The use of antidepressants and other mind-altering drugs among schoolchildren has more than quadrupled in the last decade, it is revealed today.

New figures show that GPs are prescribing pills in record numbers to combat stress, violent behaviour and even tiredness.

Under-16s were given drugs for mental health problems more than 631,000 times last year, compared to just 146,000 in the mid-Nineties.

The huge increase has been blamed on a rise in childhood mental illness sparked by family breakdown and high-stakes school exams.

But there are fears that family doctors are coming under pressure to prescribe drugs such as Prozac as a "quick fix" solution, when counselling would be better.

Politicians and children's charities last night branded the rise "very dangerous" and said a generation of young people risked becoming hooked on prescription drugs.

The findings come despite the publication of research showing that children given antidepressants run a higher risk of self-harm and are more likely to attempt suicide.

David Laws, the Liberal Democrat shadow children's secretary, who obtained the figures in a Parliamentary Question, said: "We've gone from a period when it was almost unthinkable to prescribe drugs to a child to amend their behaviour to a time when it is quite the norm.

"In a sense, it shows some of the pressure many youngsters are under - their lives are chaotic and there isn't as much stability at home. But instead of trying to treat the causes and create a more stable and supportive environment for young people, we think we can solve these problems by prescribing a pill."

New figures, published by the Department for Children, Schools and Families, show a huge year-on-year increase in medication prescribed for depression, behaviour control and severe mental disorders.

Behaviour-altering drugs soared ten-fold in a decade. These include Ritalin, for attention deficit hyperactivity disorder (ADHD), and Modafinil, for daytime sleepiness. Academics say Modafinil is increasingly used by students to stay awake and boost short-term memory.

Prescriptions in this drug group for under-16s rose from 48,264 in 1996/97 to 454,797 in 2006/07. Among 16- to 18-year-olds in full-time education there was a rise from 2,058 to 40,339.

According to figures on anti-depressants, 109,535 prescriptions were made for under-16s in 2006/07, compared to 78,353 a decade ago.

Four years ago, guidance was published saying most antidepressants - including Seroxat - should not be prescribed to under-18s. This did not cover Prozac, which is still freely prescribed to children.

NCH, the children's charity, claims that one child in 10 suffers a significant mental health problem and that rates have doubled since the 1990s.