This is an exploratory single centre, randomised controlled trial of a complex intervention based on cognitive behavioural therapy principles for patients with a recent episode of suicide and who have personality disorder/s and or substance abuse (complex comorbidity). Patients who join the study will be randomly allocated to receive either ENGAGE CBT or Treatment as Usual (TAU). We will compare the effectiveness of ENGAGE with TAU. The primary outcome will be engagement with services − the number of contacts with mental health services (e.g. drug, alcohol and CMHT) in the 3 months following the participant's randomisation.