Depression, anxiety, and internalizing symptoms in Spanish children and adolescents: estimated rates and comorbidity patterns

The mental health of children and adolescents is a critical concern, as a significant proportion of internalizing disorders emerge early in life, highlighting the importance of timely identification and intervention. However, recent data on the prevalence and comorbidity of these disorders among Spanish youth remain scarce. This study aims to examine the estimated rates and comorbidity patterns of internalizing symptoms -including depression, generalized (GAD) and social anxiety, somatic complaints, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and eating behavior problems- in a nationwide sample of Spanish children and adolescents. A total of 5,450 participants aged 9 to 16 completed the Sistema de Evaluación de Niños y Adolescentes. Results show that 10.4% of children and 14% of adolescents exhibited clinically significant symptoms of at least one disorder. In children, the most common were depression (4.7%), social anxiety (3.6%), and GAD (3.4%); while in adolescents, OCD (4.5%), eating behavior problems (4.3%), and depression (4.0%) prevailed, indicating that, while the estimated rate of certain clinically significant symptoms has increased compared to pre-pandemic data, rates remain lower than what observed during COVID-19. However, some symptoms still require attention due to their potential impact on well-being. Comorbidity patterns reveal a strong presence of clinically significant depressive symptoms with other internalizing disorders, such as GAD, PTSD, and somatic complaints. Moreover, across several domains, the presence of clinically significant symptoms of one disorder increases the risk of also presenting another. These findings emphasize the need for strengthening mental health services, promoting early detection strategies and implementing targeted interventions within public health and educational settings.