If you’ve got a teenager, you’ve probably dealt with a fair share of emotional ups and downs. But is it just moodiness, or could your child actually be suffering from depression? About one in eight teens experiences this condition, but it can be hard to discern because other behaviors like defiance and agitation may also be present. if you’re concerned about your child’s emotional state, look for these warning signals highlighted in a recent Harvard Mental Health Letter: The severity of your child’s symptoms can be a telltale sign; the more pronounced her changes in mood and behavior, the more likely it’s depression. If the duration of her bad mood lasts longer than two weeks and crosses multiple domains like home, school and friendships, try to talk about how she’s feeling. Then consider a meeting with a school counselor or psychologist to determine whether extra support is needed.