How treatment affects cognitive deficits in patients with sleep disorders: methodological issues and results.

Sleep disorders are frequently associated with impaired performance although the type and extent of cognitive deficits varies widely between different types of sleep disorders. Treatment is expected to ameliorate these deficits. However, cognitive functioning and its change with treatment depend on numerous factors. In this chapter we discuss methodological issues, including test selection, and person-specific, task-specific and environmental factors that influence cognitive functioning. In addition, features of study design and sampling strategies are discussed. The chapter ends with a short overview of routes by which treatment may affect cognition in sleep-disordered patients.