Laura Read, age 13, of Billings, Mt., for her question:

WHAT CAUSES INSOMNIA?

Insomnia is a condition in which a person h as difficulty getting sufficient sleep. Medical experts say that about 30 million people in the Untied States suffer from this problem.

In some cases, insomnia 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 fourths of all cases, the cause is psychological. After an anxiety producing event, such as a tragic occurrence, for example, a person may experience sleep difficulties for awhile. The event may be the loss of a friend or a job.

Many persons recover their normal sleep rhythm spontaneously after some anxiety producing event, but others become frustrated and depressed and develop chronic insomnia. Taking naps during the day may throw off the sleep pattern still further.

So called sleeping pills have been found to do little good for insomnia.

Currently the most effective therapy for insomnia is to identify any problems that may be preventing sleep and to attempt to solve them, meanwhile reducing the persons anxiety about the insomnia itself.