''I didn't see that I had a problem,'' said Mr. O'Donnell, the former Bally executive. ''People would try to tell me I was in trouble and I'd say, 'Don't tell me how to live my life -look at my success.' '' It was not until the head of the company told him to take a leave and get help that he began to sort out his problems. Now, after five years of trying different treatment programs, he is off cocaine and out of the corporate world. As president of the Sierra Tucson Clinic, a drug and alcohol treatment facility near Tucson, he has come to believe that ''success in life is not measured just in money and power.''

The balance between a successful career and personal fulfillment that Mr. O'Donnell seems, finally, to have found is elusive for many others. Yet some famous names in business have recognized the need for it, and have changed their worklife. James D. Wolfensohn, for example, who led Salomon Brothers into the top ranks of corporate finance, left that company to found his own one-man investment firm. The reason he gave: ''I wanted a more balanced life.''

Despite its glamour and power, the grinding pressures of Mr. Wolfensohn's position - round-the-clock negotiations and endless crises - left him with little control over his personal time. He was chairman of Carnegie Hall and an accomplished cellist, and he longed for the freedom to pursue his private interests, particularly music. With his new business, Mr. Wolfensohn says, he is able to spend the time he wants on music and his other interests ''and still make a comfortable living.''

That balance is rare among those who grow troubled as they grow more successful. Psychotherapists say that for such people, the pursuit of money and corporate advancement often block out any hints of trouble, particularly when the fruits of success are so enticing.

And the lures are clear: Billion-dollar mergers, for example, are pouring fountains of money into the bank accounts of investment bankers and corporate lawyers. Wall Street attracted 28 percent of the Harvard Business School's Class of 1985, up from only 1 percent in the Class of 1949, and for good reason: Although the median starting salary for the class was a hardly shabby $45,000, Wall Street offers considerably more. Investment bankers can make $200,000 within a few years of earning their M.B.A.'s. And in corporate law, people who become partners at top-tier firms can also make at least $200,000 a year.

It is not necessarily easy money, however. ''Those who have made it to the top in investment banking have gone through a maze to get there,'' said Byron Wien, a managing director at Morgan Stanley. ''They can handle both the challenge of the job and the personal pressures. There are lots of marriages that break up in this business, but they do in others, too. Those who can't take it shake out in the earlier rounds.

''Still, you want to do something with your life that lets you feel alive,'' Mr. Wien added. ''You'll pay a high price to do it, but work that is exciting and satisfying compensates for the personal sacrifices. I'd much rather have a demanding job I love than spend eight hours a day at a boring one that gave me more time.'' BUT for many young men and women, there are hidden perils of success, say the psychologists and psychiatrists who treat them. And those who so eagerly pursue that climb are seldom, if ever, warned about these perils. Frequently those who suffer simply do not want to admit it.