摘要：Objectives . We sought to describe the prevalence of mental health and illness, the stability of both diagnoses over time, and whether changes in mental health level predicted mental illness in a cohort group. Methods. In 2009, we analyzed data from the 1995 and 2005 Midlife in the United States cross-sectional surveys (n = 1723), which measured positive mental health and 12-month mental disorders of major depressive episode, panic, and generalized anxiety disorders. Results. Population prevalence of any of 3 mental disorders and levels of mental health appeared stable but were dynamic at the individual level. Fifty-two percent of the 17.5% of respondents with any mental illness in 2005 were new cases; one half of those languishing in 1995 improved in 2005, and one half of those flourishing in 1995 declined in 2005. Change in mental health was strongly predictive of prevalence and incidence (operationalized as a new, not necessarily a first, episode) of mental illness in 2005. Conclusions. Gains in mental health predicted declines in mental illness, supporting the call for public mental health promotion; losses of mental health predicted increases in mental illness, supporting the call for public mental health protection. The debate is no longer about whether mental illness is a public health issue, 1 – 4 but about what can reduce the prevalence of, and suffering from, mental illness. The de facto approach of mental illness treatment 4 and prevention through risk reduction has not reduced the prevalence, burden, or early onset of mental disorder. 5 , 6 A further step is mental health promotion and protection, the latter defined as the objective of preventing the loss of good mental health. 7 Whereas treatment targets those with mental illness, and prevention through risk reduction targets those vulnerable to mental illness, mental health promotion and protection targets those with optimal and less-than-optimal mental health. 8 Mental health promotion and protection seeks to promote maintenance or elevation of positive mental health and to protect against its loss. 8 – 10 Mental health promotion and protection is premised on the dual continuum model—that mental health and mental illness belong to 2 separate but correlated dimensions among the population. 11 , 12 Findings from many studies 13 – 21 support the dual continuum: one indicating the presence or absence of mental health, the other indicating the presence or absence of mental illness symptoms. For example, the latent factors of mental illness and health correlate around −0.50, meaning only 25% of their variance is shared. 13 This modest correlation supports the viewpoint that mental health is not merely the absence of mental illness. 22 , 23 Advances in the measurement of mental health 14 , 24 permit investigation of the hypothesis that mental health, like health in general, 25 is a complete state. In this study, mental health is referred to as “flourishing,” a combination of feeling good about and functioning well in life. “Languishing” mental health is referred to as not feeling good about and not functioning well in life. Survey (prevalence) data reveal that those who are flourishing report the lowest cross-sectional rates of the following: mental illness, limitations of activities of daily living, missed days of work, cardiovascular disease, physical health conditions at all ages, utilization of acute health care service, and prescription medication. 8 , 13 Central to the mental health promotion and protection's promotion hypothesis is that gains in the level of mental health decrease the risk of future mental illness; central to the mental health promotion and protection's protection hypothesis is that loss of mental health increases the risk of future mental illness. We investigated both hypotheses with the 1995 and 2005 waves of the Midlife in the United States (MIDUS) National Study of Health and Well-Being. We also investigated the prevalence of mental health and illness over time (i.e., 1995 and 2005) and the stability of mental health and illness diagnoses.
