Table 2.

Summary of study and sample characteristic and findings.

Author/s & date (Location)	Study design	Participant characteristics	Outcome measures (Demographics, risk factors, protective factors)	Self-harm definition &measure	Key findings
Arcelus et al. (2016) [11] (UK)	Cross-sectional	n = 268 Natal female: 45.2% Natal male: 50.7% Did not answer: 4.1% Age range: 17–25 years (M = 19.9)	Demographics Psychopathology: SCL-90; Self-esteem: RSE; Transphobia victimisation: Experiences of Transphobia Scale; Interpersonal functioning: IIP-32; Social support: MSPSS	NSSI: SIQ	•Natal sex (female) & severity of clinical symptomology significantly associated with NSSI •Transphobia, low self-esteem & interpersonal problems significant predictors of psychopathology levels which is a risk factor for NSSI
Almazan et al. (2021) USA) [33]	Cross-sectional	n = 27,715 Trans woman: 38.3% Trans man: 29.1% Nonbinary: 30.2% Cross-dresser: 2.5% 18+ (not provided)	Demographics Severe psychological distress: K-6; Past-month binge alcohol use & past year tobacco smoking: all 1-item	Past-year suicide ideation & suicide attempt measure not provided	•Exposure to gender-affirming surgery significantly associated with reduced past-year suicide ideation, but not past-year suicide attempts •Participants with all desired surgeries had significantly reduced suicide ideation & attempts
Andrew et al. (2020) [34] (USA)	Cross-sectional	n = 155 Non-binary: 25.2% (no further breakdown provided) AFAB: 75.5% Age range not provided (M = 29.86)	Demographics Trauma exposure: Life Events Checklist; Nightmares: Trauma-Related Nightmare Survey; PTSD: PTSD checklist for DSM-5	Suicide risk: SBQ-R	•Nightmare frequency significantly associated with increased suicide risk •Nightmare severity was not significantly associated with suicide risk
Austin et al. (2022) [35] (USA & Canada)	Cross-sectional	n = 372 Trans man: 89.2% Non-binary/gender fluid: 32.8% Man: 9.4% Trans Woman: 11.6% Woman: 3.2% Demiboy: 1.1% Transgender: 0.3% Other: 0.8% Two-Spirit: 05% * NB these categories are not mutually exclusive* 14–18 years (M = 15.99)	Demographics LGBTQ-related stigma: 5-items from NHAI; Interpersonal & environmental LGBTQ microaggressions: Interpersonal LGBTQ Microaggressions subscale & Environmental LGBTQ Microaggressions subscale (adapted from LGBQ Microaggressions On-Campus Scale)	Suicidality: 2-items from DSM-5	•Interpersonal microaggressions significantly associated with suicide attempts •Familial emotional neglect, reduced school belonging & internalised self-stigma significantly associated with past 6-months suicidality •Reduced school belonging associated with past 6-months suicidality but not lifetime suicide attempts •Internalised stigma associated with suicide ideation but not suicide attempts
Azeem et al. (2019) [36] (Pakistan)	Cross-sectional	n = 156 Transgender Age range not provided (M = 39.26)	Demographics Depression: Hamilton Rating Scale for Depression Self-reported family income, illicit substance use and smoking: measures not provided	SI: Scale for Suicide Ideation	•Illicit substance use and depression significantly associated with suicide ideation •Age, smoking, and family income not significantly associated with suicide ideation
Barboza et al. (2016) [37] (USA)	Cross-sectional	n = 350 Transgender MTF: 62% FTM: 35% Age range not provided	Demographics Victimisation: 2 items; Substance use: 1 item covering 10 illicit substances; Family social support & Counselling or psychotherapy use: both 1-item	Suicidal Risk: 2 items	•Discrimination significantly associated with increased odds of suicide attempts •Non-discriminatory physical victimisation significantly associated with increased odds of suicide ideation & attempts •Being white, lower levels of perceived family support, lack of psychological counselling/psychotherapy for TGD-related services, & past alcohol problems significantly associated with increased odds of suicide ideation& attempts •Housing instability significantly associated with increased suicide attempt risk •Higher education levels marginally associated with suicide ideation
Basar & Oz (2016) [38] (Turkey)	Cross-sectional	n = 116 Trans men: 75.9% Trans women: 24.1% Median: 25-years	Demographics Discrimination: PDS; Depression: BDI Resilience: RSA; Social support: MSPSS	Suicide attempt history; NSSI: ascertained by clinical interview	•Reduced resilience (lower RSA score) significantly associated with suicide attempt history but not NSSI
Bauer et al. (2016) [21] (Canada)	Cross-sectional	n = 380 Transgender MTF: 52.6% FTM: 47.4% 16+ (M = 32.7)	Demographics Chronic illness/pain, immigration history, religious upbringing, childhood abuse & mental health disorders: self-reported; Transphobia: Experiences of Transphobia Scale; Transphobic harassment & violence; medical transition status, hormone use, social transition status, being perceived as cisgender: self-reported; Social support: Medical Outcomes Study Social Support Scale	Past year suicide ideation & attempts: dichotomous scale	•Social support, reduced transphobia, medically transitioning though hormones/surgery, & having personal identification documents changed to appropriate/preferred sex were significantly associated with reductions in suicide risk •Parental support for gender identity was significantly associated with reduced suicide ideation •Lower self-reported transphobia associated with decrease in suicide ideation & suicide attempts •Religiosity & spirituality AND gender support from other sources except parents were not significantly associated with reduced suicidality
Brennan et al. (2017) [39] (USA)	Cross-sectional	n = 83 Trans women/MTF: 40% Trans men/FTM: 29% Various gender nonconforming identities: 31% 19–70 years (Not provided)	Demographics Depression: CES-D; Anxiety: Becks Anxiety Inventory; Gender Minority Stress: GMSR	Suicide ideation, suicide attempts & NSSI: dichotomous scale	•< 40 years more likely to have NSSI than >40 years •Distal stress (gender-related discrimination, gender-related rejection, gender-related victimisation, & non-affirmation of identity) weak positive predictor of suicide attempts •Resilience factors (pride & community connectedness) were marginal negative predictors of suicide attempt •Distal stress had weak positive relationship with suicide ideation •NSSI: age had moderate negative relationship •Suicide ideation: age had moderate positive relationship
Becerra et al. (2021) [40] (USA)	Cross-sectional	n = 1369 Transgender 18+ (Not provided)	Demographics Psychological distress: K-6; Abuse/violence: 4-items; Partner abuse/violence: 24-items: Harassment/abuse due to bathroom use: 3-items	SI & SA: 4 questions with Y/N responses	•Abuse, violence, sexual partner abuse/violence are significantly associated with suicidal thoughts and behaviours •Harassment & abuse while using the bathroom is significantly associated with suicide attempts
Bosse et al. (2023) [41] (USA)	Cross-sectional	n = 286 Transgender and Nonbinary 18–25 years (M = 21.5)	Demographics Parental acceptance-rejection: Parental Acceptance-Rejection Questionnaire; Sibling acceptance-rejection: Elder Sibling Acceptance-Rejection Questionnaire; Depression: CES-D	Suicidality: 1 item for suicide ideation, planning & attempts	•No significant relationship between race, ethnicity, ASAB, whether living with parent & suicidality •Older age significantly associated with fewer lifetime suicide planning and attempts •Higher education significantly associated with fewer lifetime suicide plans and attempts & past year suicide ideation & attempts •Higher family rejection significantly associated with increased lifetime and past year suicidality •High sibling rejection was not associated with past year suicide attempts •Rejection from male parent particularly significant
Budhwani et al. (2018) [42] (Dominican Republic)	Cross-sectional	n = 298 Transgender women Age range not provided (M = 26)	Demographics Sexual abuse, psychological abuse, torture, attempt on own life by another: dichotomous Y/N; Depression: 1 item; Illicit drugs: Dichotomous Y/N (in past 6-months); Income & education level: self-report	Suicide attempts: dichotomous Y/N	•Psychological abuse, torture & experiencing a murder attempt significantly associated with suicide attempt •Experiencing psychological abuse increases suicide attempt risk 3-fold •Experiencing torture or a murder attempt almost 3x more likely to attempt suicide •Depressed transgender women were 4x more likely to attempt suicide •Transgender women who used illicit drugs were 2x more likely to attempt suicide •Experiencing sexual abuse not associated with higher odds of suicide attempt compared to non-attempters •Low monthly income, age, & low education attainment not significantly associated with suicide attempt
Burish et al. (2022) [43] (USA & Canada)	Cross-sectional	n = 139 Transgender or nonbinary 18+ (M = 33.78)	Demographics Gender Minority Stress: GMSR Social Support: Perceived Social Support Scale from Family & Friends Scale; Optimism: LOT-R; Body Acceptance & Congruence: Transgender Congruence Scale	Suicidality: SBQ-R	•Optimism emerged as a significant protective factor •Body acceptance was a significant protective factor (and it predicted optimism) •Social support, community connectedness & pride were not significant protective factors
Busby et all. (2020) [44] (USA)	Cross-sectional	n = 868 (n = 86 identified as transgender) 18+ (Not provided)	Demographics Depression: PHQ-9; Discrimination: EDS; Interpersonal Victimisation: Interpersonal Victimisation Scale-Revised; Social Connectedness: UCLA Loneliness Scale; LGBTQ Affirmation: 3-items from LGBTQ Identity Affirmation Scale (modified from original 12-item scale)	Past year suicide ideation; lifetime suicide attempts; NSSI: 1 item from the Youth Risk Behavior Survey	•Victimisation, discrimination, connectedness, & LGBTQ affirmation were not significantly related to suicide and NSSI outcomes for transgender students •Some results were under wider LGBTQ umbrella so impossible to extract transgender-only data
Campbell et al. (2023) [45] (USA)	Cross-sectional	n = 1078 gender-conversion treatment n = 24,192 control Transgender 11–17 years when gender conversion efforts began (Not provided)	Demographics Gender conversion efforts: 1 item	Suicide attempts: dichotomous Y/N & number of attempts	•Exposure to gender conversion therapy is significantly linked with increased risk of SA in adolescents
Cerel et al. (2021) [46] (USA)	Cross-sectional	n = 2784 27.3% transgender female 27% transgender man 38.7% non-binary 1.2% transgender unspecified 5.7% transgender other 18+ (M = 34.35 suicide exposure; M = 31.33: no suicide death exposure)	Demographics Suicide attempt exposure, support from family of origin, mental health diagnosis, being a POC, gender binary status & gender identity: all self-reported	Past year suicide ideation & attempts: 4-items with dichotomous Y/N	•Exposure to suicide attempts & suicide increases likelihood of recent suicide ideation, recent & lifetime suicide attempts, lifetime NSSI, & at least one current mental health diagnosis •Exposure to the suicide attempt of a TGD person increased suicide ideation but not suicide attempts •Exposure to suicide attempts & suicide more closely correlated with suicide ideation than suicide attempts •NSSI history, female natal sex, younger age, & lacking family support & exposure to suicide attempts & suicide were associated with suicide ideation & attempts •Being white, NSSI history, & lacking familial support differentiated those with suicide ideation from those with suicide attempt in peoople exposed to suicide attempt and suicide
Chen et al. (2019) [47] (China)	Cross-sectional	n = 1309 Transgender men: n = 622 Transgender women: n = 687 Age range not provided (Transgender men M = 3.78; Transgender women M = 22.89; Overall M = 23.31)	Demographics Feelings towards natal sex, seeking hormone therapy, seeking gender reassignment surgery, intense conflicts with parents regarding sexuality, discrimination or violence in public due to sexuality, childhood adversity (incl. Bullying and insults at school), Seeking MH support services & history of major depressive disorder: all measured using unspecified measures Depression: CESD-9; Self-esteem: RSE	Self-harm, suicide ideation & suicide attempts measured using dedicated items (not specified)	• Regarding suicide ideation: •Transgender men: disliking natal sex, seeking gender reassignment surgery, depression, risk for major depressive disorder, self-harm, seeking mental health services all significantly predicted increased risk of suicide ideation •Transgender women: disliking natal sex, current or past major depressive disorder, depression, risk for major depressive disorder, self-harm, seeking mental health support services all significantly predict increased suicide ideation risk •ALL: disliking natal sex, seeking gender reassignment surgery, intense conflicts with parents, current or past major depressive disorder, depression, risk for major depressive disorder, self-harm, & seeking mental health services all significantly increased suicide ideation risk •Regarding suicide attempts: Transgender men: Experiencing violence and/or discrimination in public, current and/or past major depressive disorder & self-harm all significantly. Predicted increased suicide attempt risk •Transgender women: Being separated/divorced, current or past major depressive disorder, and self-harm all significantly predicted suicide attempt risk increase •ALL: Education level high school or equivalent, being married, being separated/divorced, intense conflicts with parents, self-harm & seeking mental health services all significantly predicted increased suicide attempt risk •No significant relationship between self-esteem, & self-harm & suicide
Chen et al. (2020) [48] (China)	Cross-sectional	n = 250 Transgender women 18+ (M = 27.9)	Demographics Anxiety & depression: K-10 Discrimination (incl. Verbal abuse), mental health status, PTSD screening, access to mental health services, alcohol & drug use, physical abuse, harassment (restricted personal freedom, economic control due to gender identity), sexual violence: all dichotomous Y/N	Suicide ideation & attempts: dichotomous Y/N	•Lack of residential status, bisexuality, homelessness before age 18, experiences of verbal, physical, or sexual violence, alcohol use, & severe mental health disorders were all significantly associated with suicide ideation & and prior suicide attempts •Moderate or severe psychological distress were associated with prior suicide attempts •Suicide ideation was strongly correlated with severe psychological distress •Moderate or severe psychological distress was significantly associated with prior suicide attempt
Chinazzo et al. (2023) [49] (Brazil)	Cross-sectional	n = 213 Transgender boys/men: 48.6% Transgender girls/women: 20.8% Non-binary: 30.7% 13–25 years (M = 18.53)	Demographics Depression: MDS; Discrimination: Lifetime & Daily Discrimination Subscale; Gender Distress: TYC-GDS; Socioeconomic Status: Deprivation Scale Social Support: MSPSS; Social Support relating to gender identity: 1 item; Gender Positivity: Gender Positivity Scale	Suicide ideation & attempts: dichotomous Y/N	•Socioeconomic deprivation & depressive symptoms significantly associated with suicide ideation & attempts •No significant relationship between discrimination & suicide ideation & attempts •Gender distress associated with suicide ideation (binary transgender people experience higher distress than nonbinary people •Gender positivity a significant protective factor & may counteract gender distress •Social support & support relating to gender were non-significant (friends' support for gender identity, affective support, positive social interaction support, and emotional/information support)
Claes et al. (2015) [50] (UK)	Cross-sectional	n = 155 Transgender men: n = 52 Transgender women: n = 103 17–77 years (M = 34.52)	Demographics Psychological Symptoms: SCL-90-R; Body Dissatisfaction: HBDS; Transphobia/victimisation: Experiences of Transphobia Scale; Interpersonal Problems: IIP-32 Perceived Social Support: MSPSS; Self-Esteem: RSE	NSSI: SIQ	•NSSI significantly associated with younger age (Mage = 26.98 vs. Mage = 38.91) •Transgender males are significantly more likely to SH than Transgender women (57.7% vs 26.2%) •Psychological/clinical symptomology significantly associated with NSSI •Transgender women report lower self-esteem, but this is not significantly related to NSSI •Transgender women reported significantly more body dissatisfaction but not significantly related to NSSI •Transphobia, interpersonal problems not significantly related to NSSI •Trans people with NSSI reported finding it harder to be assertive & sociable & were more aggressive •Transgender men received more social support but not significantly related to NSSI, though people with NSSI reported less family support •NSSI significantly associated with younger age, being male, and reporting more psychological symptoms
Cogan et al. (2020) [51] (USA)	Cross-sectional	n = 155 Various gender identities 18–67 years (M = 29.86)	Demographics Gender minority stress: GMSR; Traumatic experiences: Life Events Checklist for DSM-5	Suicide risk: SBQ-R	•Gender minority stressors (discrimination, gender-related rejection, gender-related victimisation, non-affirmation of gender identity, internalised transphobia, negative expectations of future events, concealment) and trauma are significantly associated with suicide risk •Community resilience specified in GSMR (community connectedness, pride) did not significantly mitigate suicide risk nor did it moderate relationships between stressors & risk
Cogan et al. (2021a) [52] (USA)	Cross-sectional	n = 29.86 Various gender identities 18–67 years (M = 29.86)	Demographics Traumatic experiences: Life Events Checklist; Gender Minority Stressors: GMSR	Suicide risk: SBQ-R	•Proximal stressors (internalised stress, internalised transphobia, negative expectations due to gender identity, concealment of gender identity) were all significant predictors of suicide risk •Sexual violence was a significant predictor of suicide risk
Cogan et al. (2021b) [53] (USA)	Cross-sectional	n = 29.86 Various gender identities 18–67 years (M = 29.9)	Demographics Lifetime Trauma Exposure; LEC-5; Distal gender minority stressors: GMSR	Suicide risk: SBQ-R	•Distal stressors (gender-related discrimination, rejection, victimisation & nonaffimation) were significantly associated with suicide risk & related to proximal stressors (internalised transphobia, negative expectations for future events, and concealment) •Proximal stressors (internalised stress, internalised transphobia, negative expectations due to gender identity, concealment of gender identity) also significantly related to suicide risk
Cramer et al. (2016) [54] (UK)	Cross-sectional	n = 27,658 Various gender identities 18+ (not provided)	Demographics Interpersonal correlates (HRD: family rejection, childhood harassment, rejection, discrimination); HRD in workplace, healthcare settings, health insurance; TGD-related physical assault, lifetime TGD-related intimate partner abuse; sexual assault; connection to TGD community; family support & co-worker support: measures not specified	Suicidal thoughts & behaviours: 4-items with dichotomous	•Family rejection, childhood harassment, rejection & discrimination (HRD), workplace HRD, healthcare HRD & sexual assault were all significantly associated with suicide ideation & attempts •Past year health insurance HRD, past year TGD-related physical assault & lifetime intimate partner violence were all significant associated with suicide attempts, but not suicide ideation •Family & co-worker support were significantly correlated with reduced suicide attempts, but not suicide ideation •Marginalized status (sexual, racial & disability linked to suicidal thoughts & behaviours risk •Discrimination & victimisation were significantly associated with past year suicide attempts •Being less out with TGD identity was a protective factor •Sexual minority, racial minority, lower education, lower income, military experience, disability status, & being uninsured were significantly associated with past year suicidal thoughts & behaviours risk
Davey et al. (2016) [55] (UK)	Cross-sectional	n = 97 Control: n = 97 60 Transgender women 37 Transgender men Control: 60 cisgender women 37 cisgender men Age range not provided (Transgender: M = 36.18; Control M = 37.16)	Demographics, incl. Civil status, living situation TGD people were asked for treatment stage & hormone status; General Psychopathology: SCL-90-R Self-Esteem: RSE; Body Satisfaction: HBDS; Perceived Social Support: MSPSS	NSSI: SIQ-TR	•TGD group had significantly higher prevalence of current NSSI than control group •TGD men had significantly higher prevalence rates of current NSSI than TGD women •TGD NSSI group (TGD individuals reporting current NSSI) reported significantly higher psychopathology, lower self-esteem, lower body satisfaction & social support compared to the TGD no NSSI group & cisgender no NSSI group •TGD people with NSSI were significantly younger than both other groups (cisgender & TGD no NSSI)
de Graaf et al. (2020) [56] (Canada, UK, Netherlands)	Cross-sectional	n = 2771 Natal male: n = 937 Natal female: n = 1834 13+ (M = 15.99)	Demographics, incl. age at assessment, year of assessment, full-scale IQ, parents' marital status, & parents' social class IQ: Wechsler Intelligence Scale for Children & Wechsler Adult Intelligence Scale; Parent social status/education: Hollingshead's Four-Factor Index of Social Status (non-validated scale); Items from the CBCL & YSR were used to measure desire to be the opposite sex, poor peer relations & behavioural problems	Suicidality = Item 18 from CBCL & Item 91 from YSR	•Natal sex (female) & behavioural & emotional problems were consistent predictors of suicidality across clinics & measures used •CBCL: Toronto-Amsterdam contrast: clinic, birth assigned sex, parents' marital status & social class, & general emotional & behavioural problems were all significant predictors of suicidality •Toronto-London contrasts: clinic, birth assigned sex, & general behavioural & emotional problems were all significant predictors of suicidality •Amsterdam-London contrast: clinic, birth assigned sex, & general behavioural & emotional problems were all significant predictors of suicidality •YSR: Toronto-Amsterdam: birth assigned sex, poor peer relations, & general emotional & behavioural problems were significant predictors of suicidality •Toronto-London: clinic & behavioural & emotional problems were significant predictors of suicidality •Amsterdam-London: clinic & general behavioural & emotional problems were significant predictors of suicidality •Mixed findings regarding parent's marital status & social class depending on scale (results were significant on CBCL, but not for YSR)
dickey et al. (2015) [57] (USA)	Cross-sectional	n = 773 Various gender identities Age range not provided (M = 34.5)	Demographics Depression & Anxiety: DASS-21; Feelings about body: BIS	NSSI: ISAS	•Depression, anxiety & stress were significantly associated with NSSI •NSSI significantly associated with lower BIS scores (i.e., lower body image)
Drescher et al. (2021) [58] (USA)	Cross-sectional	n = 70 Transgender men: 43.4% Transgender women: 25.7% 4 Non binary: 40% 18-65 (M = 29.97)	Demographics Homelessness & perceptions about safety: 1-item (these were adapted from the LGBT Health & Services Needs in New York State study & Seattle LGBT Commission 2010 Needs Assessment Survey respectively) Physical violence & sexual violence victimisation: 3-items	Suicidality (ideation & attempts): Dichotomous Y/N	•Suicide ideation was significantly associated with history of sexual violence, homelessness, & perceived lack of CRSA safety (safety in local area) •Suicide attempts were significantly associated with sexual violence history, homelessness, & perceived lack of CSRA safety (safety in local area) •Partner violence was not significantly associated with suicide ideation or attempts •No demographic (age, gender identity, ethnicity, household income, education attainment level, & current financial situation) characteristics were significantly associated with suicide ideation or attempts
Drescher et al. (2023) [59] (USA)	Cross-sectional	n = 115 Transgender Non-conforming 18+ (M = 27.61)	Demographic Depression: PHQ-9 Gender Minority Stressors/Resilience: GMSR Emotion Dysregulation; DERS-SF	Suicide intent & risk: SHI	•Emotion dysregulation was significantly correlated with suicide ideation, suicide attempts, suicide intent, and risk •Victimisation was significantly associated with suicide ideation, suicide attempts, suicide intent, and risk •Rejection was significantly associated with suicide ideation & suicide risk •Discrimination was significantly associated with suicide risk only
Edwards et al. (2012) [60] (USA)	Cross-sectional	n = 106 Transgender women: 40.6% Transgender men: 32.1% Questioning: 7.5% Genderqueer: 2.8% Nonbinary/gender fluid: 1.9% Neutrois: 0.9% Trans: 0.9% Intersex: 0.9% Not provided: 12.3% 18–65 years (M = 29.17)	Demographics Emotional Stability: Suicide Resiliency Inventory-25; Relational Support: Perceived Social Support from Family (PSS-FA) and Friends (PSS-FR)	Suicide risk: SBQ-R	•High levels of perceived support from friends & family significantly associated with their emotional stability which, in turn, was negatively associated with suicide risk •Participants with higher levels of support experienced increased emotional stability which led to lower suicide risk •Independently there was no relationship between perceived support & suicide risk
Goldblum et al. (2018) [61] (USA)	Cross-sectional	n = 290 Transgender 18–65 years (M = 37.01)	Demographics In-school gender-based victimisation: 2 items; Effect of gender-based victimisation: 1 item	Suicide attempt history: 2-item	•Younger age (<45) significant associated with suicide attempts •Transgender men significantly more likely to attempt suicide than transgender women •Ethnicity was significantly associated with suicide attempts •Multi-racial or ‘other’ were significantly more likely to attempt suicide, but White, African America, and Latina/o also reported high suicide attempt history •Higher socioeconomic status was significantly associated with reduced suicide attempts compared to lower & middle status •School-based gender-based violence was significantly associated with suicide attempts in transgender men and women
Gower et al. (2018) [62] (USA)	Cross-sectional	n = 2168 Natal female: 68.1% Natal male: 31.9% No age range provided but USA grades 5, 8, 9, 11 (ages 10–18) (M not provided)	Demographics Parent connectedness: 3-item scale not validated; Youth Development Opportunities: 7-item scale from Developmental Assets Profile; Teacher student engagement: 4-items from Student Engagement Inventory; Feeling safe in community: 2-item scale not validated; School safety: 1-item scale not validated; Depression: PHQ-2; Alcohol, drug, cigarette use in past 30 days: Dichotomous Y/N Single items measured how much you feel other adult relatives, friends, & adults in the community care about you	Suicide ideation and attempts: Dichotomous Y/N	•Feeling connected to parents was associated with significantly lower odds of suicide ideation and attempts •An increase in connectedness results in a one-unit reduction in odds of suicide ideation and attempts •Having caring adults in the community & feeling safe at school were associated with significantly lower odds of suicide ideation and attempts
Green et al. (2021) [63] (USA)	Cross-sectional	n = 11,914 Nonbinary: 63% Trans male: 29% Trans female: 8% 13–24 years (M = 17.62)	Demographics Depression: PHQ; Victimisation, Receipt of puberty blockers, & exposure to GICE: all 1-item Gender-affirming hormone therapy: 3 items with binary responses; Parent support for gender identity: 2 items	Suicidal thoughts & behaviours: 2 items from YRB survey	•Receipt of gender affirming hormone therapy was associated with significantly lower odds of past year suicide ideation & attempts •Gender affirming hormone therapy also significantly associated with lower rates of depression
Grossman & D'Augelli (2007) [64] (USA)	Mixed methods	n = 55 Trans female: n = 31 Trans male: n = 24 15–21 years (Trans female M = 17.5 Trans male M = 19.5)	Demographics Relation between suicide attempts & TGD status: RHAI; Lethality of suicide attempt determined by interviewer using lethality rating scale; Childhood Gender Nonconformity: GCS; Childhood Parental Abuse: Child & Adolescent Psychological Abuse Measure Body Esteem: Body-Esteem Scale for Adolescents & Adults	Suicide ideation: 3 items; Suicide attempts: Questions used in previous TGD suicide studies (cited) inc. whether drugs and/or alcohol was used at the time	•Childhood gender nonconformity was not significantly associated with suicide attempts •TGD-related suicide ideation, parental verbal abuse, parental physical abuse, lower body esteem (especially weight satisfaction & thoughts of how others evaluate one's own body) were all significantly associated with suicide attempts •Sexual minority status was significant factor for life-threatening behaviours in TGD youth
Grossman et al. (2016) [65] (USA)	Longitudinal (First panel data)	n = 129 MTF: n = 44 (34%) FTM: n = 44 (31%) MTDG: n = 14 (11%) FTDG: n = 31 (24%) 15–21 years (M = 18)	Demographics Painful & provocative events components of IPTS: PPES	Suicide ideation & attempts: 2 parts of SHBQ Suicide ideation components of IPTS: INQ Capacity for self-harm components of IPTS: ACSS	• Regarding suicide ideation: •FTM & FTDG experienced increased suicide ideation compared to MTF & MTDG •White Caucasian group reported greater suicide ideation than other racial groups but no significant differences between Hispanic & non-Hispanic groups •Suicide ideation lower in people who attended religious services •Perceived burdensomeness & thwarted belongingness were independently significantly associated with suicide ideation •Only perceived burdensomeness was significant in full model •Acquired capability to enact was not significantly associated with suicide ideation, but painful & provocative events were associated with greater acquired capability for lethal self-harm • Regarding suicide attempts: •FTDG identity was significantly associated with suicide attempts •Non-Hispanic & Caucasian youth significantly associated with suicide attempts compared to Non-Hispanic & Black/African American youth •Frequent religious service attendance was associated with fewer suicide attempts •Suicide ideation & acquired capability for self-harm was significantly associated with increased suicide attempts •Thwarted belongingness & perceived burdensomeness were both significantly associated with suicide attempts •Painful & provocative events were significantly associated with suicide attempts •No significant interaction effects between perceived belongingness & painful/provocative events or between perceived burdensomeness & thwarted belongingness •There was a significant interaction effect between thwarted belonginess & perceived burdensomeness & painful provocative events: thwarted belongingness had a significant positive association with suicide attempts only for those who experienced moderate amount of painful provocative events •Thwarted belonginess had no effect on those who experienced almost no painful provocative events
Jackman et al. (2018) [13] (USA)	Cross-sectional (quantitative in-person interviews with survey)	n = 332 Transgender 16+ (M = 34.56)	Demographics Enacted stigma: EDS Felt Stigma: SCS; Transgender congruence: TCS Family support of TGD identity: 1-item; Friend support: 4-items from MSPSS; TGD community connectedness: 5-item subscale from GMSR	NSSI: SITBI	•Age, felt stigma, & trans congruence were significantly associated with past year self-harm •Each 1-year increase in felt stigma was significantly associated with an increase x 1 year was associated with a 2.33 increase in odds of past-year self-harm •Each increase of 1-year of age was associated with decreased odds of self-harm by factor of 3.23 •Enacted stigma & income were not significantly associated with increased past-year self-harm •Increase of one point on transgender congruence scale was associated with decreased odds of past-year self-harm by factor of 0.74 suggesting higher gender dysphoria levels associated with past year self-harm •Protective factors not significant
Kaplan et al. (2017) [66] (Lebanon)	Cross-sectional interview surveys	n = 54 Trans females 18–58 years (M = 27)	Demographics Depression: PHQ-& PHQ-9; General social support & social isolation: Items from Social Relationship Scale; Peer Support: 1-item regarding friends support of TGD identity; Gender identity openness: 2-items from RHS	Suicide ideation: 4-items; Suicide attempts: 2-items	•Suicide attempt history was significantly associated with lower general social support, lower social integration, lower peer support •Suicide attempt history was significantly associated with being more open about TGD identity in public & past or current hormone use •Depression was not significantly associated with suicide attempts. However, 55% of those who experienced a SA also experienced depression •History of sexual abuse & sex work was not significantly associated with suicide attempts •Education attainment, age, homelessness, & relationship status were not significantly associated with suicide attempts •Past & current hormone use were both significantly associated with suicide attempt history
Kaplan et al. (2020) [67] (Lebanon)	Longitudinal	n = 16 Trans women 22–50 years (Median = 26-years)	Demographics Sexual health & behaviour: 11-items measuring STI history; 13-items assessing sexual risk behaviour; & 23-items measuring sexual relationship power; Mental Health (Anxiety & Depression): HADS; Depression: PHQ-9; PTSD: 4-item Primary Care PTSD Screen Family acceptance: 9-item measure of family acceptance; Lifetime trauma: 25-item Trauma History Questionnaire; Social Support: Social Cohesion Scale; GMSR & MDPSS; Gender affirmation, identity & expression: TGD specific Multigroup Ethnic Identity Measure, 6-items measuring gender typicality, & Outness Inventory; 31-items measuring desire/satisfaction of transition; 22-items measuring gender affirmation; 5-items measuring gender affirmation satisfaction; War exposure: War Event Questionnaire; Transphobia: 35-item scale (validated in population)	Suicidality: (thoughts, plans, & attempts ever & in past 3 months): Dichotomous Y/N	•Higher social cohesion was significantly correlated with reduced suicidal thoughts at 3-months post-test •Increased community connectedness was associated with reduced depression •War event exposure was associated with higher anxiety
Klein & Golub (2016) [68] (USA)	Cross-sectional	n = 3458 Transgender & Nonconforming 19-98 (M = 36.69)	Demographics Substance misuse: Dichotomous Y/N; Family rejection: 7-items	Lifetime history of suicide attempts: Dichotomous Y/N	•Younger age, binary gender identity, non-white race/ethnicity, lower education & income, & being unemployed were all significantly associated with suicide attempt history •Family rejection also significantly associated with a history of suicide attempts •Relationship between substance misuse & suicide attempts was not measured
Kota et al. (2020) [69] (USA)	Cross-sectional	n = 928 Trans women 18–65 years (M = 35)	Demographics Perceived stigma: 4-items from RHM; Psychosocial impact of gender minority status: 4-items from TAIM; Depression: 6-items from BSI; Anxiety: 3-item subscale from BSI; Excessive drinking: 3-items; Non-inject drug use & Injection drug use: both 1-item; Intimate Partner Violence: 3-items; Sexual abuse: 3-items; Child Sexual Abuse: 1-item; HIV status: 1 item	Suicide ideation: 2-items - 1 regards past-year suicide ideation & one whether this related to gender status	•33% reported suicide ideation •Anxiety, perceived stigma of being transgender, the psychosocial impact of gender minority status, experiencing sexual abuse, family verbal abuse, & stranger verbal abuse were all significantly associated with higher odds of suicidal ideation •Partner support was a significant protective factor
Kuper et al. (2021) [70] (USA0	Cross-sectional	n = 1896 Gender identity other than birth assigned sex: 78.1% AFAB 14-30 (M = −21.1)	Demographics Gender related affirmation: 7-items; Gender-related self-concept: 7-items; Victimisation (Gender & Sexual Orientation-related): 6-items; Desire for gender-affirming medical care: 1-item; Depressive symptoms: PHQ-9; Social Support: Friend & family support: MSPSS;	Past year suicide ideation, attempts & suicide risk: SBQ-R Past year suicide attempts: binary variable modified SBQ-R	•Risk Factors: Region of USA & race/ethnicity were not significantly associated with suicide-related outcomes •Gender identity & sexual orientation were significantly associated with suicide ideation, attempts & positive suicide risk score •Gender-related victimisation & depressive symptoms were independently associated with suicide ideation, attempts & positive suicide risk score •Gender-related self-concept negativity was positively associated with suicide ideation & attempts •Sexual orientation-related victimisation was positively associated with suicide attempts •Queer identity was positively associated with suicide ideation •Pansexuality was positively associated with suicide risk •Protective Factors: Age was negatively associated with suicide ideation & attempts •Male identity & friend support were negatively associated with suicide attempts (i.e., acted as protective factors) •Family support was negatively associated with suicide ideation
Leon et al. (2021) [71] (USA)	Retrospective clinical data	n = 185 AFAB: 86.6% AMAB: 13.4% 7–25 years (Median at clinic enrolment: 16.3; Median at most recent clinic visit: 18.6)	Demographics Social transition; Medical transition; Mental health history (diagnoses, history of suicide ideation & attempts, psychiatric hospitalisation, history of abuse, bullying & victimisation) all captured from electronic medical records	Documented in medical records	•Depression was significantly associated with NSSI •History of abuse (emotional, physical or sexual) was significantly associated with NSSI •Anxiety was non-significant •AFAB, transmasculine, mood disorder history, & abuse were significantly associated with NSSI •Age, race, ethnicity, social transition status, medical transition status, rural zip code residence, & nonmetro country residence were not significantly associated with a history of NSSI
Maguen et al. (2010) [72] (USA)	Cross-sectional	n = 153 Gender identity female: 25% Somewhat female: 20% Equally both: 25% Somewhat male: 24% Male: 6% 18+ (M = 47)	Demographics Mental Health Treatment: 3 items; TGD-related verbal abuse & physical violence: 2 items; IV drug use: 1 item;	Suicide attempts: Dichotomous Y/N & number of attempts	•Age & sex assigned at birth (female) were significantly correlated with past suicide attempts •Younger individuals were more likely to report attempted suicide •Psychiatric hospitalisation, ASAB (female) & TGD-related violence were all significantly associated with suicide attempts •Intravenous drug use was non-significant
Mak et al. (2020) [73] (USA)	Retrospective medical record	n = 6327 Trans men: 2875 (45%) Trans women: 3452 (55%) 3-45 (age groups: 3–17, 18–25, 26–35, 36–45, >45)	Demographics Mental health diagnoses as stated on EMR: incl. anxiety disorders, ADHD disorders, ASD, bipolar disorders, depressive disorders, schizophrenia spectrum disorders, substance use/abuse, conduct/disruptive disorders, eating disorders, dementia, other psychoses, & personality disorders	Suicide Attempts: Emergency Medical Records (as defined by ICD-9 or ICD10) Suicide Ideation: Binary variable: Ever or never	•Suicide ideation & attempts were 2–5 times higher for those with 1–2 mental health diagnoses •Suicide attempts were 7 times higher in those <18 than >45 years of age •Past suicide ideation & attempts were associated with 3 times increased likelihood of suicide attempts •No difference between trans men & and trans women regards suicide attempts
Maksut et al. (2020) [74] (USA)	Cross-sectional	n = 381 Trans women 15-29 (not provided)	Demographics Perceived, anticipated & enacted stigma (related to TGD status): Gender Identity Stigma Scale; Sexual behaviour stigma: Sexual Behavior Stigma Scale; Severe Psychological Distress: Kessler Scale	Suicide ideation & attempts: 1-item each	•Suicide ideation was significantly associated with lower income, bisexual, pansexual, queer & asexual sexualities •Suicide ideation was significantly associated with discriminatory comments from family, verbal harassment & family exclusion •Suicide ideation was significantly associated with being poorly treated in a healthcare facility, verbal harassment, & rape •Suicide attempts were significantly associated with younger age, not living in urban/suburban area (i.e., rural), rejection by friends, feeling unprotected by police, & avoiding healthcare services •Being poorly treated in a healthcare facility, being blackmailed, & hearing gossip from healthcare workers were significantly associated with suicide attempts
Marx et al. (2021) [75] (USA)	Cross-sectional	n = 610 Transgender & gender nonconforming 14–18 years (M = 15.81)	Demographics Sexual victimisation: 1-item; Sexual harassment victimisation: 1-item; Bias-based peer victimisation: 1- item; Problematic drug use: 6-items Parental monitoring & support: 7-items; School belonging: 6-items	Suicide ideation: 1-item	•Sexual victimisation, sexual harassment victimisation, drug use, & bias-based peer victimisation were all significantly associated with suicide ideation •School belonging & greater parental support were negatively associated with suicide ideation (i.e., are protective factors)
Moody & Smith (2013) [76] (Canada)	Cross-sectional	n = 134 Man/boy: 37.6% Woman/girl: (37.6% Trans: 50.4% Transgender (51.1% Transexual/transsexual: 45.1% FTM: 27.1% MTF: 29.3% On FTM Spectrum:15% On MTF Spectrum:17.3% Genderqueer: 24.8% Two-spirit: 7.5% Transman: 24.8% Transwoman: 30.8%) Man of trans experience: 8.3% Woman of trans experience: 7.5% Androgyne: 8.3% Woman, boy, gender blender, bi-gender, polygender, pangender, cross-dresser, transvestite, intersexual, drag king: 30.4% Other (gender bent, third gender, gender fucker, trans woman):10.6% (participants may be in multiple categories) 18–75 years (M = 36.75)	Demographics Optimist; LOT-R; Social support: PSS-FR & PSS-Fa; Suicide resilience: SRI-25; Reasons for living; RFL	Suicidal behaviours: SBQ-R	•Perceived social support from family and friends, emotional stability, optimism, & child-related concerns (reason for living) were associated with lower suicidal behaviour scores indicating these factors provide some protection from suicidal thoughts and behaviours in TGD people •Emotional stability (part of suicide resilience) was found to be a significant protective factor •There were no significant differences in suicidal behaviours between FTM or MTF people
Parr & Howe (2019) [77] (USA)	Mixed-methods (Cross-sectional survey data included in this review)	n = 182 Trans female: n = 107 (26.6%)/Trans male: n = 75 (18.7)/genderqueer/GNC: n = 44 (10.9%)/Other: n = 48 (11.9%) 14–65 years (not provided)	Demographics Identity nonaffirmation microaggression events: 3-items; Depression, acute sadness & loneliness: 2-items from SBQ-R	Past-year suicide ideation & lifetime suicide ideation & attempts: 2-items from SBQ-R	•A 1x unit increase in frequency of identity nonaffirmation microaggression events was significantly associated with 2.54x increased odds of past year suicide ideation or 3.20x increased odds of lifetime suicide attempts •A 1x increase in plausible values (as defined using latent logistic regression) reflecting TGD persons level of TGD identity was significantly associated with a 4.13x increase in odds of past year suicide ideation & 3.31x odds increase of lifetime suicide ideation or attempts •Each unit increase of identity nonaffirmation or denial microaggression events reported were significantly associated with a 1.39x increased odds of past year suicide ideation when adjusted for events which didn't impact social engagement •A 1x increase in number of identity nonaffirmation events leading to feeling emotionally wearied or apathetic were significantly associated with a 21% increase odds of past year suicide ideation when adjusted for increases in events producing emotional pain •Increases in number of paining events were significantly associated with a 21% increase in odds of past year suicide ideation
Perez-Brumer et al. (2015) [78] (USA)	Cross-sectional	n = 1229 Transgender: FTM n = 532; MTF n = 697 (but included multiple gender identities) Age & mean not provided	Demographics Structural Stigma: 4-item composite index based on gender minority measure; Internalised Transphobia: Transgender Identity Survey	Lifetime & past-year suicide attempts: 2-items	•MTF trans identity, being white, college education or higher (compared to high school or less education) were all significantly associate with decreased odds of lifetime suicide attempts •Higher levels of internalised transphobia were significantly associated with increased odds of lifetime suicide attempts •College or higher education was significantly associated with decreased odds of past-year suicide attempts •Higher level of internalised transphobia was associated with past year suicide attempts, but not statistically significant •MTF identity, being white, & attaining college education or higher were all significantly associated with fewer lifetime suicide attempts •Lower levels of structural stigma were associated with decreased odds of lifetime suicide attempts
Peterson et al. (2017) [26] (USA)	Retrospective chart review	n = 96 MTF: n = 54 MTF: n = 31 Gender fluid/nonbinary: n = 15 12–22 years (M = 17.1)	Demographics Psychosocial assessment at outset appointment: drug/alcohol use; history of legal problems/arrest; gang involvement; involved in fights; history of being bullied; feel safe at home; interest in weight change: All dichotomous Y/N; Body image concerns: 1-item	Suicide attempt history; cutting or self-injurious behaviour history: Dichotomous Y/N	•Older age was significantly associated with increased likelihood of suicide attempts •Drive for weight change (weight gain & weight loss) was significantly associated with suicide attempt history •Self-harm history was significantly associated with suicide attempts •FTM identity (compared to MTF) were significantly more likely to have suicide attempt & self-harm history •Body dissatisfaction or body mass index (BMI) were not significantly linked to suicide attempts
Rabasco & Andover [79] (2020)	Cross-sectional	n = 96 Transgender woman: n = 71 Transgender man: n = 26 Gender nonconforming: n = 8 Gender queer: n = 9 Other: n = 19 12–22 years (M = 17.1)	Demographics Minority stressors: GMSR; Gender Identity State Policy Score	Suicide ideation: BSS	•Victimisation & discrimination separately were statistically significant predictive of lifetime suicide attempts •Gender identity-specific state policies moderated victimisation & discrimination effects on suicide attempts: increased victimisation or discrimination increased suicide attempts at low level state policy but not medium or high levels •Fewer gender-affirmative state policies is significantly associated with increased discrimination & victimisation, & increased suicide attempts
Ross-Reed et al. (2019) [7] (USA)	Cross-sectional	n = 858 Natal male: n = 453 Natal female: n = 435 11–19 years (not provided)	Demographics Sexual violence, dating violence, Dichotomous Y/N; Gender identity Y/N to either Cis or Gender Minority; 14 resiliency questions (family, peer, school, & community): 4-point Likert scale	NSSI & past-year suicide attempts: Dichotomous y/N	•Community support was non-significant in relation to NSSI and suicide attempts •Family support was significantly correlated with lower odds for suicide attempts & NSSI •Peer support was significantly correlated with NSSI
Russell et al. (2018) [44] (USA)	Cross-sectional	n = 129 Transgender Gender non-conforming 15–21 years (not provided)	Demographics Depressive symptoms: BDI for Youth; Chosen Name Use: Whether preferred name was different from name given at birth; Are you able to go by your preferred name at home; school; work with friends Social Support: CASSS	Suicidal Ideation & behaviour: SHBQ	•Chosen name use in more contexts predicted lower depression & reduced suicide ideation & behaviours - an increase of one context (home, work, school, with friends) predicted a 5.37 unit decrease in depressive symptoms, a 29% suicide ideation decrease & a 56% decrease in suicidal behaviour •Depression, suicide ideation & suicidal behaviour were lowest when chosen name was used in all 4 contexts
Scheim et al. (2020) [80] (USA)	Cross-sectional	n = 22,286 Trans woman: 35.6% Trans man: 33.1% Nonbinary AFAB: 25.5% Nonbinary AMAB: 5.8% 18+ (M = 30.9)	Psychological Distress: K-6 Gender concordant identification: 1 item	Suicide ideation: 3-items	•Participants with all identity concordant documents for preferred name & gender had lower prevalence of suicide ideation & planning (adjusted prevalence ratio [APR] 0·78; 95% CI 0·72–0·85) •Having some (vs no) concordant documents were associated with small reductions in suicide ideation (APR 0·95; 0·91–0·98) & planning (APR 0·93; 0·86–1·00) •Participants with some or all gender identity concordant documentation were significantly less likely to attempt suicide than those with no documents
Seelman (2016) [81] (USA)	Cross-sectional	n = 2325 Trans male: 43.7% Trans female: 30.9% Gender nonconforming natal female:16.6% Gender nonconforming natal male: 2.2% Crossdresser male:4.7% Crossdresser female:1.9% 18–76 years (M = 31.02)	Demographics, incl. disability status Generation (time period) when participant attended college & age in college; Denial of bathroom access in college; Gender-appropriate housing in college (due to trans status); Interpersonal victimisation: experience of harassment/bullying; physical assault/attack; sexual assault by teachers/staff at school/college due to trans status	Lifetime suicide attempts: Dichotomous Y/N	•Race, annual household income, physical or mental disability, being denied access to a school bathroom due to being transgender, being denied access to gender-appropriate campus housing due to being transgender were all significantly associated with lifetime suicide attempts •Being a TGD POC & having a physical or mental disability are all associated with suicide attempts •Denial of access to appropriate bathrooms & denial of access to appropriate campus housing were both significantly associated with lifetime suicide attempts •TGD people experiencing interpersonal victimisation (bullying, harassment, physical attack, sexual assault, harassment) from other students (but not teachers/staff) are 1.36x more likely to attempt suicide
Snooks & McLaren (2020) [82] (USA)	Cross-sectional	n = 848 Trans men: n = 197 Trans women: n = 614 18–80 years (M = 26.27)	Demographics Gender affirming surgery: Y/N/I'd rather not say; Interpersonal Needs: INQ-R; Depression: CES-D	Suicidal thought & behaviours: SBQ-R	•Perceived burdensomeness significantly predicted suicidal thoughts & behaviours •Dispositional hope was a protective factor against suicidal thoughts & behaviours when perceived burdensomeness was lower, however not when perceived burdensomeness was higher
Staples et al. (2018) [83] (USA)	Cross-sectional	n = 237 Gender identity other: 55.9% FTM: 24.6% MTF: 10.2% Nonbinary: 9.3% 18–44 years (M = 28)	Demographics Distal TGD stress: Daily Heterosexist Experiences Questionnaire; Internalised TGD negativity; transgender identity scale (TGIS)	Suicide ideation: BSS; NSSI: DSHI	•Race/ethnicity were not significantly associated with suicide ideation or NSSI •Visibility as TGD and degree of maleness/femaleness were all significantly associated with NSSI & suicide ideation •Harassment and victimisation were both positively associatd with suicide ideation & NSSI •Internalised TGD-negativity was significantly associated with suicide ideation but not NSSI
Strauss et al. (2019) [84] (Australia)	Cross-sectional	n = 859 Transgender Gender diverse 14–25 years (M = 19.37)	Demographics Depressive Symptoms: PHQ-A; Anxiety: GAD-7; Self-reported psychiatric diagnoses, exposure to negative experiences, peer rejection, issues with educational setting, issues with accommodation, bullying, body dysphoria, discrimination, employment issues, experiencing significant loss, isolation from TGD people, isolated from services, helping others with mental health, lack of family support	Self-reported adverse health outcomes (incl. self-harm, suicidal thoughts & attempts - lifetime and past-year	•Factors significantly associated with lifetime desire to self-harm: Accommodation issues, bullying, discrimination, experiencing a significant loss, helping others with mental health issues, lack of family support, peer rejection, & school/university/TAFE issues •Factors not associated with desire to self-harm: Body dysphoria, employment issues, feeling isolated from not knowing TGD people, feeling isolated from services •Factors significantly associated with lifetime self-harm: Accommodation issues, bullying, discrimination, employment issues, experiencing a significant loss, feeling isolated from services, helping others with mental health issues, lack of family support, peer rejection, school/university/TAFE issues •Factors not associated with lifetime self-harm: Body dysphoria, feeling isolated from TGD people •Factors significantly associated with lifetime engagement in reckless life-endangering behaviours: Accommodation issues, body dysphoria, bullying, discrimination, employment issues, experiencing a significant loss, feeling isolated from services, lack of family support, peer rejection, school/university/TAFE issues •Factors not associated with lifetime engagement in reckless life-endangering behaviours: Feeling isolated from other TGD ppl, helping others with mental health issues •Factors associated with lifetime suicide ideation: Accommodation issues, body dysphoria, bullying, discrimination, employment issues, experiencing a significant loss, feeling isolated from services, helping others with mental health issues, lack of family support, peer rejection. school/university/TAFE issues •Factors not associated. with lifetime suicide ideation: Feeling isolated from other TGD people •Factors associated with lifetime suicide attempts: Accommodation issues, bullying, discrimination, employment issues, experiencing a significant loss, feeling isolated from services, lack of family support, peer rejection, school/university/TAFE issues •Factors not associated with lifetime suicide attempts: Body dysphoria & feeling isolated from not knowing other TGD people
Strauss et al. (2020) [85] (Australia)	Cross-sectional	n = 859 Transgender Gender diverse: 29.7% Trans men/men: 15% Trans women/women: 48.5% various nonbinary identities (incl. nonbinary trans masc, nonbinary transfemme, agender, bigender, pangender, and others) 14–25 years (M = 19.37)	Demographics Depressive symptom: PHQ-A (for adolescents); Anxiety: GAD-7; Self-reported psychiatric diagnoses: range of diagnoses listed (e.g., PTSD, eating disorders, substance use disorders) & n selected those which had received formal diagnoses; Exposure to abuse: various questions about negative experiences associated with poor mental health - 6 items	Self-harm & suicidal behaviours (self-harm ideation, self-harm, reckless behaviour endangering life, suicide ideation & suicide attempts): 5 items (3-point scale)	•Abuse (extrafamilial physical abuse, familial physical abuse, extrafamilial sexual abuse, intimate partner abuse other familial abuse (including emotional & verbal abuse & neglect)) were all significantly associated with self-harm & suicidal behaviours •Familial sexual abuse was significantly associated with suicide attempts & reckless behaviour which may endanger own life only
Suen et al. (2018) [86] (Hong Kong)	Cross-sectional	n = 106 Assigned male at birth: 63.2% Assigned female at birth: 38.8% 25->44 years (not provided)	Demographics Satisfaction with relationship status: Y/N; Quality of Life: 1-item- 6-point scale	Suicidality: 4-point scale -"never thought of suicide", “have had thoughts of suicide", “have often had thoughts of suicide", “have attempted suicide"	•Quality of life, age & monthly income together explained 15.8% of variance in suicidality •Quality of life was negatively & marginally significantly associated with suicide ideation (p = .058) •Age (15–24) was significantly associated with suicidality and were significantly more likely to report suicide ideation than >44 years (p = .041) •Monthly Income (<HK$6000) was significantly associated with increased likelihood of suicide ideation •Reduced quality of life was significantly associated with suicide ideation compared to people without suicide ideation (p = .007) •Age, monthly income & quality of life combined explained between 15.8% & 22% of variance in suicide ideation depending on analysis •TGD people aged 15–24 years were more likely to report suicide ideation (p = .041) •Quality of life negatively predicted suicide ideation (p = .058)
Taliaferro et al. (2018) [87] (USA)	Cross-sectional	n = 2168 Transgender, genderqueer, genderfluid, or unsure about gender identity AMAB: 31.5% AFAB: 67.2% AFAB Declined to answer: 1.2% School grades 5, 8, 9, & 11 were given. These ages are 10–16 years (not provided)	Demographics Gender identity: Y/N beside relevant gender identity; Depressive Symptoms: PHQ-2; Gender- based bullying/victimisation (2-items); Physical bullying/victimisation: 1-item Parent connectedness: 3-items; Teacher/school adult relationships: Student Engagement Instrument: Friend caring: 1-item; Connectedness to non-parental adults: 2-items; School safety: item	Past year NSSI: How many times? >10 = repetitive	•Past year NSSI was significantly associated with depression & gender-based or physical bullying victimisation •Greater connectedness to parents & non-parental adults were significant protective factors •There was a significant interaction between non-parental adult connectedness & gender-based bullying victimisation: Those who reported such victimisation to non-parental adults were less likely to report NSSI •Depression was the most significant risk factor associated with repetitive NSSI •Parent connectedness & school safety were the most important protective factors to mitigate NSSI
Taliaferro et al. (2019) [88] (USA)	Cross-sectional	n = 1635 Transgender or gender nonconforming: AMAB: 32% AFAB: 68.1% 14/15 years & 16/17 years (not provided)	Demographics Assigned sex & gender identity: 2-items; Family substance use: 2-items; Physical health problems & mental health problems: both 1-item; Positive screen for depression: 2-items; Physical or sexual abuse: 3-items; Relationship violence, witness to family violence & teasing: all 2-items; Bullying: 4-items; running away, violence perpetrator, skipped school, cigarette smoking, alcohol use, binge drinking: all 1-item Parent connectedness: 3-items; connectedness to other adults: 2-items; school engagement & teacher/school adult relationships: both 6-items; neighbourhood safety: 2-items; prescription drug misuse: 4-items; illegal drug use: 5-items; multiple sexual partners: 2-items; bullying perpetrator: 4-items; friend caring, sport participation, involvement in school activities, religious activities, physical activity, school plans, academic achievement, school safety: all 1-item	NSSI: 2-Item scale - 1 asking about past year NSSI engagement & how many times Suicide attempts: Ever attempted suicide, in past year, or no	•Being a natal female was significantly associated with increased likelihood of NSSI •People in Grade 9 (age 14/15) & receiving free/reduced price lunches were more likely to report NSSI •Mental health difficulties, being a victim of teasing due to gender/gender expression, running away from home, & alcohol use were all significantly associated with NSSI (leading factors: mental health problem, depressive symptoms, alcohol use) •No significant difference in NSSI by race/ethnicity or school location (city or other) •Long-term mental health problems, depression, running away, substance use were all significantly associated with experiencing both NSSI & suicide attempts •Physical or sexual abuse, relationship violence, bullying victimisation, less non-parental connectedness to adults, academic achievement, & marijuana use differentiated this group (NSSI & suicide attempts) from the NSSI only group: Leading factors were mental health problems, running away from home, lower levels of connectedness to non-parental adult, & marijuana use •Mental health problem, physical or sexual abuse, relationship violence, bullying victimisation, less parental connectedness, lower grades, lower levels of perceived school safety, & running away from home were all significantly associated with suicide attempts •Increased parental connectedness & school safety differentiated NSSI & suicide attempt group from NSSI only group
Tebbe & Moradi (2016) [89] (USA)	Cross-sectional	n = 353 Transgender (trans women, trans men, non-binary) 18–66 years (M = 25.21)	Demographics Prejudice & discrimination: DHEQ: Internalised antitrans attitudes: IHS; Fear of antitrans stigma: Gender-Related Fears subscale of Transgender Adaptation & Integration Measure; Drug use: Brief DAST; Alcohol use: AUDIT; Depressive symptoms: CES-D Social Support: Family, Friend, & Significant Other subscale of MSPSS	Suicide risk: SBQ-R	•Internalised anti-trans attitudes, drug use & depression all had a direct significant association with suicide ideation & attempts •Perceived discrimination, fear of anti-trans stigma, family support, significant other support, friend support, & alcohol use were not directly significantly related to suicide ideation & attempts •No difference by group (trans women, trans man, non-binary)
Testa et al. (2012) [90] (USA)	Cross-sectional	n = 271 Tran women: n = 179 Trans men: n = 92 18–69 years (M = 37)	Demographics Physical violence: 1 item, then 1 item regarding how many times these were gender-identity related; Sexual violence: 1 item, then 1 item regarding how many times these were gender-identity related; Alcohol abuse: Dichotomous Y/N; Illicit substance use: Dichotomous Y/N	Suicide ideation & attempts: Dichotomous Y/N & how many times	•Physical violence was significantly associated with suicide ideation in trans women but not trans men •Physical violence was significantly associated with suicide attempts in trans men and trans women •Sexual violence was significantly associated with suicide ideation in trans men but not trans women •Sexual violence was significantly associated with suicide attempts in trans men and trans women
Testa et al. (2017) [91] (USA & Canada)	Cross-sectional	n = 816 Trans man; Trans woman; female to different gender; male to different gender; Intersex 18+ (M = 32.53)	Demographics External & internal gender minority stress: GMSR; Belongingness & perceived burdensomeness: INQ-121	Past year suicide ideation: SIS; Lifetime suicide ideation: 1-item; Lifetime suicide attempts: SA: 1-item	•Regarding Model 1 (GMSR): Indirect path of rejection to suicide ideation through internalised transphobia & negative expectations but not non-disclosure was significant •Indirect path from non-affirmation to suicide ideation through internalised transphobia & negative expectations but not through non-disclosure was significant •Internalised transphobia & negative expectations were significantly positively associated with suicide ideation, but non-disclosure was non-significant •Regarding Model 2 (IPTS): Examined associations between internal gender minority stressors & suicide ideation through perceived burdensomeness & thwarted belongingness: Model fit was excellent •Indirect path to suicide ideation through thwarted belongingness & perceived burdensomeness •Thwarted belongingness & perceived burdensomeness were each significant predictors of suicide ideation
Toomey et al. (2018) [92] (USA)	Cross-sectional	n = 1773 Trans female: n = 202 Trans male: n = 175 Nonbinary: n = 344 Questioning: n = 1052 11–19 years (M = 14.7)	Demographics including highest parental education level, urbanicity, & gender identity	Lifetime suicide behaviour: Dichotomous Y/N 1-item: “Have you ever tried to kill yourself?"	•Nonheterosexuality, identifying as a racial/ethnic minority (non-White), older adolescents (age not specified) were all associated with higher odds of reported suicide behaviour •Higher parental education level & residing in urban spaces were significantly associated with lower odds of suicide behaviour •Within each gender identity group: Transgender adolescents: non-heterosexual sexual orientation was associated with higher odds of suicide behaviour •For questioning adolescents: parent education (higher) was a protective factor •Trans adolescents identifying as bisexual, gay, or lesbian were associated with higher odds of reporting suicidal behaviour •No sociodemographic characteristics were significantly associated with suicidal behaviour in nonbinary adolescents
Treharne et al. (2020) [93] (Aotearoa/New Zealand & Australia)	Cross-sectional	n = 700 (TGD: n = 293; cisgender; n = 308) 18–74 years (M = 30)	Demographics Discrimination: EDS; Psychological Distress: K-10 Perceived social support: MSPSS; Resilience: BRS	Suicidal ideation: SIDAS Suicide ideation & attempts: Series of single items about suicidality; Self-harm: DSHI	•TGD people were significantly more likely to have lifetime suicide attempts compared to cis people •Younger age significant for cis but not TGD people •TGD people who live with people were 5x more likely to have suicide attempts than those who live alone •Discrimination was significantly associated with suicide attempts in TGD people compared to cis people •Distress was significantly associated with suicide ideation in TGD & cis people •Distress was significantly associated with suicide ideation & attempts in TGD people only •Higher social support was significantly associated with reduced self-harm in TGD people but not cis people •Higher resilience was a significant protective factor for cis people but not trans people
Trujillo et al. (2017) [94] (USA)	Cross-sectional	N = 78 Transmen: 33.3% Transwomen: 37.2% Another gender:29.5% 18+ (not provided)	Demographics Anti-trans discrimination: HHRDS; Depression & Anxiety: HSCL-25 Perceived social support: MSPSS	Suicidality: SBQ	•Anti-TGD discrimination was positively related to suicide ideation •Harassment & rejection were both positively associated with suicide ideation •Depression was a significant predictor of suicide ideation •Anxiety was not significantly related to suicide ideation or attempts •Depression was a mediator between discrimination & harassment & suicide ideation •Social support from significant other (not from family or friends) moderated experiences of harassment & rejection with suicide ideation (so buffers impact)
Turban et al. (2019) [95] (USA, incl. Guam, American Samoa, & Puerto Rico & military bases)	Cross-sectional	n = 27,715 Crossdresser: 2.6% Trans woman: 63.4% Trans man: 21.1% Nonbinary/genderqueer AFAB: 8.5% Nonbinary/genderqueer AMAB: 4.5% 18->65 years (M = 31.2)	Demographics Lifetime exposure to GICE: binary Y/N; Experiencing GICE <10yrs; Binge Drinking during past month: >1 -day consuming >5 alcoholic drinks; Cigarette & illicit drug use (excl. marijuana); Psychological distress: K-10	Suicide ideation I in past year/SA requiring inpatient hospitalisation in past year; Lifetime suicide ideation & attempts	•19.6% reported lifetime GICE exposure •Lifetime GICE exposure was significantly associated with severe psychological distress during previous month & lifetime suicide attempts •Recalled lifetime GICE exposure was also significantly associated with higher odds of lifetime suicide attempts •After adjusting for statistically significant demographics, GICE exposure <10yrs was significantly associated with increased odds of lifetime suicide attempts
Veale et al. (2017) [15] (Canada)	Cross-sectional	n = 923 Trans girls/women Trans boys/men Nonbinary AFAB Nonbinary AMAB 14–25 years (Not provided)	Demographics Enacted stigma: Enacted Stigma Index; Stress: Single items from General Wellbeing Schedule School connectedness: School Connectedness Scale; Family Connectedness: 7-items (non-validated); 19–25 yr olds were given 8-item Parent Connectedness Scale; Friend Support: 1-item; Social Support: 19–25 yr olds: Medical Outcomes Study Social Support Survey	Suicidality: NSSI, suicide ideation & attempts: Dichotomous Y/N	•Enacted stigma, discrimination, & harassment were all positive predictors of NSSI, suicide ideation & suicide attempts (especially for NSSI) •Social support was negatively associated with NSSI, suicide ideation & suicide attempts •For 14–18-year-olds: family connectedness was the strongest protective factor
Veale et al. (2021) [96] (Aotearoa/New Zealand)	Cross-sectional	n = 610 Trans and nonbinary 14–83 years (M = 32.1)	Demographics GICE: 1-item; Mental Health: K10; Family rejection: GMSR (1-item); Internalised transphobia: 3-items from Gender Identity Self-Stigma Scale	NSSI, suicide ideation & attempts: using questions from the NZ Youth 2000 series: No to more than 5 times (5-point scale)	•GICE exposure x 2 increased odds of NSSI & suicide ideation •GICE exposure was associated with 4x increased odds of suicide attempts
Wang et al. (2021) [97] (China)	Cross-sectional	n = 1293 Transgender & gender queer 13–29 years (M = 21.93)	Demographics Depression: CESD-9; Anxiety: GAD-7; Presence or absence of parental psychological abuse; Self-esteem: RES	Suicide & self-harm risk: 4-items	•Trans women were at increased suicide and self-harm risk compared to trans men & gender queer people •Parental abuse was significantly associated with suicide & self-harm risk •Parental psychological abuse/neglect was significantly associated with risk of suicide & self-harm •Depression was significantly associated with self-harm & suicide in trans women & gender queer people
Woodford et al. (2018) [98] (USA)	Cross-sectional	n = 214 Transgender 18+ (M = 22.83)	Demographics LGBTQ interpersonal microaggressions & victimisation on campus (frequency): 7-items incl. bathroom use & being referred to as old/natal gender; Victimisation: Sexual Orientation Victimisation Questionnaire	Suicide attempts: 1-item	•TGD people reported significantly more suicide attempts than cis-LGBQ peers •Victimisation was significantly associated with TGD suicide attempts •Resilience was significantly associated with decreased odds of suicide attempt •TGD environmental & interpersonal microaggressions were not significantly related to suicide attempts •Pride & outness (with gender identity) were not significantly associated with suicide attempts
Yadegarfard et al. (2014) [99] (Thailand)	Cross-sectional (between groups)	n = 260 Trans women: n = 129 Cis men: n = 131 15–25 years (M = 20)	Demographics Family Rejection: 6-item measure designed for this study (no measure exists); Social Isolation: SSA; Loneliness: ICLA Loneliness Scale-Short; Depression: DASS-21 (short version); Sexual Risk Behaviour: ‘series of questions'	Suicidal thoughts & attempts: PANSI	•Compared to cis people, TGD people reported significantly higher family rejection, lower social support, higher loneliness, higher depression, lower protective factors (PANSI-Positive) & higher negative risk factors (PANSI negative) related to suicide behaviour •Social Isolation was a significant predictor of TGD suicidal thinking
Yockey et al. (2020) [100] (USA)	Cross-sectional	n = 790 Transgender 18+ (not provided)	Demographics Interpersonal Violence: Y/N; Lifetime substance use (cigarettes, alcohol, vaping, & prescription drugs): 4-items Y/N	Suicidal Behaviours 3-items Y/N	•Gender, age, marital status, income, transgender status disclosure, & alcohol usage were all significantly associated with suicide ideation •Age, marital status, income, transgender status disclosure, & interpersonal victimisation were all significantly associated with suicide planning •Gender, victimisation, alcohol use, cigarette smoking, vaping, & use of illegal/prescription drugs were all significantly associated with suicide attempts
Yockey et al. (2022) [101] (USA)	Cross-sectional	n = 27,715 Transgender, nonbinary, genderqueer and others 18+ (not provided)	Demographics Psychological victimisation and harassment: 1 item Y/N; Family support: 1-item 3-point scale	Past year suicide ideation: 1- item Y/N	•Older age (25–44 & 65+) was significantly associated with decreased suicide ideation in the past year •Asian/Pacific Islanders reported decreased suicide ideation compared to White people •Lower income was significantly associated with increased suicide ideation •Gender identity (nonbinary/genderqueer) was significantly associated with increased suicide ideation •Having a neutral or unsupportive family was significantly associated with increased suicide ideation •Victimisation & violence were significantly associated with suicide ideation
Zeluf et al. (2018) [102] (Sweden)	Cross-sectional	n = 796 Trans feminine: 19% Trans masculine: 23% Gender nonbinary: 44% Transvestite: 14% Missing: 0.2% 15–94 years (not provided)	Demographics TGD-related victimisation: 3-items (not specified); Stigma: SCS; Trans-related healthcare issues; 2-items; Change of legal gender: 1-item; Illicit drug use & risky alcohol consumption: 1-item each Life Satisfaction: Life Satisfaction Scale; Social Support: 1-item; Practical support: 1-item; Openness with trans identity: not specified	Past year suicide ideation: Yes once; yes, several times; No Lifetime suicide attempts: Yes, between past 2 weeks & 1 year ago; yes, more than a year ago; No	•Unemployment or long-term sick leave, country of birth other than Sweden, & risky alcohol consumption were significantly associated with suicide ideation •Older age was significantly associated with decreased risk of suicide ideation (older age offers some buffering effect against suicide ideation) •After controlling for above covariates: Offensive treatment in past 3-months, lifetime exposure to TGD-related violence, less satisfaction with contacts with friends/acquaintances & less satisfaction with own psychological wellbeing were significantly associated with suicide ideation •Unemployment or long-term sick-leave, illicit drug use in past 6-months, & risky alcohol consumption were significantly associated with lifetime suicide attempts •After controlling for these variables: Offensive treatment in past 3-months, lifetime exposure to TGD-related violence & never having practical support remained significantly associated with lifetime suicide attempts •TGD-related victimisation was significantly associated with suicidality despite access to gender-affirming healthcare •Protective factors: legal gender recognition & access to gender-affirming healthcare were non-significant (though they measured desire to or whether it had begun, rather than completed medical transition) •There was no significant association between stigma & suicidality •There were no differences in suicidality between TGD experiences (identity) nor judicial status
Zwickl et al. (2021) [103] (Australia)	Cross-sectional	n = 928 Trans male: 26% Trans female: 22% Gender non-binary: 14% Gender Queer: 4% Agender:2% Gender Fluid: 2% Gender Neutral: 1% Other - 3% 18–79 years (Median = 28 years)	Demographics Access to gender affirming hormones; access to gender affirming surgery; Access to trans support groups (Y/N/Unsure); Perceived discrimination from employment, housing, healthcare, &/or government services: items about different aspects of these factors; Self-reported depression diagnosis: Y/N; Physical assault: Y/N	Self-harm & suicide attempts: 1-item each Y/N/prefer not to say	•States of residence within Australia & locality (rural vs. metropolitan) were not significantly different in the proportion of suicide or self-harm •Unemployment, depression, desiring gender-affirming surgery in the future, history of physical assault, & institutional discrimination (incl. discrimination while accessing healthcare, including gender affirming healthcare), in employment, housing, & accessing gov services) were all significantly associated with increased odds of lifetime suicide attempts •Access to TGD support groups was not a significant protective factor •Being presumed male at birth was significantly associated with lower odds of lifetime suicide attempts •Physical assault was reported by 23% & was significantly associated with a 200% increase in lifetime suicide attempt odds •Unemployment was significantly associated with 55% higher odds of lifetime suicide attempts •Self-reported depression was significantly associated with 300% increased odds of suicide attempts •Not being able to access surgery was significantly associated with 73% increased odds of suicide attempts

Papers are ordered alphabetically.
	LEC-5 = Lifetime Events Checklist for DSM-5
Abbreviations:	LOT-R = Life Orientation Test-Revised
	MTDG = Male to different gender
ACSS = Acquired Capability Suicide Scale	MDS = Modified Depression Scale
ASAB = Assigned sex at birth	MSPSS = Multidimensional Scale of Perceived Social Support
AUDIT = Alcohol Use Disorders Identification Test	MTF = Male to Female
BDI = Beck Discrimination Inventory	NHAI = Nungesser Homosexual Attitudes Inventory
BIS = Body Investment Scale	NSSI = Nonsuicidal Self-Injury
Brief-DAST = Brief Drug Abuse Screening Test	PANSI = Positive & Negative Suicide Ideation Inventory
BRS = Brief Resilience Scale	PDS = Perceived Discrimination Scale
BSI = Brief Symptom Inventory	PHQ-9 = Patient Health Questionnaire
BSS = Beck Scale for Suicide Ideation	POC = Person of Colour
CAPA = Child & Adolescent Psychological Abuse Measure	PPES = Painful & Provocative Events Scale
CASSS = Child & Adolescent Social Support Scale	PSS-Fa = Perceived Social Support-Family
CES-D = Center for Epidemiological Studies Depression Scale	PSS-Fr = Perceived Social Support-Friends
CBCL = Child Behavior Checklist	PTSD = Post-Traumatic Stress Disorder
DASS-21 = Depression Anxiety Stress Scales	RFL = Reasons for Living Inventory
DHEQ = Modified Daily Heterosexist Experiences Questionnaire	RHAI = Revised Homosexuality Attitude Inventory
DERS-SF = Difficulties in Emotion Regulation Scale-Short Form	RHM = Reactions to Homosexuality Measure
DSHI – Deliberate Self-Harm Inventory	RHS = Reactions to Homosexuality Scale
EDS = Everyday Discrimination Scale	RSA = Resilience Scale for Adults
FTDG – Female to different gender	RSE = Rosenberg Self-Esteem Scale
FTM = Female to male	SBQ-R = Suicide Behaviors Questionnaire-Revised
GAD-7 = Generalised Anxiety Disorder Scale	SCL-90-R = Symptom Checklist 90-Revised
GCS = Gender Conformity Scale	SCS = Stigma Consciousness Scale
GICE = Gender Identity Change Efforts	SHBQ = Self-harm Behaviors Questionnaire
GMSR = Gender Minority Stress & Resilience Measure	SHI = Self-Harm Inventory
HADS = Hospital Anxiety & Depression Scale	SIDAS = Suicidal Ideation Attributes Scale
HBDS = Hamburg Body Drawing Scale	SITBI = Self Injurous Thoughts & Behaviors Interview
HRD = Harassment, rejection & discrimination	SIQ = Self-Injury Questionnaire
HRDS = Heterosexist, Rejection, & Discrimination Scale	SIQ-TR = Self-Injury Questionnaire-Trauma Related
HSCL-25 = Hopkins Symptoms Checklist-25	SRI-25 = Suicide Resilience Inventory-25
IHS = Internalised Homonegativity Subscale	SS-A = Social Support Appraisals Scales
IIP-32 = Inventory of Interpersonal Problems	STI = Sexually Transmitted Infections
INQ = Interpersonal Needs Questionnaire	TAFE = Technical & Further Education
INQ-R = Interpersonal Needs Questionnaire-Revised	TAIM = Transgender Adaption & Integration Measure
ISAS = Non Suicidal Self-Injury and Inventory of Statements about Self-Injury	TCS = Transgender Congruence Scale
IPTS = Interpersonal Psychological Theory of Suicide	TYC-GDS = Trans Youth CAN! Gender Distress Scale
K-6 = Kessler Psychological Distress Scale-6	TYC-GPS = Trans Youth CAN! Gender Positivity Scale
K-10 – Kessler Psychological Distress Scale-10	YRB = Youth Risk Behavior Survey
	YSR = Youth Self Report