Suicidal thoughts, suicide attempt and non-suicidal self-harm amongst lesbian, gay and bisexual adults compared with heterosexual adults: analysis of data from two nationally representative English household surveys

Suicide is one of the leading causes of premature death worldwide, accounting for over 700,000 reported deaths annually [1, 2]. High-quality registry-based studies indicate that minority sexual orientation is a risk factor for suicide [3]. Approximately 5500 people die by suicide annually in the UK [4], but routine mortality statistics are not broken down by sexuality (or ethnicity). This hampers our understanding of suicide risk in relation to minority status in Britain, despite sexual minority groups constituting 3.2% of the England and Wales populations [5]. A body of evidence supports an excess risk of mental health problems in sexual minority groups compared with heterosexuals [6], but there is less contemporary research comparing their self-harm and suicide-related outcomes. This is despite an estimate, based on UK survey data, that 65% of gay men and 48% of lesbians who reported ever having harmed themselves cited their sexual orientation as wholly or partly the motive [7].

The UK is a heteronormative society where lesbian, gay and bisexual (LGB) people have experienced systemic and historical persecution under British law [8]. Minority stress theory suggests that experiences of discrimination [9] or of being bullied [10] may account for mental health disparities between sexual minorities and heterosexual peers [11]. More recent cultural and legal changes in the UK have provided LGB people with greater legal protection under the Equality Act 2010, and surveys of British attitudes over this period suggest greater tolerance of same-sex relationships [12]. It is unclear, however, whether this has translated into reductions in self-harm or suicidality, where self-harm disparities between heterosexuals and sexual minority groups are apparent from early on in adolescence [13].

Systematic reviews identify clear gaps in the literature regarding self-harm and suicidality risk in sexual minority groups in the UK. A 2008 systematic review of research published up to 2005 described a twofold elevated risk of lifetime suicidal ideation and of lifetime suicide attempts in lesbian, gay and bisexual (LGB) people, although the quality of included studies was limited [14]. Only one eligible study was UK based, finding an excess risk of lifetime self-harm in gay men and lesbians compared with heterosexuals, but this used non-random sampling and did not delineate the self-harm measure used [7]. A 2017 systematic review and meta-analysis of studies on adolescents and young adults found an excess risk of suicide attempts in sexual minority adolescents and youths (over twice the risk), particularly amongst gay or bisexual men [15]. Of the 14 included studies, only 1 was UK based, and this schools-based survey found no association between sexuality and risk of suicide attempt but an excess risk of non-suicidal self-injury [16]. Methodological problems identified by the systematic review authors included issues over selection of confounders [15]. A 2022 systematic review and meta-analysis of population-based studies found an almost tripling of the risk of suicidality (aggregating suicidal ideation and/or suicide attempt) in lesbian women and gay men when compared to heterosexuals, and almost five times the risk for bisexual individuals [17]. These findings derived from only eight eligible studies investigating suicidality (none in the UK), with authors noting that studies of a higher methodological quality were less likely to find disparities in risk of suicidality [17]. Methodological limitations of the eight studies related to statistical power, sexuality definitions and selection of confounding variables. Findings also did not separate out suicidal thoughts from self-harm.

This appraisal of published evidence indicates a clear need for high-quality contemporary, UK population-based research that distinguishes between individual sexual minority groups, separates out specific suicidality outcomes, overcomes sampling methodology limitations and adjusts for appropriate confounders. It provides a rationale for the current investigation, the overarching aim of which was to understand the burden of suicidality and self-harm amongst sexual minority groups in the UK, identify likely risk factors, and ascertain whether any inequalities in suicidality have narrowed or widened over the period 2007–2014. In this study, we aimed to address the limitations of previous research by analysing data from a representative household sample with adequate statistical power to compare specific sexual orientation minority groups in the UK. Our objectives were:

Our findings regarding the absence of an association with suicide attempt, but a clear association with non-suicidal self-harm, are consistent with those of a previous UK schools-based survey [16]. However, more generally, our findings go beyond those reported in previous systematic reviews because of our ability to report comparisons between specific sexual minority groups and separate out specific suicidality outcomes. Whilst a previous meta-analysis found an elevated risk of suicidality in lesbian women and in gay men [17], this did not separate outcomes into suicidal ideation, suicide attempt and self-harm. Our own study found specific associations of lesbian/gay identity with suicidal thoughts, and of lesbian/gay and bisexual identity with non-suicidal self-harm. It is possible, given the limited statistical power of interaction tests, that our finding of no effect modification by gender may reflect inadequate sample size given our use of tighter outcomes.

The striking excess risk of lifetime non-suicidal self-harm amongst bisexual individuals is consistent with findings from previous reviews focussed on young people [15] and individuals in all age groups [17]. More work is needed to understand why bisexual people appear more likely than lesbian/gay people to cope with distress by self-harming. Our findings regarding signals of mediation by minority stress variables in the associations with suicidal ideation and non-suicidal self-harm add to evidence that discrimination and bullying on grounds of sexuality (including within the home) may help explain disparities in suicide-related outcomes [9, 10, 15]. Another potential contributor suggested by the literature on mental health disparities in sexual minorities is stigma [23]. Although we lacked a stigma variable, it is possible that stigma and discrimination are implicated in the development of common mental disorders, and that these in turn increase risk of self-harm and suicidality. Further work is needed to test the mechanistic hypotheses generated here using longitudinal data, informing the development of interventions that might address stigma, discrimination, bullying and other putative mechanistic factors.

Our prevalence estimates for lesbian/gay (1.5%), bisexual (1.1%), and other (1.5%) sexual orientations in an English household sample, with 4.1% overall defined as a sexual minority, are slightly lower than those from other studies using probabilistic sampling. Findings from a 2010 British household survey estimated that 2.5% of men and 2·4% of women self-identified as LGB, with higher estimates for same-sex attraction (6.5% and 11.5%, respectively) and same-sex sexual activity (5.5% and 6.1%, respectively) [32]. In a UK birth cohort, 1.7% of 13 year-olds self-identified as exclusively bisexual, 0.3% self-identified as exclusively gay, with 12.6% overall categorised as a sexual minority [13]. This is greater than the 3.2% estimated for the whole population in the 2021 England and Wales census [5], and is likely due to reduced stigma and greater fluidity of sexual identity in younger people [13]. Estimates based on same-sex marriages registered in Denmark and Sweden over the period 1989–2016 were 0.7% [3]. A small population-based study of Dutch adults defined by recent sexual activity identified a prevalence of 2.8% for men and 1.4% for women of same-sex partners, but this was only amongst those who were sexually active [9]. Precision in the dimensions of sexual orientation measured are clearly important when interpreting public health implications [32].

We analysed data on a large probability sample representative of England households, being the first population-based sample in the UK investigating suicidal thoughts, suicide attempt and non-suicidal self-harm by sexual orientation group. Combining data from two surveys meant that we had sufficient power to compare specific sexual minority groups, identifying important disparities within minority groups as well as more broadly when compared to heterosexual controls. Use of a large representative sample, narrow validated measures and carefully selected confounders meant that this study overcomes many of the methodological limitations of previous studies conducted in a British sample. Computer-assisted data collection for sensitive questions is also likely to have enhanced disclosure on our main exposure and outcome measures, reducing the potential for social desirability bias. Use of weightings ensured that our sample was representative of English households, although findings may not be generalisable to other UK devolved nations or countries outside the UK due to cultural differences. Due to the low level of missing data on key variables, all regression models involved samples of over 10,000 individuals. Although use of data from surveys at two separate time points allowed us to test for changes in disparities over a 7-year period, a longitudinal cohort would have been optimal, sampling the same individuals. Given the cross-sectional design, we could not be certain that the minority stress variables selected as putative mediators preceded outcomes. However, we assumed these might capture a trajectory of discriminatory or bullying experiences preceding suicidality or self-harm. The 2007 and 2014 APMS surveys did not distinguish birth sex and gender identity, so the measure used in this study lacks validity. Other limitations of this study are the lack of data on people over the age of 64, and the inclusion of the 22 individuals in 2007 who described themselves as “mainly heterosexual” within the “heterosexual and mainly heterosexual” group (despite their potentially higher risk of suicidality relating to their sexual identity). Future waves of data collection for the Adult Psychiatric Morbidity Surveys (from 2022) will collect detailed data on gender identity and sexuality in all age groups.

These findings extend our understanding of the excess risk of self-harm and suicidality in non-heterosexuals by comparing specific outcomes in specific sexual minority groups. They highlight clearly that non-suicidal self-harm is a clinical issue for non-heterosexuals across the life course, that suicidal thoughts are particularly pronounced for bisexual individuals, and that common mental disorder and experiences of victimisation may contribute to self-harm and suicidal thinking. Clinicians should be aware of these issues when caring for patients from sexual minority groups, probing sensitively for experiences of discrimination or bullying and signs of CMD, as part of screening for suicidality. Such factors will help in therapeutic assessment and management of risk [33], taking into account the historical and dynamic risk factors that interplay in precipitating suicidal ideation and suicide attempt [34]. Risk management strategies might also include challenging the cognitive biases engendered through minority stress factors, and measures to counter everyday bullying and discrimination. Society has an important role to play in this too. Government departments (such as the UK Government Equalities Office), educational settings, workplaces, and individuals need to consider their own cultures and attitudes towards people from sexual minorities when reviewing our finding of no narrowing in suicidality outcomes over the period 2017–2014.

It is possible that the specific health inequalities we reported relate to systemic issues within health service provision, especially in geographical locations or clinical services less accepting of LGB groups. We lacked the spatial variables to investigate this. Patients perceiving heteronormative environments may be less likely to disclose their sexuality, for fear of discrimination, and this hampers an understanding of their health and social needs. Services seeking to address insidious inequalities could consider raising awareness of research findings such as those presented here, recruitment of healthcare staff representing different sexual and gender minority groups, and staff training to recognise and limit heteronormative bias, including therapists [35]. These measures may help encourage disclosure of sexuality and of suicidality, promoting therapeutic alliance, and improving our responses to suicidal thoughts and self-harm in LGB groups. Providing community-based support to LGB groups is also essential, complementing appropriate healthcare provision, but is reliant on sustained funding for such voluntary sector organisations.

Further longitudinal research is needed to understand the trajectories of self-harm and suicidality in specific LGB groups and associations with mental health. Formal mediation analyses are needed to understand the roles of victimisation, family environment, stigma and other putative mediators. More work is needed to understand disparities in self-harm and suicidality amongst older LGB adults, who were not investigated in this study. This is important because of an ageing population, this group’s long experience of hostile social attitudes [30] and the importance of risk factors such as isolation in older adults [36]. The collection of sexuality data in routine administrative, clinical and survey-based datasets is essential in surveillance of suicidality in LGB people. Routine monitoring of sexuality in mental health services became compulsory in the UK in 2020 [37], yet UK mortality statistics are not broken down by sexuality, detailed gender categories or ethnicity. Such data are required to allow exploration of intersectional differences. Across a range of datasets, such work is needed to understand the needs of LGB groups who identify as transgender, migrants or specific ethnic minority groups. In all such studies, it is important to avoid aggregating sexual minority groups because of intra-group differences we have demonstrated in their mental health [23], self-harm and suicidality. Qualitative research will also help identify putative mediators of these associations in specific groups, as well as the acceptability of suggested interventions.

Our findings from a representative household sample in England identify a heightened risk of past-year suicidal thinking and lifetime non-suicidal self-harm amongst people who identify as bisexual or as lesbian/gay compared with heterosexuals. There was an evident contribution of common mental disorder and of discrimination and bullying, and findings were similar for individuals in both gender categories captured. These disparities had not narrowed over the period spanning 2007–2014, despite the range of measures taken to protect the rights of LGB people. More research is needed to understand the mechanisms underlying these associations, why bullying and discrimination due to sexual orientation is so prevalent in lesbian/gay and bisexual people, how society can prevent the emergence of suicidal thoughts and self-harm in LGB groups and how health services might better meet their needs.