A new study shows that parents have a key role to play in helping their children battle bulimia.
Researchers at the University of Chicago Medical Centre found that almost 40% of youngsters who received family-based treatment stopped binge-eating and then being sick, compared with only 18% of those who received supportive psychotherapy, the standard treatment.
And their report, which is published in the September issue of Archives of General Psychiatry, shows that almost 30% of participants who received family-based treatment were still eating normally six months later.
Of those who received supportive psychotherapy, which focuses on issues underlying the eating disorder, only 10% had managed not to revert to their previous behaviour.
In family-based treatment, parents and at times even siblings attend clinic sessions with the patient.
Parents also play an active role at home, encouraging their children to eat as normally as possible, then monitoring them during and after meals to make sure they eat and are not tempted to be sick.
Study author Dr Daniel le Grange, director of the eating disorders programme at the University of Chicago, said: "Parents are in a unique position to help their adolescents, yet treatment typically excludes them from the process.
"Now we have the evidence that we need to bring them back in."