Both rats were doomed. On had led a life of ease; the other a life of hardship and frustration. The lucky rat always found cheese when he scurried to the middle of his maze; the other invariably was met with an electric shock. One was a happy rat; the other showed symtoms of rat depression.

Into the vat of deep water they went. Scientists stood by, observing the rodents frantically paddling to survive. Early on the depressed rat resigned himself to his fate and sank to the bottom. the other rat, though, had reason to be optimistic. He swam on. And on. And on. Then he drowned.

It was a lesson to us all, the scientists concluded. The depressed rat gave up the ghost, and his life, before he really was forced to. The optimistic rat tried to prevail against overwhelming odds. After this study was published, skeptical laymen pointed out its resutls -- two dead rats -- just proved how realistic the depressed rat had been about the probable outcome of his dilemma.

Reinforcement for the poor, dead, depresses rat's action seems to be forthcoming from a recent study on humans. Its results indicate optimistic people, not depressed people, have a distorted sense of reality.

The intent of the four-year study done a Northwestern University in Evanston, Ill., was to test the learned helplessness theory of depression. This popular theory has it that people become depressed from an erroneous belief they have no control over their lives. As long as they continue believing they cannot change unhappy circumstances, they remain depressed. They feel helpless. They become victims.

The presumption holding this theory together, of course, is that it is only the depressed's view of life getting him or her down, and not life itself.

Hence the exhortation of popular psychology to "take charge of your life," to "try, try again." Therapists aim to shore up your self-esteem, make you believe you can tackle the world. And what are you now that you've stopped whining and started fighting back? Why, very possibly, you're out of touch with reality.

"We found right across all the experiments we did, our depressed subjects were relatively accurate about how much control they had over a situation," said Lauren B. Alloy, an assistant professor of psychology at Northwestern. s"The surprise was, the non-depressed people consistently made all the errors." "

The experiments involved a group of volunteers who were given a questionnaire on appetite, sex drive, attitudes and energy level -- to sort the depressed from the non-depressed. They were then led to a panel with buttons. Presumably pushing a button would cause a light to flash.

But not always. Sometimes the volunteer was actually causing the light to flash by pressing the button; other times the light was flashing of its own accord. The volunteers were asked to determine at which point they were actually controlling the lights.

"We found when the situation was neutral -- meaning there was no reward attached -- then both the non-depressed and depressed subjects judged accurately when they were actually causing the lights to flash," says Alloy.

"But when there was a positive outcome -- they would be told they had won money -- the non-depressed subjects would consistently credit themselves as being in control. Only ther weren't. When the outcome was negative, they would claim they weren't controlling the lights. In fact, they were."

According to Alloy, depressed people were objectively correct in their sense of controlling the lights regardless of the outcome. "Depressed people seemed to be more realistic," she said. "Non-depressed people have many biases and distortions when they view the world optimistically. In the study, they greatly overestimated their control of the situation. And they gave themselves credit they didn't deserve.

Alloy says her finding, which present a large challenge to the current theories of depression, are back up by studies done elsewhere in the country. One West Coast study showed that depressed people were more able to accurately rate their social skills, while the optimists judged themselves more socially adept than the observers felt they had any right to claim.

This doesn't mean, Alloy says, that depressed people, caught in the miasma of their gloom, don't distort reality. But so far, no researcher has been able to catch them at it.