Two professors who published a paper last year on the mental health benefits of 'gender-affirming' surgeries have revised their original findings.
The population study, published last October in the American Journal of Psychiatry, was conducted by John Pachankis, associate professor at Yale School of Public Health, and Richard Bränström, associate professor at Sweden's Karolinska Institute.
They analysed the mental health of 1,018 Swedes diagnosed with "gender incongruence" between 2005 and 2015 who underwent surgery to remove their genitals or make other physical alterations to their appearance.
The professors concluded that patients who underwent "gender-affirming" surgeries afterwards experienced an 8% decrease in mood and anxiety disorders year on year.
This led the researchers to conclude that public policy should support such surgeries.
"In this first total population study of transgender individuals with a gender incongruence diagnosis, the longitudinal association between gender-affirming surgery and reduced likelihood of mental health treatment lends support to the decision to provide gender-affirming surgeries to transgender individuals who seek them," they asserted.
However, the researchers were forced to re-examine their original conclusions after the journal received letters questioning the statistical methodology employed in the study.
In the correction, they now conclude that their recommendation around public policy was "too strong".
"Upon request, the authors reanalyzed the data to compare outcomes between individuals diagnosed with gender incongruence who had received gender-affirming surgical treatments and those diagnosed with gender incongruence who had not," the correction reads.
"While this comparison was performed retrospectively and was not part of the original research question given that several other factors may differ between the groups, the results demonstrated no advantage of surgery in relation to subsequent mood or anxiety disorder-related health care visits or prescriptions or hospitalizations following suicide attempts in that comparison.
"Given that the study used neither a prospective cohort design nor a randomized controlled trial design, the conclusion that 'the longitudinal association between gender-affirming surgery and lower use of mental health treatment lends support to the decision to provide gender-affirming surgeries to transgender individuals who seek them' is too strong."