Roughly half of mothers of children with autism have high levels of depressive symptoms, new research finds, a rate that’s significantly greater than for mothers of typically developing children.

In a study looking at a group of moms over an 18-month period, researchers found that about 50% of those with children on the spectrum had elevated levels of depressive symptoms while just 6% to 13.6% of other mothers experienced the same thing.

The research published recently in the journal Family Process involved 86 mothers and their children, ages 2 to 16. Half of the parents had kids with autism. Mothers were repeatedly assessed using the Inventory of Depressive Symptoms, a self-reported scale, and they were asked to report on their children using what’s known as the Child’s Challenging Behavior Scale, which measures tantrums, aggression and defiance.

Significantly, the study found that a child’s behavior problems did serve as a predictor that mothers would later experience depression — whether or not a child had autism — but depressive symptoms in a parent did not lead to behavior issues in children.

“The finding that maternal depression does not lead to worsened child symptoms is especially important for mothers of children with ASD to help alleviate guilt many mothers feel about their children’s diagnosis and behavior problems,” said Danielle Roubinov of the University of California, San Francisco, who led the study. “We hope these findings will reassure mothers that it’s both common to struggle with some depression in this high-stress situation of chronic caregiving, and that their depression likely isn’t making their child’s behavioral issues worse.”

In light of the higher rates of depression in mothers of those with autism, the researchers said that doctors should be aware and ready to provide resources.

“Given the effects of chronic stress on health and mood, caregiving parents need extraordinary emotional support in addition to the special services for their child,” said Elissa Epel, a professor at the University of California, San Francisco and a senior author of the study. “It’s as vital to provide support for parents’ mental health as it is for children’s mental health.”