The judge said that the experience of being locked in a windowless room in "appalling conditions" had taken a physical and psychological toll on the child victim.
Doctors who examined the boy said he was underweight and below average height for his age, and treated him for anaemia.
But Judge Norman Wright said that while the physical effects have been remedied, the psychological harm "will be unknown".
"It is bound, in my judgment, to be profound," he said.
More top news
The late Coronation Street actress Anne Kirkbride has been nominated for a British Soap Award.
The NHS could save millions of pounds by allowing more people with a terminal illness to die at home as most wished to do, a charity said.
A self-testing kit for HIV which promises a result in 15 minutes has gone on sale in the UK.