Timothy Daly commented on our article reporting a dose effect in a multidomain intervention to prevent cognitive decline in older adults at risk of dementia.¹ Our article modeled the dose-response relationship in a multidomain intervention and identified an optimal dosage and dose differences based on individual characteristics, such as level of frailty and education. Although Daly recognizes that the approach is of value, he questions whether efforts would be better invested to address the social determinants of brain aging.

Dementia is a complex disease the cause of which is probably multi-determined, with contributions from both the detrimental impacts of neuropathology and neuroprotective factors. It appears that personal and environmental characteristics contribute to its expression. For this reason, understanding the conditions that promote a healthy brain will require that different fields, including philosophy and sociology, put cognitive health on their agenda. We see this commentary as an important part of the interdisciplinary dialogue that should take place around these issues.

We strongly agree that brain health and dementia prevention need to be part of the public health agenda and that broader social approaches must be implemented to promote brain health including actions to address the social determinants of brain health. Evidence shows that living in a low-income neighborhood is associated with an increased risk of dementia, and certain living conditions (e.g., access to stores with healthy foods and walkability) have been identified as barriers/facilitators to the adoption of a lifestyle that is beneficial for the brain.

However, we do not see the social and personal approaches to brain health as being in opposition. For instance, longer formal time in school is associated with better cognition later in life but some studies found that it is the case for men but not for women,² illustrating the interaction between social and individual characteristics. Furthermore, individuals are driven by social and psychological factors, and are key agents of their health. Personal factors such as self-efficacy, empowerment, and education are critical dimensions and have been shown to determine individual health. Public health organizations are aware of this and contribute to awareness campaigns, as individuals’ adherence to public health messaging is essential to induce personal and societal changes.

The types of multi-domain interventions that we are proposing may be one of the tools that society can provide to older adults. Here, an analogy can be drawn with formal education programs. Today, no one would question the importance of providing children with an educational program that equips them at the cognitive level. Thus one would think that providing late-life education might be as critical for the aging brain as for the developing brain. In addition, by modifying cognition through lifestyle improvements, these interventions contribute to dementia literacy, self-efficacy, and empowerment. They can be offered at all levels in the community, and studies are initiated with a participatory approach to assess how they can be implemented and/or adapted to meet the needs of older adults and community organizations. But of course, for these programs to be implemented, their effectiveness must be demonstrated through sound design.

Timothy Daly, mentions that looking at dose effects characterizes a “pharmacological” model rather than more socially oriented models. However, dose models are not irrelevant in public health approaches. There are many examples where dose is incorporated into public health recommendations, such as for alcohol consumption, toxicants, or sun exposure. But this is also true for more general or social conditions: For example, many countries have introduced compulsory schooling up to a certain age with the idea that there is a minimum dose of education that should be beneficial to the individual. All these recommendations stem from the fact that dose is an important parameter, not only in a biological context but also for more complex socially determined conditions.

In summary, we agree that effective dementia prevention at the population level will require a public health approach, and that randomized controlled trials are much more challenging to perform in the context of long-term lifestyle interventions than for a standard drug versus placebo trials, but this does not mean that such trials are not helpful or indeed necessary. Investigating individual factors does not prevent consideration of social factors. In our view, these factors are inherently interdependent and mutually reinforcing. It is essential that researchers from different perspectives and disciplines continue their conversation about dementia prevention.

蒂莫西·戴利 (Timothy Daly) 评论了我们的文章，该文章报告了多领域干预中的剂量效应，以防止有痴呆风险的老年人认知能力下降。¹我们的文章模拟了多域干预中的剂量反应关系，并根据个体特征（例如虚弱程度和教育程度）确定了最佳剂量和剂量差异。尽管戴利承认这种方法很有价值，但他质疑是否应该更好地投入精力来解决大脑老化的社会决定因素。

痴呆症是一种复杂的疾病，其病因可能是多方面的，包括神经病理学和神经保护因素的不利影响。个人和环境特征似乎有助于其表达。出于这个原因，了解促进大脑健康的条件将需要包括哲学和社会学在内的不同领域将认知健康提上议程。我们认为这篇评论是应该围绕这些问题进行的跨学科对话的重要组成部分。

我们强烈同意大脑健康和痴呆症预防需要成为公共卫生议程的一部分，并且必须实施更广泛的社会方法来促进大脑健康，包括采取行动解决大脑健康的社会决定因素。有证据表明，生活在低收入社区会增加患痴呆症的风险，某些生活条件（例如，可以去商店出售健康食品和步行方便）已被确定为采用以下生活方式的障碍/促进因素：对大脑有益。

然而，我们并不认为大脑健康的社会和个人方法是对立的。例如，在学校正规学习时间越长，日后的认知能力越好，但一些研究发现，男性如此，女性则不然，²这说明了社会特征和个人特征之间的相互作用。此外，个人受到社会和心理因素的驱动，是他们健康的关键因素。自我效能、赋权和教育等个人因素是关键维度，已被证明可以决定个人健康。公共卫生组织意识到这一点并为提高认识运动做出贡献，因为个人遵守公共卫生信息对于引发个人和社会变革至关重要。

我们提议的多领域干预类型可能是社会可以为老年人提供的工具之一。在这里，可以用正规教育计划进行类比。今天，没有人会质疑为儿童提供认知水平教育计划的重要性。因此，人们会认为提供晚年教育可能对老化的大脑和发育中的大脑同样重要。此外，通过改善生活方式改变认知，这些干预措施有助于提高痴呆症的识字率、自我效能和赋权。它们可以在社区的各个层面提供，研究以参与式方法启动，以评估如何实施和/或调整它们以满足老年人和社区组织的需求。但是当然，

Timothy Daly 提到，观察剂量效应是“药理学”模型的特征，而不是更面向社会的模型。然而，剂量模型与公共卫生方法并非无关紧要。有许多例子将剂量纳入公共卫生建议，例如饮酒、毒物或日晒。但这也适用于更普遍或更社会的情况：例如，许多国家已经实行义务教育直至特定年龄，认为有最低限度的教育应该对个人有益。所有这些建议都源于这样一个事实，即剂量是一个重要参数，不仅在生物学背景下，而且在更复杂的社会决定条件下也是如此。

总之，我们同意在人群层面有效预防痴呆症需要公共卫生方法，并且在长期生活方式干预的背景下进行随机对照试验比标准药物与安慰剂试验更具挑战性，但这并不意味着此类试验没有帮助或确实没有必要。调查个人因素并不妨碍考虑社会因素。我们认为，这些因素本质上是相互依存和相辅相成的。来自不同观点和学科的研究人员继续他们关于痴呆症预防的对话至关重要。