But I have been trying it for twenty years. CBT and the 12 steps of AA are all about intervening on your thinking and changing it. Processing your emotions in a healthy way. Changing behavior that doesn't lead to good results. If it was just a matter of applying my CBT skills as I feel myself slipping I would have solved it years ago.

Here is the thing. The negative thinking does not precede the depression. In this case when I say the switch goes off it is then that I am in the severe depression. That is often how fast it happens. There is no negative thinking or emotion to intervene on. The negative thinking and feeling comes as a result of the depression not the cause of it. When I am deep in it I start feeling ashamed because of how it effects me and that can cause a cascade of negativity. It is much more physical for me. The switch goes off and I notice I am very fatigued. I don't want to get out of bed. I have no motivation to do what I had planned on doing. No energy. Emotionally numb. Flat affect. Don't care. No interest. The negative thinking comes because these symptoms cause me not to be able to function normally. There were no triggers or negative thinking or emotions that preceded this that I am aware of and I am a highly aware person. It just happens. I am not afraid of my thoughts and feelings. I have been journaling, processing, talking about them, changing them, for years and years. It is like everything is great and SNAP now your depressed.

When I experience mild to moderate depression I can keep fighting and often snap myself out of it. This is much more on the theory of "act as if" or "fake it till you make it". Forcing myself to do things I don't really want to do is a form of changing thinking as I am choosing. Sometimes it works sometimes it doesn't. I have been living with mild to moderate my whole life mostly. It is my norm. I am used to functioning that way with periods of doing really really good thrown in. The severe ones that hit in regular cycles are the problem. If a severe one hits me the first hot week of spring every year is that because I just have negative thinking in that week. Is it self fulfilled prophesy because it happens every year. I don't think so.