Sedative-hypnotics are used to help people sleep. Benzodiazepines and barbiturates are both sedative hypnotics. Sedative hypnotics change the effects of the inhibitory transmitter GABA which with too much excitement could result in seizures.
Even though sedative-hypnotics are used to treat insomnia it is known that sedative-hypnotics can also cause rebound insomnia which results in bizarre dreaming and insomnia. This then has the desire for a person to continue taking the drug because the insomnia actually gets worse when they stop taking the drugs. People are finding it difficult to stop because it can take up to a month for the withdrawal effects to go away.
Tranquilizers are called benzodiazepines and are used for reducing anxiety and other mental illnesses. Like barbiturates, the effects are similar to alcohol. Tranquilizers are very popular in the United States because of the growing number of mental illnesses that are being diagnosed. The danger of prescribing this drug is that about a week after discontinuing the use it is highly likely to cause a seizure.
McKim, William A. Drugs and Behavior: an Introduction to Behavioral Pharmacology. Upper Saddle River, NJ: Pearson Education, 2007. Print.