Depression and externalising behaviour disorders frequently occur together in adolescence and are associated with a marked increase in symptom severity and poorer outcome. Clinical treatment research and early intervention programs for depression have not addressed the specific cognitive and interpersonal deficits associated with comorbidity. This study presents a pilot evaluation of modifications to the ACE (Adolescents Coping with Emotions) early intervention group program for depression for 17 students attending four special behaviour schools. The modified program, m-ACE, included content to address cognitive distortions, anger management and interpersonal problems. Participants reported improvements in depression symptoms and externalising behaviours. The program achieved high satisfaction ratings from participants and the drop-out rate was low. This is a promising approach for further development and targeting of early intervention programs for this complex population.