Namaste ,
This is an informative thread with very good posts.
My regards to all the posters here.
In this Kali Yuga, where tamas is very high, there is bound to be sadness and depression, which are the qualities of tamas.
Our duty then lies in increasing our sattva , which is the guna associated with happiness and joy , and reducing tamas.
We can reduce tamas by giving up all activities associated with tamas, like intake of non-vegetarian food, alcohol and intoxicants. Similarly refrain from harsh speech at all times and speak sweetly always , as this is a tapas in itself , as taught by Krishna in Gita.
Also keep away from bad, tamasic company and keep the company of sattvic people and places.
Sattva can be increased by taking fresh vegetarian food offered to God ( just visualize offering the food to God lovingly , and then eat it as prasad ). Spending time in nature , parks or the beach also increases sattva in oneself.
I find the best way to increase sattva is by rising up early morning in Brahmamuhurtham or Amritvela ( 4:00 - 6:00 ) , taking a bath, and meditating upon God or worshipping him with love. If you can do this, the whole day would be happier, peaceful and joyful for you.
Pranaams.