Online training e- learning material Adolescence Adolescence begins around the age of 11 and lasts up to 18 or 19 years of age. Since this period covers the teens (13 to 18 or 19 years of age), adolescents are also called teenagers. In girls, adolescence may begin a year or two earlier than in boys. Also, the period of adolescence varies from person to person. Adolescence is one of the most fascinating and complex transitions in the life span. Biological processes drive many aspects of this growth and development, with the onset of puberty marking the passage from childhood to adolescence . Adolescents depend not only on their families, but also on the neighbour hoods in which they live, the schools that they att...