A within subjects clinical case series using an A-B multiple baseline design will be used. This type of design exposes participating parents to a multiple baseline period (phase A) followed by an intervention phase (phase B). This controls for potential confounds, which increases confidence that change is attributable to the use of the parenting intervention. The baseline phase will vary in length from 2 to 6 weeks. During this phase, parents will complete the treatment adherence questionnaire and parenting scale (outlined in the outcome measures section) at weekly intervals which will take 10 minutes each week (the first and last baseline session will involve completing all questionnaires stated in the primary and secondary outcome measures section). The baseline phase will be followed by the 10 week intervention phase. Here parents will commence the self-directed Teen Triple P programme. Parents will be posted a copy of the Teen Triple P workbook. They will complete a 1 hour module of Triple P each week and will also continue to complete the treatment adherence questionnaire and parenting scale each week. At week 5 and 10 of the intervention, the full set of outcome questionnaires will be administered, as well as a satisfaction survey to determine how parents are finding the Triple P intervention. Once the 10 week Triple P intervention has been completed a period of 4 weeks will elapse before the researcher will contact the parents again in order for them to complete a set of 1 month follow up questionnaires, as well as answering some questions about their experiences of taking part in the Triple P intervention.