After this story of youth violence has left the headlines what will the lasting effects be in schools around the country?

The media seems preoccupied with the effect it will have on children at the school. Little concern has been expressed for the teachers. While it seems reasonable to be more concerned by possible effects on children, it is easy to forget that teachers are not infrequently the victims of physical violence on school premises.

This event will leave them feeling particularly vulnerable. Educators can also be exposed to feelings of guilt and insecurity. They may feel that they should have done more or worry that they will be held responsible but at the same time feel powerless to prevent such incidents. A sense of responsibility accompanied by no actual power is a sure recipe for clinical levels of stress.

Yet a primary concern for teachers will also be whether this incident signals that our schools are heading in the same direction as the United States, where weapon detection technology is used routinely in public schools.

In April 1999, two white male high school students in Littleton, Colorado, entered their school - Columbine high - and attacked students with guns and explosives. In that attack 36 individuals were injured and 15 died, including the attackers and a teacher.

Nancy Brener, a child health expert at the Centre for Disease Control in Atlanta, recently conducted a nationwide study on how the Columbine shooting affected US children. She found that after Columbine the percentage of students nationwide feeling too unsafe to attend school increased by 30 per cent, while the proportion of students missing school because of safety concerns went up almost three times.

The rise was especially pronounced in rural areas (similar to Columbine) where students were 12 times more likely to miss school. The figures won’t be quite so stark for the UK, but the recent stabbing will have certainly pushed them in similar directions.

The worry about these startling figures is that students who feel more at risk of crime might be more likely to carry or keep a weapon, and so the culture of fear and violence so easily becomes a self-perpetuating one.

But there are subtler and perhaps more damaging consequences. If students perceive their surroundings to be unsafe, those perceptions will inhibit the quality of school life. As perceptions of safety decrease, people are more likely to avoid situations where problems could arise and they may become more defensive. So they won’t stay late after school for extra-curricular activities, or mingle during the day.

Pupils who feel more at risk are also less likely to share their ideas with others and are less likely to view the classroom as a secure and tolerant space.

To prevent these effects teachers need to feel supported by each other. Of course, it’s important they should feel supported by the “system”, but let’s just say the more certain support is likely to come from each other.

They should be given the time and space to sort out how they feel after any traumatic event and an early meeting with colleagues should be an urgent requirement, even if just to identify what support is available.

There is also strong case for teachers adopting a zero tolerance approach to aggression so that the culture of intimidation is not allowed to spiral out of control. The whole school needs to unite in asserting a culture of zero tolerance of the unhealthy behaviour. Eventually it means that even aggressive language like swearing will be eliminated.

Education can only occur when teachers and pupils feel safe in schools. At present too many of them only get that feeling when they arrive home after a long day on the education “front line”.

Dr Raj Persaud, a consultant psychiatrist at the Maudsley hospital in south London, presents Radio 4‘s All in the Mind