Childhood maltreatment has a profound impact on both the short- and long-term wellbeing of children. Specifically, children with autism and those with attention deficit/hyperactivity disorder have a higher risk to experience maltreatment than those with typical development. However, the reasons why this is happening, are unclear. Two studies will be conducted. The first study will investigate the relationship between childhood maltreatment and ADHD. Studies support an association between ADHD and maltreatment: Children with ADHD have higher risk of experience maltreatment than those without ADHD, as well as people who suffered childhood maltreatment have high levels of ADHD symptoms and diagnosis. Also, parental ADHD and/or experience of maltreatment could influence the strength of this association. So, we will define and analyse how genetic and social factors affect the association between ADHD and childhood maltreatment, and then how this could be developed through generations. Having assessed and display the association between ADHD and childhood maltreatment, the second study will go a step forward searching the experience of physical abuse and harsh parenting in children with ADHD and children with autism. We will conduct a comparison between children with ADHD and children with autism trying to understand how the different traits of each condition may affect different the risk of physical abuse and harsh parenting.