 However it is now rarely used in medicine, its primary use being in scientific research to investigate the effects of catecholamine depletion on behavior.There is evidence that catecholamine depletion causes an increase in sleepiness that is more pronounced than sleep deprivation, and that the fatigue lingers after the drug is discontinued.Negative mood is also a reported side effect of catecholamine depletion, although this is reported less consistently than sleepiness.