The past has an uncanny habit of returning to haunt one, Archbishop Desmond Tutu observed. For that reason, he added, it cannot be dealt with by a national commitment to collective amnesia.

His experience as a priest who heard many confessions apart, he speaks with authority for another reason: he was chairman of South Africa's Truth and Reconciliation Commission.

But the TRC's experience has shown that the ghosts of the past cannot be exorcised simply by providing the victims of abuse with a forum where they can recall their painful experiences to sympathetic listeners.

The notion that the victims can achieve psychological catharsis simply by talking about, and hence in a sense reliving, their past horrors is facile. While many victims of human-rights abuses may have felt relief by narrating their agonising tales, more often than not that very process is itself traumatic, according to Ms Trudi Borain, a clinical psychologist who worked closely with the TRC.

Based until recently at the Trauma Centre for Survivors of Violence and Torture, Ms Borain said victims, though frequently anxious while reliving past terrors, often felt a sense of relief when they had finished their testimony, whether to commission officials or to public hearings of the commission. One recalls televised images of sobbing men and women testifying before the commission. But afterwards witnesses who had apparently obtained cathartic relief "often needed psychological counselling quite urgently", Ms Borain recalled. They could not understand why they were feeling anxious and depressed, she added.

Reflecting on the process which the victims went through during and after their testimony, she said: "At times I feel overwhelmed by the complexity."

One aspect of the complexity which challenged and humbled psychological counsellors during the Truth and Reconciliation Commission hearings emerged later during the interview: Ms Borain was seconded to the commission to provide psychological services to its own staff.

Officials, having listened day after to day to harrowing testimony of suffering at the hands of zealous or even psychopathic torturers, were vulnerable to secondary or vicarious trauma, according to Ms Borain. She emphasised the need for follow-up counselling in the emotional environment of the Truth Commission hearings.

One episode illustrates the point dramatically: a police officer who admitted committing human-rights abuses went on to express his regret in person to his victims, only to be physically attacked by them. Bereft of sufficient psychological counselling, the victims were unable to contain their anger, she explained.

"The victim must be psychologically ready to meet the perpetrator," she added. These deficiencies in the commission healing process do not mean, of course, that it was without merit, merely that it would have been more effective with timely and sufficient counselling.