Dr Fazel is lead author of two papers published today in the journal Lancet Psychiatry on mental health interventions in schools.

The review papers highlight childhood as an important window for intervention because around 75% of adults who access mental health services have had a diagnosable disorder before the age of 18. What is more, estimates from high-income countries indicate that only 25% of children with a mental health problem get identified or treated.

'Mental illness often starts in adolescence but doesn't end in adolescence: it is a life-long disorder,' explains Dr Fazel. 'It is therefore essential to find innovative ways to approach treatment and to reach young people to maximise their academic, emotional, and social development, and schools are where children spend much of their time.'

In related news, a new initiative has been launched in Oxfordshire to place mental health professionals in schools to ensure more young people receive appropriate care. Dr Fazel has been pivotal in developing the programme.

Mental illness often starts in adolescence but doesn’t end in adolescence: it is a life-long disorder Dr Mina Fazel

Until recently children in the county have been dependent on adults to help them access services. Oxford Health NHS Foundation Trust is now piloting a programme in state-funded secondary schools in Oxfordshire which sees staff from its primary child and adolescent mental health services (PCAMHS) spend time every week in a designated school.

Consulting with staff about which children could benefit from being referred for additional psychological support, they also see children directly at school. This allows not only teaching staff but also children themselves to benefit from far better access to mental health services. Although not all children want to be seen at school, those who do report that it impacts less on their day, with less class disruption and less family time being taken up taking children to mental health bases that can be far from home.

Oxford Health and the University of Oxford's Department of Psychiatry are collaborating to develop and evaluate this project. The trust also hopes to work with head teachers and commissioners to roll this programme out to other secondary schools in Oxfordshire.

In their papers in the Lancet Psychiatry, Dr Fazel and co-authors explain that the most common disorders in school children are behavioural disorders and anxiety, with depression becoming common in the later years of secondary school. Untreated depression and other mental health problems affect many different aspects of a young person’s development. They can lead to school failure and non-attendance, as well as affecting long-term career choices and relationships.

Routine mental health screening in schools can be controversial. Concerns have been raised about the labelling and stigmatising of young people.

Dr Fazel disagrees: 'If 10% of children had diabetes, we wouldn't be saying that screening was a bad thing,' she says. 'Schools provide a platform to access large proportions of young people, and the vast majority of children picked up by screening would not need complex interventions.'

Dr Fazel and her co-authors write in the Lancet Psychiatry that large numbers of interventions have already been trialled and proven to work in schools, classrooms, and among selected individuals.

The primary barrier to meeting the mental health needs of young people is the gap between research and practice, says Dr Fazel. 'We know what works, but where we fall down is implementing this on a large scale in schools. We also need national policies to help education and mental health services work more closely together.

'The evidence shows that children prefer to be seen in school rather than outside school. But right now, health and education are very different systems,' adds Dr Fazel. 'The reality is that we are not maximising on the opportunities to work in these environments. We need to have an approach that is child focused and to do this health and education must become more closely aligned.'