The nation's teenagers worry most about paying for college, contracting AIDS and making the wrong decisions about their future, according to a survey released this week.

High school juniors and seniors generally think their lives are more complex than their parents' lives, the data showed.They are keenly aware that drugs, alcohol, AIDS and sexual abuse are issues that affect them and their friends, although they are less likely to admit that they are personally involved with those problems, according to the study by the American Home Economics Association.

The teens surveyed were generally happy with their own lives, said Jay Friedland of Guideline Research, which conducted the survey for the association.

But while they are happy on a "personal level," they are "fairly pessimistic about the world around them," especially about social problems and the country's future, Friedland said.

For example, 58 percent do not think there will be an end to racial discrimination in the United States in their lifetimes; 42 percent think there will be nuclear war in their lifetimes and 62 percent think their lives will be harder than those of their parents.

The study, funded by Chesebrough-Pond's Inc. and Lever Brothers Co., surveyed 510 high school juniors and seniors nationwide between March 25 and April 5. Quotas were established so that a sample of 300 teens selected at random reflected Census Bureau breakdowns of student population by sex, race and ethnicity. A supplemental group of 210 included only blacks and Hispanics.

The average age of the respondents was 17, and the survey had a margin of error of plus or minus 5 percentage points.

The teenagers were asked how concerned they were about 32 issues. Topics that drew responses of "extremely" or "very" were considered top concerns. They tended to be questions of money, the future or AIDS.

Being able to pay for college was a top concern for 39 percent of the teens surveyed, as was the fear of contracting AIDS. Thirty-four percent listed making the wrong decisions about the future and not being able to change them as a top concern.

Fear that the United States "is steadily going down hill" greatly concerned 33 percent; and the prospects of a nationwide depression worried 30 percent. Not earning enough money to enjoy the better things in life was a top concern for 29 percent.

While few teens - 11 percent - actually know of someone who has contracted acquired immune deficiency syndrome, 30 percent say they have changed their sex lives because of the fear of getting the deadly disease.