Kenneth J. Zucker

University of Toronto | U of T · Department of Psychiatry

Adolescence is a sensitive developmental period for neural sex/gender differentiation. The present study used multiparametric mapping to better characterize adolescent white matter (WM) microstructure. WM microstructure was investigated using diffusion tensor indices (fractional anisotropy; mean, radial, and axial diffusivity [AD]) and quantitative...

Recent research found that the combination of masculine gender identity and gynephilia was associated with cortical T1 relaxation time, which is considered to reflect gray matter density. We hypothesized that mean diffusivity (MD), a diffusion tensor imaging metric that reflects the degree to which water movement is free versus constrained, in comb...

Gender dysphoria (GD) is characterized by distress due to an incongruence between experienced gender and sex assigned at birth. Brain functional connectivity in adolescents who experience GD may be associated with experienced gender (vs. assigned sex) and/or brain networks implicated in own-body perception. Furthermore, sexual orientation may be re...

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 ad...

Background The number of individuals with potential gender dysphoria (GD) being referred to specialized gender identity clinics or programs is increasing internationally; these cases are initially screened using the Gender Identity/Gender Dysphoria Questionnaire for Adolescents and Adults (GIDYQ-AA). Aim The current study aimed to assess the psych...

This study reports follow-up data on the largest sample to date of boys clinic-referred for gender dysphoria (n = 139) with regard to gender identity and sexual orientation. In childhood, the boys were assessed at a mean age of 7.49 years (range, 3.33–12.99) at a mean year of 1989 and followed-up at a mean age of 20.58 years (range, 13.07–39.15) at...

Gender dysphoria (GD) is characterized by distress due to an incongruence between experienced gender and sex assigned at birth. Sex-differentiated brain regions are hypothesized to reflect the experienced gender in GD and may play a role in sexual orientation development. Magnetic resonance brain images were acquired from 16 GD adolescents assigned...

Importance: Transgender or gender nonconforming (TGNC) adolescents face a wide range of physical and mental health concerns. However, there has been no school-based study to explore the prevalence and mental health status of these adolescents in mainland China. Objectives: To assess the mental well-being of TGNC adolescents in China by comparing...

The fraternal birth order effect (FBOE) is the finding that older brothers increase the probability of homosexuality in later-born males, and the female fecundity effect (FFE) is the finding that the mothers of homosexual males produce more offspring than the mothers of heterosexual males. In a recent paper, Khovanova proposed a novel method for co...

Background This study investigated the effect of older brothers on sexual orientation in male adults diagnosed with gender dysphoria and the effect of older sisters on sexual orientation in female adults diagnosed with gender dysphoria from Iran. Aim To assess for the presence of a fraternal birth order effect in transgender androphilic males and...

Editorial

This article provides an overview of five contemporary clinical and research issues pertaining to adolescents with a diagnosis of gender dysphoria: (1) increased referrals to specialized gender identity clinics; (2) alteration in the sex ratio; (3) suicidality; (4) “rapid-onset gender dysphoria” (ROGD) as a new developmental pathway; (5) and best p...

Objective: Studies of children with gender dysphoria (GD) have reported an overrepresentation of autism spectrum disorder (ASD) or traits. One limitation of these studies has been the absence of a concurrent comparison group of children referred for other clinical problems. The present study addressed this gap by comparing 61 children referred for...

A gender social transition in prepubertal children is a form of psychosocial treatment that aims to reduce gender dysphoria, but with the likely consequence of subsequent (lifelong) biomedical treatments as well (gender‐affirming hormonal treatment and surgery). Gender social transition of prepubertal children will increase dramatically the rate of...

Introduction The prevalence of gender dysphoria in children is not known; however, there are some data on the sex ratio of children referred to specialized gender identity clinics. Aim We sought to examine the sex ratio of children, and some associated factors (age at referral and year of referral), referred to the Gender Identity Development Serv...

Temple Newhook et al. (2018) provide a critique of recent follow-up studies of children referred to specialized gender identity clinics, organized around rates of persistence and desistance. The critical gaze of Temple Newhook et al. examined three primary issues: (1) the terms persistence and desistance in their own right; (2) methodology of the f...

Editorial about Archives of Sexual Behavior, impact factors of sex- and gender-related journals, etc.

This is a Letter to the Editor, so no Abstract.

Previous research suggested that separation anxiety disorder (SAD) is overrepresented among birth-assigned male children clinic-referred for gender dysphoria (GD). The present study examined maternally reported separation anxiety of birth-assigned male children assessed in a specialty gender identity service (N = 360). SAD was determined in relatio...

We conducted a direct test of an immunological explanation of the finding that gay men have a greater number of older brothers than do heterosexual men. This explanation posits that some mothers develop antibodies against a Y-linked protein important in male brain development, and that this effect becomes increasingly likely with each male gestatio...

Objective This study assessed whether children clinically referred for gender dysphoria (GD) show symptoms that overlap with Autism Spectrum Disorder (ASD). Circumscribed preoccupations/intense interests and repetitive behaviors were considered as overlapping symptoms expressed in both GD and ASD. Methods To assess these constructs, we examined Ite...

This review provides an update on the epidemiology of gender dysphoria and transgender identity in children, adolescents and adults. Although the prevalence of gender dysphoria, as it is operationalised in the fifth edtion of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), remains a relatively 'rare' or 'uncommon' diagnosis, ther...

This study evaluated the presence of clinical range behavior problems and psychiatric diagnoses in 25 girls referred for Gender Identity Disorder (GID) in childhood (M age, 8.88 years) at the time of follow-up in adolescence or adulthood (M age, 23.2 years). At follow-up, three (12%) of the girls were judged to have persistent GID based on DSM-IV c...

Recent findings suggest that there may be a maternal immune response underpinning the etiology of sexual orientation of gay male only-children. This maternal immune response appears to be distinct from that which is purported to explain the classic fraternal birth order effect found in studies of male sexual orientation. We tested two predictions r...

Previous research has indicated that biological older brothers increase the odds of androphilia in males. This finding has been termed the fraternal birth order effect . The maternal immune hypothesis suggests that this effect reflects the progressive immunization of some mothers to male-specific antigens involved in fetal male brain masculinizatio...

For adolescents with gender dysphoria, it has become common to be offered hormonal treatment to either delay or suppress pubertal development and/or to masculinize or feminize the body. At the same time, it has been our clinical impression that the psychological vulnerability of at least some of these youth has been overlooked. Fifty consecutive re...

Early childhood is an important time for gender identity development. During this developmental period, children learn that there are gender categories and assign meaning to these categories. This chapter focuses on two aspects of gender development—gender identification (e.g., evaluations of one’s gender) and gender typing (e.g., gender-stereotypi...

Several studies indicate that homosexual males have a high proportion of older brothers compared to heterosexual males. Natal males with gender dysphoria who are likely to be homosexual also display this sibship pattern. Until recently, there was little evidence linking homosexuality and/or gender dysphoria in females to unique sibship characterist...

This study is the third in a series to examine behavioral and emotional problems in children and adolescents with gender dysphoria in a comparative analysis between two clinics in Toronto, Ontario, Canada and Amsterdam, the Netherlands. In the present study, we report Child Behavior Checklist (CBCL) and Youth Self-Report (YSR) data on adolescents a...

Journal of Adolescent Health, 2016, 58, 693-694

Gender dysphoria (GD) (DSM-5) or transsexualism (ICD-10) refers to the marked incongruity between the experience of one's gender and the sex at birth. In this case report, we describe the use of LSD as a triggering factor of confusion in the gender identity of a 39-year-old male patient, with symptoms of psychosis and 25 years of substance abuse, w...

Objective: This study examined rates of self-harm and suicidality (ideation and behavior) in children referred clinically for gender dysphoria compared with their siblings, and referred and nonreferred children from the Child Behavior Checklist (CBCL) standardization sample. Predictors or correlates of self-harm/suicidality were also examined. Me...

Summarizes the reports of the DSM-V Work Group on Sexual and Gender Identity Disorders re literature reviews.

Gender dysphoria (GD), a term that denotes persistent discomfort with one's biologic sex or assigned gender, replaced the diagnosis of gender identity disorder in the Diagnostic and Statistical Manual of Mental Disorders in 2013. Subtypes of GD in adults, defined by sexual orientation and age of onset, have been described; these display different d...

This study examined peer relations in adolescents with gender dysphoria, clinical controls, and nonreferred controls. Specifically, we examined group differences in 2 types of bullying experienced (gender identity/sexuality vs. “general” forms), numbers of same- and opposite-sex friends (relative to birth sex), and the influences of bullying and fr...

No abstract is available for this article.

Comments on the article “Serving transgender youth: Challenges, dilemmas, and clinical examples” by Tishelman et al. (see record 2015-06830-005 ). In their informative essay on transgender youth, Tishelman et al. wrote that “The Amsterdam group opened the first specialized gender identity clinic for children and adolescents in 1987 . . .” (p. 38)....

This chapter provides a review of two diagnostic conditions: Gender Dysphoria in children and adolescents and paraphilic sexual behavior (primarily sexual offenses against children) perpetrated by adolescents. For gender dysphoria, we provide an overview of diagnostic changes as reflected in the DSM-5, assessment measures, associated psychopatholog...

This study examined whether boys with gender identity disorder (GID) produced less prototypically male speech than control boys without GID, a possibility that has been suggested by clinical observations. Two groups of listeners participated in tasks where they rated the gender typicality of single words (group 1) or sentences (group 2) produced by...

This is the author accepted manuscript. The final version is available from Taylor & Francis via http://dx.doi.org/10.1080/19419899.2015.1024472

Lewin (1951) wrote that “there is nothing more practical than a good theory” (p. 169). In this issue, van Anders (2015) introduces us to “Sexual Configurations Theory,” perhaps taking the field “Beyond Sexual Orientation” as reflected in the title of her article.The Journal welcomes commentaries on the theory. Commentaries should be sent to the Edi...

A recent article in Science (Faria et al., 2014) suggested that Kinshasa (now the Democratic Republic of Congo) was, perhaps, ground zero of the early transmission of HIV-1 in the 1920s. According to the World Health Organization, approximately 35 million people worldwide were living with HIV/AIDS in 2013 (U.S. Department of Health & Human Services...

Gender identity refers to a person's basic sense of self as male or female. Gender dysphoria refers to the distress one experiences when one's gender identity does not match one's assigned sex at birth, which often leads to the strong desire to become a member of the other gender. Research suggests that gender identity differentiation is the result...

The number of adolescents referred to specialized gender identity clinics for gender dysphoria appears to be increasing and there also appears to be a corresponding shift in the sex ratio, from one favoring natal males to one favoring natal females. We conducted two quantitative studies to ascertain whether there has been a recent inversion of the...

This chapter provides a summary of the DSM-5 diagnosis of gender dysphoria, including the changes to the criteria and the rationales regarding conceptual shifts. It reviews the substantive changes from the previous diagnosis of gender identity disorder as it was conceptualized and operationalized in DSM-IV.

This study tested predictions regarding two hypothesized maternal immune responses influencing sexual orientation: one affecting homosexual males with high fraternal birth order and another affecting firstborn homosexual individuals whose mothers experience repeated miscarriage after the birth of the first child. Low birth weight was treated as a m...

Gender dysphoria (GD) and autism spectrum disorder (ASD) are associated. In 49 GD children (40 natal males), we examined ASD risk factors (i.e., birth weight, parental age, sibling sex ratio) in relation to autistic traits. Data were gathered on autistic traits, birth weight, parents’ ages at birth, sibling sex ratio, gender nonconformity, age, mat...

While reports showing a link between prenatal androgen exposure and human gender role behavior are consistent and the effects are robust, associations to gender identity or cross-gender identification are less clear. The aim of the current study was to investigate potential cross-gender identification in girls exposed prenatally to high concentrati...

In adult male samples, homosexuality is associated with a preponderance of older brothers (i.e., the fraternal birth order effect). In several studies comparing gender dysphoric youth, who are likely to be homosexual in adulthood, to clinical or non-clinical control groups, the findings have been consistent with the fraternal birth order effect in...

Since the second edition of the Handbook of Developmental Psychopathology was published 13 years ago (Sameroff, Lewis, & Miller, 2000), there has been a remarkable increase in clinical, research, and media attention afforded to children and adolescents who meet the DSM-IV-TR (American Psychiatric Association, 2000) diagnostic criteria for Gender Id...

This study examined whether children clinically referred for gender dysphoria (GD) show increased symptoms of autism spectrum disorder (ASD). Circumscribed preoccupations or intense interests were considered as overlapping symptoms expressed in GD and ASD. In gender-referred children (n = 534; 82.2% male) and their siblings (n = 419; 57.5% male), w...

With the publication of the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) (American Psychiatric Association, 2013), there is now an opportunity for wide public reactions to the sexual dysfunctions diagnoses. In their commentary, Balon and Clayton (2014) claimed that the creation of the new DSM-5 diagnosis of Femal...

This chapter reviews empirical data on the extent to which children and adolescents with gender dysphoria show other types of psychopathology or behavior problems. It then reviews several models that have attempted to account for this psychopathology when it is present. Several factors have been reasonably established as accounting for at least som...

For gender dysphoric children and adolescents, the school environment may be challenging due to peer social ostracism and rejection. To date, information on the psychological functioning and the quality of peer relations in gender dysphoric children and adolescents has been studied via parental report, peer sociometric methods, and social interacti...

The aims of the current study were twofold: (1) to assess the prevalence/severity of posttraumatic stress symptoms (PTSS) as well as cognitive and emotional responses in parents whose children were diagnosed with a disorder of sex development (DSD); and (2) to assess factors which contributed to PTSS. We hypothesized that parents would show elevate...