17 General introduction 1 One thing that can be said, is that the increase in media coverage has also let to heated discussions between people who criticize the use of early medical treatment, and the ones who support the use of it, and to polarization of the way we conceive transgender children and adolescents. Treatment strategies are no longer private conversations between minors, their parents, and their clinicians, but have become a public debate. LEGAL ASPECTS Besides media attention, case law also plays an increasing role in the care and rights of transgender individuals nowadays. In various countries, e.g. the United States, Canada and England, high profile federal appellate cases have addressed transgender individuals’ rights regarding for example bathroom visits, and outlawing reparative or conversion therapies (e.g. Andrade & Redondo, 2022; Byne, 2016; Fleming & McFadden-Wade, 2018; GLAD GLBTQ Legal Advocates & Defenders, 2017; Stolberg, 2017; Walch, Davidge-Pitts, Safer, Lopez, Tangpricha, & Iwamoto, 2021). In addition to these cases that promote transgender individuals’ rights, there are also legal cases that seek to curtail the care of transgender individuals. One of the most prominent is the case of Keira Bell. Keira Bell is a detransitioned patient of the Tavistock and Portman National Health Service (NHS) Trust and the Gender Identity Development Service (GIDS) who started treatment with PS at the age of 16, and brought her case to court. She filed a lawsuit against the NHS and the GIDS because she was, according to herself, not challenged enough before being allowed to start PS (Barbi & Tornese, 2022). In the context of this lawsuit, the High Court of Justice in London ruled in December 2020 that transgender adolescents under the age of 16 are highly unlikely to understand the long-term effects of PS, and that they therefore are not competent to decide to start this treatment (Dyer, 2020a). In response to this verdict, it was decided nationwide that transgender minors in England could no longer start treatment with PS before the age of 16, unless a court order was obtained (Dyer, 2020b). Strikingly, the verdict and subsequent treatment restrictions were carried out even though at that time there was no empirical evidence on the MDC of transgender adolescents regarding the decision to start treatment with PS. Of note, the Court of Appeal overturned this verdict and judged that ‘it was for clinicians rather than the court to decide on competence to consent’, referring to the current clinical situation (Dyer, 2021; Thornton, 2021). Still, decisions such as the one that was made in England are predominantly based on age standards prescribed by law, and on MDC assessments of clinicians which are likely to be influenced by their personal subjective views of what is in the adolescent’s best interest, rather than on scientific data (Hein et al., 2015d; de Vries, Wit, Engberts, Kaspers, & van Leeuwen, 2010). Therefore, more research is needed to fill in this gap in knowledge so that such decisions, with profound consequences for so many transgender children and adolescents, are based on scientific data on capacity development.