An editorial in the New York Times talks about the high use of sleeping pills in American society:
Americans are popping sleeping pills at a rapid rate, thanks to heavy marketing by the drug companies and a belief that a new generation of sleeping pills is safer than its predecessors. The upsurge is raising justifiable concerns that the pills will be overused by people who don't really need them or that doctors may reflexively prescribe pills while ignoring underlying conditions that may be responsible for sleeplessness.
As Stephanie Saul reported in The Times recently, some 42 million sleeping pill prescriptions were filled last year, up nearly 60 percent from 2000. More and more people are turning to a new generation of sleep aids called "Z" drugs. The best seller is currently Ambien, but over the past year it has been vigorously challenged by a newcomer, Lunesta, prompting a huge advertising and marketing battle.
Decades ago barbiturates were the drugs of choice for insomnia, but they are addictive and carry a high risk of death by overdose. In the 1970's they were largely displaced by benzodiazepines, drugs that include Dalmane and Halcion, which are less prone to overdose but have their own unpleasant side effects, including next-day drowsiness, dependence and withdrawal symptoms. The Z pills were developed to overcome such side effects.
But any implication that they are a huge breakthrough must be viewed skeptically. Roughly speaking, the recommended starting doses of two brand-name Z pills seem to cut only 15 minutes or so from the time needed to fall asleep after taking a placebo, while extending the duration of sleep by a half-hour or less. Most are classified as controlled substances because they can be abused and can cause dependence. Recent evaluations have reported finding no evidence that Z drugs are much different from their predecessors in terms of effectiveness and short-term adverse events.
Most experts believe that people should try a range of tricks, like minimizing the habits that interfere with sleep, before turning to pills. Some experts say psychotherapy, where available, has more lasting effects than sleeping pills. Insomniacs need to weigh whether sleeplessness is worse than the pills designed to ameliorate it.
I haven't heard the term "Z pill" used before. The Z pills include Lunesta, Ambien (and now Ambien CR), and Sonata. The Z pills bind to a subtype of the benzodiazepine receptor, and are more selective than the benzos such as valium and xanax. The Z pills have fewer side effects than the benzos: they are less addictive, and cause fewer memory problems.
The article mentions psychotherapy for insomnia. This is not commonly available. Here is a list of the less than 100 doctors and psychologists in the country who are certified in behavioral sleep medicine.