Up to 200,000 young people in the UK are thought to be caring for a parent with severe mental health problems, a report said.
Young people are missing out on a normal childhood and have fewer opportunities for play and learning, according to the research from the Mental Health Foundation and the Princess Royal Trust for Carers.
Isolation is an issue facing young carers, who can also suffer feelings of anxiety, frustration, guilt, resentment and stress.
The report said they are more likely to be regularly late for school, suffer difficulty completing assignments on time, be disruptive and have difficulty making friends.
Youngsters who care for adults with severe mental health problems - including schizophrenia, bipolar disorder and severe depression - are also more likely to be bullied, leave education without any qualifications and have mental health issues themselves.
The MyCare report includes views from young carers' service workers, mental health professionals, education workers and carers aged nine to 25. It calls for more support for children and young people, who can often fall through the gaps between adult and children's services.
Dr Dan Robotham, senior researcher at the Mental Health Foundation, said: "While there are examples of good practice such as young carers' support groups, much more needs to be done to meet young carers' needs more effectively.
"The MyCare report points to a number of suggested improvements for the various services involved, including the involvement of young carers in discussions about their parents' treatment, more age appropriate-information about mental health to be made available, and greater co-operation between children's, education and mental health services to give young carers the kind support they deserve "
Carole Cochrane, chief executive of the Princess Royal Trust for Carers, said: "Working with young carers, we know that without the right support, many will underachieve or drop out of school altogether, having a long and enduring impact on their future prospects.
"The aim of this project is to help children's services, education and mental health services to work together to better identify and support young carers, making the little changes to services that can make a huge difference to their lives."