This Swiss study adds to evidence that the level of parental monitoring is linked to positive effects on adolescent substance use. The analysis of data from over 7,500 adolescents aged 13-16 found that with more parental monitoring the children consumed less tobacco, alcohol, ecstasy and cannabis, and were also less likely to have friends who used these substances. The higher levels of monitoring were found in families with younger female children, higher socio-economic status, intact family structure, and satisfactory relationships with mother, father and peers. The authors suggest that if parents are encouraged to monitor their children’s activities and friends then the negative influence of peers who use substances can be reduced. In line with other studies we have covered, less closely monitored children were found to have a higher proportion of friends who consumed these substances. One interesting study we covered previously showed that kids’ substance use may also be significantly influenced by their friends’ parents.