Nine out of every 1,000 children are victims of abuse and neglect every year, according to the report, but that likely underestimates the extent of maltreatment as it counts only those whose situations are so dire they are referred to authorities. That number could be as high as 17 out of every 1,000 children.

Since the last IOM report on child maltreatment was issued 20 years ago, numerous studies have demonstrated the awful effects of physical and emotional cruelty – a literature the report calls a “new science of child abuse and neglect.”

We now know that maltreatment puts kids at risk for learning problems, depression and anxiety, conduct disorders and post-traumatic stress. As adults, many of these battered children find it difficult to thrive, and they experience psychiatric illness, drug and alcohol addiction, and chronic disease.

Just the original abuse and neglect is expensive, on par with the cost of type 2 diabetes and stroke. The IOM report notes that abuse and neglect cases cost as much as $80 billion annually—there are hospitalizations, child welfare and law enforcement expenses, early intervention services, adult homelessness programs, mental health care and more.

And yet despite the clear threat to public health, we still know little about the causes of maltreatment and how to effectively prevent it. Risk factors include substance abuse, depression, and a childhood history of harm, but then there are variables like poverty and stressful environments, all of which complicate why and when a parent abuses or neglects his or her kid. The report calls for longitudinal studies that would start before birth and track children throughout their lives to see which parents abuse and neglect and in which circumstances.

There is one spot of truly encouraging news from the report, which is that sexual abuse has unequivocally dropped by as much as 62 percent in the past two decades. There is also data indicating that the rate of physical abuse has fallen significantly as well, but there are caveats, according to the report. Surveys show a decrease, but largely for peer and sibling assaults. When parents report their own behavior, it is perhaps more flattering than reality as children continue to report physical abuse.

Neglect, a broad category that includes physical, emotional and educational needs, is where the least progress has been made. Think of a child that is sent to school for days without a bath or clean clothes. Or a toddler that is routinely denied affection. Lest the public think these are the most benign types of maltreatment, neglect accounts for three-quarters of all cases and may very well be the most harmful.

Mary Dozier, an IOM panel member and expert on child development at the University of Delaware, told me that neglect is the “absence of parental involvement,” which is critical during early childhood. The committee responsible for the report, she said, concluded that neglect is at least as “pernicious” in its effect on development as abuse.