I have successfully entered trance in the past (body asleep/mind awake), and was even able to move into Gamma brain waves for about 30 minutes (estimating). This last period of 6 months, however, I am finding it almost impossible to go slower than low-level Alpha.
What could be the cause? Is it physical, mental, emotional? I am working on building my astral body through yoga and pranayama. I am awake most mornings between 1:30 am and 4 am.