IN A recently released documentary,“Take Your Pills”, Leigh, a freckled college senior, sits on her bed and reflects on her relationship with Adderall, a stimulant widely used to treat Attention Deficit Hyperactivity Disorder (ADHD), a condition that makes it hard to focus or control impulses. “Adderall for me has always been, like, when you’re desperate…You’re like, I need this right now because I need to be my best, smartest, fastest self,” she says, after calculating what score she will need on an imminent exam to boost her final grade. Later on, Nathanael, a software engineer with piercing blue-green eyes who codes with a cat nestled in his lap, recounts how Adderall allowed him to work intensely until midnight—a coder’s dream. According to a study conducted by Milken Institute School of Public Health at George Washington University, in 2011 12% of American children and teenagers had a diagnosis of ADHD, an increase of 43% from 2003. IMS Health, a health-care information and services company, found that sales of prescription stimulants like those used to treat ADHD quintupled between 2002 and 2012 to nearly $9bn. People like Leigh and Nathanael, who sometimes turn to medication to cope with pressure, often spring to mind as typical consumers of such things. But they are not the only ones. A new study by researchers at the University of Maryland School of Pharmacy reveals high rates of psychiatric diagnosis and medication use among poor, very young Americans.

The study, which was published in JAMA Paediatrics, a medical journal,looked at 35,244 children born in an unidentified mid-Atlantic state in 2007 and followed them until the end of 2014, when they were seven years old. All the children were enrolled in Medicaid, which provides free or cheap health care to low-income Americans. By the age of eight, when children are typically learning about fractions and the solar system, nearly 20% of those studied had received a psychiatric diagnosis. The rate in the population at large is around 14%, according to the National Survey of Children’s Health. Just over 10% of children in the study group received medication to alter their mental state.

Dinci Pennap and Julie Zito, respectively a PhD candidate and professor at the University of Maryland School of Pharmacy, directed researchers to look at diagnoses including ADHD, learning disorders, anxiety disorders, depression and autism-spectrum disorders. ADHD was the most prevalent condition diagnosed, and stimulants were the most commonly prescribed drugs. The research also suggests startlingly high psychiatric diagnosis rates among young children receiving foster care. Nearly 60% of children in foster care had such a diagnosis, compared with 17% for “income-eligible” children whose families hover at or below the federal poverty level.

The finding that poor children are more likely to be medicated echoes previous research. A study conducted by researchers at Columbia and Rutgers Universities and published in 2009 found that children covered by Medicaid are provided with antipsychotic drugs, used to treat conditions such as bipolar disorder, at a rate four times higher than privately insured children, and often for less severe conditions.

“One problem is that we’re medicating behaviour,” says Ms Pennap, the Maryland study’s lead author. “If a child doesn’t do well in school, they’re medicated because they might be in homes where their parents work three jobs and don’t have the bandwidth to explore the underlying problems or nonmedical options.” Dr Zito partly blames direct-to-consumer drug advertising and the urge to reach for quick fixes. Her most pressing worry is that there has been little scrutiny of the long-term effects of exposing young children to such medication. “They have little hearts, little brains, and little livers. We really don’t know how the physiology of young kids will be impacted by these potent drugs,” Dr Zito muses. In most scenarios, poor children are likely to have less than wealthier children: less educational opportunity, less healthy food, less-safe neighbourhoods. When it comes to psychotropic drugs, the opposite is true.