Seeing issues above and beyond the terrible twos? This may be to blame.

By Abigail Wise
Updated March 13, 2015
screaming child little girl
Credit: Julia Smith/Getty Images

Throwing a fit in the grocery store, refusing to take a nap, and picky eating come with the toddler territory. But if you're dealing with excessive hitting, lying, anxiety, and sadness in your little one, there may be a bigger problem at play. And the root of it may not be what you'd expect: It turns out that depression in parents can lead to a host of toddler troubles, according to a new study.

Northwestern researchers surveyed nearly 200 couples with three-year-olds who had participated in an earlier depression study just after their children were born. Everyone filled out a survey about their own depression, their relationships with their partners, and their children's behavior. The results suggest that children with a depressed parent are more likely to act out, regardless of which parent suffers from depression. Though existing research shows that depression in moms can take a toll on children, the new study suggests that they're not the only parent who could have this effect. Dads' depression can also negatively influence children's behavior.

The results also reveal that parental depression can cause troubling behavior in toddlers even more than parents' fighting.

The researchers suggest that the reason for the children's behavior is probably due to subconscious differences in how their parents treat them. Depressed moms and dads may smile less or not make as much eye contact with their kids. “Depression affects the way people express emotions, and it can cause their behavior to change,” Sheehan Fisher, lead author of the study, said in a statement. “Early intervention for both mothers and fathers is the key. If we can catch parents with depression earlier and treat them, then there won’t be a continuation of symptoms, and, maybe even as importantly, their child won’t be affected by a parent with depression.”