However, while he agreed about the teen's diagnosed mental condition, the Crown's witness, Dr Shailesh Kumar, considered the alcohol and cannabis the teen had smoked was likely to have caused a memory blackout, meaning the insanity plea wasn't available to him.
Both psychiatrists talked of the teen's delusions, included believing his father was a "honey god", seeing cups of blood, dabbling in black magic and believing he could levitate.
The court heard the teen had been thrown out of a party for fighting, and wandered local streets before breaking into a house, where he took the infant from its cot.
The next morning he had told one person the child was his nephew, but said to another he had no idea whose baby it was, and told police he'd found the infant by a rock.
The teen was remanded to Waikato Hospital's Henry Bennett psychiatric centre until he reappears in court on November 24.
