A startling number of kids lost parents to overdoses. Experts on how to buck the trend.

More than 321,000 children lost a parent to a drug overdose between 2011 and 2021, a daunting blow that reflects the impact of the nation's addiction crisis on a generation of children.

The rate of children who lost a parent more than doubled over the decade. The average leaped from about 27 to 63 children per 100,000, according to the study published Wednesday in the medical journal JAMA Psychiatry. While the largest number of deaths involved parents of white children, the highest rates of loss were among children of American Indian or Alaska Native parents.

Dr. Nora Volkow, director of the National Institute on Drug Abuse, or NIDA, said federal researchers wanted to provide a comprehensive look at the number of children who have been orphaned or lost at least one parent to overdose during the long-running addiction crisis in the U.S. A similar study estimated the number of children who were orphaned during the COVID-19 pandemic.

The nation's overdose deaths spiked last decade due to fatal episodes with opioids, then heroin. In recent years, overdose deaths have accelerated further with the widespread availability of cheap, illicit fentanyl, which is often combined with other substances.

Researchers at NIDA, the Substance Abuse and Mental Health Services Administration and the Centers for Disease Control and Prevention used data from the National Surveys on Drug Use and Health to complete the study. The study examined 649,599 adults, aged 18 to 64, who died of an overdose between 2011 and 2021. Researchers estimated that 321,566 children lost a parent to a drug overdose.

Volkow said children who lose a parent to an overdose face a higher risk of health and social issues such as substance abuse and mental health challenges. Given that a larger number of children have been affected by overdose deaths, Volkow said it's vital to adopt programs and strategies to support these children.

"It was important to do this study to bring attention to the needs of these children," Volkow said. When a child loses a parent, "that person is no longer there providing the support for the family and that leaves the children very unprotected."

The study cited a "critical need" for policies that address people using substances and their children and other family members who are potentially harmed by a parent's substance use.

The study cited the need to prevent addiction and expand strategies to help people who use substances, including harm reduction, treatment and recovery services for parents, young families and people of childbearing age.

Even as the nation has expanded the use of harm-reduction strategies and availability of the overdose-reversal medication naloxone, the study noted there has been a lack of focus on parents. While studies have shown that such a focus might be useful, researchers said interventions such as peer-to-peer parenting training often aren't included in drug treatment.

American Indian or Alaska Native families had the highest rate of parental overdoses at 187.1 deaths per 100,000 in 2021. That was more than double the rate of 76.5 deaths per 100,000 among children of white parents. Black parents had an overdose rate of 73.2 deaths per 100,000.