Mitocondria, no hipocondria

[elipoarch]

[t]Mitochondria, not hypochondria[/t]
Thursday, January 06, 2011

University of Hull Professor of Psychology Rhona Johnston argues against the widespread belief that ME/chronic fatigue is a psychological condition…

ME/chronic fatigue syndrome (ME/CFS) is a chronic state of profound exhaustion, often accompanied by pain, sleep problems and cognitive dysfunction, and it is made worse by exercise. In my local health authority area, individuals with a long-term fatigue problem used to be sent to the immunology department at the regional hospital for diagnosis and treatment, but now they are referred to a psychiatrist. This is a growing trend throughout the UK. These days, getting a diagnosis of chronic fatigue is tantamount to getting a psychiatric diagnosis. This is good for creating work for psychiatrists, but is it good for the individuals concerned? If their condition is a physical illness, they will not receive suitable treatment and so will not make a full recovery.
The psychiatric view of what they term 'chronic fatigue syndrome' (the term 'fatigue' clearly trivialises the severity of this illness) has gained considerable ground in the UK in recent years, aided by the supposed lack of evidence of physical causes of the condition. What evidence can psychiatrists adduce to support their assertion that ME/CFS is a purely psychological illness, that is, a form of hypochondria?

Psychiatrists argue that individuals with medically unexplained symptoms have 'functional somatic syndromes' – that is, although their symptoms appear to be physical, they are psychological in origin. It has been argued, on the basis of an analysis of the literature, that having the belief that ME/CFS is a physical illness leads to a poorer prognosis, and that these faulty attributions perpetuate the illness. Thus the fact that these individuals believe that they have a physical illness is seen as a further manifestation of their psychological problems. However, if those who assert that they have a physical illness do indeed have one, the prognosis for recovery without suitable treatment is clearly going to be poor.

One of the main treatments on offer for the condition is cognitive behavioural therapy (CBT), which has been shown to lead to a significant reduction in fatigue symptoms. This finding might be taken as support for the idea that ME/CFS has a psychological cause. However, there is a higher incidence of depression in those with chronic physical illnesses than in the general population, although in the case of ME/CFS this has been found to be no higher than in, for example, rheumatoid arthritis. Thus CBT may, for a subset of individuals, ameliorate some of the tiredness resulting from a concomitant depression, while not addressing the underlying fatiguing disorder. It is unclear, however, if this is indeed the case, as the authors of these studies use ME/CFS classification criteria that take fatigue as the main symptom. The exclusion of physical symptoms allows the inclusion of individuals who do primarily have a psychiatric disorder. Thus the statistical reduction in fatigue found with CBT may be largely due to the fact that individuals suffering purely from depression are included in these studies. It should also be noted that there is a lack of evidence of long-term benefits of CBT for individuals with an ME/CFS diagnosis.

The higher proportion of women suffering from ME/CFS is also thought to be evidence that the illness is psychosomatic. It is unclear why this should indicate a psychological illness; after all, women are more prone to gallstones as well. It is noteworthy that when a doctor made a study of viral illnesses in his patients over a 40 year period, of those who subsequently experienced central nervous system pathology, 67.8% were women (of whom a third also experienced ME/CFS) and 32.2% were men (of whom a third also had ME/CFS). Thus there was a clear physical basis for the disproportionate number of females suffering from ME/CFS in this study.

It has also been asserted that ME/CFS is a psychiatric illness because patients have often experienced abuse in childhood. However, stressors like abuse are known to cause physical ailments. For example, it has been found that child abuse is associated with an increased incidence of ischemic heart disease. It has also been shown that individuals having severe chronic stressors in the 12 months prior to being deliberately exposed to a virus were significantly more likely to become ill than those with acute stressors or a low number of stressful life events.

A mitochondrial problem?
It is clear that there is little evidence in favour of a psychological explanation of ME/CFS. We therefore need to consider the biomedical evidence for a physical disorder, of which there is a considerable amount. To aid simplicity, the approach taken here is to consider the possibility that individuals with ME/CFS may in the majority of cases have a similar physical problem, but that it may have diverse causes. A recent study has found that 70 out of 71 individuals suffering from chronic fatigue had abnormally low mitochondrial function. Mitochondria are organelles within cells and are the main producers of cellular energy. Mitochondria have to have an intact inner membrane to produce energy via a process called the electron transport chain. There is evidence that a wide range of chemicals impair mitochondrial function, including pesticides, herbicides, PCBs, solvents, toxic metals (such as dental amalgam), plastics, and fluoride. Impairments can also be caused by drugs such as antibiotics, non-steroidal anti-inflammatories and anti-parasite drugs.

There are also infections that cause mitochondrial problems, such as mycoplasma. This is a micro-organism that lacks a cell nucleus and a cell wall; it damages the inner membrane of mitochondria, depleting the nutrients in the cells, disrupting the electron transport chain, and causing chromosomal aberrations in the host cell. Studies by Dr Garth Nicolson have shown that individuals with ME/CFS have many bacterial and viral infections; however, a high percentage of them have mycoplasma infections. Thus, over a number of studies, Nicolson and his group have found that between 51% and 68.9% of individuals with a chronic fatigue diagnosis have a mycoplasma infection. Most of these studies were carried out in the United States, but the higher figure comes from a Belgian study, in which only 5.6% of controls showed signs of the infection. Nicolson's group has also shown that using a supplement that restores the mitochondrial membrane leads to both a reduction in fatigue and an increase in mitochondrial function in individuals with chronic fatigue. Clearly, the infection scenario is a complicated one; susceptibility to mycoplasma and other infections may arise from having an immune system weakened by viruses, and viruses themselves might damage mitochondria. However, getting rid of a mycoplasma infection in those affected will be very beneficial for energy levels, and so reduce stress on the body.

Chronic exposure to stress can in itself damage mitochondria and also impair the functioning of the adrenal glands. Adrenal insufficiency could be a primary cause of ME/CFS in some individuals, as the symptoms are similar to those of Addison's disease. Less extreme debilitating adrenal problems also occur. It has been shown that overworking the stress system leads to problems in keeping a balance between the functioning of the hypothalamic-pituitary-adrenal (HPA) axis and the immune system. If there is an immune challenge, this produces inflammation, and the actions of the HPA axis reduce it by damping down the inflammation. However, if the body has to do this often it becomes overstressed and cannot maintain the balance – this is likely to happen if the body is dealing with a long-term infection like mycoplasma.

Treatment
What can the NHS do to help individuals with ME/CFS? At the moment, many individuals are offered expensive but harmless CBT. This technique is now widely used for so many illnesses, including cancer, that it can even be purchased online. They are also offered potentially damaging graded exercise regimes. Exercise can be very beneficial, but not if misinformed practitioners believe their patients to be depressed and persuade them to exercise beyond their reserves of cellular energy. Pacing is excellent and can cost nothing – here, individuals make sure that they keep their activity level within their energy envelope, and so avoid bouts of disabling exhaustion.

In order to help at least some people recover, it would seem a good use of resources for the NHS to screen ME/CFS patients for low mitochondrial function, adrenal problems (not just testing cortisol levels at midday) and mycoplasma infections. The latter can be treated by antibiotics, which if administered early on could mean that these individuals would avoid having to suffer this debilitating disease for decades, with the consequent weakening of their adrenal glands. Removing this infection is unlikely to lead to an immediate cure for long-term sufferers because of collateral damage to other bodily systems, but there must be a chance that a proportion of individuals will regain their health and lead happier and more productive lives.

[elipoarch]

Ya era hora que un psicólogo dijera unas cuantas verdades

[Clara]

La verdad, parece que está bien informado. El estudio de la función mitocondrial al que se refiere es al del Dr. McLaren, Dr Myhill y Dr E. Bood, hace ya unos años. De los 71 , habia uno que no estaba en el nivel bajo en uno de los 4-5 parámetros que midieron, en los otros sí.
Sabe lo que pasa cuando te esfuerzas en hacer mas de lo que debes y sugiere acompasar el ritmo, como dicen todos los especialistas que conocen la enfermedad.

Me ha gustado el articulo. Muchos mas así hacen falta.
Un abrazo a tod@s