Children as young as five are contacting ChildLIne - a free 24-hour number run by the NSPCC - because they are scared about their parents' alcohol or drug abuse.
They were three times more likely to report physical abuse than children who called for other reasons. And those worried about their parents' substance abuse were almost six times more likely to call about their own drug misuse than others.
Some 5,700 calls taken last year were about drink and drug problems, as well as physical and sexual abuse or neglect, said ChildLine.
One ten-year-old told the helpline: 'My mum drinks all the time. She leaves me alone lots of the time. I feel scared and lonely.
'I look after mum when she drinks and put her to bed. She shouts and hits me. I don't want to feel pain. I want to die.' A boy of 13 admitted: 'My mum is an alcoholic. I need to stop mum and dad arguing and fighting. This is always happening. I feel sad because she goes off for days.'
The NSPCC also said that children calling the helpline about drink and drug issues were also more likely than other callers to report abuse.
ChildLine founder, Esther Rantzen has said there are likely to be many more children who are too frightened to phone.
'These are the children that know our number and ring us, but what about the many, many thousands of children who aren't, alas, familiar with ChildLine's work and who might be fearful of ringing us?'
The helpline received more than 150,000 calls during the year. It's head, Sue Minto, said: 'The fall-out from parental drug and alcohol abuse is a ticking timebomb in many children's lives.
It's vital these children are helped before lasting damage occurs.'
What do you think about these terrible statistics, and the stories that lie behind these numbers?
Have you been affected by parental drinking or drug use?