According to UCL researchers, the frequency of major mental health problems among 17-year-olds may decline by as much as 16.8% for girls and 8.4% for boys if they were not subjected to physical violence, such as sexual assault and harassment. The new research, published in The Lancet Psychiatry, uses information from 9,971 young people born across the UK in 2000-02, who the Millennium Cohort Study is following. At the age of 17, just over 1,000 girls and 260 boys reported they had experienced sexual assault or an unwelcome sexual approach in the previous 12 months.

The researchers found that rates of two serious mental health problems - severe psychological distress and self-harm - were higher, on average, among victims than among those who did not report experiencing sexual assault or harassment by at this age. This was true even when taking into account a wide range of other factors known to affect teenagers' risk of experiencing sexual violence and mental ill health.