These drugs are used primarily to treat what psychiatrists call _endogenous_ depression--that is, major, incapacitating depression that is not associated with an outside event or situation. Depressions that occur after the loss of a job, the death of someone close, or some other external event are called _exogenous_ depressions. They can sometimes be treated effectively with antidepressants, but drug therapy for _situation-induced depression_ generally is less successful. Lithium therapy is a specific treatment primarily for manic-depressive disorders. Lithium carbonate is a naturally occurring mineral salt. For manic-depressive patients--with wide swings of mood from feeling extremely energetic and emotionally high to feeling seriously depressed--lithium therapy may offer help as a mood stabilizer. _Stimulants_ Caffeine and nicotine are the best known of the stimulants. In therapy, stimulants are used in the treatment of narcolepsy (individuals suddenly fall asleep for short periods of time, even when engaged in activities), some forms of epilepsy, and, paradoxically, hyperkinetic children (who are excessively active and have short attention spans and explosive irritability). _Antiepileptic Drugs_ For many of the two million Americans with epilepsy, these antiseizure drugs are very helpful. Epilepsy does not tend to shorten an individual's life, but it is a severe, troubling, and often disabling condition for which drug therapy can be a blessing. _Antiparkinsonian Drugs_ These drugs have helped the lives of many people who are {230} affected by the characteristic involuntary tremors of this disease, which can cause abnormalities in gait and trembling of the voluntary muscles. _Psychedelics_ Psychedelic drugs are also called _hallucinogens_. They produce altered states of consciousness and sensory distortions. Psychedelics have no established use in psychiatry at present in the United States. Great Britain and Canada, however, have experimented with psychedelics in the treatment of alcoholics, whom they sometimes appear to help. Psychedelics have also sometimes been used for the terminally ill and in certain cases of autism. _Drugs for Headache, Migraine, and Neuralgia_ Drugs for these common kinds of pain are widespread. Migraines (which may cause blurred vision, vertigo, and even temporary deafness) and cluster headaches (which cause severe pain around the eyes, tearing and reddening of the eyes, and runny nose) frequently can be treated successfully with specific drugs. Neuralgias are recurrent knifelike facial and head pains that can last for days and even months. They can be difficult to treat successfully. WHAT DRUG THERAPY IS LIKE In this section, we'll look at some of the main emotional and mental symptoms that are often helped by means of drug therapy. Since all medications have potential side effects, we will look at these as well. _Anxiety_