In infants, common signs include screaming, restlessness and weeping attacks for no clear reason. Pre-school children may behave irritably and aggressively, while schoolchildren may be listless and apathetic, the authors said.
However, adolescents with depression display symptoms more similar to adults with the conditions, they added.
The authors said up to 3.5% of children and 9% of adolescents in developed countries were depressive – the risk increasing particularly after the age of 12.
Deutches Arzteblatt International (2008) 105: 149-155