Twelve studies were included in the review (646 participants, range 24 to 167). Study design was not stated for each study but at least five studies were described as randomised controlled trials. Only one study had a follow-up of more than one year.
Family therapy (five studies): Four studies found significant improvements for psychological therapy on measures of weight. Two RCTs demonstrated significant improvements for psychological therapy compared to controls (no further treatment and treatment as usual). Another RCT and a pilot study only compared two different types of family therapy with each other. One RCT found a significant difference in weight gain in favour of the control arm (dietary advice) compared with two different types of family therapy.
CBT (four studies): One study demonstrated significantly better weight gain and lower failure rate in favour of CBT than controls. Two studies demonstrated no significant between-group differences (patients in all arms gained weight). One study demonstrated significantly greater improvement in the control group (non-specific supportive clinical management) than psychotherapy (CBT or interpersonal therapy), although it was unclear to which outcomes this applied.
Other psychotherapies (three studies): One study found cognitive therapy to be significantly more effective on BMI than dietary counselling; lack of compliance in control group may have influenced this result. Two studies found no significant between-group differences on measures of weight or other outcomes.