Mental Ill-Health in Adolescence: Psychological Distress, Self-harm, and Suicide Attempts in 17-18 year olds.

Researchers at UCL have recently published extensive data from their Millennium Cohort Study of 19,000 people born across the UK in 2000-2001.

In their most recent publication, the researchers looked at the influence of gender, sexuality, ethnicity, and socioeconomic position on mental ill-heath.

Females, on average, scored higher than males on measures of psychological distress, self-harm, and suicide attempts. Males showed a steeper increase in these measures than females between age 14-17 years, resulting in only a small gender difference by age 18. At age 17, 28% of females and 20% of males reported self-harming in the past 12 months, and approximately 10% of females and 4% of males said that they had self-harmed with the intent to end their life.

Females have higher overall levels of psychological distress, with 22.1% experiencing high levels in the past 3 days, compared to 10.1% males. Females also reported higher levels of self-harm in the past 12 months (28.2%) compared to males (20.1%), and higher rates of lifetime attempted suicide (10.6%) compared to males (4.3%).

A Generational Issue?

The previous survey, conducted with the same participants at age 14 found that 24% of females and 9.2% of males experienced high levels of depressive symptoms; substantially higher than among previous generations. A substantial proportion of participants had already reported self-harming behaviours at age 14. There is much speculation as to why these generational differences occur, with increased social media use and declining sleep just a couple of many possible influences.


Large inequalities were noted by sex, ethnicity, and income. Females were more likely than males to suffer from depressive symptoms and to self-harm. White and mixed ethnicity young people had worse mental health compared to Asian, Black and those of other ethnicities, and 14-year-olds with relatively higher household income had fewer mental health difficulties.

In particular the most disadvantaged 40% have almost twice the rates of attempted suicide (almost 12%) when compared with those with higher family incomes (around 6%). Self-harming behaviour was not clearly patterned by family income, with rates of self-harming broadly similar across all quintiles of family income.

Sexual minorities rated much higher for psychological distress, self-harm, and suicide attempts; approximately 10% of all LGBTQ+ participants. The increased risk of mental ill-health among sexual minority adolescents is alarming, with over half (55.8%) of LGBTQ+ young people reporting self-harm in the last year, and 21.7% of this group having attempted suicide.

White adolescents report higher psychological distress and self-harm relative to ethnic minorities. However, there were no difference in rates of suicide attempts. It is important to consider that existing evidence highlights reduced access to mental health support in ethnic minority groups.

No significant differences were reported by country (within UK participants).

COVID-19 Insights: Changes from age 17-19 years

There is evidence to suggest that psychological distress increased between age 17 and 19 years of age, the latter of which was measured in May 2020 during the Covid-19 national lockdown. This increase was significant for females, but not males, who showed no change since age 17. Whilst there may be a number of factors that contribute towards this rise in psychological distress at this age, the increase may be partially reflective of gender differences in response to social isolation. This is consistent with other studies that show young women experience the largest increase in mental ill-health during the pandemic.

Take-Home Message

It seems that high levels of severe mental health difficulties, stark sex differences in the prevalence of these, and large inequalities for sexual minorities and lower income households are of considerable and growing concern. These findings highlight the need to better support minority groups, and be aware of that minority adolescents might be particularly vulnerable and need appropriate support, as they often also suffer from greater bullying, victimisation and a host of adverse co-occurring health related outcomes. Young people should not be left without support when they turn 18; a vulnerable time and period of transition for many.

Patalay, P. & Fitzsimons, E. (2020). Mental ill-health at age 17 in the UK: Prevalence of and inequalities in psychological distress, self-harm and attempted suicide. London: Centre for Longitudinal Studies.

Twenge J, Cooper A, Joiner T, Duffy M, & Binau S. (2019). Age, period, and cohort trends in mood disorder indicators and suicide-related outcomes in a nationally representative dataset, 2005-2017. Journal of Abnormal Psychology, 128(3), 185-199.