"Those who are liable to times of gloom or even despair, as though a cold dark cloud overshadowed them and hid the light and the joy of life. It may not be possible to give any reason or explanation for such attacks. Under these conditions it is almost impossible to appear happy or cheerful." - Dr. Edward Bach
Key Word: Depression, deep gloom for no reason, sadness.
Human indication: When you feel depressed or sadness for no reason. Like a dark cloud that destroys normal cheerfulness.