Introduction
depressive disorder, depression, MDD
RECURRENCE, REMISSION, DISORDERS
It was previously thought that major depressive disorder (MDD), as diagnosed by the criteria used in adults, did not occur in pediatric patients. However, it became clear in the late 1970s that MDD satisfying adults diagnostic criteria exist even in adolescents (Puig et al., Manifestations of MDD in pediatric patients have been reported to vary with developmental stage, with clinical symptoms beginning to resemble those of adults with increasing age (Carlson and Kashani, Two main approaches are available for the treatment of MDD in pediatric patients: psychoeducational intervention, such as psychotherapy, and pharmacological therapy. For mild depression, according to the National Guidelines for the Treatment of MDD in Japan (Japanese Society of Mood Disorders, For moderate and severe depression, psychotherapy or pharmacological therapy are also recommended. In the United States, fluoxetine (aged 8–18 years), and escitalopram (ESC; aged 12–17 years) have been approved as pharmacological therapies for pediatric MDD patient by the Food and Drug Administration (FDA). No pharmacological therapies have been approved for use in pediatric patients in Japan. Therefore, pharmacological therapy for pediatric MDD patients in Japan appears to be an unmet medical need.ESC is a serotonin reuptake inhibitor developed by H. Lundbeck A/S. It has been shown to be effective in adult patients with MDD worldwide, including Japan. A double-blind placebo-controlled study in pediatric MDD patients aged 6–17 years was conducted in the United States, and This was followed by a double-blind placebo-controlled study of MDD adolescent patients aged 12–17 years, which showed statistically significant differences from placebo (Emslie et al., As mentioned earlier, relapse is common in MDD. Therefore, it is important to investigate the efficacy of antidepressants not only in the acute phase, but also in the prevention of relapse and recurrence after symptomatic remission or response. Since the acute efficacy of ESC has already been demonstrated in adolescent MDD patients in the United States, we conducted a 48-week relapse prevention study in adolescent MDD patients in Japan to evaluate the efficacy of ESC in preventing relapse and recurrence, as well as the safety of ESC.