In my case, being depressed means much deeper understanding and much more sharper mind. I even have an impression that the hard period I had few years ago, when I was only working and reading books, formed me intellectually.

On the other hand, I quickly realize that consequences of my thoughts are rather pointless. Not that my thoughts are pointless; far from it. The catch is that, actually, I couldn't care less about consequences of my thoughts, as they have little impact on the world.

Most of the time, I even don't care about sharing my thoughts with the world. I speak a lot with my girlfriend and a couple of friends but, for example, writing articles is pointless because I will have to deal with not understanding people.

The paradoxical consequence of thinking too much is mistrusting yourself. If you have an opinion which is very solid logically but is against 99% of the population, it is easy to wonder whom is wrong: the whole society or you.

That's why coding helps me a lot. The logical framework of code points me out that my thoughts are not pointless and my mind is not disorted anyhow. Coding helps me to get peace of mind. I'm much more relaxed when I write code.

I believe this is one of the reasons why a lot of people went to mathematics as well. If you mistrust yourself, you have to have a framework that keeps you in touch with the real world. Logic ensures that you are not crazy, yet.

Also, that's why coding is so addictive. It takes a week without coding to get me anxious. Without coding, I feel that my brain lacks some chemistry.

Personally I believe that depression, or any other unusual state of mind, is just a filter that disorts the output of your mind. It gives you a very different perspective, but if you're blind, it won't help you anyhow.

This is partially the reason why it is hard to decide whether depression is a problem, or not. Smart people might gain a lot from different states of mind; regular folks, well, not much.

To be honest, I'm not sure whether depression is actually a cause or a result, in case of some people. If you start thinking too much and realize how the world actually looks, it is easy to get depressed a bit.

PS. I've created a separate account for purpose of this comment; I feel this is too personal. Sorry that this is a bit chaotic but I don't have enough time to write the shorter comment so I wrote the longer one.