Continued reliance on nerve irritants wears down life forces, creating an escalating cycle of dependency and exhaustion.

Original passage

The continued use of these nerve irritants is followed by headache, wakefulness, palpitation of the heart, indigestion, trembling, and many other evils; for they wear away the life forces. Tired nerves need rest and quiet instead of stimulation and overwork. Nature needs time to recuperate her exhausted energies. When her forces are goaded on by the use of stimulants, more will be accomplished for a time; but, as the system becomes debilitated by their constant use, it gradually becomes more difficult to rouse the energies to the desired point. The demand for stimulants becomes more difficult to control, until the will is overborne and there seems to be no power to deny the unnatural craving. Stronger and still stronger stimulants are called for, until exhausted nature can no longer respond.