By EZEKIEL J. EMANUEL

Mention euthanasia and the image that enters your mind is of a gaunt patient lying in bed, writhing in excruciating pain. It is the image created and reinforced by TV profiles and magazine article like the one about Betty Rollins’s mother. It is for that patient - and for the fear that it may one day be you or someone you love - that the U.S. Supreme Court will hear oral ar-guments tomorrow on whether to legalize euthanasia or physician - assisted suicide.

Surprisingly, this reflexive association between pain and euthanasia - so strong and unshakable in the public mind-is a fiction. Instead, scientific studies reveal that most patients who seek euthanasia are motivated by psychological factors - often depression - not by unbearable physical suffering.

Yes, some dying patients are suffering great pain. But compiling anecdotes about such patients, as euthanasia advocates often do, yields a biased perspective. Not a single rigorous study has demonstrated that it is patients in pain who, as a rule, are motivated to seek euthanasia. To the contrary, all such studies have documented that physical pain plays a very small role in motivating patients’ interest in or requests for euthanasia.

My own study of cancer patients, published in The Lancet, found that those experiencing pain were no more likely to request euthanasia than those without pain. If anything, patients with pain were more likely to oppose legalizing euthanasia. For instance, cancer patients with pain were more likely to find euthanasia unethical - even for patients with unremitting pain. Cancer patients experiencing pain were more likely to trust a doctor less if he mentioned euthanasia or physician-assisted suicide as part of a discussion of care at the end of life. And those in pain were more likely to switch physicians if their doctor mentioned that he would be willing to perform euthanasia.

Similarly, a study of AIDS patients by researchers at Memorial Sloan-Kettering Hospital in New York City found that while many were interested in physician-assisted suicide, those experiencing pain, and limitations of function because of pain, were not very interested in physician- assisted suicide.

All Dutch and American studies of physicians who have performed euthanasia have confirmed these findings. The most comprehensive study of the Dutch experience with euthanasia - the 1991 Remmelink report - found that pain was a factor motivating requests for euthanasia in less than half of all cases. More importantly, pain was the sole motivating factor in just 5% of euthanasia cases. Another study of physicians who care for nursing-home patients in the Netherlands found that pain played a role in just 29% of requests for euthanasia and was the main rationale in only 11% of euthanasia requests. And a study in Washington state of physicians who performed euthanasia or assisted suicide found that in only 35% of cases did pain figure in the request.

All five of these studies show that psychological factors are what commonly drive patients’ interest in euthanasia and physician-assisted suicide. Depression, hopelessness, anxiety and the like are why patients request aid in dying. Among the cancer patients, those who were depressed were more likely to trust their doctors if they discussed euthanasia. Depressed patients were more likely to seriously discuss euthanasia for themselves, to hoard drugs for the purpose of suicide and to read the Hemlock Society’s suicide manual, "Final Exit." The Memorial Sloan-Kettering study confirmed that AIDS patients who scored high on formal measures of depression and hopelessness were more likely to desire physician-assisted suicide.

The same is true in the Netherlands, where the leading reason for requesting euthanasia was loss of dignity. The other factors motivating requests were all related to psychological distress: unworthy dying, dependence on others and tiredness of life. The leading reasons for requesting euthanasia or physician-assisted suicide found in the Washington state study were loss of control, being a burden, depen-dence on others, loss of dignity and severe depression.

Depression, hopelessness, anxiety over dependence and a sense of loss of control are serious problems among dying patients. They require the attention of all those who care for dying patients. Indeed, according to one study depression and psychological distress may confront more than 70% of all dying patients. Do we really think euthanasia is the solution for patients who are depressed or fear being a burden on their family?

The current euthanasia debate has been carried on in almost total ignorance of the facts and data available. The chief justification for considering euthanasia is to provide relief for patients suffering excruciating pain. But these patients are not the ones who want euthanasia.

Indeed, of the 2.3 million Americans who die each year, these data indicate that fewer than 25,000 might desire euthanasia for reasons related to pain. For the millions of others, legalizing euthanasia or physician-assisted suicide would be of no benefit. To the contrary, it would be a way of avoiding the complex and arduous efforts required of doctors and other health-care providers to ensure that dying patients receive humane, dignified care.

Dr. Emanuel, an associate professor of  medicine and social medicine at Harvard Medical School, is the author of  "The Ends of Human Life" (Harvard University Press, 1991).