Prevalence of depressive symptoms among older children and young adolescents: a longitudinal population-based study.

Introduction: This paper investigates levels of depressive symptoms among older children and young adolescents, 11-14 years of age. The population-based sample was assessed twice during a 12-month period. Point-prevalence, 12-month prevalence, and 12-month incidence were measured by a validated self-reported scale (SFMQ) and are presented in this paper.

Methods: A total of 2148 pupils were invited to participate in this study, and 1748 pupils and at least one parent/guardian provided informed consent. The population was assessed twice within one 12-month period resulting in 1439 participants at both data collection points. Depressive symptoms were measured by a validated self-reported scale, The Short Mood and Feelings Questionnaire (SMFQ).

Results: The results indicate that the point-prevalence was just under 10% in 6^th to 10^th grade with a 12-month prevalence at almost 3%. The results also indicate an incidence rate of 4.5% over 12-months. This study confirms that girls report a higher range of point prevalence, 12- month-prevalence, and 12-month incidence compared to boys.

Conclusions: The results indicate that depressive symptoms among children and young adolescents is a serious health challenge. The results demonstrate substantial gender differences even at an early age (11-14 years), where girls report significantly higher point prevalence, 12-month-prevalence, and 12-month incidence compared to boys. Results from this study suggest that depressive symptoms are an important problem that young adolescents face, and the study underlines the need for more intervention tailored to gender at the middle-school level, especially with respect to those children and adolescents who experience persistent depressive symptoms.