I understand what both of you are saying, but the mind really is the most powerful thing you possess.
Here for example:
http://www.extremetech.com/extreme/...f-human-brain-activity-takes-82944-processors
There's a VICE documentary on YouTube about a Dutch guy who climbed Mount Everest in shorts. Using intense focus he has actually been able to change his autonomic nervous system's response to intense cold.
http://youtu.be/VaMjhwFE1Zw
If he can do that, then what actually is the limit?
My point is that you have to be very careful about the medical model approach to things like depression and anxiety. It isn't just a case of neurotransmitters and hormones. A very large part of it you have direct control over, even though you might think you do not.
I'm not saying it's easy. Else like you say, everyone would be as happy as Larry. But you do make the choice as to how you response to stimuli. Whether that's external events or internal feelings.
If you don't dwell on feeling like shit, the feeling will go away. I've done this many times. For example, I'll be driving along and feel anxious or have a feeling of dread. Suddenly, a guy pulls out in front of me and I have to react. And because I'm entirely focused on something else, suddenly I don't feel anxious anymore. Once that event is over my mind may start wandering again, and the feelings may return. But with training, focus becomes a skill just like playing guitar or rock climbing.
Again, if you decide to give up your sense of control and decide your LTC is determined by complicated internal biochemical processes, then you will make things 10x worse through self-imposed powerlessness. It doesn't have to be that way.