Evidence browser

Prevalence of chronic fatigue syndrome in an Australian population.

Lloyd, A R, Hickie, I, Boughton, C R et al.·The Medical journal of Australia·1990

This Australian study estimated how common ME/CFS is in the community by looking for cases in a town of 114,000 people. Researchers found about 37 cases per 100,000 people, mostly affecting young adults of both sexes. The illness caused serious problems for patients, with nearly half unable to work or attend school.

Immunoglobulin subclass abnormalities in patients with chronic fatigue syndrome.

Wakefield, D, Lloyd, A, Brockman, A·The Pediatric infectious disease journal·1990

This study examined whether people with ME/CFS have unusual patterns in their antibodies—proteins the immune system makes to fight infection. Researchers looked at different types of antibodies in ME/CFS patients compared to healthy people. The findings suggested that ME/CFS patients may have immune system imbalances that differ from the general population.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Attributions and self-esteem in depression and chronic fatigue syndromes.

Powell, R, Dolan, R, Wessely, S·Journal of psychosomatic research·1990

This study compared how people with ME/CFS and depression think about their illness compared to people with depression alone. Researchers found that people with ME/CFS tend to blame external factors (like viruses or stress) for their symptoms, while people with depression alone tend to blame themselves. Interestingly, this outward-focused thinking may protect ME/CFS patients from some depression-related thought patterns, but may make them more vulnerable to physical symptoms like fatigue.

Epstein-Barr antibody titer and chronic fatigue syndrome.

Powell, M A·Journal of the American Academy of Nurse Practitioners·1990

This study looked at whether people with ME/CFS have higher levels of antibodies against Epstein-Barr virus (a common virus that causes mononucleosis) compared to healthy people. Researchers measured these antibody levels in patients diagnosed with chronic fatigue syndrome to see if there was a connection between past or ongoing EBV infection and the development of ME/CFS.

E2 ModerateCohortPEM not requiredObservational

The psychiatric status of patients with the chronic fatigue syndrome.

Hickie, I, Lloyd, A, Wakefield, D et al.·The British journal of psychiatry : the journal of mental science·1990

This study looked at whether people with ME/CFS have higher rates of depression and other mental health conditions than the general population. Researchers found that while some patients developed depression after getting ME/CFS, their rates of pre-existing mental illness were similar to everyone else. The study suggests that depression in ME/CFS patients is likely a response to having the illness, not a cause of it.

Immunologic abnormalities in chronic fatigue syndrome.

Klimas, N G, Salvato, F R, Morgan, R et al.·Journal of clinical microbiology·1990

This study examined immune system markers in 30 ME/CFS patients and compared them to healthy controls. Researchers found that patients had multiple immune system abnormalities, with the most consistent problem being that natural killer cells—white blood cells that fight infections and cancer—were not working properly, even though patients had more of these cells than normal. Patients also showed reduced responses to immune stimulation and changes in other types of immune cells.

E2 ModerateCohortPEM unclearCross-Sectional

Aerobic work capacity in patients with chronic fatigue syndrome.

Riley, M S, O'Brien, C J, McCluskey, D R et al.·BMJ (Clinical research ed.)·1990

This study tested how much physical activity patients with ME/CFS could manage on a treadmill and compared them to healthy people and those with irritable bowel syndrome. Researchers found that ME/CFS patients got tired much faster, had higher heart rates during exercise, and felt like they were working much harder than the other groups—even though they weren't doing as much activity.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

Tired, weak, or in need of rest: fatigue among general practice attenders.

David, A, Pelosi, A, McDonald, E et al.·BMJ (Clinical research ed.)·1990

This study asked over 600 people visiting their doctor about fatigue and what they thought caused it. About 1 in 10 people reported severe fatigue lasting a month or longer. People blamed fatigue on different causes—some physical (like infections), some psychological or social (like stress or family responsibilities)—and the study found that fatigue itself looked similar whether it lasted a short time or persisted longer.

High frequency of fibromyalgia in patients with chronic fatigue seen in a primary care practice.

Goldenberg, D L, Simms, R W, Geiger, A et al.·Arthritis and rheumatism·1990

This study looked at whether people with chronic fatigue also have fibromyalgia, a condition involving widespread muscle pain and tender points. Researchers examined 27 patients with debilitating fatigue lasting at least 6 months and found that 70% of them had the widespread pain and tender points typical of fibromyalgia. This suggests that many people with chronic fatigue may also have fibromyalgia.

Pain and Sensitization

E2 ModerateCohortPEM not requiredObservational

Asthenic symptoms in a rural family practice. Epidemiologic characteristics and a proposed classification.

Shahar, E, Lederer, J·The Journal of family practice·1990

This study looked at fatigue and weakness complaints in a rural doctor's office over 10 years. Researchers found that about 1 in 3 patients reported these symptoms at some point, with more women affected than men. Most cases improved on their own, and doctors often couldn't identify a specific cause.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Cardiac function at rest and with exercise in the chronic fatigue syndrome.

Montague, T J, Marrie, T J, Klassen, G A et al.·Chest·1989

This study looked at heart function in 41 ME/CFS patients compared to healthy volunteers. While the hearts looked normal at rest, patients became exhausted during exercise much sooner than healthy people—their heart rates climbed more slowly and didn't reach the expected levels, even though their resting heart rhythms and structure were completely normal.

Post-Exertional Malaise

Psychiatric diagnoses in patients who have chronic fatigue syndrome.

Kruesi, M J, Dale, J, Straus, S E·The Journal of clinical psychiatry·1989

This study looked at 28 patients with ME/CFS to see how often they had been diagnosed with psychiatric conditions like depression. The researchers found that psychiatric diagnoses were common in this group. Importantly, when they reviewed medical records, they discovered that most of these psychiatric conditions had started before the ME/CFS illness began, not after.

Diagnosing myalgic encephalomyelitis.

Zala, J·The Practitioner·1989

This study looked at how doctors can diagnose ME/CFS, especially when standard blood tests don't show clear evidence of infection. Researchers compared patients who had lab evidence of infection with those who didn't, and discussed what doctors should look for to make a reliable diagnosis based on symptoms and clinical presentation alone.

Immunological abnormalities in the chronic fatigue syndrome.

Lloyd, A R, Wakefield, D, Boughton, C R et al.·The Medical journal of Australia·1989

This study compared the immune systems of 100 ME/CFS patients with 100 healthy people to see if immune problems might explain why ME/CFS causes such severe fatigue. Researchers found that ME/CFS patients had fewer immune cells and weaker immune responses than healthy people. These findings suggest that problems with how the immune system works may be involved in causing ME/CFS.

E2 ModerateReviewPEM not requiredReview-Narrative

Nondiscocytic erythrocytes in myalgic encephalomyelitis.

Simpson, L O·The New Zealand medical journal·1989

Researchers looked at red blood cells from 102 people with ME/CFS using a powerful microscope and compared them to healthy people and those with multiple sclerosis. They found that people with ME/CFS had fewer normal-shaped red blood cells and more cup-shaped red blood cells than the other groups. This suggests ME/CFS may have a physical cause that could potentially be detected through a blood test.

Biomarkers

Fibromyalgia and its relation to chronic fatigue syndrome, viral illness and immune abnormalities.

Goldenberg, D L·The Journal of rheumatology. Supplement·1989

This study compared fibromyalgia and ME/CFS, two conditions that can feel similar to patients. Researchers found that most people with ME/CFS had tender points in their muscles similar to fibromyalgia patients. They also noted that both conditions may share similar underlying causes related to viral infections and how the immune system responds.

E2 ModerateCohortPEM unclearCross-Sectional

Coxsackie B viruses and myalgic encephalomyelitis.

Bell, E J, McCartney, R A, Riding, M H·Journal of the Royal Society of Medicine·1988

This study examined whether a common virus called Coxsackie B might be linked to ME/CFS. Researchers tested blood samples from ME/CFS patients and healthy people, and found that ME/CFS patients had higher rates of antibodies to this virus—suggesting they may have been infected with it. The findings suggest Coxsackie B viruses may play a role in this illness, though more research is needed to understand exactly how.

E2 ModerateBehavioralPEM not requiredObservational

The frequency of the chronic fatigue syndrome in patients with symptoms of persistent fatigue.

Manu, P, Lane, T J, Matthews, D A·Annals of internal medicine·1988

This study looked at 135 people with severe fatigue lasting at least 6 months to see how many actually had ME/CFS. The researchers found that only 6 patients (about 4%) met the criteria for ME/CFS, while most of the others had psychiatric conditions like depression or anxiety that were causing their fatigue. This suggests that ME/CFS is quite rare among people presenting with fatigue symptoms.

E2 ModerateCohortPEM unclearCase-Control

Cell-mediated immunity in patients with myalgic encephalomyelitis syndrome.

Murdoch, J C·The New Zealand medical journal·1988

This study tested immune system function in 33 ME/CFS patients compared to 33 healthy people of similar age and sex. Researchers used a skin test device called the multitest CMI to measure how well the immune system responded. They found that ME/CFS patients had weaker immune responses than healthy controls, suggesting their T-cells (a key type of immune cell) may not be working normally.