Goodnight Poor Sleep is a one off, brief (10-20-minute), sleep intervention based on principles of cognitive behavioural therapy for insomnia and motivational interviewing. First, participants complete an adapted version of the Adolescent Sleep Hygiene Scale (up to 15 minutes). Participants are then given general sleep health information and general sleep hygiene information (developed specifically for this study; delivered via flipchart). Following this, participants receive one of three treatm