Measuring the social and psychological costs of hard times has become fertile territory for a new generation of social scientists and public health experts.

In the last few years, researchers have begun updating the classic studies of the Great Depression by visiting ailing, one-industry towns in states like Connecticut, California and Michigan and have started using sophisticated statistical techniques to evaluate the long-term impact of unemployment.

Their conclusion: marriages worsen, health deteriorates and problems with children grow more severe in households where a job has been lost.

In a three-year, federally funded study of laid-off defense workers in Hartford, Conn., 12 percent of the 206 interviewed said they became alcoholics and 20 percent reported extreme anxiety and tension, according to Dr. Paula Rayman, a Brandeis University sociologist who conducted the study.

"There was much insomnia, stomach ailments, women reporting gynecological problems, depression and sleeplessness," she says.

Other research has found that child abuse is three times greater in families where the breadwinner is unemployed and that joblessness is the single most important factor in whether abuse occurs.

Another study by Lewis Margolis, a pediatrician at the University of North Carolina, showed that families affected by plant closings experience more childhood illnesses, three times the amount of child abuse than in "working" families and less plentiful food, clothing and medical care. "Children thrive on routine and continuity," he says, "and changes present a great stress risk to them."

"Within the next year at least 13 million children will live in families where the primary wage earner is unemployed for a week or more," Margolis recently told Congress. "Indeed, exposure to unemployment is so widespread that if it were an infectious disease like polio or measles, our nation would vigorously pursue policies against it." He urged Congress to require that health insurance be continued after workers lose their jobs because of the increased health risks that result from being out of work.

Harvey Brenner, a Johns Hopkins University demographer, estimates that a 1.4 percent increase in unemployment in 1970 was linked to 51,570 premature deaths by 1975 (primarily because of stress), a 3.4 percent increase in first-time mental hospital admissions, 4.1 percent increase in suicides, a 5.7 percent increase in the murder rate and a 4 percent rise in the state prison population.

Brenner says he is updating the study for the congressional Joint Economic Committee and his report, expected to be completed in March, shows physical and social costs at least equal to his earlier findings.

In his studies Brenner compares social statistics during a period when unemployment is high with figures from a more normal period and then calculates the correlation. It is a basic technique of public health research, except that Brenner attempts it on a far larger scale.

All of his results, he feels, "are gross underestimates of what is the actual suffering of the population. Recession affects all ages: fetuses, infants, elderly, preteen. The stress befalls not only those who lose, but people who fear the loss of employment and income."