Safety and efficacy of chronic hypnotic use: Study 2

The purpose of this research study is to determine how safe and effective it is to use either of two different FDA (Food and Drug Administration) approved sleeping medications on a nightly basis for six months.  For many people insomnia is a chronic problem and they use their sleeping medications chronically, but studies have not thoroughly determined whether they remain effective and safe.  This study will compare two commonly prescribed sleep medications which improve sleep, but do so through slightly different pathways in the brain.