New York: Both lack or excess of sleep can lead to health risks like hypertension, obesity, diabetes and depression among children and teenagers, warns a research team led by an Indian-origin scientist. The findings showed that insufficient hours of sleep could increase the risk of accidents and injuries as also lead to self-harm, suicidal thoughts or suicide attempts among teenagers. Conversely, sleeping for longer hours may also be associated with adverse health outcome such as hypertension, diabetes, obesity and mental health problems. "Sleep is essential for a healthy life, and it is important to promote healthy sleep habits in early childhood," said Shalini Paruthi from the American Academy of Sleep Medicine, Springfields, Illinois. A good sleep pattern can lead to better health outcome like improved attention, behaviour, learning, memory, emotional regulation, quality of life, mental and physical health. "Adequate sleep is essential for the children who are in the critical years of early development," added Nathaniel Watson, President at the American Academy of Sleep Medicine. At least 12 to 16 hours of sleep per day is imperative for infants (four to 12 months), the researchers recommended. For children between one to two years of age, 11 to 14 hours sleep is essential, and for those who are three to five years, 10 to 13 hours is needed. Nine to 12 hours for children between six to 12 years and eight to 10 hours of sleep for teenagers from 13 to 18 years is good for them and their overall health. "Making sure there is ample time for sleep is one of the best ways to promote a healthy lifestyle for a child," Paruthi noted. For the study, published in the Journal of Clinical Sleep Medicine, the team conducted a 10-month project and reviewed 864 published scientific articles addressing the relationship between sleep duration and health in children.