This study aimed to determine the prevalence and the clinical correlates of Adverse Childhood Experiences (ACEs) among 158 inpatient youths with two types of severe psychiatric disorders. ACEs were retrospectively collected with the ACEs scale and the List of Threatening Experiences Questionnaire in 77 patients hospitalized for a catatonic syndrome (average age 15.2 years) and 81 for a manic or mixed episode (average age 15.7 years). ACEs were frequent in youths suffering from bipolar disorder type I (BD-I) (58 %) and from catatonia (57 %), with around one quarter exposed to severe abuse (i.e., physical/sexual/emotional abuse or physical/emotional neglect). Youths with BD-I were more likely to be exposed to family violence compared to those with catatonia. Youths who had been exposed to ACEs did not exhibit a more severe presentation or a poorer response to treatment compared to others, either in the bipolar group or in the catatonic group.