Lack of idealism is the main cause of depression among the youth today. Life appears to be so meaningless to these children, who are either too scared of the competitive world or bogged down by heavy stimuli. They need an inspiration.... And Spirituality is that inspiration that can keep the spirit up!
Aggression is the antidote to depression. Depression sets in if there is a lack of zeal to fight. Depression is lack of energy, and anger and aggression are a bolt of energy. When Arjuna was depressed, Krishna inspired him to fight and thus reinstated life back in Arjuna. If you are depressed, don't take Prozac - just fight - for any cause!
If aggression crosses a certain limit it leads you back into depression. That's what happened with King Ashoka, who won the Kalinga war but became depressed. He had to take refuge in Buddha.
WISE ARE THOSE WHO DO NOT FALL EITHER INTO AGGRESSION OR DEPRESSION.
That's the golden line of a Yogi. Just wake up and acknowledge you are a Yogi!