Doubts cast on organophosphate poisoning as cause of Gulf War Syndrome depression

December 20, 2006

Research published in the Journal of Epidemiology and Community Health casts doubt on the belief that organophosphate poisoning causes symptoms of depression among Gulf War veterans and farmers, who are exposed regularly to these chemicals.

Several studies have found that people who are regularly exposed to organophosphates are more likely than the general population to have symptoms of depression, including irritability, difficulty concentrating and poor sleep patterns.

But these studies do not prove that organophosphates are responsible for these symptoms.

Because an individual's genetic make-up (genotype) is randomly determined from their parents' genotype at the time of conception, genes can be used to test whether a non-genetic factor (for example, organophosphates) causes a disease.

The PON1 Q192R gene comes in three versions (QQ, QR or RR) and individuals with the RR version tend to metabolise organophosphates more slowly than those with either of the other versions.

Several previous studies have shown that Gulf War Veterans and sheep dippers with the RR genotype had a higher probability of symptoms.

In a bid to look at the association more closely, the authors tested out the theory among older women between the ages of 60 and 79, who would not have been habitually exposed to organophosphates in the course of their employment.

The women were already part of a long term study of women's health, involving more than 4,000 participants from 23 British towns.

They were surveyed about their levels of depression, and blood samples were taken for genetic testing.

Women with the genetic variant were significantly more likely to report depression than those without, the findings showed.

These new findings suggest that the association of this gene with depressive symptoms is unlikely to be explained by organophosphate poisoning, because the association is the same, irrespective of exposure to organophosphates, say the authors.

In fact, they suggest that exposure to more mundane everyday toxins or activities, rather than the specific chemical hazards found in warfare and farming, are likely to have a role.

The authors also note that recent research has suggested that rather than slowing the capacity to clear organophosphates from the body, the genetic variant actually does the opposite and speeds it up, so minimising exposure.

The authors point out that their findings do not negate the biological basis theory of the Gulf War Syndrome, but suggest that reliance on genetic vulnerability studies in specific groups is 'perhaps misplaced.'
-end-


BMJ Specialty Journals

Related Depression Articles from Brightsurf:

Children with social anxiety, maternal history of depression more likely to develop depression
Although researchers have known for decades that depression runs in families, new research from Binghamton University, State University of New York, suggests that children suffering from social anxiety may be at particular risk for depression in the future.

Depression and use of marijuana among US adults
This study examined the association of depression with cannabis use among US adults and the trends for this association from 2005 to 2016.

Maternal depression increases odds of depression in offspring, study shows
Depression in mothers during and after pregnancy increased the odds of depression in offspring during adolescence and adulthood by 70%.

Targeting depression: Researchers ID symptom-specific targets for treatment of depression
For the first time, physician-scientists at Beth Israel Deaconess Medical Center have identified two clusters of depressive symptoms that responded to two distinct neuroanatomical treatment targets in patients who underwent transcranial magnetic brain stimulation (TMS) for treatment of depression.

A biological mechanism for depression
Researchers report that in depressed individuals there are increased amounts of an unmodified structural protein, called tubulin, in lipid rafts compared with non-depressed individuals.

Depression in adults who are overweight or obese
In an analysis of primary care records of 519,513 UK adults who were overweight or obese between 2000-2016 and followed up until 2019, the incidence of new cases of depression was 92 per 10,000 people per year.

Why stress doesn't always cause depression
Rats susceptible to anhedonia, a core symptom of depression, possess more serotonin neurons after being exposed to chronic stress, but the effect can be reversed through amygdala activation, according to new research in JNeurosci.

Which comes first: Smartphone dependency or depression?
New research suggests a person's reliance on his or her smartphone predicts greater loneliness and depressive symptoms, as opposed to the other way around.

Depression breakthrough
Major depressive disorder -- referred to colloquially as the 'black dog' -- has been identified as a genetic cause for 20 distinct diseases, providing vital information to help detect and manage high rates of physical illnesses in people diagnosed with depression.

CPAP provides relief from depression
Researchers have found that continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea (OSA) can improve depression symptoms in patients suffering from cardiovascular diseases.

Read More: Depression News and Depression Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.