Maternal Prenatal Psychological Distress, Poor Nutrition and Atypical Child Development

在英国，许多成年人都遭受着心理痛苦。心理困扰的范围从过度担心到情绪低落，再到更严重的问题。重要的是，现有的研究表明，有心理障碍的成年人在孩提时代通常也有认知和行为问题。了解心理困扰是如何发展的，这是帮助我们(I)确定哪些儿童面临最大风险和(Ii)制定有针对性的战略来预防或管理此类问题的关键第一步。这里的理由是，如果我们能在童年时期预防心理困扰的发展，这些孩子成年后就不太可能表现出心理困扰。我们已经知道，出现认知和行为问题的儿童往往来自风险更高的环境。例如，这些孩子的母亲可能有心理困难。此外，有心理困难的家庭也倾向于食用营养质量较差的食物(如快餐、甜食)。这两种风险(即母亲心理困扰和不良饮食)被认为以一系列方式影响发育--包括影响儿童在生物学方面的发育。孩子的生理可能受到影响的方式之一是通过孩子在怀孕期间接触到的营养(即母亲吃什么)。因此，在怀孕期间，发育中的胎儿可能会同时暴露在母亲的心理痛苦和不理想的饮食中。值得注意的是，在孩子出生后也是如此。事实上，我们之前的研究表明，母亲的心理痛苦和营养不良表现出从怀孕到孩子出生的连续性。然而，到目前为止，现有的研究还没有梳理出特定的生物学机制，可以解释怀孕期间(或出生后)特定的暴露可能与增加适应问题的风险有关。这类生物的一个潜在重要因素是DNA甲基化。DNA甲基化使个体环境的变化可以影响他们的基因构成(基因)如何影响发育。动物研究表明，母亲在怀孕期间吃什么可以改变基因的活动，这些基因对大脑区域的发育非常重要，这些区域涉及我们如何应对压力、情绪以及行为和情绪的控制。重要的是，这项工作还强调了这些DNA影响(和大脑变化)可能是可逆的。到目前为止，在人类身上进行的研究数量非常有限，显示出类似的模式。在这项研究中，我们计划解决现有研究的两个关键潜在限制：(1)现有研究没有同时检查母亲的痛苦和营养不良。(2)现有的研究没有评估哪些生物学机制可以解释母亲的痛苦和不健康的饮食可能与儿童适应问题有关。(3)现有研究没有评估在怀孕期间建立的生物脆弱性是否可以在孩子出生后继续存在。这项研究将解决现有研究的每一个主要局限性。我们处于实现这些目标的理想位置，因为我们可以获得已经从两个非常大的儿童样本收集的心理、饮食、行为和生物数据，从他们出生前到儿童和青春期(英格兰西南部的雅芳父母和儿童纵向研究和荷兰鹿特丹的R代)进行了广泛研究。我们希望这项研究的结果将有助于回答为什么一些儿童更有可能出现认知和行为问题，并指导对高危儿童的早期干预，以防止可能导致他们的非典型DNA甲基化模式。

Many adults in the United Kingdom suffer from psychological distress. Psychological distress can range from worrying a lot, to feeling down, to even more serious problems. Importantly, existing research suggests that adults with psychological difficulties often also have cognitive and behavioural problems as children. Understanding how psychological distress develops is a crucial first step in helping us (i) identify which children are most at risk and (ii) develop targeted strategies to prevent or manage such problems. The reasoning here is that if we can prevent the development of psychological distress in childhood, these children will be less likely to show psychological distress as adults. We already know that children who show cognitive and behavioural problems tend to come from riskier circumstances. For example, these children can have mothers with psychological difficulties. Moreover, families that have psychological difficulties also tend to eat foods that are of poor nutritional quality (e.g. fast foods, sweets). These two risks (i.e. mother psychological distress and poor diet) are thought to impact development in a range of ways - including on how a child develops in terms of biology. One of the ways the child's biology might be affected is through the nutrition the child is exposed to during pregnancy (i.e., what the mother eats). Therefore, during pregnancy, a developing foetus could be exposed to both psychological distresses in the mother as well as sub-optimal diets. It is important to note that the same is true for after the birth of a child. In fact, our previous research shows that maternal psychological distress and poor nutrition show continuity between pregnancy and after the birth of a child. To date, however, existing studies have not teased out the specific biological mechanisms that could explain how a particular exposure during pregnancy (or after birth) might relate to increased risk for adjustment problems. One potentially important biological factor of this kind is 'DNA methylation'. DNA methylation allows a way for changes in an individual's environment to influence how their genetic make-up ('genes') affects development. Animal research shows that what a mother eats during pregnancy can change the action of genes important for the development of brain regions involved in how we respond to stress, in emotions and in the control of behaviours and emotions. Importantly, this work also highlights that these DNA influences (and brain changes) are potentially reversible. The very limited number of studies in humans so far shows similar patterns.In this study we plan to address two key potential limitations of existing research: (1) Existing studies have not examined maternal distress and poor nutrition at the same time. (2) Existing studies have not assessed which biological mechanisms could explain how maternal distress and unhealthy diet might relate to child adjustment problems. (3) Existing studies have not assessed if biological vulnerabilities established in pregnancy can be carried forward after the birth of a child. This study will address each of these main limitations of the existing research. We are ideally placed to achieve these aims as we have access to psychological, dietary, behavioural and biological data already collected from two very large scale samples of children, extensively studied from before their birth through childhood and into adolescence (The Avon Longitudinal Study of Parents and Children, in Southwest England and Generation R, Rotterdam, The Netherlands). We hope that results from this research will help answer questions around why some children are more likely to have cognitive and behavioural problems, and guide early intervention for high-risk children to prevent atypical DNA methylation patterns that may underlie them.