Final answer:
Statement D is NOT true about the use of CNS stimulants as anorexiants and for narcolepsy.
Step-by-step explanation:
Out of the given options, statement D is NOT true about the use of CNS stimulants as anorexiants and for narcolepsy. CNS stimulants, such as amphetamines, can be used to suppress appetite in the treatment of anorexia (option A). They are commonly prescribed to enhance wakefulness in narcolepsy (option B). However, statement D is incorrect, as CNS stimulants do have an impact on appetite and sleep disorders. Side effects of CNS stimulant use may include increased heart rate and blood pressure (option C).