ADHD is a condition that is becoming a problem for mental health professionals. Earlier on it was believed that it is present in children only but now the research work has clearly indicated that attentional deficits and hyperactive behaviors can be observed in all stages of life. Although the manifestation of the symptoms may vary. This dissertation is an attempt to cover the development of ADHD symptoms across life span. It is an attempt to cover an up to date information on the topic at both national and international levels.In order to highlight the distinctive features, case examples have also been included. The dissertation also contains worksheets that can be of considerable help for developing assessment and management plans while working with individuals having ADHD symptoms.