The study included 130 participants, ages 12-18, who met clinical definitions of full or partial bulimia nervosa. They were randomly assigned to receive six months of therapy with one of three treatments: Family-based therapy, in which the parents and patient worked together to interrupt abnormal eating behaviors; cognitive behavioral therapy, which focused on changing abnormal thoughts about food, eating and body image, with a lesser emphasis on behavioral change; and supportive psychotherapy, which was included to help generate hypotheses for future studies but was not used by researchers in the main analysis of the results. Family-based therapy has been shown to be the most effective treatment for teenagers with anorexia nervosa, while cognitive behavioral therapy is considered the most effective treatment for adults with bulimia.
The big take-home message is that families can really help their kids with bulimia nervosa.
At the end of treatment, 39 percent of participants treated with family-based therapy had abstained from both binging and purging for at least four weeks, compared with 20 percent of participants receiving cognitive behavioral therapy. Six months after treatment ended, both groups continued to improve, but the gap between treatments remained: 44 percent of family-based therapy patients and 25 percent of cognitive behavioral therapy patients were abstaining from binging and purging. A year after treatment ended, the gap had narrowed and was no longer statistically significant, although the researchers are not sure if this is because the two treatments are similarly effective at that time or because some patients did not return for evaluation at the one-year point.
Treatment strategy may depend on child
Although the research did not test why family-based therapy worked better for teens, the finding is not surprising, said Lock, who directs the Comprehensive Eating Disorders Program at Lucile Packard Children’s Hospital Stanford. “The strategy for cognitive behavioral therapy requires a fair amount of abstract reasoning, motivation and persistence that often has not reached full capacity in teens,” he said, adding that doctors may need to decide on a case-by-case basis whether a teen would benefit from one treatment versus the other. “The cognitive and developmental context is very different for teens than for adult patients,” he said.
And it’s normal for teenagers to need their parents’ assistance in navigating difficult situations, he added. “The big take-home message is that families can really help their kids with bulimia nervosa.”
Lock shared lead authorship of the study with Daniel LeGrange, MD, who was at the University of Chicago when the research was conducted and is now professor of psychiatry at the University of California-San Francisco.
The research was supported by the National Institute of Mental Health (grants R01MH079979 and R01MH079980).
Stanford’s Department of Psychiatry and Behavioral Sciences also supported the work.
Agras and Lock receive royalties from Oxford University Press for contributions to a textbook about eating disorders. Lock also receives royalties from Guildford Press for books he has written about family-based treatment for anorexia nervosa and bulimia nervosa, and payments from the Training Institute for Child and Adolescent Eating Disorders, where he is a faculty member who trains other clinicians in evidence-based treatment methods for eating disorders.
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