Ultimately, the public health significance of neuroticism hinges on whether knowledge that neuroticism is a potent risk factor for many adverse outcomes can be translated into the prevention of those outcomes. Perhaps the most likely way in which this is could happen is through improved understanding of the basic nature of each of the health and mental health problems associated with neuroticism. That is, achieving a full understanding of why each disorder is related to neuroticism is almost certain to advance our understanding of both neuroticism and each disorder. Indeed, understanding why high neuroticism places persons at increased risk for such seemingly diverse outcomes as depression, schizophrenia, diabetes, asthma, irritable bowel syndrome, and heart disease could change how we conceptualize each of these disorders in fundamentally important ways. Because improved understanding often leads to improved prevention and treatment, discovering how neuroticism is related to each outcome should eventually lead to improved, and potentially innovative, ways of preventing and alleviating each of the many health and mental health problems linked to neuroticism.
In addition, it is possible, but by no means certain, that innovative approaches to prevention could be developed based on the predictive relation between neuroticism and adverse outcomes. For example, it has been suggested that mental health clinicians routinely administer a five-factor personality scale to determine if more extensive assessments of personality disorders related to neuroticism and other traits should be conducted (Widiger & Trull, 2007
). Analogously, it might be possible to inexpensively screen large numbers of individuals in the community for high neuroticism scores (e.g., over the internet). For these reasons, it is useful to speculate about ways in which screening for neuroticism could possibly play a role in future prevention strategies.
First, persons with high scores on the screen could be advised to obtain further individual physical and mental health “check ups” that would include tests specific to each of the mental or physical disorders associated with neuroticism (e.g., tests for cognitive and emotional vulnerability to suicide or tests for high cholesterol). Individuals found to be at risk for any specific adverse outcome using those tests, could then be provided with interventions tailored to their needs (e.g., cognitive-behavior therapy and antidepressants to reduce risk of suicide or statins to reduce cholesterol). If much higher proportions of screen positives than screen negatives were found to be at high risk for one or more of the specific adverse outcomes, such a strategy might prove to be an effective method of identifying at-risk persons. That would only be the case, however, if substantial numbers of persons were found to be at risk for a condition that had not been identified in other ways, such as during routine medical visits. For example, it is possible that few persons would be discovered by screening on neuroticism who did not already know that they were at risk for cardiovascular disease. Even so, a potential benefit of wide-spread screening on neuroticism might be the inexpensive early detection of at-risk persons at an early stage when preventive interventions would be most helpful.
The potential benefits of such large scale screening on neuroticism also would need to be balanced against the numbers of false positives, however. That is, if even if the threshold for the screen was carefully set, any foreseeable screen will identify some persons who screen high on neuroticism but are not actually at high risk for any adverse outcome. This is an issue of concern because persons who are incorrectly identified as being at high risk for serious physical or medical disorders using measures of neuroticism could experience unnecessary worry and subject an already over-burdened health care system to unnecessary expense. In addition, the use of neuroticism scales as a screening measure could tend to stigmatize diversity in this dimension of normal personality.
There has been a trend in the United States toward lowering thresholds for physical health indices such as blood pressure and cholesterol for the purpose of identifying more people in need of preventive treatment. Recent analyses suggest that this may
have yielded little increase in health benefits, but may have caused increases in adverse side effects because more individuals are being treated, adverse consequences of labeling, and the diversion of funds from potentially more effective health programs (Kaplan & Ong, 2007
). Much remains to be learned about this topic, but the same clearly could happen with neuroticism if the specificity of the screen was low and/or the screening threshold was set too low. Great caution should be exercised as we consider the potential utility and wisdom of screening on neuroticism to identify people in need of interventions. Nonetheless, because neuroticism is robustly related to so many different adverse outcomes, this approach to prevention should not be prematurely passed over just because it is challenging.
A second possible innovative approach based on screening for neuroticism might be to attempt to reduce high levels of neuroticism in order to indirectly reduce risks for all of the many mental and physical health problems associated with it. Even if the indirect reduction in the prevalence of each individual adverse outcome were modest, it is possible that such a strategy could be cost-effective because of the sheer number of adverse outcomes associated with neuroticism. To date, no interventions for reducing neuroticism have been identified, but such interventions seem feasible.
The potential utility of this approach to prevention would depend both on the safety, cost, and effectiveness of reducing neuroticism and on the extent to which reducing neuroticism actually resulted in reductions in the adverse health and mental health outcomes associated with neuroticism, all of which are currently unknown. The utility of such large-scale preventive interventions would depend partly on whether reducing neuroticism requires interventions more like supplementing drinking water with fluoride to prevent dental carries than like long-term individual psychotherapy. Assuming for the sake of argument that they were effective in reducing neuroticism, encouraging people with high neuroticism scores to use inexpensive interventions with few adverse side effects such as participation in moderate physical exercise (Koukouvou et al., 2004
) or taking omega-3 dietary supplements (Conklin et al., 2007
) might be cost-effective, even if they yielded only modest reductions in each of the many adverse outcomes associated with neuroticism. More expensive interventions would need to produce larger decreases in physical and mental disorders to be cost-effective. Although much remains to be learned, prescription medication might provide a way to reduce neuroticism (Knutson et al., 1998
), but only if the benefits outweighed the side effects and costs. Similarly, adaptations of cognitive and behavioral interventions like those developed for stress management (Antoni et al., 2000
; Cruess et al., 2000
; Hampel, Meier, & Kummel, 2008
), to prevent anxiety disorders and depression (Bienvenu & Ginsburg, 2007
; Stice, Rohde, Seeley, & Gau, 2008
), or to treat borderline personality disorder (Woodberry & Popenoe, 2008
) could possibly prove to be cost-effective for reducing the broad dimension of neuroticism if they were implemented in group settings and yielded significant reductions in the incidence of physical and mental disorders. This is not because these interventions are inexpensive but because the mental and physical disorders associated with neuroticism are extremely expensive in human and monetary terms. Little empirical evidence can be brought to bear on these potential prevention strategies at present, but they are very worthy of consideration.
Any serious discussion of preventive intervention targeting neuroticism also must consider other possible negative iatrogenic effects. Because wide-spread preventive interventions to reduce neuroticism might even have the unintended effect of reducing adaptive levels of fearfulness and wariness to unsafe levels in some persons, care would need to be taken. This concern might be minimized by intervening only with persons with high levels of neuroticism who requested the intervention, but in some dangerous environments in which cues signaling danger are subtle, such as some urban environments, even relatively high levels of neuroticism might be adaptive in some cases (Matthews et al., 2003
A third possible way to use of neuroticism in prevention could be to routinely assess neuroticism only in persons with the existing medical conditions that appear to deteriorate more quickly in persons who have high neuroticism scores, such as diabetes and cardiovascular disease. At a minimum, physicians could provide more intensive monitoring or interventions to prevent decline in these individuals. This could be particularly beneficial if a better understanding of the role of neuroticism in such diseases leads to improved treatments for patients high in neuroticism. In addition, is possible that interventions to reduce neuroticism could mitigate against disease progression. Again, much remains to be learned about such important topics.