Autism is not a menta illness but a neurodevelopmental disorder. However, the prevalence of mental health problems such as depression among children and young people with autism is high. One in 10 children and young people who use Child and Adolescent Mental Health Services (CAMHS) has autism. Recent research by The National Autistic Society (NAS) into the effectiveness of these services has revealed a serious lack of understanding and support, with some families reporting that they have had to wait for years to receive help. The research involved a survey of 455 parents of children and young people with autism, together with qualitative findings from parental and young people's focus groups, a survey of CAMHS professionals and visits to CAMHS sites. Responses from parents, young people and professionals indicated that CAMHS did not have the knowledge or the skills to identify or treat mental health problems in children with autism.This can have profound consequences for the health and well-being of the whole family. Autism is a complex disability that can make it harder to diagnose concomitant mental health problems. It is a condition that can make it more difficult for professionals to develop successful, trusting relationships with children, and requires services to be adapted to the individual child. Mainstream interventions and treatments, if unadjusted, will usually fail to improve the mental health of a child with autism and may even make things worse.This article explores how CAMHS services might better meet the needs of children with autism and their families, including improvements in the transition to adult mental health services. In June 2010 NAS launched You Need to Know, a campaign calling on the Government to give priority to improving CAMHS services for children with autism and to support loca areas in delivering the changes that families and front-line professionals are calling for.