Is it good to put your child on anti-depressants to loose weight if he's overeating due to depression?

Depends: I am not a child specialist, but in general i would not use antidepressants to loose wt. But i would consider the total amount of distress and disfunction associated with the depression, including, poor school performance, social anxiety, motivation, suicidal ideation, etc. Any child should get therapy as well as medications if necessary.

Overeating=coping: To help him lose weight we need to find out why he eats, what he eats, the emotions behind eating.Depending on the age of your child techniques might differ, but these are the things that need to be taken care of for your child to loose weight. If there's a need for antidepressant than it should be taken to help with depression. Seeing a child psychologist will help establish more adaptive coping.