6.  21st century sensory overload in the form of sounds, rapid visual and auditory effects from television, movies, computer games, electronic monitors flickering faster than the eye can detect, radio waves, fluorescent lighting, as wells as stress generally, hurried lifestyle, overwork: All require the brain to modulate a level of sensory bombardment for which it was not designed.  This overstimulation probably has an impact on NTs and NT receptors; the brain must then calm itself down using it’s precious supply of calming (inhibitory) neurotransmitters.

7.  Environmental toxins and environmental toxicity; rapid changes in hormone levels, rapid changes in blood sugar, and inadequate exposure to sunlight (causing serotonin to be converted to melatonin) are among other factors that may contribute to neurotransmitter imbalance.