In order to examine the differences between the groups in the reduction of the primary and secondary outcome, HLM will be performed using MPlus. This analysis involves two levels of analysis: intra-subject (Level 1, which analyzes the change of subjects over time) and inter-subject (Level 2, through which the effect of treatment is examined). Repeated measures of symptoms are nested in each subject, and the analysis allows estimating a change parameter along repeated measurements. The analysis tests whether the change parameter varies according to the treatment group, and other covariates. HLM allows to consider in the analyses all participants (including those who abandoned the study). Therefore, these analyses will be conducted according to the principle of intention to treat.