Scientists who study the brain and nervous system say the age at which you become an adult is different for everyone.

Research suggests people aged 18 are still going through changes in the brain which can affect behaviour and make them more likely to develop mental health disorders.

Professor Peter Jones, from Cambridge University, said: “What we’re really saying is that to have a definition of when you move from childhood to adulthood looks increasingly absurd.

“It’s a much more nuanced transition that takes place over three decades.”