Professor Peter Fonagy, who worked on the guidance, suggesting parents of children with conduct disorders should be trained on behavioural approach said, parents should avoid using the word "no".
He said that if children misbehave, the parents response is not always the most rational, most reasonable or most effective.
Words like 'no, don't do that' can appear to be the best possible intervention, except that for a kid where the word 'no' triggers misbehaviour, there needs to be alternative strategies to help them reinforce good behaviour.
In some parent training programmes the first few sessions are all about learning to play with your kid, learning to do something positive, getting money into the bank so the kid finds something really rewarding in being with you as a parent.
More top news
The Canadian government has settled thousands of refugees fleeing conflict in Syria.
The shadow chancellor will set out his plans for a government that protects its industries, on Monday.
It will stay drier and brighter for Scotland, Northern Ireland and eastern England for a large part of the day.