Psychological Functioning in Non-binary Identifying Adolescents and Adults

Abstract

Gender diverse individuals who do not conform to society’s binary gender expectations are more likely to experience difficulties in acceptance and in recognition of gender, compared to binary-identifying transgender people. This may accentuate the feeling that their gender identity is not socially recognized or validated. This study aimed to investigate psychological functioning among gender diverse adolescents and adults who identify beyond the binary gender spectrum. In both study populations, 589 clinically-referred gender diverse adolescents from the UK (n = 438 birth-assigned females and n = 151 birth-assigned males), and 632 clinically-referred gender diverse adults from the Netherlands (n = 278 birth-assigned females and n = 354birth-assigned males), we found that a higher degree of psychological problems was predicted by identifying more strongly with a non-binary identity. For adolescents, more psychological problems were related to having a non-binary gender identity and being assigned female at birth. In the adult population, experiencing psychological difficulties was also significantly related to having a stronger non-binary identity and having a younger age. Clinicians working with gender diverse people should be aware that applicants for physical interventions might have a broader range of gender identities than a binary transgender one, and that people with a non-binary gender identity may, for various reasons, be particularly vulnerable to psychological difficulties.

Introduction

Respondents of an online survey amongst 3500 American college students used more than a hundred different ways to describe their gender identity (Rankin & Beemyn, 2012). A growing number of community surveys and population studies, just like this example, illustrate that increasingly more individuals are openly challenging the traditional binary gender categories (male and female). In line with this trend, specialist gender identity services are emerging across the world and existing gender identity services are often faced with a rising demand of gender diverse service users. The field of transgender healthcare continues to move forward and expand, leading to increased awareness of gender diversity in the general population as well as in clinical contexts (de Graaf & Carmichael, 2019; Richards et al., 2016).

Gender diversity is an umbrella term that is used to describe gender identities that differ from the cultural norms prescribed for people of a particular birth-assigned gender. Subsequently, in this paper, the term gender diverse individual is used to describe individuals who feel that their gender identity is not in line with their birth-assigned gender. This includes treatment-seeking as well as non-treatment-seeking transgender people who identify across the gender spectrum. Those identifying between or outside the gender binary are referred to as non-binary (Richards, Bouman, & Barker, 2017). We acknowledge that language regarding gender identities continues to evolve and that non-binary individuals go by a variety of labels with some creating and adopting titles unique to themselves. These labels often represent a variety of approaches to gender, inclusive of, but not limited to, agender (an absence of gender), bigender (a blending of male and female), genderqueer (a gender that is neither, both, or a combination of male and female genders) and ambigender (a gender that alternates between gender positions) (Barker & Richards, 2015; Fiani & Han, 2019).

While some gender diverse individuals might not express the need for professional support, others do seek-out help from specialist gender identity services to support them with their gender diverse experiences. It is important to note that not all people who report gender diverse experiences opt for medical interventions (Kuyper & Wijsen, 2014; Van Caenegem et al., 2015). For those who experience severe distress associated with their feelings of gender incongruence, a diagnosis of Gender Dysphoria might be applicable (American Psychiatric Association, 2013).

Both gender diverse adolescents and adults have reported poorer mental health outcomes compared to the general population (de Vries, Steensma, Cohen-Kettenis, VanderLaan, & Zucker, 2016; Dhejne, Van Vlerken, Heylens, & Arcelus, 2016; Heylens et al., 2014; Steensma et al., 2014). To date, most studies on gender diverse individuals were largely based on populations which were characterized by individuals expressing a binary gender identification and a prominent desire for feminizing or masculinizing medical interventions from specialist gender identity services (de Graaf & Carmichael, 2019; Moradi et al., 2016). While these characteristics were fairly common over the past few decades, we now start to see fundamental shifts in the ways in which individuals are presenting and describing themselves (Barker & Richards, 2015; Richards et al., 2016; Twist & de Graaf, 2018).

In line with this development, new research is slowly starting to investigate potential differences in wellbeing and psychological functioning between gender diverse individuals who identify as binary or non-binary. In an online survey in gender diverse youth across Canada, Vaele et al. (2017) recruited a community sample of 923 transgender people up to 25 years old. Non-binary individuals reported poorer mental health outcomes and higher rates of self-harming thoughts and/or behaviors than binary individuals. Similarly, Thorne et al. (2019), reporting on 388 transgender youth (aged 16-25 years) attending an adult gender identity service in the UK, showed that those identifying as non-binary reported poorer mental health (specifically anxiety and depression) and lower self-esteem compared to binary transgender youth (Thorne et al., 2019).

For gender diverse adults, similar outcomes were found in two community sample studies across the US. According to James et al. (2016), reporting on one of the largest community samples in the US (n = 27.715), 49% of non-binary respondents reported serious current psychological distress compared to 35% of binary transgender men and woman (James et al., 2016). In another study including 64 non-binary adults, Budge, Rossman, and Howard (2014) reported that 53% of the respondents reported clinical levels of depression and 39% reported clinical levels of anxiety (Budge et al., 2014).

However, there are also studies reporting contradicting results. For example, Rimes, Goodship, Ussher, Baker, and West (2019), who recruited 667 LGBTQ youth (aged 16-25 years) in the UK through youth organizations and social media, found no evidence that non-binary participants had higher rates of mental health problems than binary participants (Rimes et al., 2019). Furthermore, Jones, Bouman, Haycraft, and Arcelus (2019), who recruited adult participants through LGBTQ + organizations within the UK, showed that non-binary people who were assigned male at birth reported better mental health when compared to binary transgender females. Similarly, non-binary people who were assigned female at birth had better mental health outcomes than binary transgender males. For both studies, choices with regard to recruitment strategy, participation sample, (non-validated) instruments, or the participant’s country of origin, may have played a role in the contradicting outcomes compared to the earlier studies.

From the limited evidence that is available, it remains unclear how non-binary identifying adolescents and adults are functioning psychologically, and whether any differences can be found between those assigned male at birth and those assigned female at birth. Research on psychological functioning in clinically referred gender diverse adolescents and adults, acknowledging a non-category based approach, has not yet been performed (Nicholas, 2019). Therefore, this study aimed to analyze non-binary gender identification as a continuum, rather than using gender-categories, in a group of adolescents and adults who present to gender identity services. In the first study, psychological functioning and non-binary identity were assessed in gender diverse adolescents, aged 12 to 18 years, attending the Gender Identity Development Service (GIDS) in the UK. The second study investigated psychological functioning and non-binary identity in gender diverse adults from the Center of Expertise on Gender Dysphoria from the Amsterdam UMC in the Netherlands. In both studies, assigned-gender at birth was taken into account when conducting the analysis. Because of the differences in study design and measurements across the two populations, both studies were described separately. Based on previous findings, it was hypothesized that a higher score on the non-binary gender identity measures was associated with a higher report of psychological problems.

STUDY 1: Psychological Functioning and Non-Binary Gender Identity in Adolescents

Methods

Participants and procedure

Information on psychological functioning and the degree of non-binary gender identification was collected in 720 adolescents (age range 12-18 years) who first visited the GIDS between June 2016 and August 2018. Prior to their first appointment, families and young people attending GIDS were informed about the questionnaire pack which would be gathered as part of the clinical assessment. At this stage the service users were asked if they would be willing for their data to be used for service evaluation and research purposes, underlining that personal information will be kept confidential and no identifiable information will be disclosed. The consent form clearly stated that taking part was entirely voluntary and that the decision to withdraw or decline participation would not affect the quality or nature of clinical care that they will receive from the service. The questionnaire pack that was administered at baseline, during the first or second assessment, consisted of several measurements gathering demographic information, psychological functioning and gender identification.¹ At this stage, none of the participants included in this study had received any form of medical interventions related to their gender identity, such as the administration of puberty suppression treatment, hormonal treatment or had undergone any surgical procedures, nor had they received any of these interventions elsewhere. As the questionnaires were part of GIDS’ routine outcome measures, and the data were coded and used anonymously, the local ethics committee (NOCLOR) advised that ethical approval was not required.

Out of the 720 adolescents, questionnaire data were not available for n = 148 (20.5%) due to not completing one of the questionnaires at baseline. There were no other exclusion criteria. Therefore, a total of 572 participants were included in this study of which 432 (75.5%) participants were assigned female at birth and 140 (24.5%) participants were assigned male at birth. No significant difference was found between the mean age for birth-assigned males (M = 15.74, SD = 1.45) and birth-assigned females (M = 15.71, SD = 1.33), t(570) =.22, p > 0.05.

Measures

Non-binary identity was measured using the Gender Diversity Questionnaire (GDQ) (Twist & de Graaf, 2018). This questionnaire consists of 8 open-ended questions, 3 scales and 15 tickbox-questions, investigating service users’ self-defined gender identity and gender expression. Because of the mixed-models set-up, it is not possible to determine its psychometrics. However, data from the scales and tickbox-questions can be retrieved and used for quantitative analyzes, as reported by Twist and de Graaf (2018). For this study, we looked at data from one of the scales, the non-binary scale. The adolescent was asked whether they could “indicate on the scale if or how much they identify with this [non-binary] identity”. The scale ranged from ‘Not at all’ at one end, to ‘Completely’ at the other end. The marks on a 10 centimeter scale were transformed into scores, ranging between zero (0) – which meant not identifying with a non-binary gender identity – to a hundred (100) – which meant completely identifying with a non-binary identity.

Psychological functioning was measured using the Youth Self-Report for Ages 11-18 (YSR) (Achenbach, 1991). The YSR consists of 119 items which are scored on a three point scale (0 = not true; 1 = sometimes true; and 2 = very true). From these scores, three subscales scores can be calculated which were used in this study: a Total problem score, an Internalizing problem score and an Externalizing Problem score. Following previous studies, item 110 from the YSR, which is specifically related to cross-gender identity (‘I wish I were of the opposite sex’), was excluded from the calculation of scores to prevent potential bias (de Graaf, Cohen-Kettenis, et al., 2018; de Vries et al., 2016; Steensma et al., 2014; Zucker et al., 2012). In addition, there are 14 social desirable items which were also excluded in the score calculations. Higher scores on the YSR scales reflect a greater degree of psychological difficulties.

Statistical analysis

To examine the relationship between psychological functioning, non-binary identity and assigned gender at birth in the adolescent group, hierarchical multiple regression analysis were performed. The three YSR subscales (Total problem score, Internalizing problem score and Externalizing problem score) were used as outcome variables. The Non-binary scale (NB-scale) was entered in Step 1, Assigned-Gender at Birth (AGAB) was entered in Step 2, and the Interaction variable Assigned-Gender at Birth X Non-binary scale (AGAB x NB-scale) was entered in Step 3. A significance level of 5% (p=.05) was used.

Results

First it was established that the Non-binary scale was equally distributed between adolescent birth-assigned males (M = 16.8, SD = 25.5) and birth-assigned females (M = 18.1, SD = 26.4), t(560)=-0.506, p > 0.05, indicating that there were no differences in the ways in which birth-assigned males and birth-assigned females identified across the non-binary gender spectrum.

The steps performed in the hierarchical multiple regression analysis for the adolescents are shown in Table 1. For the Total Problem score, the final model (step 3), which included the two predictors and the interaction variable, was the most suitable model to predict the reported psychological problems, R² = .05, F(3, 571) = 10.50, p<.05. It was found that the Non-binary scale scores significantly predicted the Total Problem Score, β = .19, p<.05, as did Assigned-Gender at Birth (AGAB), β = −.10, p<.05, meaning that a stronger non-binary gender identity and a female-AGAB were associated with a higher Total Problem score. No significant association was found for the Interaction variable (AGAB x NB-scale).

Table 1. Multiple regression analysis on psychological functioning in adolescents

	Total Problems				Internalizing Problems				Externalizing Problems
	B	SE B	β		B	SE B	β		B	SE B	β
Step 1
NB-scale	.24	.05	.19	*	.10	.02	.20	*	.03	.01	.09	*
R²			.04				.04				.01
Step 2
NB-scale	.22	.05	.18	*	.09	.02	.19	*	.03	.01	.08
AGAB	−9.15	2.9	−1.26	*	−4.11	1.20	−.14	*	-.59	.82	-.03
R²			.05				.06				.01
Step 3
NB-scale	.24	.06	.19	*	.09	.02	.19	*	.04	.02	.11	*
AGAB	−7.49	3.6	-.10	*	−4.22	1.45	-.14	*	.35	.99	.02
AGAB x NB-scale	-.12	.15	−.04		.01	.06	.01		-.07	.04	−.09
R²			.05				.06				.01

Psychological functioning was measured by three indices, Total Problems, Internalizing Problems and Externalizing Problems, which are subscales of the Youth Self Report. NB-scale stands for Non-binary scale, measured by the Gender Diversity Questionnaire, a continuous variable ranging from 0-100. AGAB stands for Assigned Gender At Birth, coded 1 = Assigned Male at Birth and 0 = Assigned Female at Birth. * indicates a p-value < 0.05.

For the Internalizing Problem score, the final model including two predictors and the interaction variable best explained the reported internalizing problems, R² = .06, F(3, 570) = 11.98, p<.05. The Non-binary scores significantly predicted the Internalizing Problem Score, β = .19, p<.05, as did Assigned-Gender at Birth, β = −.15, p<.05. This means that both a stronger non-binary identity and a female-AGAB were associated with a higher Internalizing Problem score. No significant association was found for the Interaction variable (AGAB x NB-scale).

In the final model for the Externalizing Problem score, R² = .01, F(3, 570) = 2.54, p<.05, the Non-binary identity scores significantly predicted the reported externalizing problems, β = .11, p<.05. Thus, a stronger non-binary identity was associated with an increase in Externalizing Problems.

Overall, these results showed that, for adolescents, the stronger the non-binary gender identity, the more psychological problems were reported. On the Total and Internalizing problem scores, it was found that the higher problem scores were also associated with those who were assigned female at birth.

STUDY 2: Psychological Functioning and Non-Binary Gender Identity in Adults

Methods

Participants and procedure

Information on psychological functioning and non-binary identity were collected from gender diverse adults (age range 17 to 67 years) who visited the Center of Expertise on Gender Dysphoria at the Amsterdam UMC, the Netherlands, between 2013 and 2016. Prior to their first appointment, all adults were informed the that questionnaires which would be gathered as part of their clinical assessment could also be used for research purposes for which consent was signed. The questionnaires were administered at baseline, at the start of the assessment phase. At this stage, none of the participants included in this study had received any form of medical interventions related to their gender identity, such as the administration of puberty suppression treatment, hormonal treatment or had undergone any surgical procedures, nor had they received any of these interventions elsewhere. Ethical approval for administering the questionnaires was obtained from the local ethics committee.

All adults who completed both questionnaires were included in this study. In total, data of 607 adults were available, of which 264 (43%) participants were assigned female at birth and 343 (57%) participants were assigned male at birth. The mean age in years was 28.7 (SD = 11.9). Birth-assigned males in this sample were found to be significantly older (mean age = 31.15, SD = 12.73) compared to the birth-assigned females (mean age = 25.48, SD = 9.88), t(1, 605)=5.98, p<.01).

Measures

Non-binary identity was assessed using the Genderqueer Identity Scale (GQI), a validated questionnaire that measures the degree to which one has a genderqueer identity (McGuire, Beek, Catalpa, & Steensma, 2019). The GQI consists of 23 items which can be subdivided into 4 subscales; 1) Challenging the Binary, 2) Social Construction, 3) Theoretical Awareness and 4) Gender Fluidity. Each item is scored on a 5-point Likert scale, ranging from 0 ‘Strongly Disagree’ to 4 ‘Strongly Agree’. Example items are “I am non-binary, genderqueer, or an identity other than male or female” or “In the future, I think my gender will be fluid or change over time”. The total score can range between zero (0) and ninety-two (92). Higher scores on the GQI indicate a gender identity on the more non-binary end of the spectrum (McGuire et al., 2019).

In the adult sample, the Dutch Symptom Checklist (SCL-90-R) was used to assess psychological functioning (Arrindell & Ettema, 2003). In accordance with the original structure of the SCL-90-R (Derogatis, 1977, 1994), the Dutch SCL-90-R is a multidimensional self-report questionnaire and consists of the subscales Anxiety, Agoraphobia, Depression, Somatization, Cognitive-Performance Deficits, Interpersonal Sensitivity, Hostility, and Sleep Deprivation. Ninety items can be scored on a five-point rating scale, ranging from ‘not at all’ (0) to ‘extremely’ (4). At the Amsterdam UMC, this questionnaire was used to assess psychological problems experienced in the past week. The Dutch SCL-90-R total score has a range between 0-360. A higher score reflects a greater degree of psychological difficulties (Smits, Timmerman, Barelds, & Meijer, 2014).

Statistical analysis

To predict whether psychological functioning was significantly associated by non-binary identification and/or by birth-assigned gender, an hierarchical multiple regression analysis was performed. The SCL-90-R total score was used as the outcome variable for psychological functioning. Age was added into the regression model, to control for the differences found between birth-assigned males and birth-assigned females within the study population. The Non-binary scale (GQI) and Age were entered in Step 1, Assigned-Gender at Birth (AGAB) was entered in Step 2, and the interaction variable Assigned-Gender at Birth X Non-binary scale (AGAB X GQI) was entered in Step 3. Results were considered statistically significant if p < .05.

Results

First, a significant difference was found for the Genderqueer Identity Scale (GQI) between birth-assigned males (M = 30.3, SD = 11.2) and birth-assigned females (M = 28.1, SD = 11.4); t(630)=2.375, p=.018. On average, birth-assigned males scored higher on the Non-binary scale compared to the birth-assigned females.

The results for the hierarchical multiple regression analysis are presented in Table 2. The first model, including the two predictors GQI and Age, was found to be the best model to account for the reported psychological problems in the adult population, R² = .135, F(2, 606) = 46.978, p < .05. It was found that both Non-binary identity, β = .30, p < .05, as well as Age, β = −0.186, p < .05, significantly predicted psychological problems. No significant outcomes were found for Assigned-Gender at Birth (AGAB) or the interaction AGAB x GQI. This shows that, the more the individual identifies with a non-binary gender identity, and the younger they are, the more psychological problems they experienced.

Table 2. Hierarchical multiple regression analyses on psychological functioning in adults

		SCL Psychological Problems
	B	SE B	β
Step 1
GQI Total	.82	.10	.30	*
Age	−0.46	.09	−0.19	*
R2			.14
Step 2
GQI Total	.81	.10	.30	*
Age	−0.48	.10	−0.19	*
AGAB	1.80	2.31	0.31
R2			.14
Step 3
GQI Total	.81	.16	.30	*
Age	−0.48	.10	−0.19	*
AGAB	1.88	6.40	0.32
AGAB x GQI Total	−0.00	.21	−0.00
R2			.14

Psychological Total Problems were measured by the SCL-90-R, GQI scale stands for Genderqueer Inventory scale which measures non-binary identity on a scale of 0-92, AGAB stands for Assigned Gender At Birth, coded 1 = Assigned Male at Birth and 0 = Assigned Female at Birth. * indicates a p-value < 0.05.

Discussion

The findings of our studies showed a similar pattern in both gender diverse adolescents and adults presenting to gender identity services; the stronger the non-binary identification, the more psychological problems they reported. These results were in line with several studies which comparing non-binary and binary transgender people in community samples, which showed that individuals who identified as non-binary experienced more mental health difficulties compared to those with a binary (cis-or trans-) gender identity (Budge et al., 2014; James et al., 2016; Thorne et al., 2018; Veale, Watson, Peter, & Saewyc, 2017). The higher levels of psychological problems experienced by non-binary identifying individuals may well be the result of extrinsic factors as well as intrinsic factors, or a combination of both.

Individuals who do not conform to society’s binary gender expectations are likely to experience difficulties with how they are being perceived by others, which may be experienced as an additional burden that goes beyond the difficulties of binary transgender people (Jones & Mullany, 2019). As a result, non-binary adolescents and adults may be misgendered and addressed inappropriately more frequently than binary individuals. Repeated exposure to such intentional and unintentional behavior by strangers as well as relatives or friends could be stressful for non-binary individuals and may accentuate the feeling that their gender identity is not socially recognized or validated (Fiani & Han, 2019; Monro, 2019; Nicholas, 2019). Subsequently, lack of acknowledgement or invisibility of one’s gender identity may result in insecurity, low self-esteem or emotional problems (Nicholas, 2019). The issue of invisibility is also pertinent to policy making in healthcare or politics, where health monitoring systems as well as governmental bodies issuing passports continue to use gender binary categories (Monro, 2019).

Despite the growing number of non-binary individuals presenting at specialist gender identity services, there is a lack of information available to non-binary individuals. Furthermore, people with a non-binary identity are rarely culturally represented compared to binary individuals (Fiani & Han, 2019; Monro, 2019; Nicholas, 2019; Thorne et al., 2018). This context also has implications for the identity exploration for non-binary individuals, which, compared to binary individuals, tends to be delayed (Fiani & Han, 2019; Thorne et al., 2018). Thus, it is likely that non-binary individuals’ poorer mental health can - at least partially - be explained by the lack of recognition and the absence of information, resources or non-binary role models (Fiani & Han, 2019; Jones et al., 2019; Nicholas, 2019).

Furthermore, the literature highlights that gender diverse individuals are often faced with societal challenges such as discrimination or stigmatization (Richards et al., 2016). Following the minority stress theory, mental health problems in minority populations are often a result of individuals being stigmatized (Hendricks & Testa, 2012). It is known that gender diverse people are often harassed, discriminated against and bullied because of their gender identity or expression (Grossman & D’augelli, 2007; Holt, Skagerberg, & Dunsford, 2016). This may be particularly true for non-binary individuals, who experience more discomfort and social pressure to conform to traditional gender labeling compared to binary transgender individuals, who seem to be more at ease with blending/passing in society (Fiani & Han, 2019). Additionally, non-binary people tend to avoid expressing their gender identity due to fear of negative reactions (Monro, 2019). One factor that non-binary people may struggle with in particular are linguistic challenges, not only in the social world, but also in the medical world, when presenting to gender identity services (Taylor, Zalewska, Gates, & Millon, 2019). Although gender identity services’ key role is to allow gender diverse individuals to explore their gender identity and/or support them in accessing physical interventions, still many non-binary individuals struggle with the limitations of an inherently binary language to articulate their identities (Ellis, Bailey, & McNeil, 2015; Vincent, 2019). At the same time, it might also be challenging for the wider community to comprehend the possible fluctuating nature of a non-binary gender identity (Taylor et al., 2019). The notion that the relationship to the body can vary at different time points in relation to a dynamic gender identity also presents challenges in terms of accessing physical treatment. Non-binary individuals may wish to partially feminize or masculinize. These individual treatment wishes may be read as unconventional, which has often resulted in delayed access to physical treatment for non-binary individuals (Taylor et al., 2019; Vincent, 2019). Consequently, non-binary individuals may face even greater mental health risks due to stigmatization and discrimination.

Higher levels of psychological difficulties among non-binary adolescents and adults may also be attributed to intrinsic factors. First, struggling with or questioning one’s gender identity, or having a gender identity that is not easily identifiable, can be stressful in itself. Fiani and Han (2019) reported that non-binary individuals tend to face more challenges related to the expression of their gender and have a later onset of exploration of gender identity compared to binary individuals. Together with the lack of protective factors, such as social support and peer relationships, non-binary individuals may be more prone to experience internalized stigma, which involves adapting one’s self-concept to be congruent with the stigmatizing responses of society’s conceptualization of gender (Austin, 2016; de Graaf, Cohen-Kettenis, et al., 2018; de Vries et al., 2016; Levitan, Barkmann, Richter-Appelt, Schulte-Markwort, & Becker-Hebly, 2019). Experiences of internalized stigma, such as trans-negativity and internalized transphobia, are associated with poorer coping skills and greater psychological distress (Austin & Goodman, 2017; Grossman & D’augelli, 2007; Mizock & Mueser, 2014). Perhaps the same is true in case of internalized non-binary phobia.

While it seems likely that non-binary identifying adolescents and adults are dealing with similar issues, a few notable differences between the two studies could be identified. For adults, psychological problems were predicted by having a non-binary gender identity and having a younger age, whereas for adolescents psychological problems were predicted by having a non-binary identity and being assigned female at birth. First, the distribution in sex ratio of clinical referrals was far less pronounced in the adult sample compared to the adolescent sample, which could explain why birth-assigned gender was not a contributing factor for gender diverse adults. In adolescents, however, the vast majority (74%) of the study sample were assigned female at birth, which resembles the current sex ratio of referrals to GIDS (de Graaf, Giovanardi, Zitz, & Carmichael, 2018). Recent literature on gender diverse adolescents continue to report an increasing number of birth-assigned females presenting to gender identity services reporting more psychological difficulties compared to those assigned male at birth (de Graaf, Cohen-Kettenis, et al., 2018; de Graaf, Giovanardi, et al., 2018; de Vries et al., 2016; Kaltiala-Heino, Sumia, Työläjärvi, & Lindberg, 2015). Why more birth-assigned females tend to present to gender identity services in adolescence, and why they report more psychological difficulties than birth-assigned males, remains unclear. One hypothesis could be that birth-assigned females experience puberty at an earlier age, which could lead to an earlier onset of gender exploration compared to birth-assigned males. Hence, birth-assigned females may have a longer history of gender identity related issues, resulting in more psychological difficulties (Aitken et al., 2015). A similar pattern has also been found in the general UK adolescent population, where psychological wellbeing seems poorer amongst birth-assigned female adolescents compared to birth-assigned male adolescents (Gunnell, Kidger, & Elvidge, 2018).

Interestingly, in the adult population, higher percentages of birth-assigned males tend to report a gender diverse, non-binary or gender ambivalent identity (Kuyper & Wijsen, 2014; Van Caenegem et al., 2015). Nevertheless, the extent of the experienced psychological difficulties were similar for both gender diverse assigned males and assigned females. One explanation for this could be that it might be harder for adult birth-assigned males to completely live in the female role (van de Grift et al., 2016). Additionally, having a younger age was found to be a predictor for experiencing more psychological difficulties. From the available evidence on this topic, we could argue that younger adults may be more prone to fluctuation of or uncertainty about their gender identity, whereas for older adults, their gender identity may be more crystallized (Taylor et al., 2019). Another hypothesis could be that it may be an artifact of their stage in life. In this case, it could be suggested that searching for peer acceptance could be a more important factor for younger adults than for older adults.

The developmental pathways of both birth-assigned genders clearly require further attention. Longitudinal studies are of great importance to investigate similarities and differences between the groups, in childhood, adolescence and adulthood.

Strengths and limitations

To the best of our knowledge, the present study is the first study to analyze gender identity as a continuum, rather than as dichotomies. Given the fluid nature of gender constructs, it is important that research continually evolves its methods and analysis to acknowledge the nuances in transgender and gender diverse identities, experiences, and expressions. We believe that our studies contribute to inclusion of gender diverse individuals by stepping away from binary gender assumptions, labeling or categorization.

Another strength of this study is that it includes two study populations, treatment-seeking adolescents from the age of 12 years, as well as treatment-seeking adults. Research on these populations were still lacking from existing literature. Additionally, the numbers of participants in both samples, adolescent (n = 572) and the adult (n = 607), were very high, making the results fairly robust.

However, some limitations warrant comment. In the adolescent sample, non-binary identity was measured by the use of one item, the non-binary scale. As gender identity consists of various components, people may have responded to different aspects of this concept (Egan & Perry, 2001). Furthermore, it should be taken into account that not all gender diverse individuals seek professional help from specialist gender identity services. Some individuals may use self-medication or seek treatment abroad, others do not need any professional assistance to live or express themselves in their experienced gender identity. Therefore, the participants included in both studies might not reflect the full range of gender diverse individuals. It is possible that especially those individuals at the more non-binary end of the gender spectrum who do not seek any (medical) support from specialist gender services are underrepresented in this study. The findings in our study should therefore not be generalized to gender diverse individuals who are not in contact with clinical gender identity services.

It is important to note that the participants from the adolescent and adult population differed substantially. For example, the sex distribution between the two samples significantly differed, χ²(1, 1179) = 124.94, p<.01, which meant that any interpretation between the two populations was not possible. The study might have been further limited by the fact that no direct comparisons between adults and adolescents could be made. Different psychometric measures were necessary to analyze psychological functioning and non-binary identity in both populations. Also, the study populations came from different countries, reflecting different cultural societies, which could have an impact on the assumptions that can be drawn from this data.

Finally, other potentially relevant information or demographic variables that could add toward explaining our findings were not taken into account at this instance. For example, information on the sexual orientation of the adolescents or the adults was not collected. Furthermore, it is advised that future research includes factors such as family support, peer relations, place of residency, family connectedness or broader cultural and sociological factors, which might contribute to more insight in the relationship between gender diversity and psychological functioning (de Vries et al., 2016; Levitan et al., 2019).

Conclusion and recommendations

Clinicians should be aware that applicants for gender-affirming treatment might have a broader range of gender identities than a transgender one. A non-binary gender identity may be more difficult to live with than a transgender or cisgender identity, resulting in more psychological difficulties. Therefore, it is recommended that counseling of gender diverse individuals should focus on providing support in coping with extrinsic societal or cultural challenges that may be more prominent to non-binary identifying people, as well as dealing with internalized challenges that may be different for non-binary identifying persons, compared to transgender or cisgender identifying individuals. Further research among gender diverse adolescents and adults is needed to gain a better understanding of the development of the whole spectrum of gender identities. Such studies might profit from including factors that may improve psychological wellbeing, especially for those individuals with a non-binary identity.

Notes

1 An overview of the measures that were administered at baseline: Demographics; Child Behavioural Checklist; Youth-Self-Report; Social Responsiveness Scale-2; Body Image Scale; Gender Identity Interview; Recalled Childhood Gender Identity; Utrecht Gender Dysphoria Scale; Gender Diversity Questionnaire.