Antidepressant drug raises new hopes

by Cesar Chelala

The news that Dallas Cowboys football player Terrell Owens had attempted to commit suicide because of depression alarmed sports fans worldwide, for whom he is one of the game’s biggest stars. However, recent information on the uses of a drug with positive effects on depressed patients raises hopes that the problem may be successfully confronted in a not too distant future.

It is estimated that almost 15 million people in the United States are affected by depression in any given year. Worldwide, the World Health Organization estimates that over 120 million people meet the criteria for clinical depression.

Depression is a democratic disease, since it affects people from all social strata. Even presidents suffer from it, the most notable example in the past being Abraham Lincoln, who suffered from prolonged bouts of depression while he was president of the country. In spite of that, he is one of the most admired presidents in U.S. history.

Now come the news that ketamine, a drug that was first synthesized in 1962, had an almost immediate effect in relieving depression from some patients. Although the drug is unlikely to be used in patients because of some serious side effects such as hallucinations and other unwanted psychological side effects, it can point the way toward developing a new class of faster and longer-acting medications. The results of a study involving the drug called ketamine were published in the Archives of General Psychiatry.

A show if its efficacy is that people with treatment-resistant depression experienced significant relief as quickly as two hours after a single dose of ketamine in amounts lower than what is normally used as an anesthetic in humans and animals. As a contrast, antidepressants usually take eight weeks or more to exert their effect in the same kind of patients.

For this study 18 treatment-resistant depressed patients were randomly assigned to receive either a single dose of ketamine or a placebo, an inactive compound. Depression improved in 71 percent of all those who received ketamine while those receiving a placebo didn’t show any effect. In 35 percent of patients who showed improvement, that improvement lasted for over seven days after receiving a single dose of the medication.

According to Dr. Thomas R. Insel, Director of the National Institute of Mental Health in the United States, “This is the first report of any medication or other treatment that results in such pronounced, rapid and prolonged response with a single dose.”

Scientists involved in the study believe that current antidepressant medications take a much longer time to work because they act on targets close to the beginning of a series of reactions that regulate mood. Ketamine may act by skipping many of these intermediate steps and thus may reach its target much faster than other medications.

In this regard, as Dr. Carlos A. Zarate Jr., lead researcher of the NIMH Mood and Anxiety Disorders Program stated, “This may be a key to developing medications that eliminate the weeks and months patients have to wait for antidepressant treatments to kick in.”

Further analysis of the way ketamine acts may help scientists understand how and why depression occurs, and develop new and more specific medications to treat this disease, as well as find specific markers to aid in early diagnosis.

The potential of ketamine to deal with other problems is also significant. Research is being carried out in France, Russia and the U.S. into the drug’s usefulness in pain therapy and for the treatment of alcohol and heroin addiction. Because of its potential for illicit use, however, it cannot be used by the general public without prescription.

Because it acts in different ways than previous medications, it opens the way to research of new antidepressants that are not just variations of existing ones. Ketamine efficacy in the treatment of depression has enormous public health implications, given the significant amount of people who suffer from it. For many of them, it can mean the difference between life and death.