Association between depression severity and amygdala reactivity during sad face viewing in depressed preschoolers: an fMRI study.

Background: Previous research has indicated that symptom severity and amygdala reactivity during the viewing of facial expressions of emotion are related in depression. However, it remains unclear how early in development this can be detected.

Methods: A sample of 11 depressed preschoolers (4.5±0.8; 6 males) participated in an fMRI experiment where they viewed facial expressions of emotion. A region of interest approach was used in order to examine the relationship between amygdala activation and depression severity. Additional whole-brain analyses were conducted and the results of these analyses were examined for potential relationships with depression severity.

Results: Findings indicated that depressed preschoolers exhibited a significant positive relationship between depression severity and right amygdala activity when viewing facial expressions of negative affect. In addition, we found a significant positive relationship between degree of functional activation in the occipital cortex while viewing faces and level of depression severity.

Limitations: Additional research including a larger sample of depressed preschoolers, as well as a healthy comparison group, is needed to replicate the current findings and examine their specificity at this age.

Conclusions: This is the first study directly examining brain function in depressed preschoolers. The results suggest that, similar to older children and adults with depression, amygdala responsivity and degree of depression severity are related as early as age 3.