Depression is among the most common psychological disorders of adolescents. Its management is based on pharmacological treatment, psychological therapy, or a combination thereof. Cognitive behavioral therapy (CBT) is the most extensively tested intervention for adolescent depression. A PubMed search was conducted for randomized controlled trials (RCT) of the efficacy of CBT in treating adolescents with depressive symptoms published in 2005-2015. Keywords were "cognitive behavioral therapy", "group therapy", "depression" and "adolescent". Of the 23 papers that were retrieved, only six met all inclusion criteria. Three of them reported a significant reduction in depressive symptom severity after either individual or group (G)-CBT compared with the control group, even with a small number of CBT sessions (six rather than 10-12), with a medium or medium-to-large effect size. One study reported improved self-awareness and a significantly greater increase in perceived friend social support compared with bibliotherapy and check with brochure. Two studies reported clinical symptom reduction without significant differences compared with the control group (activity contrast). This review highlighted primarily that very few RCT have applied CBT in adolescents; moreover, it confirmed the effectiveness of G-CBT, especially as psychotherapy, although it was not always superior to other interventions (e.g. other activities in prevention programs). Comparison showed that G-CBT and group interpersonal psychotherapy were both effective in reducing depressive symptoms. Successful G-CBT outcomes were related to the presence of peers, who were an important source of feedback and support to observe, learn, and practice new skills to manage depressive symptoms and improve social-relational skills.