Chronic fatigue syndrome
- Researchers have discovered 88 different genes in patients with chronic fatigue syndrome (CFS) related to blood disease, immune system function, and infection. Within this group of genes, the researchers identified seven subtypes, which could relate to infection response, and which might be used as part of a diagnostic test. They also honed in on five genes that could be possible targets for treatment.
- Researchers have discovered further evidence that a faulty stress response contributes to CFS. Women with CFS have significantly lower levels of the stress hormone, cortisol when they wake up in the morning compared with women who don't have the condition. Men with CFS do not have a similar drop in cortisol level, suggesting that a difference in the cortisol response may contribute to the increased risk of CFS only in women.
- Depression is a common symptom of CFS. In one study, 36% of CFS patients were depressed. Depression in these patients was associated with lower self-esteem and an increased likelihood of suicidal thoughts.
- CFS patients appear to have slower motor speed and reduced working memory than those without the condition, and these changes don't seem to be related to any psychological conditions or medication use.
- Children with CFS have more difficulty than usual paying attention and remembering, which may explain why kids with this condition have more trouble in school than their peers.
- Cognitive behavioral therapy (CBT) is effective at reducing the symptoms of fatigue compared with usual care. This treatment appears to be more effective than other psychological therapies.
Chronic fatigue syndrome (CFS), sometimes called immune dysfunction syndrome or myalgic encephalomyelitis (in Europe), is not a new disorder. In the 19th century the term neurasthenia, or nervous exhaustion, was applied to symptoms resembling CFS. In the 1930s through the 1950s, outbreaks of disease marked by prolonged fatigue were reported in the United States and many other countries. Beginning in the early- to mid-1980s, interest in chronic fatigue syndrome was revived by reports in America and other countries of various outbreaks of long-term debilitating fatigue.
Unexplained chronic fatigue describes fatigue that lasts for more than 6 months, impairs normal activities, and has no identifiable medical or psychological problems to account for it. In addition to fatigue, people may complain of other problems, such as difficulty with memory or concentration, headaches, or sore muscles or joints.
The symptoms of CFS may be categorized as follows:
- Chronic fatigue syndrome (CFS). A number of criteria must be met in order for a patient's symptoms to be described as CFS. Six million patient visits are made each year because of fatigue, although only a very small percentage of these visits can be attributed to actual chronic fatigue syndrome.
- Idiopathic chronic fatigue. If the symptoms do not meet the criteria for CFS, the condition is referred to as idiopathic chronic fatigue, meaning the cause is unknown.
Although the exact causes of CFS are not known, researchers think infection, genetics, hormonal imbalances, and chemical toxins play roles in different patients.
In studies of large patient groups, 15 - 27% of people complain of long-term fatigue, but the majority of this fatigue can be explained by other medical or psychological problems. According to surveys, chronic fatigue syndrome (CFS) itself affects more than four out of every 1,000 Americans.
CFS occurs in both sexes, at all ages, and in all racial and ethnic groups. The Centers for Disease Control and Prevention (CDC) estimates that between 1 and 4 million people in the U.S. have the disease, but only half of people with CFS have seen their doctor for the condition. About 40% of people who report symptoms of CFS have another medical or psychiatric condition, according to the CDC.
Age and Gender
People ages 40 - 50 most often experience chronic fatigue. Studies have found that four out of five people with CFS are women, although women do not appear to have more severe symptoms than men with the disorder.
Children and adolescents can also have CFS. Most studies indicate that girls are more likely than boys to develop CFS, although one study found the incidence of the syndrome to be equal in children of both genders.
Depression and Psychological Factors
The link between psychological disorders and chronic fatigue syndrome is problematic because so many of the symptoms overlap. The rates of depression are very high in CFS patients, possibly higher than in patients with other conditions (notably fibromyalgia and multiple chemical sensitivity).
Studies report that most children and adolescents with CFS have psychiatric disorders. Psychological factors during childhood may increase susceptibility for CFS later in life, although studies have not found any consistent association between emotional or personality disorders and CFS to explain any causal role. Some psychological factors may, however, be risk factors for CFS.
Depression is very common in the general population. It affects up to one-fifth of all Americans at some point in their lives, and most depressed people feel fatigued.
There is some evidence that stress may trigger CFS in people who are genetically at risk for the disease.
Conditions That Commonly Occur in CFS Patients
A number of conditions overlap or coexist with chronic fatigue syndrome and have similar symptoms. Patients with CFS may also have a diagnosis of fibromyalgia, multiple chemical sensitivity, or both. It is not clear whether these and other conditions are risk factors for CFS, are direct causes, have common causes, or have no relationship at all with CFS.
Fibromyalgia. Fibromyalgia causes prolonged fatigue and widespread muscle aches. It is the disease most often confused with CFS. The two conditions also commonly appear together. In fact, many experts believe fibromyalgia is simply another variant of chronic fatigue syndrome or they are different manifestations of the same disease. CFS patients experience severe fatigue, whereas fibromyalgia patients experience more pain. One hypothesis is that the connection between the two conditions may be found in central sensitization, which is thought to cause fibromyalgia and may also cause CFS.
A characteristic feature of fibromyalgia is the existence of at least 11 distinct sites of deep muscle tenderness that hurt when touched firmly. The sites often include the:
- Side of the neck
- Top of the shoulder blade
- Outside of the upper buttock and hip joint
- Inside of the knee
Some patients with CFS exhibit similar tender pressure points. Recurrent sore throat, headache, low fever, and depression are also common symptoms of fibromyalgia. Like CFS, fibromyalgia is chronic and not curable.
Multiple Chemical Sensitivity. Multiple chemical sensitivity (MCS) is a term now used to describe a condition in which certain chemicals are believed to cause symptoms similar to CFS in some people. MCS has also been observed in people with CFS. The following proposed criteria can help recognize people with MCS:
- The symptoms are reproducible with repeated exposure to a chemical. (These are often common chemicals found in popular products, such as perfumes, fabric softeners, and air fresheners.)
- The condition is chronic.
- Symptoms can be produced by exposure to the chemical at levels lower than the person previously or commonly tolerated.
- The symptoms improve when the chemical is removed.
- Symptoms can be triggered by multiple substances that are chemically unrelated.
- Symptoms involve multiple organ systems.
As with CFS and fibromyalgia, there is uncertainty as to whether MCS is an actual medical condition or is psychologically based. In one study, for example, CFS patients who believed their problem was chemically triggered were exposed to either an active chemical or a placebo (an inactive substance). Both groups reported symptoms, including those exposed only to the placebo. It should be noted that everyone is exposed to many chemicals on a daily basis, and it is very difficult to determine whether chemicals are responsible for specific symptoms.
Eating Disorders. Eating disorders, notably bulimia and anorexia, have been observed in patients with CFS. The conditions often have overlapping risk factors, although it is unclear whether one causes the other.
Other Conditions that Commonly Coexist With CFS. A number of other conditions also may coexist with CFS and occur at higher-than-average rates among CFS patients:
- Chronic headaches
- Cognitive problems such as difficulty concentrating, impaired memory, and symptoms of attention deficit hyperactivity disorder (ADHD)
- Interstitial cystitis
- Irritable bowel syndrome
- Sleep problems
- Temporomandibular disorder (TMD)
Theories abound about the causes of chronic fatigue syndrome. No primary cause has been found that explains all cases of CFS, and no blood tests or brain scans can definitively diagnose the condition.
Convergence of Factors. A number of experts believe that CFS develops from a convergence of conditions that may include the following:
- Genetic factors
- Brain abnormalities
- A hyper-reactive immune system
- Viral or other infectious agents
- Psychiatric or emotional conditions
For example, most patients report some moderate-to-serious physical illness (such as a chronic viral infection) or emotional event (like an episode of depression) before CFS. Some experts theorize that such events, alone or in combination, may interact with certain neurologic and genetic abnormalities to trigger CFS.
Still, it is not clear what sequence of events actually leads to the fatigue and other prominent symptoms of this disorder. Nor is there any specific brain or nervous system problem that experts can point to with assurance.
CFS has been linked with genes involved in the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. These genes control response to trauma, injury, and other stressful events. Nevertheless, researchers have been unable to determine how the genetic variations influence symptoms.
A number of studies have found alterations in genes involved with immune function, communication between cells, and transfer of energy to cells.
Researchers have identified many different genes in patients with CFS related to blood disease, immune system function, and infection. However, no clear pattern has been found.
Central Nervous System and Hormone Abnormalities
Abnormal levels of certain chemicals regulated in the brain system known as the hypothalamus-pituitary-adrenal (HPA) axis have been proposed as a cause of CFS. This system controls important functions, including sleep, stress response, and depression. Of particular interest to researchers are the following chemicals and other factors controlled by the HPA axis:
- Changes in Important Neurotransmitters. Some patients with CFS have abnormally high levels of serotonin -- a neurotransmitter (chemical messenger in the brain), deficiencies of dopamine -- an important neurotransmitter associated with feelings of reward, or imbalances between norepinephrine and dopamine. However, routine clinical testing for such chemical imbalances is cost-prohibitive.
- Stress Hormone Deficiencies. A number of studies on CFS patients have observed lower levels of cortisol, a stress hormone produced in the adrenal glands. Deficiencies of cortisol have been suggested as the reason why CFS patients have an impaired and weaker response to psychological or physical stresses, such as infection or exercise. However, administering replacement cortisol improves symptoms only in some patients.
- Disturbed Circadian Rhythms. Evidence suggests that, in certain patients, CFS is a disorder of the sleep-wake cycle, which is regulated by the so-called circadian clock, a nerve cluster in the HPA axis. Some mentally or physically stressful event, such as a viral infection, may disrupt natural circadian rhythms. An inability to reset these rhythms results in a perpetual cycle of sleep disturbances. Medications that improve sleep can be very helpful for certain patients with CFS.
It is still not clear whether any of these changes are causes of chronic fatigue syndrome, or merely findings in some patients.
Because most of the features of CFS resemble those of a lingering viral illness, many researchers have focused on the possibility that a virus or some other infectious agent causes the syndrome in some cases.
Still, not all CFS patients show signs of infection. Although experts have long been divided on whether infections play any role in this disorder, subtypes of viral-related and non-viral CFS may both exist.
Viruses. The theory that CFS has a viral cause is not based on hard evidence, but on various observations that suggest an association, such as the following:
- CFS patients may be found to have elevated levels of antibodies to many organisms that cause fatigue and other CFS symptoms. Such organisms include those that cause Lyme disease, candida ("yeast infection"), herpesvirus type 6 (HHV-6), human T cell lymphotropic virus (HTLV), Epstein-Barr, measles, coxsackie B, cytomegalovirus, or parvovirus. Many of these infectious agents are very common, however, and none has emerged as a significant cause of CFS. Well-designed studies of patients who met strict criteria for chronic fatigue syndrome and of patients with chronic fatigue without any known cause have not found an increased incidence of any specific infections.
- In up to 80% of cases, chronic fatigue syndrome starts suddenly with a flu-like condition. However, there is no evidence that CFS is spread through casual contact, such as shaking hands or coughing, or by intimate sexual contact.
- In the U.S., there have been reports of cluster outbreaks of CFS occurring within the same household, workplace, and community (but most have not been confirmed by the Centers for Disease Control and Prevention). However, most cases of CFS occur sporadically in individuals, and do not appear to be contagious.
Immune System Abnormalities
CFS has sometimes been referred to as the "chronic fatigue immune dysfunction syndrome." A number of studies have found many irregularities of the immune system. Some components appear to be over-reactive, while others appear to be under-reactive, but no consistent picture has emerged to explain CFS as a disease of the immune system.
Allergies. Some studies have reported that a majority of CFS patients have allergies to foods, pollen, metals (such as nickel or mercury), or other substances. One theory is that allergens, like viral infections, may trigger a cascade of immune abnormalities leading to CFS. However, most allergic people do not have CFS.
Autoimmune Abnormalities. The risk profile for chronic fatigue syndrome is similar to the risk profiles for a number of autoimmune diseases. Studies are inconsistent, however, in reporting the presence of autoantibodies (antibodies that attack the body's own tissues) in CFS, and the disease is unlikely to be due to autoimmunity.
Low Blood Pressure
Studies have observed that some patients who fit the strict criteria for chronic fatigue syndrome also have symptoms of a condition known as neurally mediated hypotension (NMH). NMH causes a dramatic drop in blood pressure when a person stands up, even for as little as 10 minutes. Its immediate effects can be lightheadedness, nausea, and fainting.
However, studies have reported no higher incidence of NMH in chronic fatigue patients.
Psychological, personality, and social factors are strongly associated with chronic fatigue in most patients. The complex relationship between physical and emotional factors has yet to be fully understood, however. Studies have not found any consistent association between emotional or personality disorders and CFS to explain a causal role. Psychological factors, then, are unlikely to be a primary cause of CFS. However, they may play a role in increasing susceptibility to the disorder. In many cases, CFS promotes psychological and social dysfunction.
It is very difficult to diagnose chronic fatigue syndrome. Even experts do not have a clear definition of what chronic fatigue actually is, or what mechanisms in the brain or nervous system are responsible for it. The best diagnostic approach is to determine whether the patient matches the criteria for CFS and to rule out other possible causes of symptoms.
Criteria for Chronic Fatigue Syndrome
In May 2006, the Centers for Disease Control and Prevention (CDC) released a revised definition for Chronic Fatigue Syndrome based on a consensus of many of the leading CFS researchers and doctors (including input from patient group representatives). In the revised definition, chronic fatigue syndrome is considered a subset of chronic fatigue, a broader category defined as unexplained fatigue that lasts for 6 months or longer. Chronic fatigue is considered a subset of prolonged fatigue, which is defined as fatigue that lasts for 1 month or more.
Unexplained chronic fatigue can be classified as CFS if the patient meets the following criteria:
- Unexplained persistent or relapsing chronic fatigue that is either new or that started at a definite period of time; is not the result of ongoing exertion; is not substantially relieved by rest; and significantly reduces activities such as work, education, and social life.
- Also, four or more of the following symptoms, which must have continued or recurred during 6 or more consecutive months of illness and must not have started before the fatigue:
- Significant impairment in short-term memory or concentration
- Sore throat
- Tender lymph nodes
- Muscle pain
- Joint pain without swelling or redness
- Headaches of a new type, pattern, or severity
- Unrefreshing sleep
- Malaise that lasts for more than 24 hours after exertion
Conditions that Can Rule Out a CFS Diagnosis
- Any active medical condition that may explain the presence of chronic fatigue, such as:
- Untreated hypothyroidism (underactive thyroid gland)
- Sleep apnea and narcolepsy (common sleep disorders)
- Side effects of medication
- An illness (such as cancer, or hepatitis B or C virus infection) that relapsed or did not completely get better during treatment, that could explain the presence of chronic fatigue.
- A past or current major depressive disorder, such as:
- Bipolar affective disorder
- Delusional disorder
- Anorexia nervosa or bulimia nervosa
- Alcohol or other substance abuse that occurs within 2 years of the onset of chronic fatigue and at any time afterward.
- Severe obesity, as defined by a body mass index (BMI) equal to or greater than 45. (Note: Body mass index values vary considerably among different age groups and populations. No "normal" or "average" range of values can be suggested. The range of 45 BMI or higher was selected because it falls within the range of severe obesity.)
Any other abnormality found during an exam or other tests that could explain CFS symptoms must be resolved before further attempting to classify the condition.
In 2007, the National Institute for Health and Clinical Excellence (NICE) released new guidelines for the diagnosis and management of CFS in adults and children. According to these guidelines, CFS may be diagnosed if the person has disabling fatigue that starts suddenly, lasts a long time, keeps coming back, and can't be explained by another condition.
People with CFS also can have the following symptoms:
- Difficulty thinking, concentrating, remembering, finding the right words, planning, and organizing
- Difficulty sleeping
- Dizziness or nausea
- General malaise or flu-like symptoms
- Muscle or joint pain in many areas of the body without inflammation
- Painful lymph nodes without disease
- Fast heartbeat (palpitations) without heart problems
- Sore throat
- Worsening of symptoms with physical exertion
After ruling out other possible causes, the doctor should consider a diagnosis of CFS if symptoms have lasted for 4 months in adults or 3 months in children. Children should be diagnosed by a pediatrician.
Personal and Medical History
A doctor should first take a careful personal and family medical history (which may include a psychological profile), as well as perform a thorough physical examination. Patients should be prepared to answer questions such as:
- When did the fatigue first begin?
- Does anything make it worse or better?
- Is it better at certain times of the day?
- Does physical activity make it worse?
- Are there any other symptoms?
- Has anyone else in the family ever complained of fatigue?
- Is your personal and professional life stressful?
The doctor may also ask about any changes in weight, or request that a patient monitor his or her morning and afternoon body temperatures. Patients should report any drugs they are taking, including vitamins and over-the-counter or herbal medications.
Standard tests are typically recommended to rule out specific conditions that can cause persistent fatigue. These tests include:
- Blood count
- Blood tests for gluten sensitivity
- C-reactive protein
- Creatine kinase
- Erythrocyte sedimentation rate or plasma viscosity
- Liver function
- Random blood sugar (glucose)
- Serum calcium
- Serum creatinine
- Serum ferritin levels (only in children)
- Thyroid function
- Urea and electrolytes
- Urine test for protein, blood, and glucose
No blood, urine, or other laboratory test can specifically diagnose CFS. If any test is abnormal, it is not useful for diagnosing CFS specifically, and the doctor should look for other causes of these abnormalities.
That said, research has found that certain components in urine are unique in people with CFS, and may someday be considered biomarkers of the disease. Additionally, antibodies to Epstein-Barr virus, increased levels of isoprostanes, and decreased levels of alpha-tocopherol (vitamin E) -- markers of oxidative stress -- have been found in the blood of people with CFS.
Identifying Other Causes of Chronic Fatigue Syndrome
Among the many other common conditions that can lead to feelings of temporary exhaustion are the following:
- Extreme exercise
- Excessive stress
In most of these cases, fatigue can be relieved with adequate rest. It is important to note that longstanding fatigue can be a sign of a serious medical or psychological problem. A number of more serious conditions may cause persistent fatigue and other symptoms of CFS and should be ruled out. Patients and doctors should not overlook these diseases, even if the conditions have been previously treated, because they may not have completely resolved or they may cause residual fatigue. Doctors can usually distinguish these diseases from CFS after a clinical evaluation and laboratory testing.
Infectious Mononucleosis and Epstein-Barr Virus. Infectious mononucleosis is marked by fatigue and swollen glands. It primarily affects adolescents and young adults. Some patients may have fatigue that lasts for many months. Blood tests will indicate the Epstein-Barr virus (EBV), which causes mononucleosis.
Autoimmune Diseases. Some diseases, including systemic lupus erythematosus, multiple sclerosis, and rheumatoid arthritis, are caused by autoimmunity, a condition in which the person's immune system attacks the body's own tissues. The early symptoms of these conditions may mimic some of those that appear in CFS, such as muscle and joint pain and fatigue. These diseases, like CFS, also occur more often in women than in men. Most of these conditions can be confirmed with laboratory or x-ray/radiologic findings. However, some autoimmune diseases may evolve slowly. Even if a diagnosis of chronic fatigue syndrome is considered, doctors should keep track of any changes in symptoms over time to rule out these serious illnesses.
Post-Lyme Disease Syndrome. Rarely, patients treated for Lyme disease continue to have nonspecific symptoms, which can last for years after antibiotic treatment and that resemble symptoms of chronic fatigue syndrome.
Depression and Severe Mental Disorders. The Centers for Disease Control (CDC), which established the definitions for chronic fatigue syndrome, recognizes depression as one of the symptoms of CFS. In one study, 36% of CFS patients were depressed. Depression in these patients was associated with lower self-esteem and an increased likelihood of suicidal thoughts. However, according to the CDC, anyone with a history of major depression or other severe psychiatric disorders, including bipolar disorder and schizophrenia, does not meet the criteria for chronic fatigue syndrome.
Symptoms of major depression include the following:
- A depressed mood every day
- Significant weight gain or loss (10% or more of an individual's usual body weight)
- Insomnia or excessive sleeping
- Restlessness or a sense of being slowed down
- Low energy every day
- Worthless or inappropriately guilty feelings
- An inability to concentrate or make decisions
- Suicidal thoughts
- Loss of interest and enjoyment
Major depression is likely if a person has several of these symptoms and no physical symptoms (such as sore throat, aches and pains, or fever). The longer fatigue has continued without physical symptoms, the more likely that the diagnosis is depression.
A persistent form of minor depression called dysthymia may be more difficult to differentiate from CFS and may actually account for a subset of CFS cases. Dysthymia is characterized by many of the same symptoms that occur in major depression, but they are less intense and last much longer -- at least 2 years. The symptoms of dysthymia have been described as a "veil of sadness" that covers most activities.
Patients with depression generally perceive their illnesses differently than people with CFS:
- Patients with depression have significantly lower self-esteem, more thought distortions (for instance, focusing on the negative or personalizing their situations), and believe their condition stemmed from psychological factors.
- CFS patients, even those who also have depression or dysthymia, tend to identify medical causes as the source of their problems and to focus on physical symptoms.
Many previously healthy patients with CFS become depressed and anxious because they feel so exhausted all the time. CFS may also lead to highly stressful socioeconomic situations, such as social isolation and poverty. These situations can contribute to, and even cause emotional disorders in susceptible individuals, which can worsen CFS.
Sleep Disturbances. Certain sleep disorders may cause persistent fatigue and can be confused with CFS:
- Sleep apnea is a common disorder that can cause daytime fatigue without the patient being aware of the problem. Apnea is actually a breathing disorder that is often marked by loud snoring and thrashing in bed. A person may not realize the problem exists unless it is brought to his or her attention by a sleeping partner or observer.
- Narcolepsy is a peculiar and rare disorder in which a person suddenly falls asleep without any previous signs of fatigue.
- Other sleep disorders that cause daytime fatigue include insomnia and restless legs syndrome.
Researchers have found that people with CFS have altered amounts of slow wave sleep, which could indicate a problem with sleep regulation. Non-restorative sleep and nighttime restlessness are the most common complaints of people with CFS.
Conditions that Cause Joint Pain, Muscle Aches, or Both. A number of illnesses cause one or more CFS symptoms, including arthritic symptoms, fever, and fatigue.
Severe Obesity. People who are severely obese often have symptoms of chronic fatigue because of the stress imposed by their weight. People who are obese are also at higher risk for sleep apnea, which can confuse the diagnosis.
Other Medical Conditions that Usually Rule Out CFS. Many diseases, both benign and serious, can fully explain prolonged or chronic fatigue, including:
- Hemochromatosis (a hereditary disease caused by iron overload)
- Various forms of cancer
- Neuromuscular diseases (such as myasthenia gravis)
Drugs and Alcohol. Fatigue is a side effect of many prescription and over-the-counter medications, such as antihistamines. In addition, dependency on or abuse of alcohol or illicit drugs may manifest as chronic fatigue. Medications should be considered as a possible cause of fatigue if an individual has recently started, stopped, or changed medicines. Withdrawal from caffeine can produce depression, fatigue, and headache.
The physical severity of chronic fatigue syndrome varies. Most commonly, patients with CFS report that they have trouble fulfilling both home and work responsibilities.
Many CFS sufferers cannot work more than part-time. In unusual cases, patients are severely disabled and even bedridden. Such patients can do virtually nothing -- even light housework.
Patients with CFS are more likely to lose their jobs, possessions, and support from friends and family than are people who have other conditions that cause fatigue.
Most patients say that while fatigue is the most incapacitating symptom, mental impairment, such as an inability to concentrate or remember, is the most distressing symptom. The effects of CFS on mental functioning are complex. Some experts believe that the impaired mental functioning is due to depression, which is common in CFS patients. However, one study found that CFS patients have slower motor speed and reduced working memory than those without the condition, and these changes were independent of any psychological conditions or medication use.
Athough general intelligence is not impaired, CFS patients may test lower in certain mental functions, particularly speed and efficiency in processing complex information, and 40 - 60% have memory impairments. This impaired mental function occurs even if there is no depression or other psychiatric disorders.
Long-Term Outlook in Adults
Because the illness remains elusive and poorly defined, and there are few objective measures for recovery, experts have found it difficult to determine the long-term course of the disease. Many patients are not covered by insurance or have difficulty finding good care, so available statistics may be incorrect. Bearing these factors in mind, some studies have reported that more than half of patients who complain of chronic fatigue are still fatigued at 2 years. Although a variety of studies have attempted to identify factors that predict a more chronic or severe course, no clear conclusions can be made. Even if patients get progressively worse, however, the disorder is not fatal.
Outlook in Children
Although children with symptoms of chronic fatigue have not been as rigorously studied as adults, limited evidence suggests that CFS can be significantly disabling in young people. Studies report that adolescents who meet the criteria for CFS also have greater anxiety, depression, and school absenteeism than their peers. One study found that children with CFS have more difficulty than usual paying attention and remembering, which may explain why these kids have more trouble in school than their peers.
Still, some studies indicate that children have a better prognosis than adults and most will recover after 1 - 4 years. Several studies have indicated that cognitive-behavioral therapy is an effective treatment for adolescents with CFS.
There is no proven or reliable cure for CFS, and no drug has been developed specifically for this disorder. Because CFS remains poorly understood, many patients have problems finding good care. Overall, the recommended strategy for treatment includes a combination of the following:
- A healthy diet
- Antidepressant drugs in some cases, usually low-dose tricyclics
- Cognitive-behavioral therapy (CBT) and graded exercise for certain patients
- Sleep management techniques
Patients with the best chance for improvement are those who remain as active as possible and who seek to have some control over the course of the disorder. Patients should choose physicians who are willing to consider the problem as a medical condition with psychiatric components. They should be very wary, however, if the physician recommends excessive and expensive treatments that may have serious adverse effects and that have no proven benefits. For patients with severe CFS that cannot be managed with lifestyle changes and standard medications, asking the physician about enrolling in any available clinical trials may be helpful.
CBT is designed to help CFS patients regain a sense of control, and is proving to have substantial benefits for some patients. Some experts believe that patients who are diagnosed with CFS should be referred to therapists trained in cognitive-behavioral therapy. (Psychoanalysis and other interpersonal psychological therapies, which are concerned with subconscious thoughts and early childhood memories, are not generally helpful for CFS patients.)
The Goals of Cognitive-Behavioral Therapy. The primary goals of cognitive-behavioral therapy (referred to below as just cognitive therapy) are to change any distorted perceptions that individuals have of the world and of themselves, and to change their behavior accordingly. For CFS patients, this means learning to think differently about their fatigue, improving their ability to deal with stressful situations, and managing their disorder. CBT can also help people manage their sleep problems and find the appropriate activity levels for them. Cognitive therapy is particularly helpful for defining and setting limits, behaviors that are extremely important for these patients.
The Procedure. CBT is usually performed over 6 - 20 sessions, each lasting about an hour. Patients are also given homework, which usually includes keeping a diary and attempting tasks that they have avoided because of previous negative attitudes.
A typical cognitive therapy program may involve the following measures:
- Keep a Diary. The patient is almost always asked to keep an energy diary, which can be a key component of CFS cognitive therapy. The diary serves as a general guide for setting limits and planning activities. The patient uses the diary to track any factors, such as a job or relationship, that may be making the fatigue worse or better. It is also used to track the times of day when energy levels are at their highest and lowest.
- Adjust Schedule. The patient adjusts schedules to conform to energy peaks and valleys recorded in the diary. For instance, the patient may take a nap during low-energy times and plan important activities during high-energy times. Developing regular daily routines around probable energy spurts or drops may help establish a more predictable pattern.
- Confront Negative or Discouraging Thoughts. Patients are taught to challenge and reverse negative beliefs (such as "I'm not good enough to control this disease, so I'm a total failure."), and to use coping statements ("Where is the evidence that I can control this disease?")
- Be Flexible. Energy levels will most likely never be entirely predictable. Patients must be prepared to adapt to energy variations. Instead of taking a long nap, for instance, patients may need 5- to 10-minute rest periods every hour or more, possibly involving relaxation or meditation.
- Set Limits. Limits are designed to keep both mental and physical stress within a manageable framework so that patients do not get discouraged by forcing themselves into situations in which they are likely to fail. For example, tasks are broken down into incremental steps and patients focus on one step at a time.
- Prioritize. Patients learn to drop some of the less critical tasks or delegate them to others.
- Manage Impaired Concentration. Patients seek out activities that are appealing, focus attention, and help increase alertness. They learn to request instructions given as concise, simple statements. External distractions, such as music or talking, are kept to a minimum.
- Accept Relapses. Over-coping and accomplishing too much too soon can often cause a relapse of symptoms. Patients should respect these relapses and back off. They should not consider them a sign of treatment failure or personal failure.
Using both self-observation and specific tasks, patients gradually shift their fixed ideas that they are helpless against the fatigue that dominates their lives. They move to the perception that fatigue is only one negative experience among many positive ones.
Success Rates. One review of CFS trials reported that, of all therapies available to CFS patients, only cognitive behavioral therapy (CBT) and graded exercise showed conclusive benefits. CBT is effective at reducing the symptoms of fatigue compared with usual care, and it appears to be more effective than other psychological therapies. Although CBT doesn't bring patients completely back to normal, research has found that people who use the therapy have higher mental health scores, and are able to walk faster and with less fatigue than those who did not use CBT. Cognitive therapy may also be an effective treatment for adolescents with CFS. Young patients who received CBT have reported improvements in fatigue, functional status, and school attendance.
Not all studies support the benefits of cognitive therapy for CFS. It is important to note that different therapists may have different fundamental assumptions about CBT and may use different techniques. For instance, some therapists believe that CFS is a purely psychological problem and that patients must reject the notion of physical causes, abandon all reliance on assistive devices, and participate in challenging exercise programs. Other therapists do not attempt to change patients' underlying beliefs, but instead focus on helping patients conserve energy and better cope with the limitations of their illness. When considering CBT, patients and their families must be aware of such important differences in therapists.
The power of the mind to improve or oppose health problems is significant, and treatments that promote a positive outlook are beneficial for any disease.
A number of studies have suggested that a graded exercise program, in which patients perform increasingly more intense levels of exercise tailored to their individual abilities, has benefits for many patients with CFS. Exercise is best performed in combination with cognitive behavioral therapy.
Reports have found that 75% of CFS patients who were able to engage in exercise, particularly aerobic exercise, reported less fatigue and better daily functioning and fitness after a year. A review of clinical trials found that exercise therapy is beneficial for CFS, particularly when combined with patient education.
Some patient groups and experts contend that such studies use only patients with less severe conditions, and therefore the results do not apply to many CFS patients. Many patients have severe conditions, and some are very incapacitated (such as being wheelchair bound). These patients are unlikely to be able to do graded exercise. All CFS patients, in fact, have a lower exercise capacity than healthy individuals, and over-exercising can intensify symptoms. Some patients experience profound fatigue following even modest exercise. It is the primary reason for the low activity levels in these patients.
The following tips may be helpful for CFS patients when embarking on an exercise program:
- Work with your health care provider to determine a good starting level of activity for you. Start slowly and incrementally, beginning with as few as 3 - 5 minutes of moderate exercise a day. The goal is to increase activity by about 20% every 2 - 3 weeks, until you can handle about 30 minutes a day. Once you reach 30 minutes a day, start to increase the aerobic intensity of your workouts. (Capacity varies greatly among CFS sufferers, however, and some people may not be able to increase their aerobic intensity.)
- Establish limits and keep within them to avoid overexertion and relapse.
- Experiment with different forms of physical activity that suit your available energy levels. Some patients report great benefits from yoga or tai chi, which combine exercise with meditation.
- Setbacks will occur, but do not become discouraged.
Work with your health care provider to find a level of activity you can handle. Then gradually increase your activity level. Activity management should involve:
- Balancing your time between activity, rest, and sleep
- Spreading out more challenging tasks throughout the week
- Breaking big tasks into smaller, more manageable ones
- Avoiding doing too much on days when you feel tired
Although there is no evidence to support any specific dietary factors in CFS, patients should be sure to maintain a healthy diet that includes:
- Plenty of fresh, dark-colored fruits and vegetables, which are rich in antioxidants
- Fiber-rich foods
- Limited saturated fats (found in animal products)
- Omega-3 essential fatty acids, found in certain fish and oils
- Increased salt (only for those with low blood pressure)
- Starchy foods, particularly for nausea
Other Approaches for Managing Chronic Fatigue Syndrome
Stress Reduction Techniques. One panel of experts concluded that relaxation and stress-reduction techniques were helpful in managing chronic pain. These techniques also can help relieve the stress associated with the disease. They are not useful, however, as the primary treatment for CFS. A number of relaxation techniques are available, including:
- Deep breathing exercises
- Massage therapy
- Muscle relaxation techniques
Light Therapy. Patients with seasonal affective disorder (SAD) experience more depression during the winter, when the hours of sunlight decrease. With light therapy (phototherapy), the patient sits for about 30 minutes each day a few feet away from a box-like device that emits very bright fluorescent light (4,000 lux). Light therapy is best performed immediately after awakening in the morning.
Some CFS patients don't have much improvement from light therapy. However, the treatment may still help some patients with CFS whose symptoms are similar to those of patients with SAD.
Supportive Family and Groups. Having strong, supportive relationships with family and friends can help CFS patients get better. However, CFS patients should try not to impose unreasonable expectations on loved ones. Attending support groups with fellow patients may be very helpful. In one study, sharing experiences in a group therapy setting proved to be the most valuable component in treatment, and it improved patients' coping abilities.
No medications are specifically approved to treat CFS. However, some may be useful for pain or other symptoms, or in cases where CFS may have a specific cause. Doctors generally use combinations of drugs to accomplish specific goals, such as medication at night to improve sleep and medication in the morning to improve cognition and energy. Treatment is very individualized.
Mild Pain Relievers
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs). Patients with CFS may find relief using NSAIDs -- common pain relievers that reduce pain and swelling. Types of NSAIDs include aspirin, ibuprofen (Motrin, Advil, Nuprin), and naproxen (Aleve, Naprosyn, Naprelan, Anaprox).
Although NSAIDs work well, long-term use can cause stomach problems, such as ulcers and bleeding. In April 2005, the FDA asked NSAID manufacturers to include a warning label on their products that alerts users of an increased risk for cardiovascular events and gastrointestinal bleeding. Due to its proven cardiovascular benefits, aspirin was excluded from these labeling revisions.
NSAIDs can also increase blood pressure, particularly among people already being treated for hypertension. (About 12 - 15% of elderly people take both an NSAID and an antihypertensive drug.) Piroxicam, naproxen, and indomethacin appear to pose the greatest risk of high blood pressure. Sulindac has the smallest effect.
Other side effects of NSAIDs include:
- Ringing in the ears
- Skin rashes
- Possibly depression
NSAIDs can cause kidney damage. (The damage gets better once the patient stops using the drug.) People with high blood pressure, severe circulation disorders, or kidney or liver problems, as well as people taking diuretics or oral hypoglycemics, must be closely monitored if they need to use NSAIDs on a long-term basis. Because NSAIDs reduce blood clotting, NSAID users who are scheduled for surgery should stop taking those drugs a week before the operation.
COX-2 Inhibitors (Coxibs). Coxibs block an inflammation-promoting enzyme called COX-2. This class of drugs was initially believed to work as well as traditional NSAIDs, but with fewer stomach problems. However, numerous reports of cardiovascular events, skin rashes, and other adverse effects prompted the FDA to re-evaluate the risks and benefits of the COX-2 drugs. Rofecoxib (Vioxx) and valdecoxib (Bextra) were withdrawn from the U.S. market following reports of heart attacks in patients taking the drugs. Celecoxib (Celebrex) was still available at the time of this report, but labeled with strong warnings and a recommendation that it be prescribed at the lowest possible dose for the shortest duration possible. Patients should ask their doctor whether the drug is appropriate and safe for them.
Because of the association between depression and CFS, antidepressants are often tried, with varying degrees of success. Common side effects of many antidepressants include:
- Dry mouth
- Reduced sexual drive
- Slightly increased heart rate
Virtually all antidepressants have complicated interactions with other drugs, and some of these interactions are very serious.
Tricyclic Antidepressants. Antidepressants known as tricyclics may be particularly helpful for CFS patients. For example, the tricyclic amitriptyline (Elavil) is known to relieve many of the symptoms of CFS, including sleeplessness and low energy levels. These drugs may provide benefits by promoting deep sleep and inhibiting pain pathways in the nervous system. Improvement in symptoms can take 3 - 4 weeks. Other tricyclics include doxepin (Sinequan), desipramine (Norpramin), nortriptyline (Pamelor), clomipramine (Anafranil), and imipramine (Tofranil, Janimine). Patients with CFS normally respond to much lower doses than those used to treat people with depression. In fact, many CFS patients cannot tolerate the higher doses commonly used to treat depression. As with all medications, tricyclics must be taken as directed. An overdose can be life-threatening. Tricyclics should not be taken together with SSRIs, because of the possibility of dangerous side effects.
Other Antidepressants. Newer, so-called designer SSRIs, including bupropion (Wellbutrin), nefazodone (Serzone), or mirtazapine (Remeron), affect combinations of different neurotransmitters, and some may have moderate benefits for CFS patients. For example, in one study, nefazodone improved mood, fatigue, and sleep disturbances.
SSRIs. The popular antidepressants known as selective serotonin-reuptake inhibitors (SSRIs) may be helpful for the subgroup of CFS patients who experience significant depression. These drugs include fluoxetine (Prozac), sertraline (Zoloft), and paroxetine (Paxil). Cymbalta (duloxetine) is a new antidepressant that is classified as a selective serotonin and norepinephrine reuptake inhibitor (SSNRI).
Other Drugs Being Investigated for CFS
Psychostimulants. Psychostimulants may be helpful for a subgroup of patients with CFS who have cognitive problems, such as difficulty concentrating, memory problems, and other attention deficit hyperactivity disorder (ADHD)-like characteristics. Psychostimulants include Dexamphetamine, Adderall, methylphenidate (Ritalin) and Ritalin-like drugs such as Focalin, Concerta, Ritalin LA, and Metadate, as well as Strattera and Provigil. The NICE guidelines for CFS do not advise taking Dexamphetamine or Ritalin. However, a 2007 study found that taking two 10 mg doses of Ritalin each day works much better than placebo at relieving fatigue and concentration problems. More research is needed to study the long-term effects of Ritalin on CFS patients.
Because of the difficulties in treating chronic fatigue syndrome, many patients seek alternative therapies. Some of these therapies, such as acupuncture, yoga, and relaxation techniques, may be helpful and are not dangerous. No scientific evidence exists that vitamin and mineral supplements will relieve CFS, but some people do report that they find supplements helpful.
Herbal and Dietary Supplements. Popular herbal and dietary supplements for CFS include coenzyme Q10, vitamin B12, vitamin C, magnesium, multivitamins, DHEA, ginseng, and acetylcarnitine. None have been rigorously tested. Some herbs, such as St. John's wort, ginkgo, and comfrey, may cause serious side effects and drug interactions.
Herbal remedies and dietary supplements are not regulated by the FDA. This means that manufacturers and distributors do not need FDA approval to sell their products. In addition, any substance that can affect the body's chemistry can, like any drug, produce side effects that may be harmful. There have been a number of reported cases of serious and even lethal side effects from herbal products.
Some so-called natural remedies have been found to contain standard prescription medication. Of specific concern are studies suggesting that up to 30% of herbal remedies imported from China have been laced with potent pharmaceuticals, such as phenacetin and steroids. Most reported problems occur in herbal remedies imported from Asia. One study reported that a significant percentage of such remedies contain toxic metals.
CFS patients should be wary of the following remedies:
- St. John's wort. This herbal remedy is being investigated for mild depression. In one study, St. John's wort lessened fatigue in CFS patients, even in those who did not consider themselves to be depressed. However, the substance may have some serious side effects; for example, it can interact with blood thinning medication. Also, the package may not always contain what it promises. In a brand comparison, only three out of eight St. John's wort products contained within 10% of the active ingredient amounts claimed on the labels.
- Melatonin. Some patients use melatonin, based on the association between CFS and possible sleep abnormalities. However, the small amount of research available has not shown melatonin to be helpful.
- Gingko. Although the risks for gingko appear to be low, there is an increased risk of bleeding at high doses. In addition, gingko can interact with high doses of vitamin E and anti-clotting medications. Commercial gingko preparations have also been reported to contain colchicine, a substance that can be harmful in pregnant women and in people with kidney or liver problems. Some brands of gingko have no effect.
- Comfrey. Comfrey is an herbal remedy used for a number of inflammatory problems. Recently, evidence has emerged that comfrey can be toxic to the liver, and animal studies have reported a possible cancer risk. Comfrey is banned in Canada and other countries, but is still widely available in the U.S.
- Products containing the ingredient Ma Huang. This ingredient contains the stimulants ephedrine and kola nut, a caffeine source. Serious adverse reactions, including seizures, psychosis, and several deaths, have been reported in people taking this supplement.
Other alternative remedies with no proven benefit and possible toxic and dangerous side effects include:
- Hydrogen peroxide injection (can cause blood clots or strokes)
- Megadoses of vitamins (can be toxic and have shown no benefits)
- High colonic enemas
- Bee pollen (can cause an allergic reaction)
- Injections of liver extract
- Superoxide dismutase (SOD)
- www3.niaid.nih.gov -- National Institute of Allergy and Infectious Diseases
- www.cdc.gov/cfs - Centers for Disease Control and Prevention, Chronic Fatigue Syndrome information
- www.cfids.org -- The Chronic Fatigue and Immune Dysfunction Syndrome Association of America
- www.ncfsfa.org -- National Chronic Fatigue Syndrome and Fibromyalgia Association
- www.theacpa.org -- American Chronic Pain Association
- www.ampainsoc.org -- American Pain Society
- www.iasp-pain.org -- International Association for the Study of Pain
- www.medicalacupuncture.org -- American Association of Medical Acupuncture
Blockmans D, Persoons P, Van Houdenhove B, Bobbaers H. Does methylphenidate reduce the symptoms of chronic fatigue syndrome? Am J Med. 2006;119:e23-30.
Fuller-Thomson E, Nimigon J. Factors associated with depression among individuals with chronic fatigue syndrome: findings from a nationally representative survey. Fam Pract. 2008;25:414-422.
Goldman L, Ausiello D. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier, 2007.
Haig-Ferguson A, Tucker P, Eaton N, Hunt L, Crawley E. Memory and attention problems in children with CFS/ME. Arch Dis Child. 2008 Nov 11 [Epub ahead of print].
Hampton T. Researchers find genetic clues to chronic fatigue syndrome. JAMA. 2006;295(21):2466-2467.
Kerr JR. Gene profiling of patients with chronic fatigue syndrome/myalgic encephalomyelitis. Curr Rheumatol Rep. 2008;10:482-491.
Knoop H, Stulemeijer M, de Jong LW, Fiselier TJ, Bleijenberg G. Efficacy of cognitive behavioral therapy for adolescents with chronic fatigue syndrome: long-term follow-up of a randomized, controlled trial. Pediatrics. 2008;121:e619-e625.
National Institute for Health and Clinical Excellence. Chronic fatigue syndrome/myalgic encephalomyelitis (or encephalopathy): diagnosis and management of CFS/ME in adults and children. August 2007.
Price JR, Mitchell E, Tidy E, Hunot V. Cognitive behaviour therapy for chronic fatigue syndrome in adults. Cochrane Database Syst Rev. July 2008(3):CD001027.
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.