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
Prince Harry received a great big hug from four-year-old Carson Hartley.
The mother of "bucket list" cancer patient Stephen Sutton has said signs of her son's illness were "ignored".
Boxing champion and occasional actor Mike Tyson has been praised for coming to the aid of a motorcyclist injured in a crash in Las Vegas.