According to an observational study, Depressive symptoms are more common among sexual minority youth than heterosexual youth at age 10, develop faster during adolescence, and continue into young adulthood, but start to decline from age 18. The study has been published in The Lancet Child & Adolescent Health journal.
Young people who identify as sexual minorities–including those who identify as lesbian, gay, bisexual, not exclusively heterosexual, or not sure of their sexual orientation–consistently experience more symptoms of depression and report more self-harm than heterosexual youths throughout their school years and into early adulthood.
Previous research found that annually between 2001 and 2014, on average across 10- to 19-year-olds in the UK, around 37 per 10,000 girls and 12 per 10,000 boys were treated for self-harm .
The findings suggest that sexual minority youth and are four times more likely to report recent self-harm at ages 16 and 21 years than their heterosexual peers, and are at higher risk of depressive symptoms from as young as 10 years old.
“It is very concerning that despite changes in public perceptions and attitudes, sexual-minority youth remain at increased risk of long-term mental health problems,” says Dr Gemma Lewis from University College London, UK, who led the research. “Our findings underscore the importance of mental health problems before conscious self-identification and labelling of sexual-minority orientation. It is imperative that we find new ways to reach these adolescents and that they are able to access high-quality support services from a young age.” 
Recent estimates suggest that around 1 in 25 people aged 16-24 years in the UK identify as lesbian, gay, or bisexual. Previous studies have consistently shown that young people who identify as sexual minorities are more likely than their heterosexual peers to become depressed, self-harm, and attempt suicide. However, little research has looked at when the increased risk for these mental-health problems emerges and how it develops over time.
In this study, researchers analyzed data on 4,843 adolescents born between April 1991 and December 1992 from the UK Avon Longitudinal Study of Parents and Children (ALSPAC) who reported their sexual orientation at aged 16 years . The majority (87%; 4,203/4,843) of participants identified as heterosexual, and (13%; 625/4,843) as sexual minorities. Just over half of the participants, 53% were female. Depressive symptoms were assessed seven times between the ages of 10 and 21 years using a questionnaire. Additionally, a self-harm questionnaire was completed at ages 16 and 21 years.
Modelling was used to compare depressive symptoms and self-harm in sexual minority youth and heterosexual youth from early adolescence through to young adulthood after adjusting for other factors such as sex, age, maternal education, and social class.
The authors note that the study is observational, so no firm conclusions can be drawn about cause and effect, but they speculate that the poorer mental health reported by sexual minorities may in part be due to the potentially hostile and stressful social environments created by the stigma, prejudice, and discrimination they face.
“The lack of sexual-minority role models and unquestioning acceptance of rigid concepts of gendered behaviour should be challenged in schools and society at large. We also need to ensure that doctors and those working in mental health are aware of this inequality and recognise the needs of sexual minorities,” says Dr Lewis.
The authors also point to several limitations, including that that the study is limited by its use of one dataset from one UK region, therefore the findings might not be generalisable to other populations. They also note that they did not examine mental health outcomes for different sexual-minority groups. Furthermore, the study only measured sexual orientation at one-time point and may not have captured changes which could lead to subsequent mental-health problems. Lastly, the study could not distinguish between those who attempted suicide without a history of self-harm from those who had a history of both self-harm and attempted suicide.
For more details click on the link: DOI:https://doi.org/10.1016/S2352-4642(18)30343-2