Although the present study did not examine biological mechanisms that might explain how prenatal maternal depression symptoms and nutrition can affect child cognitive development, Monk and colleagues10 highlighted that maternal consumption of certain nutrients (e.g. protein, B vitamins, folate) not only show effects on brain development, but can also have a role in stress response, as their metabolism can be altered by exposure to stress. Hence, it appears possible that maternal depression (as a proxy of stress) could affect brain development via the biological ‘cross-talk’ between stress and nutrition.10 Given the non-biological nature of the data used in the current study, however, the above statement is speculative, but might be considered an important area of investigation for future research.