But in the latter half of the 1800s, cross-dressing and being transgender became viewed as an increasing societal danger.William A. Hammond wrote an 1882 account of transgender Pueblo shamans (mujerados), comparing them to the Scythian disease. Other writers of the late 1700s and 1800s (including Hammonds associates in the American Neurological Association) had noted the widespread nature of transgender cultural practices among native peoples. Explanations varied, but authors generally did not ascribe native transgender practices to psychiatric causes, instead condemning the practices in a religious and moral sense. Native groups provided much study on the subject, and perhaps the majority of all study until after WWII.Critical studies first began to emerge in the late 1800s in Germany, with the works of Magnus Hirschfeld. Hirschfeld coined the term "transvestite" in 1910 as the scope of transgender study grew. His work would lead to the 1919 founding of the Institut für Sexualwissenschaft in Berlin. Though Hirschelds legacy is disputed, he revolutionized the field of study. The Institut was destroyed when the Nazis seized power in 1933, and its research was infamously burned in the May 1933 Nazi book burnings. Transgender issues went largely out of the public eye until after World War II. Even when they re-emerged, they reflected a forensic psychology approach, unlike the more sexological that had been employed in the lost German research. 20th century medical understanding
Benjamin suggested that moderate intensity male to female transsexual people may benefit from estrogen medication as a "substitute for or preliminary to operation."
A 2009 review of Medline literature suggests the total rate of patients expressing feelings of doubt or regret is estimated to be as high as 8%.A 2010 meta-study, based on 28 previous long-term studies of transsexual men and women, found that the overall psychological functioning of transsexual people after transition was similar to that of the general population and significantly better than that of untreated transsexual people. Prevalence
Estimates of the prevalence of transsexual people are highly dependent on the specific case definitions used in the studies, with prevalence rates varying by orders of magnitude. In the United States, the Diagnostic and Statistical Manual of Mental Disorders (DSM-V 2013) gives the following estimates: "For natal adult males [MTF], prevalence ranges from 0.005% to 0.014%, and for natal females [FTM], from 0.002% to 0.003%." It states, however, that these are likely underestimates since the figures are based on referrals to specialty clinics.The Amsterdam Gender Dysphoria Clinic over four decades has treated roughly 95% of Dutch transsexual clients, and it suggests (1997) a prevalence of 1:10,000 among assigned males and 1:30,000 among assigned females.Olyslager and Conway presented a paper at the WPATH 20th International Symposium (2007) arguing that the data from their own and other studies actually imply much higher prevalence, with minimum lower bounds of 1:4,500 male-to-female transsexual people and 1:8,000 female-to-male transsexual people for a number of countries worldwide. They estimate the number of post-op women in the US to be 32,000 and obtain a figure of 1:2500 male-to-female transsexual people.