Background: Externalizing problems among adolescents are prevalent, which are associated with a range of maladaptive developmental outcomes. Existing studies investigated the influence of childhood trauma, and attentional control on and how sensory processing sensitivity (SPS) is related to adolescents' externalizing problems. However, it is unknown whether attentional control plays a mediating role in the relationships between childhood trauma and adolescents' externalizing problems, and whether SPS plays a moderating role in these relationships. The present study examined these issues with a six-month-interval longitudinal study design.

Methods: A total of 1933 junior school students (Grade 7, Mage = 12.82, 47.7 % girls) from a large follow-up project in a city of eastern China participated in the study. After half a year (wave 2), the data of 1890 participants (Grade 8) were collected. The Childhood Trauma Questionnaire (CTQ), Attentional Control Scale (ACS-C), Highly Sensitive Child Scale (HSCS), and the Child Behavior Checklist (CBCL-YSR) were administered to the participants to assess their childhood trauma, attentional control, SPS, and externalizing problems in two waves. The immediate and longitudinal moderated mediation models were utilized to investigate the relationships among these factors.

Results: Childhood trauma significantly and positively predicted adolescents' externalizing problems. Attentional control played an immediate and longitudinal mediating role in the relationship between childhood trauma and externalizing problems. SPS moderated the relationship between childhood trauma and adolescents' attentional control. Childhood trauma had a greater effect on the attentional control of adolescents with SPS levels.

Conclusions: This study suggests that childhood trauma might impair adolescents' attentional control and then increase their externalizing problems. The influence of childhood trauma on attentional control is more serious among adolescents with lower SPS levels. Therefore, decreasing and preventing childhood trauma and building a warm nurturing environment might be beneficial to improving adolescents' attentional control ability and then reduce their externalizing problems.