An analogy: you are told that a medicine has been shown effective in treating mental illness. You learn the medicine goes by many names. Then you learn the medicine can include any ingredient, is delivered in any means conceivable, in any dose. As long as the medicine is called one of its brand names, everything counts as that medicine. Your confidence in that medicine might guide your confidence in religion being effective in treating mental illness. What is religion? Whatever somebody says it is, especially if they are sincere or violent. What is spirituality? A quiet claim that whatever religion might be, it is bad for geese but good for ganders.
Medicines that work that way do exist in reality.
I'm not sure if I'm arguing with you, or summarizing you.
I get papers cited at me, (the first is about "religion and spirituality", the rest about specific meditation disciplines) about but I can't tell whether they're well-done or not. I believe LessWrong is the ideal place to ask about this because there's a healthy combination of interest for self-improvement techniques and solid skepticism against quackery. I thought it would be a solid enough topic to merit its own thread rather than a discussion in Open Thread.