I've had my suspicion about adrenal fatigue and honestly this could be a driving force that leads to DP. An overly anxious person will constantly have cortisol and adrenaline running through their body. DP sufferers most likely have an overactive amygdala. Interestingly enough, the amygdala is responsible for memory, survival and...wait for it, emotions.
In distress, the amygdala recognizes a threat (perceived threat), this signals the hypothalamus to release CRH, this, in turn, activates the pituitary gland to release ACTH and lastly, it tells the adrenal glands to produce cortisol, the stress hormone.
Now, when there is an imbalance cortisol is continuously released, causing these heightened perceptions.
If DP is due to adrenal fatigue, then most lilkey many of us are suffering from some hormonal imbalance.
Lastly, this may just be one piece of the puzzle.