ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

3381–3400 of 6,161 studies

E2 ModerateCohortPEM not requiredCross-Sectional

Sleep abnormalities demonstrated by home polysomnography in teenagers with chronic fatigue syndrome.

Stores, G, Fry, A, Crawford, C·Journal of psychosomatic research·1998

Researchers used home sleep monitoring equipment to measure sleep quality in 18 teenagers with ME/CFS compared to healthy teens of the same age and gender. They found that teenagers with ME/CFS woke up much more frequently during the night—both for brief moments and longer periods—compared to the healthy group. These frequent sleep disruptions could help explain why young people with ME/CFS feel so exhausted during the day.

Sleep

E2 ModerateBehavioralPEM not requiredCross-Sectional

Chronic fatigue syndrome and seasonal affective disorder: comorbidity, diagnostic overlap, and implications for treatment.

Terman, M, Levine, S M, Terman, J S et al.·The American journal of medicine·1998

This study looked at whether ME/CFS symptoms get worse during winter months, similar to seasonal depression. Researchers asked 110 ME/CFS patients about their symptoms in summer and winter, and found that about one-third showed a seasonal pattern with winter worsening. This suggests that some ME/CFS patients might benefit from light therapy, a treatment commonly used for seasonal depression.

Sleep

E2 ModerateCohortPEM not requiredCross-Sectional

Factor analysis of unexplained severe fatigue and interrelated symptoms: overlap with criteria for chronic fatigue syndrome.

Nisenbaum, R, Reyes, M, Mawle, A C et al.·American journal of epidemiology·1998

Researchers surveyed over 1,500 people to understand how severe fatigue and related symptoms cluster together. They found that when fatigue lasts 6 months or longer, it tends to occur alongside three groups of symptoms: mood and thinking problems, flu-like symptoms, and vision problems. This pattern of symptoms matches what doctors use to diagnose ME/CFS, suggesting these conditions share common features.

E2 ModerateBehavioralPEM not requiredCase-Control

Chronic fatigue syndrome in psychiatric patients: lifetime and premorbid personal history of physical health.

Endicott, N A·Psychosomatic medicine·1998

This study compared 46 ME/CFS patients with two groups of psychiatric patients without ME/CFS to see if there were differences in their past physical health histories. Researchers found that ME/CFS patients reported more lifetime infections (including repeated mono-like illnesses), irritable bowel syndrome, and allergies before developing ME/CFS than the comparison groups. This suggests that a pattern of poor overall physical health earlier in life may play a role in developing ME/CFS.

E2 ModerateCohortPEM unclearCross-Sectional

Secretion of growth hormone in patients with chronic fatigue syndrome.

Berwaerts, J, Moorkens, G, Abs, R·Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society·1998

This study looked at growth hormone levels in people with ME/CFS, because low growth hormone has been seen in related conditions like fibromyalgia. Researchers tested 20 ME/CFS patients and compared them to healthy controls, measuring growth hormone in different ways. They found that ME/CFS patients had lower levels of a growth hormone marker (IGF-I) and tended to produce less growth hormone at night, though other growth hormone tests were similar between groups.

Endocrine Disruption

E2 ModerateCohortPEM not requiredCross-Sectional

Chronic fatigue syndrome: physical and cardiovascular deconditioning.

De Lorenzo, F, Xiao, H, Mukherjee, M et al.·QJM : monthly journal of the Association of Physicians·1998

This study compared the hearts and bodies of 273 ME/CFS patients with 72 healthy people. Researchers found that ME/CFS patients had smaller hearts and blood vessels, along with changes in blood markers like cholesterol and blood cells. The study suggests that ME/CFS patients may experience physical deconditioning similar to what happens when people are very inactive.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Correlations among Epworth Sleepiness Scale scores, multiple sleep latency tests and psychological symptoms.

Olson, L G, Cole, M F, Ambrogetti, A·Journal of sleep research·1998

This study looked at whether a simple questionnaire about daytime sleepiness (the Epworth Sleepiness Scale) actually measures the same thing as a more complex sleep test that measures how quickly people fall asleep. The researchers found that these two tests don't measure the same thing—the questionnaire is influenced by mood and psychological symptoms, while the objective sleep test is not.

Sleep

E2 ModerateReviewPEM not requiredReview-Narrative

Relationship Between Chronic Fatigue Syndrome and Neurally Mediated Hypotension.

Calkins, H, Rowe, PC·Cardiology in review·1998

This study explored a possible connection between ME/CFS and a condition called neurally mediated hypotension, where blood pressure drops suddenly due to problems with nerve signals that control blood vessels. Researchers found that when they treated patients for this blood pressure problem, about two-thirds of ME/CFS patients felt better. While these early results were promising, the study notes that larger, more rigorous trials were needed to confirm whether this treatment truly helps.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredCross-Sectional

Detection of Mycoplasma genus and Mycoplasma fermentans by PCR in patients with Chronic Fatigue Syndrome.

Vojdani, A, Choppa, P C, Tagle, C et al.·FEMS immunology and medical microbiology·1998

Researchers tested blood samples from 100 ME/CFS patients and 50 healthy people to see if a bacterium called Mycoplasma fermentans was present. They found this bacterium's genetic material in more than a third of ME/CFS patients compared to only 8% of healthy controls. Patients with higher amounts of the bacterium also had stronger immune responses against it, suggesting their bodies were reacting to the infection.

Immune System

E2 ModerateCohortPEM not requiredCross-Sectional

Relation between neuropsychological impairment and functional disability in patients with chronic fatigue syndrome.

Christodoulou, C, DeLuca, J, Lange, G et al.·Journal of neurology, neurosurgery, and psychiatry·1998

This study looked at whether memory and attention problems in ME/CFS patients are linked to how much their daily activities are limited. Researchers tested 53 ME/CFS patients and 32 healthy people on memory and concentration, and found that patients with more failing test scores reported spending significantly more days inactive. Importantly, this connection held true even when accounting for depression, suggesting the cognitive problems themselves—not just mood—contribute to disability.

Cognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

Exploring the validity of the Chalder Fatigue scale in chronic fatigue syndrome.

Morriss, R K, Wearden, A J, Mullis, R·Journal of psychosomatic research·1998

This study tested whether the Chalder Fatigue Scale—a common questionnaire used to measure tiredness in ME/CFS patients—actually measures what it claims to measure. Researchers analyzed responses from 136 ME/CFS patients and found that fatigue has four distinct components: mental tiredness (linked to thinking problems), sleep difficulties, physical weakness (linked to low fitness), and depression. The results suggest the 11-item version of the scale works better than the original 14-item version for measuring fatigue in ME/CFS.

SleepCognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

The role of delayed orthostatic hypotension in the pathogenesis of chronic fatigue.

Streeten, D H, Anderson, G H·Clinical autonomic research : official journal of the Clinical Autonomic Research Society·1998

This study looked at whether problems with blood pressure regulation—specifically a delayed drop in blood pressure when standing up—might explain why some people with chronic fatigue syndrome feel so exhausted. Researchers surveyed 431 patients with various neurological and hormonal disorders and found that fatigue was very common in people with delayed blood pressure drops and low cortisol levels (70-83%), but much less common in people with other conditions like multiple system atrophy (7-33%). This suggests a possible connection between blood pressure regulation problems and severe fatigue.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredCross-Sectional

The low dose ACTH test in chronic fatigue syndrome and in health.

Scott, L V, Medbak, S, Dinan, T G·Clinical endocrinology·1998

This study tested whether people with ME/CFS have a subtle problem with their stress hormone system, specifically the pituitary gland's ability to signal the adrenal glands to release cortisol. Using a sensitive test with a very small dose of ACTH (a hormone that triggers cortisol release), researchers found that people with ME/CFS showed a weaker cortisol response than healthy people, suggesting their adrenal system may not be functioning optimally.

Endocrine Disruption

E2 ModerateBehavioralPEM not requiredCross-Sectional

The persistence of fatigue in chronic fatigue syndrome and multiple sclerosis: development of a model.

Vercoulen, J H, Swanink, C M, Galama, J M et al.·Journal of psychosomatic research·1998

This study tested whether thoughts, behaviors, and emotions affect how severe fatigue becomes and stays in ME/CFS patients. Researchers found that when patients believe their symptoms are purely physical, they tend to be less active, which makes fatigue worse. They also found that how much control patients felt they had over symptoms and how much they focused on body sensations directly affected fatigue levels. Importantly, the patterns that explained fatigue in ME/CFS were different from those in MS patients.

Cognitive Impairment

E2 ModerateCohortPEM not requiredObservational

Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever.

White, P D, Thomas, J M, Amess, J et al.·The British journal of psychiatry : the journal of mental science·1998

This study followed 250 people who had either glandular fever (caused by Epstein-Barr virus) or a common cold to see how many developed long-lasting fatigue. Nearly half of those with glandular fever experienced severe tiredness immediately after infection, compared to only one-fifth with a common cold. About 9-22% of people with glandular fever developed chronic fatigue syndrome within six months, suggesting that this infection may trigger ME/CFS in some patients.

E2 ModerateCohortPEM not requiredCross-Sectional

Screening instruments for psychiatric morbidity in chronic fatigue syndrome.

Morriss, R K, Wearden, A J·Journal of the Royal Society of Medicine·1998

This study tested whether two common questionnaires can reliably detect anxiety and depression in ME/CFS patients. Researchers found that the Hospital Anxiety and Depression scale (HAD) works well for this purpose, but the Medical Outcome Survey's mental health scale produced too many false alarms and is not recommended for ME/CFS screening.

E2 ModerateCohortPEM not requiredCross-Sectional

Influence of exhaustive treadmill exercise on cognitive functioning in chronic fatigue syndrome.

LaManca, J J, Sisto, S A, DeLuca, J et al.·The American journal of medicine·1998

This study looked at how exercise affects thinking and mental processing in people with ME/CFS compared to healthy people. Both groups did exhausting exercise on a treadmill, then took thinking tests right after and 24 hours later. People with ME/CFS performed worse on these thinking tests after exercise, particularly on tasks involving speed and attention, and their thinking stayed impaired the next day.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Urinary free cortisol excretion in chronic fatigue syndrome, major depression and in healthy volunteers.

Scott, L V, Dinan, T G·Journal of affective disorders·1998

This study measured a stress hormone called cortisol in urine samples from people with ME/CFS, people with depression, and healthy individuals. The researchers found that people with ME/CFS had lower cortisol levels than healthy people, while people with depression had higher levels. This suggests that ME/CFS and depression affect the body's stress response system in opposite ways.

Endocrine Disruption

E2 ModerateCohortPEM not requiredCross-Sectional

A comparison of salivary cortisol in chronic fatigue syndrome, community depression and healthy controls.

Strickland, P, Morriss, R, Wearden, A et al.·Journal of affective disorders·1998

This study measured cortisol (a stress hormone) in saliva from women with ME/CFS, women with depression, and healthy women to see if cortisol levels differed between groups. Researchers found that women with ME/CFS had lower cortisol levels, especially in the evening and morning, compared to both depressed and healthy women. This suggests that ME/CFS involves different biological changes than depression.

Endocrine Disruption

E2 ModerateCohortPEM not requiredCase-Control

Yersinia enterocolitica and the chronic fatigue syndrome.

Swanink, C M, Stolk-Engelaar, V M, van der Meer, J W et al.·The Journal of infection·1998

This study looked for signs that a bacterium called Yersinia enterocolitica might cause ME/CFS by testing blood samples from 88 ME/CFS patients and 77 healthy people. Researchers found that antibodies (immune markers) to this bacterium were equally common in both groups, suggesting this particular infection is unlikely to be a major cause of ME/CFS.

Immune System

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Sleep abnormalities demonstrated by home polysomnography in teenagers with chronic fatigue syndrome.

Chronic fatigue syndrome and seasonal affective disorder: comorbidity, diagnostic overlap, and implications for treatment.

Factor analysis of unexplained severe fatigue and interrelated symptoms: overlap with criteria for chronic fatigue syndrome.

Chronic fatigue syndrome in psychiatric patients: lifetime and premorbid personal history of physical health.

Secretion of growth hormone in patients with chronic fatigue syndrome.

Chronic fatigue syndrome: physical and cardiovascular deconditioning.

Correlations among Epworth Sleepiness Scale scores, multiple sleep latency tests and psychological symptoms.

Relationship Between Chronic Fatigue Syndrome and Neurally Mediated Hypotension.

Detection of Mycoplasma genus and Mycoplasma fermentans by PCR in patients with Chronic Fatigue Syndrome.

Relation between neuropsychological impairment and functional disability in patients with chronic fatigue syndrome.

Exploring the validity of the Chalder Fatigue scale in chronic fatigue syndrome.

The role of delayed orthostatic hypotension in the pathogenesis of chronic fatigue.

The low dose ACTH test in chronic fatigue syndrome and in health.

The persistence of fatigue in chronic fatigue syndrome and multiple sclerosis: development of a model.

Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever.

Screening instruments for psychiatric morbidity in chronic fatigue syndrome.

Influence of exhaustive treadmill exercise on cognitive functioning in chronic fatigue syndrome.

Urinary free cortisol excretion in chronic fatigue syndrome, major depression and in healthy volunteers.

A comparison of salivary cortisol in chronic fatigue syndrome, community depression and healthy controls.

Yersinia enterocolitica and the chronic fatigue syndrome.

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