Diagnosis of damage caused by OPs is a 'positive' for victims
BOB DAVIES, a consultant psychiatrist, began researching organophosphates and their possible link to mood disorders in the 1990s. In 1997 he published a clinical description of what appeared to be a distinctive syndrome related to chronic exposure to OPs - which he designated Chronic Organophosphate Induced Neuropsychiatric Disorder, or COPIND.
Dr Davies, based in Somerset, has now seen in excess of 200 patients with the disorder, and remains one of very few who have officially recognised the illness. However, he believes GPs, along with many others in the health system, are becoming more receptive to the idea that COPIND exists - the problem remains that the government and its advisors are not.
"You have to remember that dipping was compulsory for over 15 years, so if it was shown that a significant number of people suffered ill-health as a result of this policy; the compensation bill for the Government and the agrochemical industry could be huge."
According to Dr Davies this would explain the Government's reluctance to fund in-depth research into OP poisoning which might prove a positive result. However, there is another facet to this reluctance, what Dr Davies refers to as the UK's 'odd approach' to medically unexplained diseases, such as ME and OP poisoning.
"If you look at the International Classification of Diseases published by the WHO, ME is classified as neurological as opposed to psychiatric, which is also the feeling upheld in continental Europe. Depressive illnesses have physiological concomitants and as such they are basically disorders of chemical transmission.
"However, for some obscure reason in the UK there is a movement to say illnesses like ME and OP poisoning are not physical at all. This has caused a lot of damage and driven many people to despair after being told all they need is psychotherapy" he added.
Dr Davies believes the most positive thing he has done is simply to say to people 'this isn't in your mind, you're not going mad, you have actually been damaged by something'. While little can be done to treat people, recognition that the physical illness exists allows his patients to go forward.
There is often confusion in diagnosing OP poisoning, due to the number of symptoms involved, however the fact that there are so many also provides 'strong' evidence for the existence of a syndrome.
"There are whole string of conditions which would explain a sub-set of the symptoms of COPIND, but I know of nothing which explains the totality."
"The most common confusion arises between COPIND and chronic fatigue syndrome (CFS) but the question is: what is CFS? It isn't a syndrome because if you look at the percentage of people reporting any given symptom other than fatigue itself, the highest will be 15-20 per cent whereas with OP patients it will be about 80-90 per cent, and we don't use fatigue as part of our diagnostic criteria.
"In the first 20 or 30 cases I saw the same symptoms keep cropping up - they weren't related and varied from problems with mood and memory to physical problems and sensitivity to alcohol, but everybody reported them" he added.
Dr Davies put this theory to the test when he carried out a survey of 145 farmers in Cornwall and West Devon. "Again, there was a remarkable consistency: approximately 10 per cent of those exposed to OPs experienced ill health and a whole stack of these symptoms."
"An argument often put forward by epidemiologists is that the symptoms are non-specific and therefore don't point to any particular cause, but if that was the case you would expect there to be a lot of people with no symptoms, a few with one, but then almost nobody with more than seven or eight.
"However in our survey, those who had been exposed showed a completely different trend with a peak at around the eight symptom mark."
The graph Dr Davies then extrapolated from the survey showed a pattern which is about the strongest evidence there is for existence of a syndrome.
"I have shown the graph to colleagues that aren't involved in the OP story and their mouths literally drop open.
"Further evidence came from when we were able to compare the symptom-counts between groups of exposed and nonexposed. Statistically the difference was enormous, again very strong evidence that OP exposure is strongly associated with this particular syndrome.
"However, in theory what we can't actually say is that exposure is causal, but I would challenge anybody to provide me with a more plausible explanation of the results," he added.
There have been many exercises looking at OPs and the potential existence of a syndrome, but Dr Davies said they have all been fatally flawed.
"Since our earlier work we haven't done much," admits Dr Davies. "To do solid research on this now would be extremely time-consuming and there just isn't the funding.
"Another argument also appears to be that there are no objective tests to what we have done - we are simply reporting on what people have told us, but that is true of all psychiatry;
"One of the most convincing cases I have heard is of a patient who met our criteria and so removed all sources of OPs from his house. Over time his condition improved, until one day he returned home and suddenly started feeling very ill with 'dipper's flu-like' symptoms. The reason? A fly-strip which was impregnated with an OP. It was removed and he began to feel better again.
"Now that is about as good an underlying study of this syndrome that I know, but it would be clearly unethical to test OP victims in this way because there is always a risk that further exposure could produce more damage," he added.
"It seems OPs require a totally different standard of proof compared to just about any other health hazard - you seem to have to prove beyond any shadow of a doubt that these things cause harm, but whatever happened to erring on the side of caution?"