One of the drawbacks of antidepressants is that there is a waiting period of days or weeks before physician and patient know whether a particular drug is going to help. If, after four to six weeks, an antidepressant has not reduced a patient's depression, then a second drug may be tried, and, again, there will be a delay of days or weeks before it is clear whether the medication is going to work. One needed area of research in psychopharmacology is to devise tests that will help to tell a doctor what antidepressant is most likely to be effective for the individual patient. At present, though some general guidelines exist, matching patient with an effective and tolerable medication is a process of intelligent trial and error. Lithium has been used to treat manic depression since 1954. Lithium is absorbed quickly from the gastrointestinal tract, but it acts slowly, so it also takes time to know if it is going to be of value. Blood levels of lithium need to be checked once or twice a week during the first month, twice a month for the next month or two, and then once every one to two months. Lithium is sometimes helpful in treating chronic simple depression, that is, depression that is not associated with periodic "highs." Unlike most drugs used in psychiatry, lithium usually has few noticeable side effects and does not tend to produce a feeling of sedation or stimulation. When side effects occur, it is usually because the lithium level in the blood has become excessive. Side effects then can include vomiting, lack of coordination, muscular weakness, or drowsiness. In addition to antidepressant drugs, electroconvulsive therapy (ECT) is sometimes used to treat severe depression, as it is to treat some other conditions, including schizophrenia. Although ECT is not itself a form of drug therapy, it is important to {234} mention it here since it is one of the main _medical_ treatments (as opposed to the "talk therapies" of psychotherapy) used by psychiatry today. ECT is administered after a patient has been sedated and given a general anesthetic. The main advantage of ECT is that it acts much faster than any of the antidepressants. For a seriously suicidal patient, this can be important. The main disadvantages of ECT are that it can cause temporary memory loss, temporary disorientation and confusion after treatment, and possible permanent changes in brain function--regarded by many psychiatrists as "subtle," i.e., fairly minor. Another discouraging finding is that depression recurs after ECT in many patients--in up to 46 percent within six months after ECT. ECT has received "poor press." As now administered, the actual treatment is painless. It is, nevertheless, a forceful, "invasive" approach, so many psychiatrists prefer not to use it if medication can be successful. As more biochemical methods of treatment are discovered, ECT very likely will be used less and less. _Psychosis_