This is an interesting idea:
The network approach also has a strong message for all of us who care about mental health and illness. We should abandon the last vestiges of our belief that mental disorders are best seen as medical diseases. The symptoms of depression, PTSD, or social anxiety don’t point to an underlying disorder. They are the disorder.
So what if, instead of trying to find the “underlying” cause of depression we simply treated people based on their symptoms? Your lack of interest in anything is leading to lethargy, sadness, loneliness, etc. so let’s focus on how to treat that lack of interest, for example, instead of trying to find some other physical reason for your lack of interest?
I’m not sure where I fall in regards to this theory, but I do know that we are not winning this battle currently, so it is beyond time to start trying some different things.