1. For the purposes of this Schedule—
(a)an individual is a child if they have not yet attained the age of 18 years old;
(b)an individual is a young person if they are aged 13 years old or over but have not yet attained the age of 21 years old; and
(c)an individual is an adult if they are aged 18 years old or over,
unless, for the purposes of a service specified in this Schedule, the Board, or the person providing such a service pursuant to a commissioning contract with the Board, considers on clinical grounds that an individual should otherwise be treated as a child, a young person or an adult.