-BILL BELK, freed Iran hostage, quoted in “444 Days,” by Tim Wells

They blink happily into the welcoming lights, flash grateful, ear-to-ear grins, surreptitiously pinch themselves to see if they’re dreaming. British journalist John McCarthy waved jubilantly to the crowds greeting him after his five years in captivity, and a few days later, frail, 60-year-old Edward Tracy managed to thrust up his hands in triumph as he stepped onto the tarmac of a German airport. Yet for many released hostages, that first exhilarating moment of homecoming may be the last moment of unmixed elation. Upon returning, they face recurrent nightmares about their imprisonment along with the uncertainties of a world that has rushed past them. For some, the next scariest moment after being captured comes after they are released. For some, freedom can be almost as frightening as captivity.

There are individual differences, of course. Much depends on what a hostage’s life was like before capture. Some former hostages readjust and get on with their lives relatively quickly; others spend years learning to release emotions they had kept bottled up. “Time marches on, and so do all the affiliations a person has had of family and work,” says Rona Fields, a Washington, D.C., psychologist who has worked with hostages and victims of terrorism. “There is that time-warp feature for anyone returning from a long absence.”

The experiences of the 52 Iran ex-hostages may be instructive for the captives in Lebanon. In 1982, a year after they came home, many were reporting sleep disturbances, flashbacks and other symptoms of posttraumatic stress disorder; four had divorced or separated, at least a dozen needed psychiatric care and two were institutionalized for extended periods.

Captivity itself may produce lasting trauma, not only from beatings and torture, but as a result of the sharp restriction of movement. At first there is enormous anger, then, after about three months, a “hibernation” effect, including a slowdown of mental activities. Many ex-hostages continue hibernating for a time after their return. Psychologists believe that was observable in the eccentric, sometimes disjointed remarks made by Edward Tracy, though by some accounts Tracy had shown signs of bizarre behavior before his capture in 1986. “It’s self-protective,” says Samuel Karson, retired chief psychiatrist of the State Department. “People don’t deal with shifting realities that quickly. One day in jail, the next day a hero, and then you’re on the phone with the president. Is it really happening? That’s what breaks people down.”

Doctors who examined the freed Iran captives found that one of the worst features of the experience was the imposed passivity. For the length of their incarceration, they had no control over the most basic decisions in their lives-including when they could use the bathroom. Often, even their perceptions could be determined by their captors. Fields, who was a consultant in the Patty Hearst case in 1976, believes that is essentially what happened to Hearst, who came to accept “other people’s assertions, other people’s authority”-something like the so-called Stockholm syndrome, in which prisoners begin to identify with their captors.

Understandably, hostages come home with a certain mistrust of people, fearing the power of others. Benjamin Weir, a Presbyterian minister who was released by his Lebanese captors in 1985, said last year that the sense of vulnerability had remained with him, and helped him identify with oppressed people everywhere. But for some, it means avoiding intimate relationships. Meanwhile, as with gulf war veterans, family roles at home have shifted. Children have grown older, wives have taken more central responsibility. Doctors describe the contradictions of what is known as the homecomer phenomenon: the homecomer believes nothing is different, yet in many ways a lot is. The people he returns to expect he is different, but he really isn’t. “He’s been kept in isolation and prevented from changing,” says Charles Figley, director of the stress-research program at Florida State University, “while the family has had a good deal of change.”

After long separation, both husband and wife may have demands for compensation. In an example Figley cites, the wife feels she has been deprived through all the years of his captivity and wants him to be especially sensitive to her needs. “But he feels she’s had all this freedom while he was gone and now she wants to deprive him of his freedom.” Doctors advise freed hostages not to evaluate their relations during the transitional time just after their return, when there is an idealized expectation on all sides that a marriage-or romance-will somehow resume with more commitment than ever. Some relationships do heal, others break up. “Time can start again now, everything is new and fresh,” said John McCarthy’s girlfriend Jill Morrell in a television interview. But she wisely avoided announcing an actual resumption of their old relationship.

Despite his buoyant youthfulness, McCarthy was kept under strict medical surveillance at an Air Force base west of London last week. Doctors there said he was suffering from malnutrition. First reports on Tracy, meanwhile, indicated that he was showing acute symptoms of stress and exhaustion. No one was saying how soon the two men could be expected to be up to snuff again. But it seems clear that no matter how swiftly freed hostages regain their physical health, they are likely to remain psychic captives to their experience for years longer.