More than 6 million Americans work night shifts on a regular or rotating basis. 
The negative consequences of shift work have been established, and recent 
evidence suggests that patients with shift work sleep disorder (SWSD) are at 
increased risk of these consequences and co-morbidities. SWSD is a relatively 
common but under-recognised, and hence undertreated, condition with potentially 
serious medical, social, economic and quality-of-life consequences. In addition 
to increased risk of gastrointestinal and cardiovascular disease, patients with 
SWSD experience clinically significant excessive sleepiness or insomnia 
associated with work during normal sleep times, which has important safety 
implications. A number of studies have evaluated countermeasures or 
interventions in shift workers; proposed treatments include chronobiotic 
interventions, such as light exposure, melatonin, hypnotic agents, caffeine and 
CNS stimulants (amphetamine), and the wake-promoting agents modafinil and 
armodafinil. However, most studies evaluating pharmacological therapies and 
nonpharmacological interventions simulate night-shift work under conditions that 
may not accurately reflect real-world activities. Pharmacological and 
nonpharmacological countermeasures evaluated mostly in simulated laboratory 
conditions have been shown to improve alertness or sleep in shift workers but 
have not yet been evaluated in patients with SWSD. To date, three randomised, 
double-blind clinical studies have evaluated pharmacological therapies in 
patients with SWSD. These studies showed that modafinil and armodafinil 
significantly improve the ability to sustain wakefulness during waking 
activities (e.g. working, driving), overall clinical condition, and sustained 
attention or memory in patients with SWSD. In conclusion, SWSD is a common 
condition that remains under-recognised and undertreated. Further research is 
needed to evaluate different treatment approaches for this condition, to clarify 
the substantial health and economic consequences of SWSD, and to determine the 
potential for interventions or treatments to reduce the negative consequences of 
this condition.