About 1-2% of the population have a Learning disability (LD). This is a lifelong condition characterised by an intelligence quotient (IQ) of less than 70, general developmental delay and limitations in day to day activities. Children and adults with LD are some of the most under-served groups in society, with well documented health disparities and at four times the risk of developing a mental disorder. Reports indicate that challenging behaviour, e.g. temper tantrums, aggression or self injury, occurs in as many as 40,000 young people under 18 years living in England. There is a significant evidence from research in the general population that parenting groups which support parents in developing skills to manage such behaviours in their child can be helpful. These programmes, if offered to parents early on, may reduce and even prevent serious emotional problems and possible criminality from developing in the child later in life. Cost benefits are associated with improved health and social outcomes in the young person.

The National Institute of Health and Care Excellence (NICE) guideline on behaviour that challenges reviewed all the available evidence and found very few thoroughly researched programmes specifically developed for children and young people with LD and challenging behaviour. NICE, therefore, recommended that further research should be undertaken to address the lack of evidence based interventions to reduce challenging behaviour in the population of young people with LD.

In this study, the investigators propose to evaluate a programme called level 4 Stepping Stones Triple P (SSTP) delivered by trained practitioners to groups of parents of young children aged 30-59 months with moderate to severe LD. The programme lasts for 9 weeks and has shown positive results in small trials outside the United Kingdom, indicating that it is a potentially helpful. However, it needs to be tested within the UK health system before recommendations can be made to roll it out. Level 4 SSTP helps parents understand and manage their child's behaviour and parents may benefit from peer support in a group setting. The investigators shall recruit 258 parents who will be allocated to one of two groups by chance: one will receive SSTP and treatment as usual and the other treatment as usual, a list of resources and the Contact a Family guide to challenging behaviour. Treatment as usual includes support and advice by General Practitioner's or child development teams. The investigators shall use parental reports and observations of child behaviour to examine whether SSTP reduces challenging behaviour at four (short term) and 12 (long term) months after randomisation. They will also ask other caregivers' about the child's behaviour, the child's and the parent's health related quality of life, difficulties with care, parent stress, service use and how the parent has found the intervention using both questionnaires and face to face interviews.The investigators shall interview the service managers and the therapists about their experience of hosting and delivering the intervention. Parents will also be recruited to the Parent Advisory Group to advise about various aspects of the study, e.g. materials, interview topic guides, dissemination. The researchers and clinicians have expertise in LD, child health and early intervention and have conducted several large trials with this population. The trial will last 48 months and will follow all statutory research governance requirements to ensure that it is high quality, safe and ethical.