent of cross-gender behavior) than in heterosexual controls. These findings have been interpreted from both biological and psychological frameworks with no evidence to suggest that either explanation is more valid.

Lastly, birthweight appears to be lower in boys with GID than in controls. Again this may reflect a neurodevelopmental factor which is related to a general vulnerability to psychopathology as low birth weight has also been found as a vulnerability factor to psychotic disorders.

3.4 Psychosocial Factors

As indicated in Sect. 2 above, Money et al. (1955) reported on their follow-up of children born with ambiguous genitalia. They concluded that sex of assignment and rearing, particularly when that was begun unambiguously prior to 24 months of age, was able to override a child’s anatomy. These early studies by Money et al. led to the belief that gender identity was developed during a sensitive period and became relatively fixed at an early age. Despite challenges, this position has not been significantly refuted. Questions were raised by the finding that individuals with 5alpha-reductase deficiency, apparently raised as girls, for the most part begin to self-identify as males at puberty when their bodies begin to masculinize. This and other similar findings appear less to have refuted Money et al.’s findings than to have suggested that in some instances gender identity may be less fixed than had originally been proposed. This same malleability of gender identity appears to be relevant in the case of males with Transvestic Fetishism who although originally identified as male begin, over a number of years, to self-identify as female. Other anomalous situations include males with accidental ablation of the penis at a young age. One such case has been used to argue that biology overrides rearing while another suggests the opposite. Generally, however, individuals with GID are physically normal and so psychosocial factors appear to be particularly relevant.

Parents have been shown to respond differently to male and female children, generally encouraging samesex behavior more than opposite-sex behavior. Parents of children with GID tend to be neutral about if not encouraging of their child’s cross-gender behavior. Further they appear to be less encouraging of samesex behavior. Despite Stoller’s premise of a ‘blissful symbiosis’ between a boy with GID and his mother, Green (1974) found that both parents spent significantly less time with their son with GID than did parents of controls. Further, both mothers and fathers of children with GID have elevated levels of psychopathology, which would suggest impairments in their relationships with each other and with their children. Lastly, clinical observations suggest high levels of conflict between children with GID and their parents, which these sensitive children interpret as rejection.

Etiological factors are reviewed more thoroughly in Zucker and Bradley (1995) where a complete set of references is also available. Clinical formulations of these etiological factors are available in Coates (1990) and Zucker and Bradley (1995).

4. Management

There are few formal studies assessing management of children or adults with GID. Current management of children with GID involves addressing the familial and child issues through different combinations of parent counseling, parent groups, and child psychotherapy.

Adolescents with GID may be referred for psychotherapy to rule out factors that if addressed might change the wish for sex reassignment and to ensure the stability of the cross-gender wish. Some clinics use hormonal treatment to reduce the development of secondary sex characteristics and reduce sex drive when such adolescents have been considered treatment eligible (Cohen-Kettenis and Gooren 1999). Psychological support is considered very important but often rejected by the adolescent.

Management of the adult with GID is somewhat similar to that of the adolescent but can proceed to surgical reassignment after the individual has demonstrated their capacity to surmount the hurdles of living as the other sex for a period of time (1–2 years). Once more, psychological support is considered critical but is not always welcomed by the individual with GID. Hormonal therapy (estrogens to male-to-females and androgens to female-to-males) are begun in some clinics at the beginning of the real-life test and in other clinics somewhat later. Sex reassignment surgery typically is not undertaken until sometime in early adulthood although those individuals with a history of Transvestic Fetishism may not have surgery until their thirties or forties.

5. Outcome

Children with GID can relinquish their desire to be the opposite sex. This appears to be facilitated when parents address some of the familial issues thought to contribute to the child’s gender dysphoria. Children presenting at a later age (10–12) or whose families cannot address the contributing familial issues appear to do less well and continue to display significant gender dysphoria. Adults who undergo sex reassignment are generally satisfied although the capacity of surgery to produce well-functioning genitals, especially in the female-to-male, is quite limited.

6. Methodological Issues

Given the relative rarity of this condition sample sizes adequate to test hypotheses are only available in one or two clinics in the world. Evaluating treatment is similarly complicated by small sample sizes in any one geographic location. Multisite studies are needed to address some of these issues.

7. Future Directions

Comparison of children with GID vs. contrast groups such as children with anxiety disorders are needed to address general (psychopathology) vs. specific (to GID) etiological factors. Evaluation studies of interventions in children, adolescents, and adults are needed.

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