Backgrounds: In the context of increasing hate crimes, legislative challenges, and anti-LGBTQ + sentiment, we conducted the first study that comprehensively examined long-term mental health disparities across sexual orientations in the UK from 2010 to 2021. Prior studies predominantly relied on cross-sectional or limited longitudinal designs, thus failing to capture evolving trends over a decade and providing crucial insights into the dynamics of mental health challenges faced by sexual minorities, essential for devising targeted public health interventions and policies.Waves 2–12 of the UK Longitudinal Household Survey for adults (n = 52,591) were used. MCS-12 (Mental Health Component Scale of the Short-Form Health Survey) for mental functioning and GHQ (General Health Questionnaire) for psychological distress were included as the main outcomes, along with other measures of well-being. Mixed-effect longitudinal models were used to examine the trends of mental health disparities across sexual orientations.Relative to their heterosexual counterparts, psychological distress (GHQ) increased for gay men, lesbians, and women with “other” orientations. Bisexual women saw the steepest increase from 1.69 higher GHQ vs. their heterosexual counterparts in 2010 (95%CI: 0.81 to 2.57), up to 3.37 in 2021 (95%CI: 2.28 to 4.45). Similar trends were also shown in the other measures.The study highlights increases in mental health disparities between sexual minorities and heterosexuals. The escalating psychological distress among sexual minorities, particularly bisexual women, calls for an urgent, multi-faceted, and intersectoral response. This approach must address both symptoms and the social structures perpetuating these disparities across sexual orientations.Methods: In the context of increasing hate crimes, legislative challenges, and anti-LGBTQ + sentiment, we conducted the first study that comprehensively examined long-term mental health disparities across sexual orientations in the UK from 2010 to 2021. Prior studies predominantly relied on cross-sectional or limited longitudinal designs, thus failing to capture evolving trends over a decade and providing crucial insights into the dynamics of mental health challenges faced by sexual minorities, essential for devising targeted public health interventions and policies.Waves 2–12 of the UK Longitudinal Household Survey for adults (n = 52,591) were used. MCS-12 (Mental Health Component Scale of the Short-Form Health Survey) for mental functioning and GHQ (General Health Questionnaire) for psychological distress were included as the main outcomes, along with other measures of well-being. Mixed-effect longitudinal models were used to examine the trends of mental health disparities across sexual orientations.Relative to their heterosexual counterparts, psychological distress (GHQ) increased for gay men, lesbians, and women with “other” orientations. Bisexual women saw the steepest increase from 1.69 higher GHQ vs. their heterosexual counterparts in 2010 (95%CI: 0.81 to 2.57), up to 3.37 in 2021 (95%CI: 2.28 to 4.45). Similar trends were also shown in the other measures.The study highlights increases in mental health disparities between sexual minorities and heterosexuals. The escalating psychological distress among sexual minorities, particularly bisexual women, calls for an urgent, multi-faceted, and intersectoral response. This approach must address both symptoms and the social structures perpetuating these disparities across sexual orientations.Results: In the context of increasing hate crimes, legislative challenges, and anti-LGBTQ + sentiment, we conducted the first study that comprehensively examined long-term mental health disparities across sexual orientations in the UK from 2010 to 2021. Prior studies predominantly relied on cross-sectional or limited longitudinal designs, thus failing to capture evolving trends over a decade and providing crucial insights into the dynamics of mental health challenges faced by sexual minorities, essential for devising targeted public health interventions and policies.Waves 2–12 of the UK Longitudinal Household Survey for adults (n = 52,591) were used. MCS-12 (Mental Health Component Scale of the Short-Form Health Survey) for mental functioning and GHQ (General Health Questionnaire) for psychological distress were included as the main outcomes, along with other measures of well-being. Mixed-effect longitudinal models were used to examine the trends of mental health disparities across sexual orientations.Relative to their heterosexual counterparts, psychological distress (GHQ) increased for gay men, lesbians, and women with “other” orientations. Bisexual women saw the steepest increase from 1.69 higher GHQ vs. their heterosexual counterparts in 2010 (95%CI: 0.81 to 2.57), up to 3.37 in 2021 (95%CI: 2.28 to 4.45). Similar trends were also shown in the other measures.The study highlights increases in mental health disparities between sexual minorities and heterosexuals. The escalating psychological distress among sexual minorities, particularly bisexual women, calls for an urgent, multi-faceted, and intersectoral response. This approach must address both symptoms and the social structures perpetuating these disparities across sexual orientations.Conclusions: In the context of increasing hate crimes, legislative challenges, and anti-LGBTQ + sentiment, we conducted the first study that comprehensively examined long-term mental health disparities across sexual orientations in the UK from 2010 to 2021. Prior studies predominantly relied on cross-sectional or limited longitudinal designs, thus failing to capture evolving trends over a decade and providing crucial insights into the dynamics of mental health challenges faced by sexual minorities, essential for devising targeted public health interventions and policies.Waves 2–12 of the UK Longitudinal Household Survey for adults (n = 52,591) were used. MCS-12 (Mental Health Component Scale of the Short-Form Health Survey) for mental functioning and GHQ (General Health Questionnaire) for psychological distress were included as the main outcomes, along with other measures of well-being. Mixed-effect longitudinal models were used to examine the trends of mental health disparities across sexual orientations.Relative to their heterosexual counterparts, psychological distress (GHQ) increased for gay men, lesbians, and women with “other” orientations. Bisexual women saw the steepest increase from 1.69 higher GHQ vs. their heterosexual counterparts in 2010 (95%CI: 0.81 to 2.57), up to 3.37 in 2021 (95%CI: 2.28 to 4.45). Similar trends were also shown in the other measures.The study highlights increases in mental health disparities between sexual minorities and heterosexuals. The escalating psychological distress among sexual minorities, particularly bisexual women, calls for an urgent, multi-faceted, and intersectoral response. This approach must address both symptoms and the social structures perpetuating these disparities across sexual orientations. [ABSTRACT FROM AUTHOR]