Evidence browser

Increased IgA and IgM responses against gut commensals in chronic depression: further evidence for increased bacterial translocation or leaky gut.

Maes, Michael, Kubera, Marta, Leunis, Jean-Claude et al.·Journal of affective disorders·2012

This study looked at whether depression might be linked to bacteria leaking from the gut into the bloodstream. Researchers measured immune proteins (IgA and IgM antibodies) in the blood of depressed patients that target common gut bacteria, and found these antibodies were higher in depressed people than in healthy controls. The findings suggest that if gut bacteria do leak into the blood, the body's immune system reacts to them, which could contribute to depression—particularly long-lasting depression.

Chronic fatigue syndrome: acute infection and history of physical activity affect resting levels and response to exercise of plasma oxidant/antioxidant status and heat shock proteins.

Jammes, Y, Steinberg, J G, Delliaux, S·Journal of internal medicine·2012

This study examined whether a history of intense exercise or serious infections in ME/CFS patients affects how their bodies handle oxidative stress (cellular damage) and produce protective heat shock proteins. Researchers compared 43 ME/CFS patients with different backgrounds to 23 healthy controls, measuring stress markers and protective proteins both at rest and after exercise. They found that ME/CFS patients with a history of high-level sports or infections showed signs of greater cellular damage and weaker protective responses to exercise.

Post-Exertional Malaise

Subjective sleep quality and daytime sleepiness in a large sample of patients with chronic fatigue syndrome (CFS).

Mariman, A, Vogelaers, D, Hanoulle, I et al.·Acta clinica Belgica·2012

This study looked at sleep problems in 415 ME/CFS patients by asking them to complete questionnaires about sleep quality and daytime sleepiness. The researchers found that ME/CFS patients reported both poor sleep quality and high daytime sleepiness, but these two problems didn't always occur together—some patients had poor sleep quality without feeling sleepy during the day, and a smaller group resembled people with insomnia. The findings suggest that sleep problems in ME/CFS are complex and may affect different patients in different ways.

Sleep

Absence of xenotropic murine leukemia virus-related virus in blood donors in China.

Mi, Zhiqiang, Lu, Ying, Zhang, Shana et al.·Transfusion·2012

Researchers tested 391 healthy blood donors in China to see if they carried a virus called XMRV, which had been found in some people with chronic fatigue syndrome. Using sensitive laboratory tests, they found no evidence of this virus in any of the blood donors. This suggests that XMRV may not be present in the Chinese blood donor population.

E2 ModerateCohortPEM unclearCross-Sectional

Absence of XMRV in peripheral blood mononuclear cells of ARV-treatment naïve HIV-1 infected and HIV-1/HCV coinfected individuals and blood donors.

Gingaras, Cosmina, Danielson, Bryan P, Vigil, Karen J et al.·PloS one·2012

Researchers tested blood samples from HIV-infected patients, people with both HIV and hepatitis C, and healthy blood donors to see if they carried a virus called XMRV. XMRV had been reported in some ME/CFS patients, so scientists wanted to check if it was more common in people with weakened immune systems. They found virtually no XMRV in any of the blood samples tested, suggesting this virus is not present in these groups.

Humoral and cellular immune responses after influenza vaccination in patients with chronic fatigue syndrome.

Prinsen, Hetty, de Vries, I Jolanda M, Torensma, Ruurd et al.·BMC immunology·2012

This study tested how well people with ME/CFS respond to the flu vaccine compared to healthy people. Researchers measured both antibody production (humoral immunity) and T cell activity (cellular immunity) before and after vaccination. The results showed that people with ME/CFS had immune responses to the flu vaccine that were similar to healthy controls, suggesting their immune systems can respond normally to this vaccine.

E2 ModerateCohortPEM unclearCase-Control

Inflammatory and cell-mediated immune biomarkers in myalgic encephalomyelitis/chronic fatigue syndrome and depression: inflammatory markers are higher in myalgic encephalomyelitis/chronic fatigue syndrome than in depression.

Maes, Michael, Twisk, Frank N M, Ringel, Karl·Psychotherapy and psychosomatics·2012

This study found that people with ME/CFS have higher levels of inflammatory markers (immune chemicals) in their blood compared to people with depression, even though both conditions can cause fatigue and other similar symptoms. The researchers measured specific immune proteins and found that while both ME/CFS and depression involve some immune system changes, ME/CFS shows a distinctly different immune profile that helps distinguish it from depression.

Chronic fatigue syndrome and subsequent risk of cancer among elderly US adults.

Chang, Cindy M, Warren, Joan L, Engels, Eric A·Cancer·2012

Researchers investigated whether people with ME/CFS have a higher risk of developing cancer. Using medical records from over 1.2 million elderly Americans, they found that people with ME/CFS had a slightly increased risk of non-Hodgkin lymphoma (a blood cancer), particularly certain subtypes. The study does not prove that ME/CFS causes cancer, but suggests that shared immune system problems or infections might explain the connection.

E2 ModerateCohortPEM unclearObservational

[Epidemiology, diagnostics, and treatment of complications after neuroinfections: chronic fatigue syndrome].

Verner, O M, Murashko, N K·Likars'ka sprava·2012

This study looked at how often ME/CFS occurs in people who have had brain infections, finding that more than 20% of patients who recover from certain infections develop ME/CFS afterward. The condition was more common in people aged 40-59, and women were affected about 4 times more often than men. While the exact cause remains unknown, researchers think it may be related to genetics, immune system problems, or lingering effects from infections like Epstein-Barr virus.

E2 ModerateBehavioralPEM not requiredObservational

Therapist effects and the dissemination of cognitive behavior therapy for chronic fatigue syndrome in community-based mental health care.

Wiborg, Jan F, Knoop, Hans, Wensing, Michel et al.·Behaviour research and therapy·2012

This study looked at how well cognitive behavior therapy (CBT) for ME/CFS works when delivered by different therapists in regular mental health clinics rather than specialized centers. Researchers found that the individual therapist made a big difference in patient outcomes—accounting for 21% of the improvement variation. The therapist's beliefs about using treatment manuals and the specific clinic where treatment happened both influenced how well patients did.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Confidence judgment in depression and dysphoria: the depressive realism vs. negativity hypotheses.

Szu-Ting Fu, Tiffany, Koutstaal, Wilma, Poon, Lucia et al.·Journal of behavior therapy and experimental psychiatry·2012

This study looked at how accurately people judge their own knowledge and abilities. Researchers compared three groups: healthy people, those with clinical depression, and people with chronic fatigue syndrome who felt sad or low. They found that people with depression were overly critical of themselves, while people with chronic fatigue syndrome were more realistic about their abilities—similar to healthy controls.

Cognitive Impairment

E2 ModerateBehavioralPEM unclearLongitudinal

Lyme disease in a British referral clinic.

Cottle, L E, Mekonnen, E, Beadsworth, M B J et al.·QJM : monthly journal of the Association of Physicians·2012

This UK study looked at 115 patients who were referred to a specialist clinic because doctors suspected they had Lyme disease. The researchers found that only 23% actually had Lyme disease, while about one-third had ME/CFS instead. Importantly, some ME/CFS patients had been incorrectly told they had Lyme disease by non-specialist doctors, leading them to take unnecessary antibiotics.

A preliminary prospective study of nutritional, psychological and combined therapies for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) in a private care setting.

Arroll, Megan Anne, Howard, Alex·BMJ open·2012

This study looked at whether three different approaches—psychology-based treatment, nutrition-based treatment, or a combination of both—could help people with ME/CFS over a 3-month period. All three groups reported feeling better in terms of fatigue, daily functioning, and overall symptoms, with the psychology group also feeling more in control of their condition. However, the study had important limitations: people weren't randomly assigned to groups, there was no control group to compare against, and many participants dropped out, so the results need to be interpreted carefully.

Alternative diagnoses to chronic fatigue syndrome in referrals to a specialist service: service evaluation survey.

Devasahayam, Anoop, Lawn, Tara, Murphy, Maurice et al.·JRSM short reports·2012

This study looked at patients referred to a specialist ME/CFS clinic to see how often doctors correctly identified ME/CFS versus other conditions. Researchers found that about half of all referred patients actually had different medical or psychiatric conditions instead of ME/CFS—most commonly sleep disorders or depression. This shows that careful specialist assessment is important to make sure patients get the right diagnosis.

Diagnostics

No biological evidence of XMRV infection in cervical smears from HIV/ HPV positive and negative Kenyan women.

He, Xiaotong, Walker, Thomas D J, Maranga, Innocent O et al.·PloS one·2012

This study tested whether a virus called XMRV could be found in cervical samples from 224 Kenyan women, some with HIV and some without. Using sensitive lab techniques, the researchers found no trace of XMRV in any of the samples. This supports the idea that XMRV, once linked to ME/CFS, is likely a lab contamination rather than a real human infection.

Absence of evidence for bornavirus infection in schizophrenia, bipolar disorder and major depressive disorder.

Hornig, M, Briese, T, Licinio, J et al.·Molecular psychiatry·2012

Researchers tested whether a virus called Borna disease virus (BDV) might cause depression, bipolar disorder, or schizophrenia. They carefully compared blood samples from 198 patients with these conditions and 198 healthy people, looking for signs of the virus. They found no evidence that the virus was present in either group, suggesting BDV is not responsible for these psychiatric illnesses.

E2 ModerateCohortPEM unclearCase-Control

Xenotropic and polytropic murine leukemia virus-related sequences are not detected in the majority of patients with chronic fatigue syndrome.

Paolucci, Stefania, Piralla, Antonio, Zanello, Cinzia et al.·The new microbiologica·2012

This study looked for two viruses (XMRV and MLV-related viruses) that had been suggested as possible causes of ME/CFS. Researchers tested 12 ME/CFS patients and 40 healthy control subjects. They found these viruses in only 2 of the 12 patients, while all controls tested negative. The results suggest these viruses are not common in ME/CFS patients, and previous reports of finding them may have been due to laboratory contamination with mouse DNA.

Responses to exercise differ for chronic fatigue syndrome patients with fibromyalgia.

Cook, Dane B, Stegner, Aaron J, Nagelkirk, Paul R et al.·Medicine and science in sports and exercise·2012

This study compared how the bodies of ME/CFS patients respond to moderate exercise on a stationary bike. Researchers found that patients who have both ME/CFS and fibromyalgia (a condition causing widespread pain) showed different heart and breathing responses during exercise compared to healthy people, including higher perceived effort and different blood pressure patterns.

Post-Exertional Malaise

Impaired blood pressure variability in chronic fatigue syndrome--a potential biomarker.

Frith, J, Zalewski, P, Klawe, J J et al.·QJM : monthly journal of the Association of Physicians·2012

ME/CFS is often associated with problems in the autonomic nervous system, which controls heart rate and blood pressure. This study measured how heart rate and blood pressure respond to position changes in 68 ME/CFS patients and 68 healthy controls. The researchers found that ME/CFS patients showed abnormal patterns in blood pressure variability that could potentially be used as a diagnostic test.

Autonomic Nervous System