A European Network for the Investigation of Gender Incongruence in adolescents.

BACKGROUND: Knowledge regarding the effects and side effects of gender-affirming hormone therapy (GAHT) in adults is rapidly growing, partly through international research networks such as the European Network for the Investigation of Gender Incongruence (ENIGI). However, data on the effects of puberty suppression (PS) and GAHT in transgender and gender diverse (TGD) youth are limited, although these data are of crucial importance, given the controversies surrounding this treatment. AIM: We sought to present a detailed overview of the design of the ENIGI Adolescents study protocol, including the first baseline data. METHODS: The ENIGI Adolescents study is an ongoing multicenter prospective cohort study. This study protocol was developed by 3 European centers that provide endocrine care for TGD adolescents and were already part of the ENIGI collaboration: Amsterdam, Ghent, and Florence. OUTCOMES: Study outcomes include physical effects and side effects, laboratory parameters, bone mineral density, anthropometric characteristics, attitudes toward fertility and fertility preservation, and psychological well-being, which are measured in the study participants during PS and GAHT, up to 3 years after the start of GAHT. RESULTS: Between November 2021 and May 2023, 172 TGD adolescents were included in the ENIGI Adolescents protocol, of whom 51 were assigned male at birth (AMAB) and 121 were assigned female at birth (AFAB); 3 AFAB participants reported a nonbinary gender identification. A total of 76 participants were included at the start of PS, at a median (IQR) age of 13.7 (12.9-16.5) years in AMAB and 13.5 (12.4-16.1) years in AFAB individuals. The remaining 96 participants were included at start of GAHT, at a median (IQR) age of 15.9 (15.1-17.4) years in AFAB and 16.0 (15.1-16.8) years in AMAB individuals. At the time of this report the study was open for inclusion and follow-up measurements were ongoing. CLINICAL IMPLICATIONS: In response to the rising demand for gender-affirming treatment among TGD youth, this ongoing study is fulfilling the need for prospective data on the effects and safety of PS and GAHT, thus providing a foundation for evidence-based healthcare decisions. STRENGTHS AND LIMITATIONS: This study has a strong multicenter, prospective design that allows for systematic data collection. The use of clinical and self-reported data offers a broad range of outcomes to evaluate. Nevertheless, the burden of additional measurements and questionnaires may lead to withdrawal or lower response rates. Few participants with a non-binary gender identity have been included. CONCLUSION: With the ENIGI Adolescents study we aim to create a comprehensive dataset that we can use for a wide range of studies to address current controversies and uncertainties and to improve healthcare for TGD adolescents.

The risk of psychosis for transgender individuals: a Dutch national cohort study.

BACKGROUND: The stressful minority position of transgender persons may result in a high risk of psychosis. Conflicting data suggest that the observed risk depends on setting of recruitment. We assessed the relative risk of non-affective psychotic disorder (NAPD) in a large, representative cohort of transgender persons. METHODS: This cohort was composed using: data on legal sex change from the Dutch population registry and data on dispensing of cross-sex hormones (route 1), and a registry of insurance claims from mental health care including persons with a diagnosis of gender identity disorder (DSM-IV) or gender dysphoria (DSM-5) (route 2). They were matched by sex at birth, calendar year and country of birth to controls from the general population. Transgender persons (N = 5564) and controls (N = 27 820), aged 16-60 years at 1 January 2011, were followed until the first insurance claim for NAPD in 2011-2019. RESULTS: The incidence rate ratio (IRR) of NAPD for transgender persons selected exclusively through route 1 (N = 3859, IRR = 2.00, 95%-CI 1.52-2.63) was increased, but significantly lower than the IRRs for those selected exclusively through route 2 (N = 694, IRR = 22.15, 95%-CI 13.91-35.28) and for those found by both routes (N = 1011, IRR = 5.17, 95%-CI 3.57-7.49; p value for differences in IRR < 0.001). CONCLUSIONS: This study supports the social defeat-hypothesis of NAPD. The results also show the presence of a substantial number of transgender persons with severe psychiatric problems who have not (yet) taken steps to gender-affirmative care.

[Children and adolescents with gender questions: dilemmas in the hormonal treatment by multidisciplinary teams]. / Jongeren met genderincongruentie.

In the Netherlands but also in many other countries, there is an increasing social discussion about gender identity and gender diversity, and an increasing number of children and adolescents are seeking medical help because of questions about their gender identity. The cause of this increase is still unknown. Gender questions are diverse and require an individual approach by a multidisciplinary team. A number of adolescents have additional problems such as mood problems, autistiform symptoms and systemic problems. Diagnosis and treatment takes place in accordance with the quality standard for transgender care somatic and psychological. Hormonal treatment can help to reduce gender dysphoria and improve mental health.

GenderJourney: Participatory development of an ethics support tool to foster dialogue and reflection on shared decision-making in gender-affirming medical care.

OBJECTIVE: To describe and reflect on the development process of GenderJourney: an ethics support tool that seeks to foster (dialogue and reflection on) shared decision-making (SDM) in gender-affirming medical care (GAMC). METHODS: Part of a larger project, this study used a participatory design. We included transgender and gender diverse (TGD) clients and healthcare professionals (HCPs) throughout the study in co-creation workshops. In an iterative process, we (1) established stakeholders' needs, (2) reached a consensus on the aims, content, and design, (3) developed and tested successive renditions, and (4) presented the final version of the tool. RESULTS: The final tool aims to (A) elucidate the client's care request and corresponding treatment preferences, (B) foster an explicit dialogue between TGD client and HCP about expected/preferred decisional roles and collaboration, (C) stimulate a systematic joint reflection on and handling of SDM-related ethical challenges. CONCLUSION: The GenderJourney provides non-directive ethics support to jointly reflect on and foster good SDM, including its inherent ethical challenges. Future studies should focus on its implementation and actual contribution to good SDM. PRACTICE IMPLICATIONS: GenderJourney may be used in GAMC to support the dialogue on what good SDM entails and the identification, discussion, and handling of SDM-related ethical challenges.

The Gender-Diversity and Autism Questionnaire: A Community-Developed Clinical, Research, and Self-Advocacy Tool for Autistic Transgender and Gender-Diverse Young Adults.

Background: Autistic transgender people face unique risks in society, including inequities in accessing needed care and related mental health disparities. Given the need for specific and culturally responsive accommodations/supports, the characterization of key experiences, challenges, needs, and resilience factors within this population is imperative. This study developed a structured self-report tool for autistic transgender young adults to communicate their experiences and needs in a report format attuned to common autistic thinking and communication styles. Methods: This cross-nation project developed and refined the Gender-Diversity and Autism Questionnaire through an iterative community-based approach using Delphi panel methodology. This proof-of-principle project defined "expertise" broadly, employing a multi-input expert search approach to balance academic-, community-, and lived experience-based expertise. Results: The expert collaborators (N = 24 respondents) completed a two-round Delphi study, which developed 85 mostly closed-ended items based on 90% consensus. Final item content falls within six topic areas: the experience of identities; the impact of experienced or anticipated discrimination, bias, and violence toward autistic people and transgender people; tasks and experiences of everyday life; gender diversity- or autism-related care needs and history; the experience of others doubting an individual's gender identity and/or autism; and the experience of community and connectedness. The majority of retained items relate to tasks and experiences of everyday life or the impact of experienced or anticipated discrimination, bias, and violence. Conclusions: This study employed a multipronged multimodal search approach to maximize equity in representation of the expert measure development team. The resulting instrument, designed for clinical, research, and self-advocacy applications, has parallel Dutch and English versions and is available for immediate use. Future cross-cultural research with this instrument could help identify contextual risk and resilience factors to better understand and address inequities faced by this large intersectional population.

Why is this an important issue?: Transgender and gender-diverse are words used to describe people whose gender varies from their assigned sex at birth. Many autistic people identify as being transgender/gender-diverse. Autistic gender-diverse/transgender young adults often describe difficulties getting the care they need, which can increase their chances of experiencing stress and mental health challenges. This study created a self-report questionnaire for autistic transgender/gender-diverse young adults to share about their health care, support needs, and broader experiences. What were the results of the study?: A diverse group of experts in the autism and gender diversity co-occurrence, including autistic transgender people, worked together to develop the questionnaire. The researchers found experts by searching the internet and talking to people in the community and research field. The questionnaire is called the Gender-Diversity and Autism Questionnaire and has 85 questions that are grouped into 6 different areas: the experience of identities; the impact of experienced or anticipated discrimination, bias, and violence toward autistic people and transgender people; tasks and experiences of everyday life; gender diversity- or autism-related care needs and history; the experience of others doubting an individual's gender identity and/or autism; and the experience of community and connectedness. The questionnaire has English and Dutch versions so it can be used for research in different countries. What do the authors recommend for future research on this topic?: Researchers are currently using the new questionnaire to compare the experiences and needs of autistic transgender young adults in the Netherlands and the United States. The results may help explain why some outcomes are different between autistic transgender young people in the two countries and how culture and society play a role. How will these findings help autistic adults now or in the future?: We created the questionnaire to be used in different settings, including clinics and in research. The questionnaire gives autistic transgender young adults a structured way to communicate their experiences, needs, challenges, and areas of strength. The answers that an autistic transgender young adult gives on the questionnaire could help other people understand the clinical and community supports that the young adult wants and needs. Future studies may use the questionnaire to understand obstacles that autistic transgender young adults may face.

Uncertainty in complex healthcare settings - The need for a comprehensive approach.

Uncertainty is increasingly recognized as a crucial phenomenon throughout medical practice. Research on uncertainty so far has been scattered across disciplines, leading to a lack of consensus about what uncertainty represents and minimal integration of knowledge obtained within isolated disciplines. Currently, a comprehensive view of uncertainty which does justice to normatively or interactionally challenging healthcare settings is lacking. This impedes research teasing apart when and how uncertainty manifests, how all stakeholders experience and value it, and how it affects medical communication and decision-making. In this paper, we argue that we need a more integrated understanding of uncertainty. We illustrate our argument using the context of adolescent transgender care, in which uncertainty occurs in myriad ways. We first sketch how theories of uncertainty have emerged from isolated disciplines, leading to a lack of conceptual integration. Subsequently, we emphasize why it is problematic that no comprehensive approach to uncertainty has yet been developed, using examples from adolescent transgender care. Finally, we advocate an integrated approach of uncertainty to further advance empirical research and to ultimately benefit clinical practice.

Children and adolescents in the Amsterdam Cohort of Gender Dysphoria: trends in diagnostic- and treatment trajectories during the first 20 years of the Dutch Protocol.

BACKGROUND: Twenty years ago, the Dutch Protocol-consisting of a gonadotropin-releasing hormone agonist (GnRHa) to halt puberty and subsequent gender-affirming hormones (GAHs)-was implemented to treat adolescents with gender dysphoria. AIM: To study trends in trajectories in children and adolescents who were referred for evaluation of gender dysphoria and/or treated following the Dutch Protocol. METHODS: The current study is based on a retrospective cohort of 1766 children and adolescents in the Amsterdam Cohort of Gender Dysphoria. OUTCOMES: Outcomes included trends in number of intakes, ratio of assigned sex at birth, age at intake, age at start of GnRHa and GAH, puberty stage at start of GnRHa, proportions of adolescents starting and stopping GnRHa, reasons for refraining from GnRHa, and proportions of people undergoing gender-affirming surgery. RESULTS: A steep increase in referrals was observed over the years. A change in the AMAB:AFAB ratio (assigned male at birth to assigned female at birth) was seen over time, tipping the balance toward AFAB. Age at intake and at start of GnRHa has increased over time. Of possibly eligible adolescents who had their first visit before age 10 years, nearly half started GnRHa vs around two-thirds who had their first visit at or after age 10 years. The proportion starting GnRHa rose only for those first visiting before age 10. Puberty stage at start of GnRHa fluctuated over time. Absence of gender dysphoria diagnosis was the main reason for not starting GnRHa. Very few stopped GnRHa (1.4%), mostly because of remission of gender dysphoria. Age at start of GAH has increased mainly in the most recent years. When a change in law was made in July 2014 no longer requiring gonadectomy to change legal sex, percentages of people undergoing gonadectomy decreased in AMAB and AFAB. CLINICAL IMPLICATIONS: A substantial number of adolescents did not start medical treatment. In the ones who did, risk for retransitioning was very low, providing ongoing support for medical interventions in comprehensively assessed gender diverse adolescents. STRENGTHS AND LIMITATIONS: Important topics on transgender health care for children and adolescents were studied in a large cohort over an unprecedented time span, limited by the retrospective design. CONCLUSION: Trajectories in diagnostic evaluation and medical treatment in children and adolescents referred for gender dysphoria are diverse. Initiating medical treatment and need for surgical procedures depends on not only personal characteristics but societal and legal factors as well.

Body Image in Adolescents with Gender Incongruence and Its Association with Psychological Functioning.

During adolescence, many individuals with gender incongruence (GI) experience distress related to body dissatisfaction. This study aims to describe the body (dis)satisfaction of Dutch adolescents referred for GI and to describe the influence of body image on their psychological functioning. Self-report measures on body satisfaction (Body Image Scale) and psychological functioning (Youth Self-Report) were obtained from 787 adolescents (aged 10-18) who were referred to the Center of Expertise on Gender Dysphoria at the Amsterdam University Medical Centers between 1996 and 2016. First, a general description of body satisfaction in adolescents with GI was developed. Secondly, multiple linear regression analyses were performed to determine the association between body image and psychological functioning, both for total problems and for internalizing and externalizing problems separately. Third, regression analyses are repeated for body area subscales. Adolescents with GI report the greatest dissatisfaction with the genital area, regardless of birth-assigned sex. For all other body areas, there were birth-assigned sex differences in satisfaction. The analyses showed that body satisfaction was significantly related to total psychological problems and both internalizing and externalizing problems. Greater body dissatisfaction is significantly associated with worse psychological functioning in adolescents with GI. Clinicians should monitor the body image of adolescents with GI over time, especially during puberty and medical interventions.

Demographics and gender-related measures in younger and older adolescents presenting to a gender service.

Transgender adolescents may present to gender identity specialty services earlier or later in adolescence. The aim of this study was to examine whether, 'younger' and 'older' presenters could be identified in a large cohort of transgender adolescents and if differences exist between the two groups. The study sample consisted of 1487 adolescents (506 birth-assigned males, 981 birth-assigned females) referred between 2000 and 2018. The distribution of age at intake was evaluated. Demographic, diagnostic, and treatment characteristics, the Recalled Childhood Gender Identity/Gender Role Questionnaire (RCGI) to measure childhood gender nonconformity and the Body Image Scale (BIS) to measure body image were collected. Based on a stem-and-leaf plot and a histogram, two groups were identified: adolescents presenting at ≤ 13.9 years ('younger presenters') and adolescents presenting at 14 years or older ('older presenters'). The sex ratio was more extreme in the group of older presenters favoring birth-assigned females (Χ2(1, N = 1487) = 19.69, p < 0.001). Furthermore, more adolescents from the younger presenting group lived with both biological parents (Χ2(1, N = 1427) = 24.78, p < 0.001), were diagnosed with gender dysphoria and started with medical gender-affirming treatment (Χ2(1, N = 1404) = 4.60, p = 0.032 and Χ2(1, N = 1487) = 29.16, p < 0.001). Younger presenters showed more gender nonconformity in childhood (ß 0.315, p < 0.001, 95% CI 0.224-0.407). Older presenters were more dissatisfied with various aspects of their bodies (p < 0.001). The differences between older and younger presenting adolescents suggest that there may be different developmental pathways in adolescents that lead to seeking gender-affirming medical care and argues for more tailored care.

Ensuring Care for Transgender Adolescents Who Need It: Response to 'Reconsidering Informed Consent for Trans-Identified Children, Adolescents and Young Adults'.

Adolescent transgender care is increasingly surrounded by controversies and criticism. One of these concerns expressed in a review article by Levine et al. entitled 'Reconsidering Informed Consent for Trans-Identified Children, Adolescents and Young Adults' is the limited evidence base, especially of the Dutch studies which provided the first and mostly cited basis for medical intervention at a young age. This Response is written by the first author of two of those studies that showed effectiveness of the approach that included puberty blockers. The author rebuts several of the concerns that Levine et al.have regarding these Dutch studies, among which are the limited statistical improvements of psychological measures, the use of the Utrecht Gender Dysphoria and the selection of participants. The author further refers to several shorter term longitudinal follow up studies that have been published, which are not mentioned by Levine et al.. They also show improvement or stable psychological functioning and relief of gender incongruence. Finally, a careful evaluation and informed consent provision has always been recommended in all editions of the WPATH's Standards of Care and are also part of the 8th version as well as the Endocrine Society guidelines. The author agrees therefore with Levine et al. that clinicians in transgender care should follow these international guidelines and provide such an assessment in order to ensure that medical interventions are appropriately provided for those transgender adolescents who need them.

Medical decision-making competence regarding puberty suppression: perceptions of transgender adolescents, their parents and clinicians.

According to international transgender care guidelines, transgender adolescents should have medical decision-making competence (MDC) to start puberty suppression (PS) and halt endogenous pubertal development. However, MDC is a debated concept in adolescent transgender care and little is known about the transgender adolescents', their parents', and clinicians' perspectives on this. Increasing our understanding of these perspectives can improve transgender adolescent care. A qualitative interview study with adolescents attending two Dutch gender identity clinics (eight transgender adolescents who proceeded to gender-affirming hormones after PS, and six adolescents who discontinued PS) and 12 of their parents, and focus groups with ten clinicians was conducted. From thematic analysis, three themes emerged regarding transgender adolescents' MDC to start PS: (1) challenges when assessing MDC, (2) aspects that are considered when assessing MDC, and (3) MDC's relevance. The four criteria one needs to fulfill to have MDC-understanding, appreciating, reasoning, communicating a choice-were all, to a greater or lesser extent, mentioned by most participants, just as MDC being relative to a specific decision and context. Interestingly, most adolescents, parents and clinicians find understanding and appreciating PS and its consequences important for MDC. Nevertheless, most state that the adolescents did not fully understand and appreciate PS and its consequences, but were nonetheless able to decide about PS. Parents' support of their child was considered essential in the decision-making process. Clinicians find MDC difficult to assess and put into practice in a uniform way. Dissemination of knowledge about MDC to start PS would help to adequately support adolescents, parents and clinicians in the decision-making process.

Perceptions on the function of puberty suppression of transgender adolescents who continued or discontinued treatment, their parents, and clinicians.

Purpose: Treatment of transgender adolescents with puberty suppression (PS) was developed to provide time for exploration before pursuing gender affirming medical treatment (GAMT) with irreversible effects. It may also result in a more satisfactory physical outcome for those who continue with GAMT. Despite being the current first choice treatment, little research has examined the function of PS from the perspectives of transgender adolescents, their parents, and clinicians. Insight into the perceived functions of PS will help to adequately support adolescents in their decision-making process and give them the care they need. Methods: Qualitative study using interviews with eight transgender adolescents who proceeded with GAMT after PS ("continuers"), six adolescents who discontinued PS ("discontinuers") and 12 parents, and focus groups with ten clinicians. Results: All informants considered inhibition of development of secondary sex characteristics an important function of PS. Most continuers saw PS as the first step of GAMT. Nevertheless, some were glad that the effects were reversible even if they didn't expect to change their minds. Some discontinuers did experience PS as an expanded diagnostic phase. One continuer used the time on PS to get used to living in the affirmed gender role, and several parents found the time helpful to adapt to their child's new gender role. PS provided clinicians more time for diagnostic assessment. Conclusions: Adolescents, parents and clinicians do not all report the same functions of PS. Although international guidelines emphasize providing time for exploration of gender identity as an important reason for PS, many adolescents nowadays seem to have clear ideas about their gender identity and treatment wishes, and experience PS as the first step of GAMT. For some discontinuers however, PS offered a valued period of exploration. Guidelines could be modified to provide more customized care, taking adolescents' and parents' ideas about the functions of PS into account.

Self-Perception of Transgender Adolescents After Gender-Affirming Treatment: A Follow-Up Study into Young Adulthood.

Purpose: Early medical treatment for transgender adolescents should contribute to healthy psychological development, including the development of positive self-perception. However, at present, there are no longitudinal studies that have examined whether current treatment approaches meet this expectation. Therefore, the aim of this single-arm retrospective study was to examine transgender adolescents' self-perception changes over the course of irreversible medical gender-affirming treatment. Methods: The total study sample consisted of 70 adolescents (49 trans men and 21 trans women). Self-perception was assessed before the start of gender-affirming hormone treatment (mean age = 14.65, standard deviation (SD) = 2.08) and at least 6 months after gender-affirming surgeries (mean age = 20.70, SD = 1.49) by Self-Perception Profile for Adolescents (SPPA). The SPPA is a self-report measure that examines self-perception on seven different domains: Scholastic competence, social acceptance, athletic competence, physical appearance, behavioral conduct, close friendship, and global self-worth. Multilevel modeling (random intercepts model) was conducted to determine the effect of time for all domains of self-perception. Results: It was found that the domains of physical appearance and global self-worth improved significantly over the course of treatment. No domain worsened significantly over the course of treatment. The domains of scholastic competence, social acceptance, athletic competence, and close friendship remained stable over time. Conclusion: This study provides the first suggestive evidence that irreversible gender-affirming treatment for adolescents could contribute to the development of a more positive self-perception.

Talking About Sexuality With Youth: A Taboo in Psychiatry?

BACKGROUND: Young people who have psychiatric problems are more likely than their peers to endure difficulties during their sexual and gender identity development. AIM: This study aims to examine the communication between mental health care providers and their patients about the topics of relations, sexuality and gender identity, including a description of professionals' attitudes toward these topics and the factors that contribute to and inhibit communication. METHODS: Study participants (n = 242, response rate = 31%) were a representative sample of a large multicenter cohort of 768 mental health care professionals (eg, medical doctors, psychiatrists, psychologists, group counselors, parent counselors) of 7 institutions and 5 solo practices in the Netherlands, who completed a survey on communication about sexuality and gender identity with their young patients (age 12-21 years). OUTCOMES: Sexuality and gender identity are infrequently discussed by mental health care providers with their young patients or their patients' parents. RESULTS: Of the study sample, 99.5 % valued sexuality as an important topic to discuss with their patients. However, only 17.1% of the professionals reported that they discussed sexuality-related issues with the majority (>75%) of their patients (adolescents: 19.9%, parents: 14.4%) Additionally, only 2.3 % of the participants discussed gender nonconformity regularly with patients. Information about sexual side effects of prescribed medication was infrequently (20.3%) provided: antidepressants (40.0%), antipsychotics (34.0%), benzodiazepines (5.1%) and stimulants (2.4%). The most frequently cited reasons for not discussing these topics were a lack of awareness, own feelings of discomfort, and the patients' supposed feelings of shame. There was no gender differences observed. CLINICAL IMPLICATIONS: Recommendations for professionals include to be aware of these topics, initiating age-appropriate conversation and use inclusive language. STRENGTHS AND LIMITATIONS: The present study included a diverse and representative group of mental health care professionals. Frequency of sexual communication was based on self-report, which brings a risk of bias. CONCLUSION: Despite a recognized need to engage in age-appropriate communication about sexuality and gender identity in youth mental health care, mental health providers seem to remain hesitant to discuss such topics. Bungener SL, Post L, Berends I, et al. Talking About Sexuality With Youth: A Taboo in Psychiatry?. J Sex Med 2022;19:421-429.

Suicidality in clinic-referred transgender adolescents.

Gender and sexually diverse adolescents have been reported to be at an elevated risk for suicidal thoughts and behaviors. For transgender adolescents, there has been variation in source of ascertainment and how suicidality was measured, including the time-frame (e.g., past 6 months, lifetime). In studies of clinic-referred samples of transgender adolescents, none utilized any type of comparison or control group. The present study examined suicidality in transgender adolescents (M age, 15.99 years) seen at specialty clinics in Toronto, Canada, Amsterdam, the Netherlands, and London, UK (total N = 2771). Suicidality was measured using two items from the Child Behavior Checklist (CBCL) and the Youth Self-Report (YSR). The CBCL/YSR referred and non-referred standardization samples from both the U.S. and the Netherlands were used for comparative purposes. Multiple linear regression analyses showed that there was significant between-clinic variation in suicidality on both the CBCL and the YSR; in addition, suicidality was consistently higher among birth-assigned females and strongly associated with degree of general behavioral and emotional problems. Compared to the U.S. and Dutch CBCL/YSR standardization samples, the relative risk of suicidality was somewhat higher than referred adolescents but substantially higher than non-referred adolescents. The results were discussed in relation to both gender identity specific and more general risk factors for suicidality.

Assessing Medical Decision-Making Competence in Transgender Youth.

BACKGROUND: According to international transgender care guidelines, an important prerequisite for puberty suppression (PS) is transgender adolescents' competence to give informed consent (IC). In society, there is doubt whether transgender adolescents are capable of this, which in some countries has even led to limited access to this intervention. Therefore, this study examined transgender adolescents' medical decision-making competence (MDC) to give IC for starting PS in a structured, replicable way. Additionally, potential associated variables on MDC, such as age, intelligence, sex, psychological functioning, were investigated. METHODS: A cross-sectional semistructured interview study with 74 transgender adolescents (aged 10-18 years; 16 birth-assigned boys, 58 birth-assigned girls) within two Dutch specialized gender-identity clinics was performed. To assess MDC, judgements based on the reference standard (clinical assessment) and the MacArthur Competence Assessment Tool for Treatment (MacCAT-T), a validated semistructured interview, were used. RESULTS: Of the transgender adolescents, 93.2% (reference standard judgements; 69 of 74) and 89.2% (MacCAT-T judgements; 66 of 74) were assessed competent to consent. Intermethod agreement was 87.8% (65 of 74). Interrater agreements of the reference standard and MacCAT-T-based judgements were 89.2% (198 of 222) and 86.5% (192 of 222), respectively. IQ and sex were both significantly related to MacCAT-T total score, whereas age, level of emotional and behavioral challenges, and diagnostic trajectories duration were not. CONCLUSIONS: By using the MacCAT-T and clinicians' assessments, 93.2% and 89.2%, respectively, of the transgender adolescents in this study were assessed competent to consent for starting PS.