By DR. TIFFANY CHAO and DR. SHARI BARNETT:

The March 2011 earthquake that triggered plant explosions and a meltdown in a Japanese nuclear power plant caused a chain reaction in the psyche of the workers at this plant, making them more vulnerable to emotional stress from perceived discrimination shortly after the disaster, according to a new study.

Researchers behind the study, published Tuesday in the Journal of the American Medical Association, administered a questionnaire to two sets of power plant workers in May and June of 2011. One group was from the Daiichi plant, where the major meltdown occurred, while the other was from the Daini nuclear power plant, which exhibited some damage but remained mostly intact.

Since the power plants had been criticized for their response efforts in the wake of the disaster, the researchers included questions designed to assess whether subjects had been the targets of discrimination or slurs from others.

The study found that while there was no difference between the number of acts of discrimination experienced by the two groups, the barbs seemed to be especially hurtful to workers who had staffed the doomed Daiichi plant. Ten percent more workers from this plant reported that they experienced psychological as well as post-traumatic stress response, compared with stress then reported by the Daini workers.

Reported psychological stress symptoms included feelings of nervousness, hopelessness, restlessness and worthlessness, as well as depression.

"This is the first study to our knowledge to explore discrimination as a factor in post-disaster mental health," lead study author Dr. Jun Shigemura of the department of psychiatry at National Defense Medical College in Saitama, Japan, wrote in the study.

Psychiatrists agree that the perception of discrimination after the meltdown clearly played an important role in the development of post-traumatic stress response in the workers.

"This study leads us to the conclusion that discrimination of survivors of life-threatening situations such as the meltdowns in Japan is very important in PTSD," says Dr. Gene Beresin, director of child and adolescent psychiatry at Massachusetts General Hospital and McLean Hospital.

Other doctors acknowledge that the workers were affected not only by the disaster, but by their collective experiences that followed.

"It would not be surprising that both experience at the disaster, as well as discrimination, will have a psychological impact on the disaster workers," says Dr. Bennett L. Leventhal, deputy director of the Nathan Kline Institute for Psychiatric Research in Orangeburg, N.Y. "However, it is also possible that a number of other factors will play equally, if not more, critical roles in affecting the response to the disaster experience."

Indeed, discrimination is just one kind of continuing stress being experienced by the workers.

"On top of being exposed to significant trauma by experiencing a huge earthquake, witnessing an explosion, and losing colleagues and family, the residents in Fukushima are currently living under the fear of the unknown effects of radiation in the air and grounds that their children play in," says Dr. Mai Uchida, a fellow in child and adolescent psychiatry at Massachusetts General Hospital in Boston.

Nevertheless, Uchida points out that despite the workers' reports of discrimination, the country as a whole has still been supportive overall.

"In Japan, every single governmental employee received a 10 percent reduction in their salaries this year so that the government can use that money for helping the recovery of disaster areas," Uchida says. "I cannot see any other country pass this arrangement without a riot from people who were not affected by the disaster.

"The value of harmony, fairness and helping each other in Japan has been incredibly impressive during this disaster recovery time."