The good news about sleep aids involves the popular Ambien. It is now available in a low-cost generic form.

Modern prescriptions for insomnia include:

¥ Zolpidem, Ambien, is most useful for sleep-onset insomnia, usually experienced by people who have trouble shutting off a busy mind. It works in seven to 27 minutes and has a low risk of dependence.

Ambiem CR is a timed-release form which keeps people sleeping longer but may cause morning drowsiness.

¥ Eszopiclone, Lunesta, helps to initiate sleep, works within 10 minutes and has a low risk of dependence.

Its controlled release form keeps people sleeping longer but may also cause morning drowsiness.

¥ Zaleplon, Sonata, works for night wakening, called sleep-maintenance insomnia. It wears off before morning and has a low risk of dependence.

¥ Ramelteon, Rozerem, is a melatonin agonist and related to the natural hormone melatonin. It attempts to duplicate the body's natural mechanisms that stimulate sleep. It works in 30 minutes and is not habit-forming, but it's not as strong as other sleep aids An older class of prescription sleep aids is called benzodiazepines. They carry more risks, especially for the elderly, and they may interact with other medications. They are not recommended by the Mayo Clinic. This class includes such names as Restoril and its generics, Klonopin and generics and Halcion and its generics.

Over-the counter sleep aids such as diphenhydramine (Benadryl and others) or doxylamine (Unisom and others) are designed for occasional use. They offer little help for actual insomnia and may have side effects, say Mayo doctors.