An evaluation of the first year of the Youth Mental Health First Aid (MHFA) in Schools programme found that students in all six schools visited by researchers said the stigma and taboo associated with mental health remained a barrier to speaking openly.
The Department of Health and Social Care-funded scheme aims to train a member of staff in every state secondary school in the country in mental health awareness by 2020.
Over the first year of the scheme, more than 1,200 staff completed a one-day course on how to spot the signs and symptoms of mental health issues in young people and how to support them.
The percentage of teachers reporting increased skills and knowledge of mental as a result of the training increased from 30 per cent before the course to 87 per cent three terms afterwards. But despite this, students said they still felt shy, awkward or feared being bullied.
One year 7 boy from a school in north east England said: "I don't think anybody wants others to know due to bullying so I want the school to be more aware of bullying and kids that are getting bullied."
Another child from a south coast school said: "I don't think people would feel comfortable going to a teacher."
Teachers told researchers from the Institute of Education they would like to see mental health training included in initial teacher training, as they were seeing rising cases of mental health problems year-on-year.
One West Midlands teacher said: "I would say basic mental health training in teaching qualifications and teaching assistant qualifications if you're within a school and that should be completely normal."
They also called for a supervision structure to be introduced to support teachers who were dealing with traumatic mental health cases, such as medical staff receive within the NHS.
One teacher said she had to support a child who had self-harmed so badly she had to accompany him to hospital in an ambulance, only to return back to school and be expected to support his classmates.
"You're expected to pick up another child that's, you know, got their head on a desk in a lesson and its really tough," they said.
The report did show that in one school in north London that had introduced an anonymous box where children could report issues, a mental health club, and targeted assemblies following the MHFA training, 19 students interviewed by researchers all said they felt comfortable talking about mental health.
MHFA England director of communities and content development Caroline Hounsell said the results showed the scheme was having a "positive impact".
"Today's report findings demonstrate that skilling school staff in MHFA is having a really positive impact on their confidence around interacting with students," she said.
"Whilst this programme is the first step in addressing the mental health training gap in schools, we hope to build on its success by continuing to give access to these skills to school staff across England."
Barnardo's chief executive Javed Khan said it was vital mental health skills were "given to school staff across the country so they can intervene early and help children get the support they need".
Research by the teacher's union NASUWT last year revealed that although 98 per cent of teachers have contact with pupils who they believe are experiencing mental health issues, 46 per cent report never having received any training on youth mental health.