ABSTRACT
Transition from childhood to adult life (adolescence) has a broad range of definitions. In North America it has developed as a medical specialty in its own right within an age band spanning 15-25 years. It encompasses a period of life when physical, psychological and sociological maturity and independence are intermingled. The North American definition is one of convenience, as it recognises the transition from paediatricians who care for families and children to the physicians and surgeons who care for adults. Physical maturation becomes established in girls at around the age of 12 years, with the onset of menarche or first menstrual period at approximately 13 years of age, although this has a wide variation (from 9 to 18 years). There is no such clear-cut identifier in boys, but peak height velocity, which is associated with sexual maturation, occurs at around the age of 12 years in girls and approximately 2 years later in boys. This gender difference has
important implications, as girls not only mature physically in advance of boys but they also tend to achieve adult attributes ahead of them. This is reflected by the fact that young women tend to leave the family home and establish their independence several years ahead of their male counterparts.
