A conversation about early childhood development and ADHD symptoms with Hanna Gustafsson, Ph.D. and Elinor Sullivan, Ph.D.

Early childhood may hold critical clues to understanding, and potentially reducing, the risk of attention-deficit/hyperactivity disorder (ADHD).

In a new longitudinal study of 300 families in Portland, Oregon, Hanna Gustafsson, Ph.D., associate professor of psychiatry in the Oregon Health & Science University’s School of Medicine, and Elinor Sullivan, Ph.D., professor of psychiatry and behavioral neuroscience in the Oregon Health & Science University’s School of Medicine, tracked parents from pregnancy through their children’s early years to explore how biological factors before birth and caregiving experiences in infancy shape later development. Their findings suggest that higher levels of inflammation during pregnancy are linked with greater ADHD symptoms at age three, but that “sensitive caregiving” in infancy, in which caregivers consistently notice, understand and warmly respond to a child’s cues, can buffer children against this early biological risk.

Gustafsson and Sullivan recently sat down with Managed Healthcare Executive to discuss their findings and what they hope readers take away from them.

This interview has been edited for length and clarity.

MHE: Can you provide an overview of your study?

Gustafsson: The goal of this study was to look at how the early environment, first during pregnancy and then in infancy, works together to shape children's development. We found that when mothers had higher levels of inflammation during pregnancy, children were more likely to show ADHD symptoms when they were three years old. But importantly, sensitive caregiving during infancy appeared to buffer children against these negative effects. This is really exciting because it suggests that supportive relationships early in children's lives may be able to offset early biological risks of ADHD.

MHE: What biological components were measured?

Sullivan: We measured cortisol in hair samples. What's really cool about measuring cortisol in hair is that you can look at cortisol as a measure of stress output across the three trimesters of pregnancy, just based on how much your hair grows.

The other biology that we measured here was inflammation, and to do that, we collected maternal blood samples during the second and third trimesters, and we assessed 30 inflammatory factors in maternal blood.

MHE: How was behavior measured?

Gustafsson: We invited families to our laboratory, gave them some age-appropriate toys and asked them to interact as they typically would. To make this feel as comfortable as possible, we usually videotaped these interactions, and then later, we had a team of “observational coders" who quantified not just behaviors but behavioral exchanges. There are coding systems that can then be applied to that behavior. To try to understand children's behaviors and emotions when they're three, we have a number of different measures such as surveys or questionnaires. We also have a clinical interview where a clinician talks to the parents and asks them questions about their behavior and emotions with the child.

MHE: What are some examples of early, sensitive caregiving behaviors?

Gustafsson: We often will talk about it as being a caregiver who notices and responds to children's cues in a timely way. They try to understand what their child needs when they're upset, and they try to respond with warmth and consistency. Sometimes that's something as simple as following their child's lead during play or comforting the child when they're upset, and sometimes it means celebrating their excitement.

Early in life, children are building the systems that help them to pay attention, to handle frustration and to regulate their impulses, and we know that caregivers who engage in sensitive and supportive caregiving behaviors can help to strengthen those developing skills.

MHE: Why is it important to identify ADHD in children early?

Sullivan: We know that early identification of risk for ADHD, along with other neurodevelopmental disorders, is really important because it allows us to be able to have an early intervention, which is found to be most effective in reducing children's symptoms of ADHD and in improving outcomes in other areas of their lives.

MHE: What inspired you to do this study?

Sullivan: I think we've been thinking about these questions for a very long time. The study actually was launched in 2018, and so we're now releasing data after the children are turning four and five, and in this case, three years old. It just took us a long time to get from study conception to having all of the data that we need to be able to answer these questions. I think it's based on our own personal experiences as parents and knowing how important that support is and having questions about child behavior and child development and how we can best support that, both for the child and for the birthing parent as well.

MHE: What are the next steps for this study?

Gustafsson: We've started to follow up with these children when they're older to really understand the long-term effects of these early experiences. We encouragingly see very similar effects at year four so far, but we'd like to follow them up to five and six and seven because that's an important developmental period for us to be able to assess ADHD and other developmental outcomes. We’re also interested in how we can translate this into something that has direct applicability to parents with young kids.

Sullivan: Other interventions that we're interested in pursuing are ways to reduce inflammation during pregnancy, because we saw that inflammation exposure during pregnancy was also related to the child's ADHD symptoms. We have some other findings to show that consuming a high level of omega three fatty acids in your diet is also protective. Exercise interventions and mindfulness are other hopeful tools that we're hoping to provide parents with.

MHE: What do you hope readers take away from this study?

Sullivan: We want people to understand that both the prenatal and the postnatal environments shape children's development, and our study suggests that both the biology during pregnancy and the early experiences with caregivers are important factors in shaping children's development. We also want to make sure that parents don't hear these findings and think that parenting determines whether your child has ADHD. This is not what the study shows. ADHD has a really strong biological and genetic influence and is a result of many different interacting factors. We hope that people will see that the study supports that relationships really early in life can be a powerful source of resilience for children and a tool that parents can use to help their children.