These infants don't show appproptiate responces to stimuli, such as following objects with their eyes.
Most teenagers diagnosed with depression have school difficulties including bad behaior.
Basically, symptoms of depression are similar to all ages, but teenage depression is more often undetected because teenager's mood is supposed to jump up and down because of sometimes very little things. Again, the difference is that a trully depressed teenager has no hope of feeling better an happy events in their live do not lift their mood up. Most of the teenagers know they feel abnormally sad, but they do not know that what they are feeling is a symprom of an illness, not merely a down mood. A feeling of sadness and hopelessness. Changes in social life.