Subthreshold depression in adolescence: a systematic review.

In adolescence, the number of depressive symptoms is rising notably. Individuals may have relevant depressive symptoms without meeting the full criteria of a major depressive episode (MDE), a condition referred to as subthreshold depression (sD). This article presents a review on adolescent sD examining the prevalence, the quality of life (QoL), the risk of developing MDE, and preventive programs available for adolescents living with sD. A systematic literature search from the year of the introduction of Diagnostic and Statistic Manual for Mental Disorders Fourth Edition (DSM-IV) until 2012 (18 years) was conducted with a special focus on adolescent sD. Data from 27 studies were included into this review. The results show high prevalence of sD among adolescents, with a negative impact on QoL, and provide evidence that sD is a significant risk indicator of later MDE; therefore, individuals with sD represent good targets for preventive interventions. Our review highlights the fact that sD is a significant health problem among adolescents indeed, and adolescents with sD could be a subgroup of youth, who need further help to reduce their clinically significant depressive symptoms for the successful prevention of a later MDE.