Sir

I read your News story “Brain-scan ethics come under spotlight” (Nature 433, 185; 2005) with a feeling of déjà vu.

Nearly 20 years ago, my colleague Alfredo Vazquez and I reported a group of ‘normal’ volunteers who were discovered to have serious abnormalities during the course of research.

Of the three apparently healthy young medical students concerned, one was found to have chronic persistent hepatitis, another had a tumour in the parietal lobe of the brain, and the third had positive HIV serology (M. Phillips and A. J. Vazquez Control. Clin. Trials 8, 338–342; 1987).

Everyone's perceived roles suddenly changed, and the outcome was devastating. The subjects ceased to be healthy students with bright prospects. They were furious that the research had transformed them into patients under threat of death. The researchers ceased to be physicians in full control of the situation. They were transformed from investigators into counsellors, and that left them confused and defensive.

All the research studies had been approved by an ethical committee.

We suggested two ways to improve future research protocols: participants should be alerted in advance to the possibility that the research in which they are participating might reveal a previously unsuspected illness, and investigators should be required to formulate a plan to cope with this contingency.

Maybe the time has come to act on this modest proposal?