For all experimental groups and the waiting-list control group, the inclusion criteria are:  Aged between 15 and 18 years old at screening phase; Self-reported intensity of social anxiety higher than that reported by a normative comparable sample (Cunha et al., 2004); Main diagnosis of Social Anxiety Disorder as evaluated via the Mini-Kid (Rijo et al., 2016).  For the normative control group, the inclusion criteria are:  Aged between 15 and 18 years old at screening phase; Self-reported intensity social anxiety close or lower to the average levels reported by a normative comparable sample (Cunha et al., 2004); No psychiatric diagnoses as evaluated via the Mini-Kid (Rijo et al., 2016).  Exclusion criteria for all experimental and all control groups are:  Psychotic symptoms or suicidal risk as assessed via the Mini-Kid (Rijo et al., 2016); Being part of the special needs teaching system.