tion, and demands the concerted efforts of medical caregivers, environment health specialists, community organizations, and lawmakers, as well as regulatory officials at all levels of government.
Physical fitness and exercise are widely recognized as important modulators of stress, and there is some evidence of their effectiveness for the treatment of depression (Craft, Freund, et al., 2008). A meta-analysis of exercise interventions targeting depression and anxiety, primarily in college students, showed significant positive effects related to depression and positive but not significant effects related to anxiety (Larun, Nordheim, et al., 2006). However, the 16 available trials were of low methodological quality. A clear relationship between physical fitness and exercise and the prevention of MEB disorders in children is even less well documented. Given the clear relationship between exercise and stress, however, both general and medical education for children and their families should include discussion of appropriate exercise and advocacy for overall family fitness.
Extended television viewing has been linked to the occurrence of ADHD (Christakos, Zimmerman, et al., 2004) and limiting television time for children as a preventive measure has received increasing attention. The American Academy of Pediatrics recommends no television viewing for children under two years of age and no more than two hours a day thereafter. Exposure of children to violence through television and other media has been linked to conduct problems in children and adolescents (Bushman and Huesmann, 2006; Huesmann, Moise-Titus, et al., 2003). Attempts to reduce exposure of children to violence have had very little effect on the content of entertainment programming, and management of this risk falls largely to in-home restriction.
Exposure to adequate sunlight and light in general may affect mental health. Vitamin D deficiency can occur because children today are outside for shorter periods of time and are often protected by sunscreen. Vitamin D may have effects not only on bone mineralization, but also on immunity to infectious agents. Vitamin D plays an important role as well in brain development and function. Subtle effects of vitamin D deficiency on behavior have been suggested, but a causal relationship has not been firmly established (McCann and Ames, 2008). Whether prevention of vita-