title: Widgets: why are some interventions better than others?
authors.forename: Pim
authors.initials: P
authors.lastname: Cuijpers
authors.forename: Annemieke
authors.initials: A
authors.lastname: van Straten
mesh_terms: D006801:Humans; D015201:Meta-Analysis as Topic; D011613:Psychotherapy / Q000379:methods*; D011614:Psychotherapy, Brief; D019966:Substance-Related Disorders / Q000628:therapy*; D016896:Treatment Outcome