Insomnia, condition in which a person has difficulty getting sufficient sleep. It can be caused by an overactive thyroid gland, diabetes, violent muscle twitching, or drinking caffeine-containing beverages before going to bed, but experts estimate that in three-quarters of all cases the cause is a psychological one. After anxiety-producing events such as the death of a loved one or loss of a job, a person may experience sleep difficulties for a while. Many people recover their normal sleep rhythm spontaneously, but others become frustrated and depressed and develop chronic (long-term) insomnia. Napping during the day may throw off the sleep pattern further.
So-called sleeping pills, such as barbiturates, have been found to be less effective than tranquillisers. Minor tranquillisers may be used for a few nights to restore the sleep cycle and to reduce anxiety, but they are not meant as a long-term treatment. Currently the most effective therapy is to identify any problems that may be preventing sleep and to attempt to solve them, meanwhile reducing the person's anxiety about the insomnia itself.