I have suffered on and off with depression for the last 16 years (basically since leaving employment.) I think the original catalyst was suffering with my back (I was unable to ride or walk far for about 2 years...) and then the heart ache of leaving IBM. I have taken anti-depressants for too long. They do not seem to work for me. I mapped the system that is my energy based on my experiences. It is a very complex system (over 4,000 feedback loops!) My observations on context being very important. The plant not getting the right sun, water, soil conditions, companions. I recently met fellow PhD student of systems science, consultant and former psychiatrist, Peter Robertson, at the ISSS. He told me that depression is a natural phenomenon somewhat akin to hibernation in certain animals.In hibernation the body shuts down to survive a difficult environment. In depression the body goes into pseudo hibernation as a survival technique when context doesn't work. The issue is that when psychiatrists give anti depressants and boost energy of those with suicidal thoughts. -> result is suicides!! I have a book in progress on my experiences of managing my energy. It is called "Life Dynamics". One day I may actually finish it! I have also written a few articles on this: One on the effects of exercise on mood and the other on my experiences of cognitive behaviour therapy.