Reporting in the March issue of the Journal of the American Academy of Child and Adolescent Psychiatry, the researchers say that preschoolers can become clinically depressed, and a key symptom for identifying that depression is what psychiatrists call anhedonia -- the inability to experience pleasure from activities and play. Another common symptom is that depressed children often use play to explore themes about death and sometimes even suicide.
"One of the most surprising findings of this study is that depressed children just don't derive pleasure from the same things as a typical 3- to 5-year-old child," says principal investigator Joan L. Luby, M.D., assistant professor of child psychiatry and director of the Early Emotional Development Program at the School of Medicine. "They're less joyful when they encounter the pleasures of daily life."
Luby and colleagues studied 174 children between the ages of 3 and 5-and-a-half to determine whether it was possible in children this young to clearly identify depression as a distinct disorder. They used a parent questionnaire and special interview techniques designed for young children to identify signs and symptoms of depression and to learn whether very young children displayed those symptoms.
"One of the reasons this area of research has been slow to develop is that we've only recently learned how to ask children this young about how they are feeling," Luby says. "An age-appropriate puppet interview is now available, in which we have two puppets converse with one another about how they feel and then ask the child to point to the puppet that best expresses his or her own emotion."
The team also observed children in various play schemes designed to induce a range of emotions -- from joyful responses to frustration -- and videotaped the children to obtain objective measures of behavior.
Children in the study were divided into three groups: depressed; those with other psychiatric disorders, such as attention-deficit/hyperactivity disorder (ADHD) or oppositional defiant disorder (ODD); and a control group of children who did not have any diagnosable psychiatric disorder.
As in older depressed children and adults, very young children tended to have more than one psychiatric disorder. Forty-two percent of depressed children also had ADHD. Sixty-two percent also had ODD, and 41 percent of depressed children had both disorders. Another 29 percent of the depressed children had anxiety disorders.
But the symptoms of depression -- anhedonia, sadness and grouchiness, low energy, recent changes in energy level, low self-esteem, crying and play themes involving death -- were much more common in children with depression than in those who had only ADHD or ODD without depression. In fact, among the children in this study, anhedonia was unique to those who were depressed.
The researchers also looked for masked symptoms of depression, such as stomachaches or other physical complaints. Some developmental psychologists have proposed that such symptoms are key to diagnosing depression in young children, but the data from this study found otherwise. Although some depressed children did have these symptoms, eight other classes of symptoms were more common than these physical complaints in this sample of preschoolers.
"It has been a clinical assumption for years that if a child is depressed, he or she won't necessarily look sad or not enjoy things but instead will complain of a stomachache or another indirect manifestation," Luby says. "We found that children between 3 and 5 do, in fact, have direct depressive symptoms very similar to older children and adults. They also might have a stomachache, but symptoms such as anhedonia, sleep problems, restlessness and irritability are much more common."
In fact, they found that the core features of depression in a preschooler appear in an identical, but age-adjusted fashion to how they appear in adults. The only big difference involves duration. For an adult or older child to be considered clinically depressed, symptoms must persist for at least two weeks. Luby says depressed preschoolers may not stay persistently sad that long.
"Children have more fluctuating mood states than adults during the course of any given day," she says. "That's something we need to investigate in a more detailed, directed fashion."
There's also the question of treatment. Even if it's possible to diagnose depression in a 3-year-old, is it a good idea to give that child antidepressant drugs? Luby says scientists don't know whether such drugs are effective for depression in young children. But, she believes depressed preschoolers need some sort of immediate help.
"The normal developmental curve for any child is very steep at this point in life and being depressed and dysfunctional for a long period of time could actually impair normal development." Luby says. "It's very important that we identify these kids and find a safe way to help them get better."
Luby JL, Heffelfinger AK, Mrakotsky C, Brown KM, Hessler MJ, Wallis JM, Spitznagel EL. The clinical picture of depression in preschool children. Journal of the American Academy of Child and Adolescent Psychiatry, vol. 42:3, pp. 340-348, March 1, 2003.
This research was supported by a grant from the National Institute of Mental Health of the National Institutes of Health.
The full-time and volunteer faculty of Washington University School of Medicine are the physicians and surgeons of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.