Do you remember the bollywood movie "Dear Zindagi"? Aliabhat's acting was so good in the movie, and when I read this question, I immediately got connected to her. She seems to be very normal with a good career and loving friends, but deep inside she has the scar of traumatic childhood which ruins her love life. This results in Depression and how she finally comes over the depression is the story of the movie.
Moving forward, I have observed many people closely in my friends and acquaintances and I have observed many signs of depression in otherwise normal looking people. They may not show the signs of depression evidently, they try to look brighter from outside, but deep in there, there is frustration, depression, and feeling of helplessness.
Here are some signs of Depression in normal looking people:
It is sad that many times we talk to that person daily but we will not understand that they are under Depression. We just think over-analyzing, confusion, and inability to do anything properly is their weakness. They feel too proud to ask help and if we say anything about how they are behaving, they may get angry.
We have to deal with them very sensitively and with a lot of patience and love.