121 Trajectories of adolescents treated with gonadotropin‑releasing hormone analogues for gender dysphoria 6 in such a trial if this means they will not receive treatment that is available at other centres. Mul and colleagues (2001) experienced this problem and were unable to include a control group in their study on treatment with GnRHa for adopted girls with early puberty because all that were randomized to the control group refused further participation. An alternative approach that has been suggested to gain more insight into the effect of treatment on gender identity development is to collect baseline data at the time of referral from adolescents who are on a long waiting list for diagnostic evaluation and treatment and compare the percentage of these adolescents in whom gender dysphoria is still present after a certain period of time to that in adolescents on treatment with GnRHa (Zucker, 2019). In conclusion, this study shows that a small number of adolescents discontinued treatment with GnRHa because they no longer wished GAMT. This indicates that not all adolescents and parents assume that transgender outcome is the only possible outcome and shows that gender identity can still fluctuate when using GnRHa, at least in some adolescents. However, gender dysphoria subsided in a small number of adolescents and it is uncertain if this would have been different without treatment with GnRHa. Some adolescents used GnRHa for a prolonged period before starting GAH while regularly meeting with an MHP which is consistent with the use of treatment with GnRHa as an extended diagnostic phase. The great majority who had started treatment with GnRHa continued with GAH. It is important to take this into account when counselling adolescents who consider this treatment and their parents.