Toddlers who did not frolic and smile and laugh were once called pensive or shy or quiet but now a Preschool Feelings Checklist
can label kids as depressed at 3 years of age. 

Using that as a factual basis, a paper in the American Journal of Psychiatry has found that depressed preschoolers were 2.5 times more likely to suffer from the condition in elementary and middle school than kids who were not diagnosed as depressed at very young ages.

Doctors and scientists maintain that children as young as 3 or 4 can not be clinically depressed. 

Using a two-way mirror, Washington University researchers observe children from preschool age through middle school. Credit: Luby Laboratory, Washington University

"It's the same old bad news about depression; it is a chronic and recurrent disorder," said child psychiatrist Joan L. Luby, MD, Washington University School of Medicine in St. Louis and one of the co-inventors of the Preschool Feelings Checklist. "But the good news is that if we can identify depression early, perhaps we have a window of opportunity to treat it more effectively and potentially change the trajectory of the illness so that it is less likely to be chronic and recurring."

The scholars followed 246 children, now ages 9 to 12, who were enrolled in the study as preschoolers when they were 3 to 5 years old after the Preschool Feelings Checklist diagnosed them as depressed.

How was the evaluation done? Interviews about their children's expressions of sadness, irritability, guilt, sleep, appetite, activity and play. Researchers also used two-way mirrors to evaluate child-caregiver interactions because they say that a lack of parental nurturing is an important risk factor for recurrence of depression. It seems that cold, unfeeling parents are cold and unfeeling even when they know they are being evaluated for their levels of cold unfeelingness using a two-way mirror. 

Obviously some kids do have problems. Parents don't need an interview to see it unless they don't want to see it and in cases where children were found to be seriously depressed or in danger of self harm, or if their caregivers requested treatment, they were referred to mental health providers.

Did it help? There are no good treatments. Available therapy and medications are effective only about 50% of the time. Sugar pills are effective 30% of the time. 

At the start of the study, the
Preschool Feelings Checklist
 declared 74 of the children as having depression. When the researchers evaluated the same group 6 years later, they found that 79 children met the full criteria for clinical depression based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V). While the book is the American Psychiatric Association's official guidelines for diagnosing and treating psychiatric illnesses, the National Institute of Mental Health has declared they will not use it as more than a glossary, it is not valid for diagnosis.

More than 51 percent of the 74 children who originally were diagnosed as preschoolers also were depressed as school-age kids. Only 24 percent of the 172 children who were not depressed as preschoolers went on to develop depression during their elementary and middle school years.

The scholars found that school-age children had a high risk of depression if their mothers were depressed and that children diagnosed with a conduct disorder as preschoolers had an elevated risk of depression by school age and early adolescence, but this risk declined if the children were found to have significant maternal support. But neither a mother with depression nor a conduct disorder in preschool increased the risk for later depression as much as a diagnosis of depression during preschool years.

"Preschool depression predicted school-age depression over and above any of the other well-established risk factors," Luby explained. "Those children appear to be on a trajectory for depression that's independent of other psychosocial variables. The reason it hasn't yet become a huge call to action is because we don't yet have any proven, effective treatments for depressed preschoolers. Pediatricians don't usually want to screen for a condition if they can't then refer patients to someone who can help."

Luby now is testing potential parent-child psychotherapies that appear promising for preschoolers with depression, but it's too early to determine whether they work. Her team also will continue following this group of children through puberty to determine whether depression during preschool remains a risk factor for depression during young adulthood.