The Hidden Harm survey reckons that lots of kids are hurt either physically or mentally because of their parent's problem.

It means that the kids have to look after and care for themselves without their mums and dads help.

And sometimes they even end up having to look after their mums and dads, because they've become so ill through taking loads of drugs.

The Advisory Council on the Misuse of Drugs did the survey.

It reckons that many kids are too embarrassed and frightened to tell anyone.

Kids 'frightened'

Some are so used to their parent using drugs that they don't realise the mum or dad has a problem.

Dr Laurence Gruer who works for the council, said: "From birth onwards their parents' drug problems can damage kids health in many ways."