Psychotropic drug prescriptions among preschoolers leveled off by the end of the last decade, according to a new study.

While the percentage of very young children receiving psychiatric drug prescriptions peaked in 2004, it stabilized between 2006 and 2009. Boys, white children and those lacking private health insurance had increased usage during this time.

"I'm very excited that the use of these drugs in this age group seems to be stabilizing," Dr. Tanya Froehlich, the study's senior author from Cincinnati Children's Hospital Medical Center in Ohio, told Reuters. "It's good to get a gauge on what we're doing with psychotropic medications in this age group, because we really don't know what these medications do to the developing brain."

The study, published in the journal Pediatrics, which used a national representative sample of 43,000 U.S. children between 2- to 5-years-old, showed that children diagnosed with attention-deficit/hyperactivity disorder (ADHD), as well as anxiety and mood disorders, were less likely to receive a prescription for psychotropic drugs within the past decade compared to 1994 to 1997.

Although there was increase rate in diagnosis in psychiatric disorders for the age group in the 2000s, 29 percent of the children were given medication compared to 43 percent between 1994 to 1997.

Previous studies have shown higher rates of psychiatric drug use during the 1990s for children with conditions such as attention deficient hyperactivity disorder (ADHD), but they were limited to demographics, Medicaid samples or a single medication class.

One reason behind the stabilization could be health warnings issued by the U.S. Food and Drug Administration on psychotropic medications including risk of suicide, and heart complications from ADHD drugs.

"I think those warnings gave doctors pause," Froehlich told LiveScience. "It seems like from mid- to late-2000s, we started exercising more caution."

The latest study shows that between 1994 and 1997, 1 percent of preschoolers were given a psychotropic prescription. Between 1998 to 2001 the rate dropped to 0.8 percent, then jumped to 1.5 percent between 2002 and 2005 before leveling off to 1 percent between 2006 and 2009.

"We were very pleased to see that the rate of psychotropic drug use in this age group isn't going steadily up each year," Froehlich told MedPage Today. "Our findings reveal not only a stability of overall psychotropic use over time in very young children but a diminished likelihood of psychotropic use for those with behavioral diagnoses," the researchers wrote.