With a heightened energy level, highs are higher and lows are lower.
Wherever we place our attention the energy will flow.
It can be easy to be carried away by moods, by thoughts that thrive within particular moods. A sad thought that would have been easily overcome under normal circumstances will become overwhelmingly tragic. An impulse that would have been just a passing desire may become an obsessive need.
Acquiring an ability to notice where we are placing our attention before we are swept away by our own nightmares fueled by our own surplus of energy is essential.
Seeing our thoughts and feelings as being only subjectively real and fleeting is useful, but it is more that "seeing" that will help us to move through our troubled inner landscapes unscathed.
It is habit that can carry us through, a practiced use of attention. If we are not actively using our attention, the energy will travel in the usual directions, into our habitual states. It is important to develop desirable, useful habits.
If we achieve a higher energetic state (through "spiritual" exercises, through artistic creation, through psychedelics, etc.) but don't develop new subtle habits, we are surely headed on a straight road to disaster. The first symptom (and only the first!) will be the loss of the higher energy state. The rest will fall like dominoes.