Abstract
BACKGROUND: Severe emotional dysregulation (SED) may represent an endophenotype of attention-deficit hyperactivity disorder (ADHD) and major affective disorders. However, the specific effects of SED and related psychiatric disorders, including ADHD, bipolar disorder (BD), and major depressive disorder (MDD), on matrix metalloproteinase-9 (MMP-9), proinflammatory cytokine levels, and inhibitory control function remain unclear. METHODS: This study included 48 adolescents with ADHD, 39 with first-episode BD, 53 with first-episode MDD, and 46 healthy adolescents. SED was defined according to total T scores ≥210 on the Child Behavior Checklist Dysregulation Profile. Levels of MMP-9, interleukin (IL)-6, and C-reactive protein (CRP) were measured. Inhibitory control was assessed using the go/no-go task. RESULTS: Generalized linear models adjusted for demographic and clinical data revealed significant main effects of diagnoses on MMP-9 (P = .009), CRP (P < .001), and IL-6 (P = .029) levels and on the standard deviation of mean response time on the go/no-go task (P = .004). A significant main effect of SED on MMP-9 levels (P = .048) was also observed. Adolescents with BD exhibited the highest MMP-9 and CRP levels and the poorest performance on the go/no-go task compared with the other groups. Adolescents with SED had significantly elevated MMP-9 levels than did those without SED. DISCUSSION: Diagnoses of adolescent psychiatric disorder were associated with increased MMP-9, IL-6, and CRP levels and with inhibitory control dysfunction. In particular, SED was associated with elevated MMP-9 levels.