Adolescent psychologist Dr Michael Carr-Gregg has said about one in four young people battle a mental illness before they reach the age of 18.

He said that it is vital for children to learn resilience in their early years and this can be done effectively through play.

"Children teach themselves to crawl, stand and walk through repetitious practice play," News.com.au quoted Carr-Gregg as saying.

"At the preschool level, children engage in dramatic play and learn who is a leader, who is a follower, who is outgoing, who is shy. They also learn to negotiate their own conflicts," he added.

Play not only promotes social skills but children who receive an enriched, play-oriented parenting and early childhood program have higher IQs at age five than other children deprived of such experience, said Carr-Gregg.

With technological development children have unintentionally moved indoors.

"Children who might once have enjoyed a pick-up game of football now watch the game on TV, sitting on their couch," he said.