116 Chapter 6 Prolonged use of GnRHa Twenty adolescents (three transgirls and 17 transboys) had used GnRHa for longer than minimally required by protocol. One was the transboy mentioned above who needed more time to decide about testosterone treatment. He had used GnRHa for 2.5 years when he was referred from the paediatric clinic to a clinic for adults elsewhere. The other 19 adolescents had subsequently started GAH. The median duration of GnRHa monotherapy in these 19 adolescents was 1.0 year (0.8-2.4). Reasons for prolonged use of GnRHa were (sometimes there was more than one reason): unstable situation due to family issues such as lack of parental support and/or acceptance of gender dysphoria (n = 6) or social problems such as lack of a safe home, excessive school absenteeism (n = 5); (psychiatric) comorbidity (n = 8) such as autism spectrum disorder or depression; more time needed for decision about treatment with GAH by the adolescent (n = 1) or for further diagnostics by the gender team (n = 1 , because of non-binary aspects); and logistic issues such as missed/rescheduled appointments (n = 8; in seven this was the only reason). The 11 adolescents who received prolonged treatment with GnRHa because of mental health and/or psychosocial problems had regular (approximately monthly on average) appointments with a psychologist at the gender identity clinic (n = 5) and/or received support from a local MHP (n = 9) during this period. Discontinuation of GnRHa treatment From the 143 adolescents who started treatment with GnRHa, nine (6%; one transgirl, eight transboys) stopped this treatment after a median duration of 0.8 years (0.1-3.0), at a median age of 15.0 years (13.4-18.9). Four individuals discontinued although they did wish further endocrine treatment because for gender dysphoria. One stopped treatment because of an increase in mood problems and suicidal thoughts, and confusion attributed to treatment with GnRHa and restarted treatment (treatment with GAH) at an adult gender identity clinic elsewhere. He later indicated: “I was already fully matured when I started GnRHa, menstruations were already suppressed by contraceptives. For me, it had no added value.” - Interview with a transboy, age 19 years Another transboy experienced hot flushes, an increase in migraine, and had fear of injections in addition to stress due to problems at school and unrelated medical issues and therefore wished to temporarily discontinue treatment with GnRHa after four months. He restarted five months later and subsequently started testosterone treatment. A third transboy experienced mood swings starting four months after he had begun treatment with GnRHa. A year later, he started to frequently feel unwell and miss school. After 2.2 years, he developed severe nausea and rapid weight loss for which no cause was