Caffeine and Depression?

I know there are probably plenty of studies out there that can verify what I was thinking about this morning, but it's so much more fun for me to come to conclusions by myself. If you're a neuroscientist studying caffeine and you're reading this and you would like to tell me that I'm completely incorrect...well I don't know leave a snarky comment or something.

Anyway, I was reading yesterday about how caffeine works, namely by inhibiting the binding of Adenosine to neurons in the brain, and I started thinking on the possible linkages to depression...I found them.

Adenosine is a neurochemical that naturally slows down our brain when it has been working for too long. As you use your brain you are also producing adenosine, which slows down the firing of neurons in your brain and makes it slow down so that it can rest. Caffeine binds to the same receptors as adenosine does, and thus your body is tricked into thinking that it's not producing adenosine, however caffeine does the opposite of slow you down, it speeds up the firing of neurons (or, depending on how much you intake, keeps it at the same level).

The downside of caffeine intake is that your body continues producing adenosine even when your receptors are blocked by the caffeine, this means that when the caffeine finally gets broken down by your body -which can take up to 12 hours- you experience the effects of the built up adenosine and you get the all too common "crash" attributed with the working man's elixir.

Now the conclusion I came to this morning was that the massive amount of caffeine I regularly consume might be correlated with the rather tumultuous mood swings that I get. I did a quick search just now for "adenosine and depression" and it turns out that higher levels of adenosine has been attributed with depression in mice. So when you're experiencing a caffeine crash, you're also opening yourself up to increased levels of depression. And since caffeine has a fairly long biological half-life (Wikipedia says 5 hours), its effects on depression can be prolonged indefinitely (since, you know, you generally have coffee several times every day).

Also Mayo Clinic lists several other ways that caffeine could contribute to more depression.  

This is a distressing conclusion I came to because I adore coffee and despise decaf....

WORTH IT.