Researchers are looking for women who took part in a Leeds-based trial of antidepressant drugs in 1983.
The study had to be stopped after the participants suffered extreme side effects - and now experts want to know whether they had long-term problems.
Psychiatrist Prof David Healy is leading the search for the 12 women who tested the drug sertraline.
He said: “If alive, the women would be between 56 and 72. They may be living near Leeds still.”
The study was carried out by the-then Human Psychopharmacology Research Unit at the University of Leeds in 1983 on 12 healthy women then aged between 27 and 43. It was testing sertraline, a type of anti-depressant which was later launched under the brand name Zoloft.
Half of the women on the trial were given the drug and the other half had a placebo.
However the planned two-week study had to be stopped on the fourth day because of severe side effects. The results were never published.
Now Prof Healy, director of the North Wales Department of Psychological Medicine of Cardiff University, wants to find the women involved.
He said he had seen a medical report from the trial in the archive of drug company Pfizer in New York.
“The side effects that seemed most clearly linked to sertraline were apprehension, insomnia, movement disorders, and tremors,” he said.
In 2003 drugs watchdog the Medicines and Regulatory Authority issued a warning about certain types of anti-depressants, including sertraline, saying they should not be prescribed to children and young people because of an increased risk of suicidal behaviour in these age groups.
Research psychologist Dr Joanna Le Noury, who is working with Prof Healy, said they now wanted to track down the Leeds participants.
Dr Le Noury said: “The idea is to get some interviews about what went on with the study and their experiences.
“It’s also to find out how things have panned out since. Because they had a strange reaction to the drug at the time, whether they have had similar drug reactions since.”