WHAT should secondary teachers do if a backward pupil bullies classmates; if a child regularly skips classes but is excused by parents; if 14-year-olds are inattentive on Mondays because they habitually drink at weekends? How do teachers explain to a class that one of their number committed suicide during the holidays?

Suggested approaches to these and other examples of at-risk behaviour - including warnings of how not to react - are in a new guide being sent to all secondary-school staff as part of a government preventive campaign. Its launch coincides with evidence that more teenagers are getting drunk, smoking dope and cigaretters, and taking drugs.

“Yes, use of tobacco and alcohol is widespread among pupils; yes, drug addiction exists in schools; yes, there are suicides,” said schools minister Segolene Royal launching the campaign last week with Nicole Maestracci, chairwoman of the inter-ministerial commission against drugs and addiction.

Ms Royal added that it was time to “lift the law of silence” that surrounded such incidents. Since taking office two years ago, she has tackled other previously taboo issues such as paedophilia and bizutage (violent or humiliating initiation rites practised at some post-secondary schools).

Since it began its research six years ago, the commission has found “an enormous change in the behaviour of young people”, said Ms Maestracci. Smoking cannabis is now commonplace, with one-third of those asked admitting having tried it, half of whom are regular consumers.

But the main problem now, she said, were synthetic drugs. Ecstasy is the most common with its use increasing among the young from 0.1 per cent of Paris lyceens in 1991 to 3 per cent in 1998. Another worry was stimulants, which 10 per cent of 15 to 19-year-olds admitted taking to improve memory or physical endurance, or to reduce stress during exams.

A further finding was that while the young were generally drinking less alcohol, excessive drunkenness had increased; more than one-quarter of teenagers in 1997 had had at least three binges in the previous year compared with only 17 per cent in 1993. Numbers smoking more than 10 cigarettes a day had fallen, but half of all lyceens now smoked occasionally or regularly.

The campaign will also involve parents, community services and official authorities such as the police.