Put a group of children in a playground and all of them may seem happy. But, under the skin, some may already be well on their way to developing depression, addictions or other mental disorders.
Scientists in Singapore have uncovered how the stresses of pregnancy and poor parenting choices may affect children's brains and hurt them later in life.
They found that when women are more anxious during pregnancy, the children's brains tend to grow more slowly in the first six months of life compared to the offspring of relaxed mothers.
When children are abused, genes in their brains that respond to stress also become more active, causing them to suffer more, and more easily, from stress later in life.
Even emotional neglect can leave physical marks. These so-called epigenetic marks are chemical modifications of DNA that control the activity of genes.
In a Canadian study that looked at two types of rat mothers - those that licked their pups a lot and those that did not - the pups that were licked more produced less cortisol, a stress hormone, when they were provoked.
This could mean that, for infants, a parent's touch could be far more than just warm and comforting: It could set them up to be more stable people who are not easily panicked.
Being able to identify these physical changes that occur in the brain would allow doctors and authorities to more effectively single out which children and families need help, said Professor Michael Meaney from the Agency for Science, Technology and Research (A*Star).
The 60-year-old noted that the epigenetic changes are reversible. "It's not that an individual's fate is cast in stone in early life, and therefore unalterable. Quite the opposite," he said.
The Canadian citizen led the rat study as a professor of psychiatry and neurology at that country's McGill University. He is still a professor there, and is now also director of the Integrative Neuroscience Programme at A*Star's Singapore Institute for Clinical Sciences (SICS).
This week, he will be awarded the 2014 Klaus Jacobs Research Prize from the Swiss charity Jacobs Foundation, for his work in how parental behaviour affects children's brain development and lifelong function.
He intends to use the 1 million Swiss francs (S$1.35 million) prize money to fund local and overseas research that uses biology studies to find out how to identify and help the vulnerable children.
He said that, currently, authorities tend to use blunt indicators such as poverty to predict risk. "But many children grow up in poverty without family dysfunction and major health problems," he said.
"What we need to do is to understand the impact of social adversity on the individual child."
He noted that such personalised treatment is already available for some physical diseases: "In heart disease, we can take a blood sample, look at it, and say to the person, you need lipid-reducing medicine, or you are likely to benefit from physical exercise."
Singapore's Gusto (Growing Up in Singapore Towards Healthy Outcomes) study, which Dr Meaney and SICS are involved in, is one such attempt to identify the epigenetic imprints of parents' choices and mental well-being.