Tevis Simon grew up in West Baltimore back in the 1980s, a neighborhood that lacked attention from the city and investment from the government. From day to day, she was never sure what version of her mother she'd encounter.

"I knew that if my mom had her drugs, that she was fun, mommy. And if she didn't, then she was mean mommy," Simon says.

Simon's mother was addicted to opioids and her issues with the drug led to abuse and neglect, she says.

Millions of children struggle with what Simon went through. More than 4% of children in the United States live in a household with a parent who misuses opioids, according to estimates from the Department of Health and Human Services.

Many of those children feel confused and anxious about what their parents are going through. Now Sesame Workshop, the educational nonprofit behind one of the world's most famous children's shows, is trying to give young kids a better understanding of addiction in families. The intention is to build their emotional resilience in a way that can help them in the moment, and later in life.

"The experience of having a parent with an opioid use disorder is traumatic for children," says Ruth Paris, an associate professor at Boston University who specializes in early childhood trauma.

For Simon, living with a parent with addiction led to major depressive disorder, anxiety and agoraphobia.

"It always had me in a state of flux," she says. "Always kind of wondering, waiting, fearful of what would happen next. That evolved to be anxiety. I remember being a little girl, I would pick the sides of my fingernails and the cuticles until they bled, I was so scared. I very rarely spoke."

Paris says early intervention can help reduce some of those effects of addiction on children.

"Being able to address trauma in early childhood is imperative, and can make a difference in that child's growth and development in terms of cognitive development, emotional development and social development," Paris says.

A few years ago, Sesame Workshop, the umbrella organization for the show Sesame Street, began developing some of the first materials specifically created for children aged 1 to 6 whose parents may use drugs or in recovery.

Now, a recent grant from the Foundation for Opioid Response Efforts will enable Sesame Workshop to produce more videos, stories and resources focused on addiction, treatment, and healing.

Some of the free materials are available online, and feature famous Muppets like Karli and Elmo, and Chris, one of the shopkeepers on Sesame Street.

Parents or caregivers can read or talk about the material with children, and social workers and therapists can use these tools during therapy sessions to guide kids through the tough emotions of having a parent or caregiver struggling with addiction.

The materials include coloring books, short videos and storybooks about handling emotions around addiction and answering simple questions like why parents need to attend recovery meetings every day.

Karli, a Muppet whose mother is going through treatment for addiction, personifies some of the challenges kids face. In one video, Elmo asks his father why his friend Karli's mom is sick.

His father explains some of the basics of recovery: "Addiction makes people feel like they need a grown-up drink like alcohol, or another kind of drug, to feel okay. That can make a person act strange in ways they can't control."

One coloring book helps children articulate and address their own feelings about needs around addiction by reminding children to remember the seven C's: "I didn't Cause the problem. I cannot Control it. I cannot Cure it. BUT... I can help take Care of myself by Communicating my feelings, making healthy Choices, and Celebrating myself."

There are few trusted materials for explaining to young children the issues surrounding addiction, despite their proximity to it, says Jeanette Betancourt, the senior vice president for U.S. social impact at Sesame Workshop.

"The resources that are out there now tend to focus more on older youth and on adults," she says. "Because there's this myth that with young children they don't understand or they may not be aware."

This isn't the first time Sesame Workshop has tackled hard issues. In the early 1980s, the actor who played Mr. Hooper died and the show focused on death and grief.

Sesame Workshop has an online catalog of resources to help children learn about and process experiences like divorce, bullying, community violence or a parent going on military deployment.

There are developmentally appropriate materials addressing diagnoses such as autism, HIV, asthma and COVID-19.

Paris explains that acknowledging young children's emotions and allowing them to express themselves, especially around a complex addiction, are extremely important in building resilience.

"The material enables a young child to recognize that they can have a host of different feelings. I think Sesame Workshop focuses a lot on the sadness around the separation from the parent who might be in a treatment setting, and need to separate from them," Paris says.

"For the child, those simple messages — being allowed to have your feelings, it's not your fault — I think are really important," Paris adds.

Tevis Simon, whose mother struggled with addiction when she was a child, says Sesame Workshop's materials would have brought welcome stability to the chaotic world she grew up in.

"If there were a Muppet at the time that was talking about parents going through addiction, and how that makes their children feel, that they feel alone and scared and some children are abused verbally and physically. It would have helped me not go into a downward spiral," Simon says.

As the new material around addiction is produced, Sesame Workshop will make it available online as part of its "How to Talk to Kids about Tough Topics" resource library.

This story comes from NPR's health reporting partnership with WYPR and KFF Health News.