ABSTRACT
Medications, drugs of abuse, and alcohol can affect sleep performance either directly or indirectly. Direct effects, such as the promotion of wakefulness by stimulants, are usually intended therapeutic effects mediated through the central nervous system (CNS), whereas indirect effects may be inadvertent side effects, such as insomnia caused by stimulating antidepressants (1) or the withdrawal of a centrally acting (2) or a systemically acting medication (3).
