Classification of transsexuals

The classification of transsexuals and people who experience various types of gender dysphoria has been attempted by many researchers and clinicians. A discussion of classifications cannot be cleanly separate from a discussion of the terminology used because new terms were defined alongside new classifications.

Terminology overview
Magnus Hirschfeld coined the term transvestite in his seminal work on the matter, Die Transvestiten. In that work, he describes what today would be referred to as transvestic fetishism (or erotic cross-dressing) and transsexualism. In 1930, he supervised the first known sex reassignment surgery on Lili Elbe of Denmark.

The term "transexual" (with one 's') was first used by D. O. Cauldwell in 1949. Transsexual was also used by Harry Benjamin during his work of the 1950s and 1960s, which culminated in The Transsexual Phenomenon in 1966. This term continues to be used by the public and medical profession today.

The terms "Gender Dysphoria" and "Gender Identity Disorder" were not used until the 1970s when Laub and Fisk published several works on transsexualism using these terms.

The Harry Benjamin scale
Harry Benjamin's Sex Orientation Scale (S.O.S.) was an attempt to classify and understand various forms and subtypes of transvestism and transsexualism in biological males. It was a seven-point scale (with three types of transvestism, three types of transsexualism, and one category for typical males); it was analogous to the Kinsey scale of sexual orientation, which also had seven categories. Much like Kinsey's understanding of sexual orientation, Dr. Benjamin understood the nature of gender identity and gender expression not as a discrete scale, but as a spectrum, a continuum with many variations, much more than those featured in the scale. But the scale he developed seemed to be an easy, rational and clinically useful way to diagnose different forms of transsexualism and to distinguish between those who needed surgical and/or hormonal treatment and those who didn't. Benjamin noted, "It must be emphasized again that the remaining six types are not and never can be sharply separated."

Ray Blanchard
Ray Blanchard conducted a series of taxonomic studies of male-to-female transsexuals in the 1980s, concluding that there exist two distinct types. One group are those who are exclusively attracted to men, whom Blanchard called homosexual transsexuals (also sometimes called androphilic transsexuals). The other group include those who are attracted to females (gynephilic), attracted to both males and females (bisexual), and attracted to neither males nor females (asexual); Blanchard referred to this latter set collectively as the non-homosexual transsexuals. Blanchard has also reported that the non-homosexual transsexuals (but not the homosexual transsexuals) exhibit autogynephilia, a paraphilic interest in having a female body.

Peter Bentler
Bentler divided male-to-female transsexuals into homosexual transsexuals, asexual transsexuals, and heterosexual transsexuals, with the adjectives referring to sexual orientation being based on individuals' sex at birth.

DSM-III
Transsexualism was included for the first time in the DSM-III in 1980.

"Gender Identity Disorder" was a term created in the DSM-III in regard to transsexuals, and the categories were "GID/Children Transsexualism"; "GID/Adolescent and Adult, Non-transsexual type" and "GID/Not Otherwise Specified". Notably, this did not address Late-onset transsexualism, where patients may not have had symptoms as children. Interestingly, in the major revision of the DSM, DSM-III-R, they were placed in the category "Disorders Usually First Evident in Infancy, Childhood or Adolescence". The problem was that it got lost here, as well as the issue of adult onset explained above.

In the DSM-III, the terms "Homosexual", "Heterosexual", and "Asexual" were used - with quite a bit of confusion. (These terms were replaced in the DSM-IV by "Attracted to males", "Attracted to Females", "Attracted to Both" and "Attracted to neither.")

DSM-III-R
The DSM-III-R, published in 1987, retained the term transsexualism. It was located under "Disorders Usually First Evident in Infancy, Childhood or Adolescence".

DSM-IV and DSM-IV-TR
Gender Identity Disorder in Adolescents and Adults replaced the term transsexualism. In the DSM-IV-TR, the current version, GID is placed in the category of Sexual Disorders, with the subcategory of Gender Identity Disorders. The names were changed in DSM-IV to "Gender Identity Disorder in Children", "Gender Identity Disorder in Adolescents or Adults", and "Gender Identity Disorder Not Otherwise Specified".

ICD-10
In the International Classification of Diseases, ICD-10, transsexualism is classified within Gender identity disorders, F64 in ICD-10 Chapter V: Mental and behavioural disorders under the heading "Disorders of adult personality and behaviour".