Conduct problems in children and young people include stealing, fighting and lying. Evidence suggests that children who develop such difficulties before the age of 10 (‘early onset’) are at a greater risk for a persistent pattern of criminal offending, and for numerous other adverse outcomes, later in life. Understanding how such conduct problems develop, including possible differences between those who develop them early and those who do not, 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.

We know already that children who show an early onset of conduct problems tend to come from come from more deprived circumstances characterized by poverty and high levels of psychosocial distress in their mothers. Maternal psychosocial distress is thought to impact development in a range of ways – including via influences on how a child develops in terms of biology. One of the ways a child’s biology is affected is that mothers suffering from psychosocial distress (e.g., depression, anxiety) tend to eat unhealthily. Therefore children of these mothers are also exposed to poor nutrition during pregnancy (i.e., what the mother eats). After birth and in early childhood, adverse experiences such as exposure to unhealthy nutrition (e.g., fat and sugar) may further affect the child’s development.

To date, however, existing conduct problem studies that have examined prenatal or postnatal adversity exposure have generally looked at maternal psychosocial distress or unhealthy diet, but not how the two may interact to affect child development and wellbeing. In addition, most researchers who have looked at unhealthy nutrition have done so by asking mothers to report on what they eat themselves and what they feed their children. Equally important are biological measures of diet, such as metabolites of food intake. This measure roughly allows a look at what sort of foods are being digested, including healthy fats (such as omega-3 from fish, walnuts, spinach) and unhealthy fats (such as omega-6, from vegetable oils used to fry crisps and chips, but also in cookies and fast foods). A favourable ratio of omega-3 to omega-6 fatty acids is important for healthy brain development in children. An unfavourable ratio associates with mental health problems in children and adults.

In this study we plan to address three key potential limitations of existing research: (1) Existing studies of conduct problems in children have not assessed the degree to which prenatal and postnatal maternal psychosocial distress associates with metabolites of omega-3 and omega6 fatty acids. (2) Research has not assessed the degree to which prenatal and/or postnatal omega-3 and omega6 fatty acids associate with early onset conduct problems. (3) It is not currently known if the risk for early onset conduct problems that is usually attributed to maternal psychosocial distress is also partly associated with an unhealthy ratio of omega-3 and omega-6 fatty acids. If our hypotheses are supported, the research could potentially provide an important psychosocial and biological framework for a better understanding of how maternal distress and nutrition can impact child development. This is an important research question, as nutrition is something that is changeable and therefore diet-focused interventions could benefit not only the children, but also the wellbeing of mothers.

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 dietary, behavioural and biological data already collected The Avon Longitudinal Study of Parents and Children (UK).

We hope that results from this research will help answer questions around why some children are more likely to show an early onset of conduct problems, and guide early intervention for high-risk children to prevent unhealthy dietary patterns that may underlie it.