But the international study, led by Newcastle University in England, concluded that having a caring mother was the single most important factor in preventing youngsters from taking drugs.
The study, funded by the European Commission, found that 14 and 15 year-olds were far less likely to have drug and alcohol habits if they lived with both parents, were properly supervised and enjoyed high quality family relationships.
The research team led by Dr Paul McArdle, of Newcastle Universitys Department of Child Health, found evidence that these protective effects were being eroded in areas where drug availability was particularly high. This was probably due to the additional peer pressure on teenagers to try drugs.
The one exception was among teenagers who had strong attachments to their mothers, which was found to remain a very effective barrier to drug abuse even in areas of high availability.
The research team commented that their findings underlined the role of families but especially the unique role of mothers in regulating the behaviour of the great majority of young people.
Dr McArdle and his colleagues analysed the answers to questionnaires filled in by 3,984 youngsters, aged 14-15, selected at random from cities in England, Eire, Italy, Germany and the Netherlands.
The youngsters were asked whether they took drugs such as cannabis, amphetamines, ecstasy, LSD or tranquillizers or were regular alcohol drinkers.
They were also asked whether they lived with both parents and a series of questions designed to assess the quality of their relationships and how well they were supervised. Questions included whether their parents cared about them watching excessive TV, whether someone was at home after school, whether they were they
Contact: Michael J Warwicker
University of Newcastle upon Tyne