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Public mental health: evidenced-based priorities

The Chief Medical Officer's Annual Report, 2013, Public Mental Health Priorities: Investing in the Evidence, will be published in England this week.1 This report, similarly to others before it, brings together the best evidence about mental health and is set within a contemporary policy context that informs the Chief Medical Officer's recommendations. Unlike many other areas of health, public mental health is difficult to define because there are contested boundaries and terminology. Although the varied landscape is undoubtedly a potential strength, we are concerned by an inability to agree about fundamental issues in this broad field. These issues include the definition and key components of public mental health; the relation of concepts within mental health to one another; how mental health variations of importance are measured and experienced; the value placed on mental health and its consistency across society; and our approach to the generation, accumulation, and assessment of evidence and policy in public mental health. We discuss these topics further in the Chief Medical Officer's Annual Report, in a chapter written by S Davies and N Mehta, who are also authors of this Viewpoint.1
In 2001, WHO defined mental health as “a state of wellbeing in which the individual realises his or her own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to his or her community”.2 Although helpful, further evidence and conceptual clarity was needed. In response, WHO published two reports about prevention of mental disorders3 (2004) and promotion of mental health4 (2005), which articulated that mental health is more than the absence of illness, is intimately connected with physical health, and forms an integral part of general or overall health. Those messages were forerunners of current policy priorities for mental health care in England, and the key messages in the Chief Medical Officer's report—namely, that the organisational and conceptual division of physical from mental health is a barrier to the improvement of general health.
WHO further recognised that mental health and mental illness were viewed as residing outside public health. This was partly because of “the similarities and boundaries between concepts of mental health and illness, and between prevention and promotion”.3 WHO argued that this compromised the specialty of public mental health such that any opportunities to promote mental health were missed and efforts to reduce the burden of mental illness focused mainly on the treatment of ill individuals. These issues were perpetuated by the euphemistic use of the term mental health to describe matters related to mental illness, which caused damaging confusion regarding the association between the two. WHO suggested instead that “the twin aims of improving mental health and lowering the personal and social costs of mental ill-health can only be achieved through a public health approach”.4 In 2013, WHO published the Mental Health Action Plan, 2013—2020, in which the concepts of mental health promotion, mental illness prevention and treatment, and rehabilitation were incorporated into a roadmap for global mental health.5
With WHO's approach as context, we look at mental health in England, particularly the notion of wellbeing insofar as it relates to public mental health. The Government Office for Science published the Foresight Report on the topic of mental capital and wellbeing in 2008.6 This report provided major impetus for a political and policy interest in wellbeing and mental health, which continues to gather pace. Foresight proposed a bold hypothesis that a focus on mental capital and mental wellbeing would enable everyone to realise “their potential and flourish in future”.6 Such was the perceived potential of this approach that Foresight declared: “Achieving a small change in the average level of wellbeing across the population would produce a large decrease in the percentage [of people] with mental disorder[s], and also in the percentage [of people] who have sub-clinical disorder[s] (those ‘languishing’).”6
In policy terms, the stage was set for the promising and exciting concept of wellbeing to revolutionise the way in which we understand, measure, and intervene in the population. Prioritisation of wellbeing in policy was to improve public mental health and reduce the prevalence of disorder by considering concepts spanning a wider, more meaningful, population range. The wellbeing agenda and a diversity of associated narratives—not all consistent—have since been prominently embedded throughout mental health policy. A necessary step in the rapid ascendency of wellbeing as a key concept in public health is to build a robust evidence base to support what this evolving area might offer, on the basis of clear and agreed definitions. We therefore appraised the evidence.1
As mental health policy, commissioning, and practice in England prioritises framing and embedding of wellbeing at every level of health and social care, there has been a simultaneous rising tide of calls for better definitions of wellbeing that go beyond merely an “account or description” and towards a “clear and definite statement of the exact meaning of the term”.7 Many theoretical approaches can contribute towards an understanding of wellbeing, drawing from disciplines including philosophy, sociology, and psychology. Every approach has strengths and weaknesses, but there is no consensus about the best way to define and measure wellbeing within the context of mental health and illness.8, 9 When combined with contested boundaries within mental health and the widespread use by researchers and policy makers of an array of unvalidated proxy measures of varying lengths and sophistication,1, 10 production of a body of wellbeing-related evidence that is scientifically robust enough to support decision making for public health policy in general, and public mental health policy in particular, is difficult.
For example, England's Office for National Statistics includes personal wellbeing as one domain within its Measuring National Wellbeing Programme. One of the measurement items in this domain is “overall how anxious did you feel yesterday?”11 The Office for National Statistics analyses the associations between responses to such questions and other subjectively defined measures, such as satisfaction with health. Conclusions are drawn such as “people who are employed but want a different or additional job have lower levels of personal wellbeing (including higher so-called anxious yesterday scores) than employed people who are not looking for another job”.12 However, inclusion of anxiety items as a measure of personal wellbeing risks further blurring the boundaries between mental illness and mental wellbeing before the psychometric associations between them are adequately defined. High anxious yesterday scores might apply to individuals from various different population groups with varying degrees of mental health or diagnosable mental illness. It is widely accepted that it is possible to have a mental illness and simultaneously enjoy high levels of subjective wellbeing—and vice versa. The notion that mental illness is not the pole opposite of mental wellbeing, but that mental illness is one of the main causes of unhappiness is also generally accepted.1, 13 By simply including anxious yesterday scores as a measure of personal wellbeing, the resulting noise from true mental illness becomes impossible to distinguish in the analysis of the data before these important associations are clarified, and so the measure has little meaning.
Similar contradictions are apparent in the widespread but mistaken use of the General Health Questionnaire (GHQ) as a measure of wellbeing by the Office for National Statistics and others. The GHQ items are widely validated screening measures of psychiatric distress in groups in which cases of common mental illness are likely to be diagnosable.14 The GHQ-12 is moderately negatively correlated with the widely used wellbeing scale the Warwick Edinburgh Mental Well Being Scale (WEMWBS),15, 16 suggesting some overlap in their measurement range. What this tells us about the existence of one continuum of mental health variation from wellbeing to disorder is unclear. What is absolutely clear is that the GHQ-12 was neither intended nor validated as a measure of wellbeing. Simplistic notions of reversing the score or singling out positively phrased items to achieve a measure of wellbeing are problematic.1 Furthermore, in view of the moderate negative correlation of the GHQ-12 with WEMWBS, the association between people's psychiatric distress and low WEMWBS scores in terms of probable GHQ morbidity scores is a key unresolved topic. To rapidly establish, with supporting clinical data, whether the lower range of WEMWBS measures diagnosable depression should be possible and is necessary, because wellbeing narratives in health do not address this. We are concerned that the online NHS wellbeing self-assessment “how happy are you?” informs the lowest WEMWBS scorers that it recommends the “evidence-based” five ways to wellbeing as an intervention.17 If the WEMWBS at this range is proved to be measuring disorder, this intervention could be regarded as dangerous advice, not least because there is no robust evidence for five ways to wellbeing.1 Until we understand the psychometric associations between the concepts, the evidence base for mental wellbeing is being built on shifting sands.
An approach to mental wellbeing that incorporates measures of disorder might have spawned an agenda in which terms describing very different populations are used interchangeably. The result is inconsistent blurring of the boundaries between population approaches to positive mental health and wellbeing promotion, prevention of mental illness and treatment and rehabilitation, often with little apparent thought about the interrelated concepts in question. This has resulted in much of the scientific review literature, on which public mental health policy in England is built, inappropriately describing the results of intervention studies in more established areas of research about mental illness as part of a wellbeing evidence base to which they cannot scientifically be said to apply. Proxy outcomes are frequently rebadged as wellbeing outcomes, crucially compromising the credibility of the evidence base on which policy is subsequently built. Much of this and other widely cited evidence for wellbeing approaches to mental health is published within the non peer-reviewed (grey) scientific literature. We hear regular pronouncements that wellbeing should nonetheless have equal weight in policy development, and this Chief Medical Officer has even been asked to take a leap of faith regarding the case for wellbeing in mental health.1 The quality of wellbeing research and policy must improve significantly. In the meantime, an alternative approach is needed to ensure the effective integration of evidence-based public mental health within wider public policy.
Of further concern is the use of Foresight's model as justification for framing mental health policy in terms of wellbeing and, of course, to invest accordingly.18, 19 The original proponent of the Foresight model was Huppert, who argued that the so-called Rose hypothesis20 can be applied to mental health, after observing that a linear association existed between changes in a marker of the prevalence of common psychiatric disorder and changes in the mean number of psychiatric symptoms in one health and lifestyle survey population.21 Huppert stated that “A very small shift in the population mean of the underlying symptoms or risk factors can do more to enhance wellbeing and reduce disorder than would any amount of intervention with individuals who need help.”22 However, since this work began in 1996, evidence for interventions that shift the curve has simply not been forthcoming. To continue to propagate the case for wellbeing, defined by both Huppert and Foresight as primary prevention of mental disorder, in the absence of any empirical evidence, is no longer appropriate.
There is insufficient evidence to justify the framing of public mental health policy and commissioning in terms of wellbeing. In challenging economic times, public funds must be prioritised for investment in the many areas of public mental health for which we have robust evidence for effectiveness and cost-effectiveness. Generic objectives such as improvement of wellbeing and mental health should give way to the more refined WHO approach: that is, at local and national scales, there are ample opportunities for the interrelated concepts of mental illness prevention, mental health promotion, and treatment of and rehabilitation or recovery from common mental illness that we have the potential—and growing evidence base—to address within an integrated public health system.23 Interventions based on robust evidence with this approach have the potential to address a public health challenge that results in a 15—20 year premature mortality gap, in which 75% of people with common mental disorders receive no treatment,24, 25 and which is increasingly sidelined as wellbeing policy ahead of the evidence.
Although treatment and rehabilitation or recovery are important concepts in WHO's approach, their evidence base is more readily understood and will not be discussed further here. We focus next on promotion and prevention, much of the evidence for which features in the Chief Medical Officer's Annual Report 2013. WHO conceptualises mental health promotion as “the creation of individual, social and environmental conditions that enable optimal psychological and psychophysiological development…[the achievement of] positive mental health, enhancement of quality of life and narrowing the gap in health expectancy between groups. It is an enabling process done by, with and for the people.”3 This definition enables different disciplines to provide evidence for interventions targeting specifically defined and measured elements of positive mental health, in accordance with the holistic bio-psycho-social model of health, without unhelpfully and unsystematically rebadging studies as wellbeing evidence and dismissing alternative perspectives as biomedical or reductionist.1
WHO defines mental illness prevention as aiming “to reduce the incidence, prevalence, recurrence of mental disorders, time spent with symptoms, or risk factors for a mental illness, preventing or delaying recurrences and decreasing the impact of illness in the affected person, their families and society”.3 Although there is no good evidence for primary or universal prevention of mental illness, there is evidence for secondary, tertiary, and selected and indicated prevention.
With use of the WHO framework, it becomes straightforward to identify robust evidence and to understand the relation of this evidence to the broader concept of public mental health and its component parts. We call on key players in mental health in England to unite behind this common understanding of public mental health by building on this model. The time to rethink our approach to wellbeing and regard it as one strand of a bigger picture has come. Taking the lead from the WHO, we encourage England to blaze a trail in public mental health.
Contributors
NM reviewed the scientific literature and wrote the manuscript. TC wrote about the psychometric epidemology of populations in the manuscript. SCD provided intellectual input and policy context.
Declaration of interests
TC reports grants from GL Assessment (2008—11) held while at the University of Cambridge for an ability test standardisation project of the British Ability Scales (3rd revision), a personal fee from GL Assessment for psychometric callibration of the British Ability Scales (3rd revision) outside the submitted work. NM and SCD declare no competing interests.
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a Office of the Chief Medical Officer, Department of Health, London, UK
b Hull York Medical School (HYMS) and Department of Health Sciences (Mental Health and Addiction Research Group), University of York, Heslington, York, UK