9 June 1995

OP/suicide link-up?

FARMINGS high suicide rate could be linked to organophosphorus chemical exposure, says consultant psychiatrist Dr Robert Davis.

He told the NFU/BMA conference there was strong evidence to suggest OPs disrupt a human biochemical pathway related to psychiatric disorders. "There is a clear neuro-chemical way in for OP exposure to influence serotonin systems," said Dr Davis.

Psychiatric disorders influenced by serotonin, a biochemical that transmits messages to nerves, include depression, anxiety, obsessive compulsive disorder, impulsive suicide and aggression and sleep disorders. The "major effect" of OPs on serotonin may, in part, explain the high suicide rate among farming folk, he added.

"I am not saying if you are exposed to OPs you will develop depression. But we are talking about vulnerability," said Dr Davis. But OP exposure could shift this vulnerability. "Therefore, you are more likely to develop these psychiatric disorders than if you had not been exposed," he said.

Further basic scientific research was needed to investigate the exact cause and effect relationship. But policy makers also needed to consider a moratorium on the use of OPs because the argument linking psychiatric disorder to OP exposure was so strong.