A number of limitations should be noted regarding the present research. First, only 16 of the 41 studies included used ITT analyses, and the use of completer analyses appeared to lead to greater effect sizeestimates.EvenamongstudiesusingITTanalyses,resultsfromour riskofbiasassessmentindicatedthatmanystudiesdidnotaccountfor missingdataproperly,ordidnotprovideadequateinformationforwhy data were missing or how missing data were dealt with. Relatedly, the present results may have been influenced by publication bias. In addi- tion, criteria for treatment response varied between studies, poten- tially contributed to increased heterogeneity in the effect sizes for categoricaloutcomes.