In the Soviet Union, people caught questioning the wisdom of the authorities are officially judged to be off their rockers and packed off to the funny farm, without any foolishness about due process or fairness.

Here we do it differently. Even in Ronald Reagan's government, where supposedly every penny is counted, a large sum is allocated for a study that will show, ever so objectively, that taxpayers opposed to a government policy may be -- how shall we put it -- "tetched."

That's the case with a daffy and disquieting new $85,000 study, entitled "The Psychology of the Phobic Fear of Nuclear Energy," being done by a professor of clinical psychiatry named Dr. Robert L. DuPont. He is an advocate disguised as an expert. He is an authority on phobias, not on nuclear power plants.

Says James MacKenzie of the Union of Concerned Scientists, who has analyzed DuPont's analysis of what ails people who are nervous about nukes in their neighborhoods, "He wouldn't know a nuclear plant from a McDonald's."

The Department of Energy, which commissioned the study, knows pretty much what it will say before it is completed. DuPont is, like the DOE, a booster of nuclear power.

In 1983, he wrote a stern article for the New York Daily News telling the public to pull up its socks and get over its "widespread and irrational fear of nuclear power."

But in his "educational booklet" prepared for the study he protests that he has no intention of influencing the reader's "political views." "It is designed to help you understand the widespread fear of nuclear power, and if you have any fear, to help you reduce it," he says.

He has a soothing conclusion for the addled who can't get over their aversion to the nuclear waste piling up in the countryside and other hazards of unbridled nuclear power expansion: "It is usually a fear of what might happen rather than what has happened or is happening."

Zany booklets from the government are fairly routine. Some department is always earnestly seeking answers to questions nobody is asking, about the mating habits of butterflies, or why people fall in love. One such study made an inquiry about whether a person's beauty affects a person's life, even though examples go back to Helen of Troy.

But putting nuclear fears on the couch could be a foretaste of what we can look forward to in a second Reagan term when a public policy encounters resistance. The president did not hesitate to suggest a lack of gray matter in those opposing his weapons buildup. He accused supporters of the nuclear freeze of being "dupes" of the Kremlin, even though their ranks included a fair number of Nobel laureates and others who had persuaded the rest of the world that they had all their marbles.

Can we expect studies hinting at the emotional instability of people who want to spend money on welfare rather than MXs, who do not agree with the secret war in Nicaragua or who quarrel with the president over such social measures as the two health-care bills he vetoed this week, and who think that the Public Broadcasting System, which he hates to fund, is a good thing?

They may not feel that their dissent is unpatriotic, which DuPont suggests is the case if they are fretting about nuclear power: "This fear is harmful both to the fearful individual and our community as a whole because it can distort decisions about how best to meet our energy needs."

People do not appreciate being told, at their expense, that they're not quite all there. True, if they go to a psychiatrist they probably are not surprised to hear, for a stiff price, that they have what DuPont calls "irrational, often handicapping, phobic fears."

But they can tell the difference between a phobia and a concern without his help. They have reached their level of skepticism and aversion with a massive assist from the nuclear power industry. Its record of carelessness and inattention to detail exploded in the public consciousness in 1979, when the plant at Three Mile Island came within 30 to 40 minutes of a meltdown.

The details revealed in the investigations of that accident did not reassure the public. Indications of inadequately trained personnel operating with less-than-fail-safe equipment helped to nurture doubt in many minds about the desirability of using nuclear power to generate electricity.

The prolonged controversy over the Diablo Canyon plant in California, which was built over an earthquake fault, made people think that utilities might do well to cultivate a phobic fear about safety when dealing with radioactive materials. Maybe the DOE should commission a study on why they haven't.