Emerging adulthood (ages 18-15) is increasingly viewed as among the highest sexual risk age groups. A variety of factors, including biological, psychological, and environmental have been associated with various adolescent risk-taking behaviours, put particularly with sexual risk-taking. This book provides an overview of the current status of STI and HIV rates in women, provides descriptions of the prevalent STIs afflicting women and the physical sequelae of such infections, and discusses potential strategies to combat risk factors and recommendations for preventing STIs in women. This book also provides an outline of depression, sexual risk-taking and sexually transmitted infections (STIs) in adolescents, as well as explores the association between depression and sexual behaviours during the period of adolescence. Implications and recommendations for future studies and practice with adolescents is included as well. Such advances will ultimately improve the current medical and psychological services provided to at-risk adolescents.