When I was in North India I don't have like support of food. When I went to USA then I get chance to with South Indian people.they used to eat curd rice l.
When I tasted it,I liked it very much. It become part of my diet. When you eat curd rice,you feel it satisfied and happy. The main source of chemical that make you feel happy is tryptofan in curd or yoghurt .
Tryptofan is amino acid that helps in making seratonin in the body that helps from remembrance to digestion. Serotonin work as a mood regular regulator that makes us feel happy.
This acid makes us emotionally strong,less worryfull and peaceful person. When you have a less serotonin in the body then you have a chances of depression. Serotonin is also a stimulus to bring sleep,therefore you feel sleepy after eating curd rice.
tryptofan in serotonin does not reach in the mind .It is made for possible by mixing rice with the curd. Therefore it eaten with starch loaded food like rice then the tryptofan reach in the mind and makes you happy and you also like to eat some sweet thing .
So one should start eating curd rice to feel happy & get rid of depression.