Young people in secure accommodation are at high risk of depression and self-harm. This study investigates the relationship between depressive symptoms, negative self-schemas and the cognitive vulnerability to depression in 38 young people in secure accommodation. The impact of a) current suicidal ideation and b) a previous history of self-harm behaviour on latent negative self-schemas was examined using a mood induction task. The low mood condition indicated these young people had a latent cognitive vulnerability to depression. However, this vulnerability was exacerbated in the context of current suicidal ideation but not by a history of self-harm behaviours. An unexpected finding was the negative self-schemas of young people from ethnic minority backgrounds were particularly susceptible to the mood induction. The findings are discussed both in terms of the cognitive vulnerabilities of adolescents detained in secure accommodation and the role of participant characteristics on the validity of mood induction studies in adolescence.