Depression is a state of low mood and aversion to activity.
Often it is caused by a mixture of things. For example,your child may have inherited a tendency to depression and also have experienced some difficult life events such as bullying in the school or sexual abuse or separation of parents,
Irritability (not sadness)
Aggression
Aches and pains
Lethargy
Not spending time in play
Disturbed sleep and appetite
Feeling of being not loved
Bed wetting

Consequences:
Drug abuse
obesity
run away
Loneliness
Risk of heart attack in adulthood
The problem remains undiagnosed, and untreated, because the parents are not aware
If you think your child is depressed
It's important to talk to them. Try to find out what's troubling them and how they are feeling. Take it seriously. It could be a major problem.
The word depression carries a 'stigma' and it is very hard for the parents to accept the diagnosis.They need to take action and take the child to a psychiatrist.