True, Intellectuals tend to be depressed because they spend most of their time in their heads, absorbed in thought. Thinking is a great thing, but it's only a simulation created by your brain. You simulate some other place, some other time, some other reality, etc. These simulations can be valuable, but they also take you out of present-day reality.
Using your example : You think you'll be screwed at some point in the future. There's a possibility that simulation could actually happen, but it's not happening right now. Sadly, if you believe these thoughts, then your body reacts to the the simulation as if you really are screwed right now. From that reaction springs things like fear, anxiety and depression.
The key is to learn to step back a bit and not get so absorbed your thoughts, because they really are just simulations.
(former depressed intellectual who learned to meditate)