•Higher childhood trauma exposure frequency predicted elevated adulthood major depressive (MDD), panic (PD), and alcohol use disorders (AUD).•Longitudinal structural equation modeling mediation analyses were conducted.•Trait anger expression mediated the relation between childhood trauma and adulthood MDD.•Greater retrospective childhood trauma was associated with higher trait anger expression.•Higher trait anger expression predicted future MDD, PD, and AUD, but not GAD. General aggression and evolutionary models posit that more severe early exposure experiences to trauma (physical, emotional, sexual abuse and/or neglect) place one at risk for adulthood psychopathology through heightened trait anger expression–internal (Anger-In) and external (Anger-Out). However, there are a dearth of empirical studies explaining the longitudinal childhood maltreatment–adulthood psychopathology relation. Therefore, this study investigated if childhood maltreatment exposure severity predicted elevated adulthood major depressive disorder (MDD), generalized anxiety disorder (GAD), panic disorder (PD), and alcohol use disorder (AUD). Moreover, we tested if trait anger expression – internal and external – mediated the childhood maltreatment–adulthood MDD, GAD, PD, and AUD symptom associations. Participants took part in two waves of measurement spaced approximately 9 years apart. Time 1 childhood trauma severity (retrospectively-reported Childhood Trauma Questionnaire), Time 2 Anger-In and Anger-Out (State-Trait Anger Expression Inventory), and Time 3 adulthood MDD, GAD, PD (Composite International Diagnostic Interview–Short Form), and AUD (Alcohol Screening Test) diagnoses were measured. Anger-Out and Anger-In partially mediated the relations between childhood trauma severity and adulthood psychopathology diagnoses after adjusting for Time 2 symptoms. Higher Time 1 childhood trauma severity was related to greater Time 2 Anger-Out and Anger-In, and increased Time 2 Anger-Out and Anger-In were thereby related to elevated Time 3 adulthood MDD, PD and AUD, but not GAD severity. Trait anger accounted for 14 to 50% of the variance of childhood trauma–adulthood MDD, PD and AUD relations. Theoretical and clinical implications, such as the need for trauma-informed care, are discussed.