Evaluation of the Effectiveness of Hormonal Treatment in Adolescents Suffering from Gender Dysphoria

Multicenter, controlled, randomized, open trial with blinded evaluation of the primary endpoint (Prospective Open Blinding Endpoint PROBE study). Randomization will be stratified by sex assigned at birth and the investigating center. The primary analysis will be intention-to-treat and multiple imputation methods will be used to handle missing data. After verification of the inclusion criteria by the child psychiatrist (selection visit), then the pediatric endocrinologist (inclusion visit), the adolescent will be included in the study and will benefit from an initial evaluation (T0) by a psychologist trained for the primary criterion (CGAS) and secondary psycho-affective criteria.The patients will then be sent again to the pediatric endocrinologist who will randomize the patient (via an IT platform) and give them the treatment corresponding to their assigned group. Adolescents in both groups will be reassessed at 16 years +/- 6 months (T1). At the end of this evaluation, patients in the control group will begin their hormonal treatment. Adolescents will undergo a final evaluation at 18 years +/- 6 months (T2), at which time the same criteria as at T0 and T1 will be collected.

Main objective: To evaluate, in gender dysphoric adolescents, having completed their social transition, having or not undergone prior pubertal suppression, the effectiveness of hormonal treatment with estrogens or testosterone initiated at 14 years +/- 6 months of age on the overall functioning of the teenager at 16 years +/- 6 months old.

Primary endpoint: Children's Global Assesment Scale (CGAS) score at age 16 +/- 6 months

Secondary objectives : Evaluate, in gender dysphoric adolescents who have completed their social transition, whether or not they have benefited from prior pubertal suppression:

• the effectiveness of hormonal treatment started at 14 years old +/- 6 months vs. 16 years old +/- 6 months on the overall functioning of the adolescent at 18 years old+/- 6 months,
• the safety (side effects) of hormonal treatment started at age 14 +/- 6 months,
• and the relevance of hormonal treatment started at 14 years old +/- 6 months on other parameters assessed at 16 +/- 6 months and 18 +/- 6 months years old (gender identity, depression, anxiety, emotional, behavioral disorders and other comorbidities, objective and subjective quality of life, body image, height, waist/hip ratio, bone mineral density, BMI).

Inclusion criteria

• Adolescents aged 14+/- 6 months,
• Having initiated puberty: tanner score ≥2 for FtM; tanner score ≥2 (clinic and/or testosterone >0.3 ng/mL) for MtF
• Presenting the criteria for gender dysphoria according to the DSM5 assessed by at least two child psychiatric interviews at least six months apart where the diagnosis of gender dysphoria was clinically established and that of associated autism spectrum disorder refuted and/or associated cognitive impairment, confirmed by specific scales (Gender Identity / Gender Dysphoria Questionnaire for Adults and Adolescents (GIDYQ-AA) and Utrecht Gender Dysphoria Scale (UGDS))
• Whose indication for hormonal transition has been validated in a multidisciplinary consultation meeting after at least one consultation with the pediatric endocrinologist with clinical examination, blood pressure measurement, and information on hormonal treatments in the context of gender dysphoria.

Exclusion criteria

• Contraindication to hormonal treatment (see paragraph 1.5)
• Hormonal treatment needs to be adjusted (FtM patients treated with anti-coagulants or with thrombophilia).
• Patients with risk of aggravation of certain diseases under oestrogen treatment (MtF patients with uncontrolled diabetes with HBA1C > 8%, patients with cholelithiasis, biliary lithiasis, systemic lupus erythematosus, severe asthma, severe arterial hypertension, severe migraines, otosclerosis, epilepsy not controlled by treatment).
• Patients with cancer with a risk of hypercalcemia (and associated hypercalciuria), linked to bone metastases.
• Severe cardiac, hepatic or renal failure or ischemic heart disease, due to the risk of severe complications characterized by edema, with or without congestive heart failure.
• Uncontrolled high blood pressure.
• Patients with epilepsy and migraine.
• Patients with current or history of thromboembolic events.
• Severe untreated chronic depression
• Current anticoagulant treatment
• Severe autism Spectrum Disorder (clinical screening, confirmed in cases of doubt by the Social Responsiveness Scale (SRS) Raw-score > 76, carried out as part of usual care in cases of clinical evidence,
• Cognitive deficit (clinical screening, confirmed by an QI < 80 on the Weschler scale (WISC V), carried out as part of the usual treatment in the event of clinical evidence.
• Refusal to participate in the study on the part of the adolescent or one of the holders of parental authority (both holders and the adolescent must sign a written consent after receiving appropriate information).
• No social security cover
• Participation in other intervention research
• Pregnancy in progress
• Insufficient knowledge of French