One of the suggestions was to love bomb.
Sounds quite hippyish but on further exploration is an initiative that has worked for hundreds of families in the same position as my friend.
It's an idea from psychologist Oliver James. The idea behind it is to reset the emotional thermostats of children aged 3 to puberty. It entails spending a period of time alone with your child, offering them unlimited love and control.
He says it works for a wide variety of common problems, severe or mild; from defiant - even violent - aggression to shyness, sleeping problems or underperformance at school.
"This is not the same as "quality time"- just hanging out with your child," he writes.
"When you love bomb, you create a special emotional zone wholly different from normal life, with new rules. More than 100 families have tried it, nearly all with positive results.
"So, how exactly does it work? First, you explain to your child that, sometime soon, the two of you are going to spend time together, one to one, and have a lot of fun. Your child is going to decide what they want and when they want it, within reason. You give the message that this is going to be a big event, it's coming soon ... how exciting."
He says the child draws up a list of things to do and throughout the experience, you are trying, as much as possible, to give them the feeling of "whatever I want, I get" - of being in control and of being gratified, as well as bombed with love.
He says some people might think he's mad, that rewarding a child who's misbehaving will only make them worse.
"This is understandable. Love bombing seems to fly in the face of conventional wisdom, which often recommends more control, not less, when a child is not complying, and stricter, firmer reactions to undesirable behaviour.
"But the love bomb zone is separate from ordinary life. Outside the zone, you continue to set boundaries, consistently and firmly. In fact, the love bombing experience will feed back in a benign way, greatly reducing the time you spend imposing limits, nagging and nattering - the "Don't do that", "I've told you before, put that down", "Leave your sister alone" into which all parents get sucked sometimes. Almost any child - even happy ones - will benefit."
He suggests getting the child to give the experience a name before doing it, like Special Time or Mummy Time or Daddy Time. Often it helps to have a material object to remind them of the experience, like a stone from a beach or a teddy bear. Using this and the name to help as prompts, on returning, parents are asked to try to carve out half an hour an evening when they can briefly re-enter the love-bomb zone together, even if only to watch TV.
James says he has heard back from families 18 months later where love bombing is still working and that family relationships are much better than before.
"Often it is not just the child's thermostat that is corrected, it is also the parents' in relation to the child. After love bombing, many report that it has been the first time for months, or years, they have remembered how much they love their child.
"However you do love bombing, there is nothing to lose. What's not to like about spending time having fun with your child? If it transforms them and your relationship, so much the better - the worst that can happen is you return from the zone having had a good time."
Love Bombing: Reset Your Child's Emotional Thermostat is published by Karnac Books, or visit www.lovebombing.info for more ideas.