Happier youths are also healthier youths, according to Emily Shaffer-Hudkins and her team, from the University of South Florida in the US. Adolescents' positive emotions and moods, as well as their satisfaction with life, could be more important than their anxiety or depression levels for predicting their physical health（身体健康） , they argue. Looking at teenagers' so-called 'subjective well-being' could help identify those likely to develop health problems in the future and target them with appropriate prevention strategies. Shaffer-Hudkins' work is published in Springer's journal Applied Research in Quality of Life. To date, the majority of the research looking at the relationship between mental health and physical health in young people has focused primarily on how symptoms（症状） of poor mental health, or psychopathology（精神病理学） , such as anxiety and depression, relate to physical functioning. This approach fails to take into account the potential influence of positive indicators of mental health, such as positive emotions and mood states and life satisfaction, known as subjective well-being.

Shaffer-Hudkins' study is the first to look at both positive and negative indicators of mental health in relation to（关于，涉及） physical health in a sample of 401 students in grades 6-8 from a suburban（郊区的） southeastern middle school in the United States. The teenagers rated their satisfaction with life, whether they had recently felt excited, strong and proud (positive affect) as well as lonely, guilty and sad (negative affect). They were also asked about feeling withdrawn, anxious and depressed and about delinquent（过失的） and aggressive behavior (all indicators of psychopathology). Finally, they told researchers about their physical health.

Overall, perceived（感官的） good physical health was strongly linked to life satisfaction and feeling excited, strong and proud. Those who said they felt lonelier, guiltier, more anxious and depressed and who were more likely to display undesirable behaviors reported being less healthy physically. More specifically, mental health indicators explained 30 percent of the difference in physical health ratings and four out of the five mental health indicators were unique predictors of physical health. Positive affect in particular had the greatest effect.

In light of（根据，鉴于） these findings, the authors argue that both positive and negative indicators of mental health need to be considered when developing a comprehensive model of mental health. Wellness models need to be holistic（整体的，全盘的） with a joint mind and body approach.

They conclude: "Findings from the current study underscore the importance of attending to positive wellness-focused indicators of mental health among youth. Subjective well-being is a significant, unique, and primary predictor of important physical health outcomes in youth and is more strongly associated with physical functioning than is psychopathology（精神病理学） . Examining only psychopathology may lead to an underestimation of the relationship between mental health and physical health in young people."