How many teens suffer from chronic fatigue?

Chronic fatigue syndrome (CFS)-as difficult as it is to diagnose-is more common than previously thought, with about 1 in 50 adolescents affected, according to a new study from the United Kingdom.

The study is the largest ever to study CFS. Overall, the researchers calculated that 1.9% of 16-year-olds were affected by CFS lasting at least 6 months, while almost 3% had CFS lasting 3 months or longer.

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“This is an important study because it shows that CFS/ myalgic encephalomyelitis (ME) is much more common in teenagers than previously recognized,” says Esther Crawley, MD, PhD, of the University of Bristol. “Treatment at this age is effective for most children but few have access to treatment in the United Kingdom. …  As pediatricians, we need to get better at identifying CFS/ME, particularly in those children from disadvantaged backgrounds who may be less able to access specialist care.”

Chronic fatigue syndrome, also known as ME or systemic exertion intolerance disease, can have a major negative impact on the lives of the individuals it affects, and presents as persistent exhaustion that doesn’t go away with sleep. The report notes that adolescents with CFS missed an average of more than a half-day of school each week.

The UK study reviewed the cases of nearly 5800 adolescents in the Avon Longitudinal Study of Parents and Children (ALSPAC) and also found that girls are almost twice as likely as boys to have CFS. The condition was also more common in children whose families experienced a lot of adversity such as poor housing, financial problems, and lack of support from parents.

Impact also varied by age, according to the report. Researchers found that 1.3% of 13-year-olds experienced chronic, disabling fatigue lasting 6 months or more, and boys and girls were equally affected in this age group. By age 16 years, 1.9% of the cohort reported CFS symptoms, with nearly twice as many cases in girls than in boys by that age.

Adolescents with CFS also reported increased school absences and depressive symptoms than those without chronic fatigue, according to the report.

The diagnoses of the participants in the study were primarily self-reported or reported by parents, rather than from a physician.

Chronic fatigue syndrome can be difficult to recognize, leading to underdiagnosis or missed diagnoses.

According to the Association of Young People with ME, 94% of children with ME/CFS say no one believed them when they complained about symptoms, and only 10% of adolescents suffering from CFS have access to a specialist.

NEXT: The study's results

In the United Kingdom, severe chronic fatigue lasting 3 months or longer warrants a CFS diagnosis, while in the United States, a CFS diagnosis requires that fatigue symptoms that are not due to any other condition, a result of strenuous activity, or relieved by rest for at least 6 months.

According to the Centers for Disease Control and Prevention (CDC), more than 1 million people in the US have CFS. The condition is more common among women than men and people in their 40s and 50s, though CFS can affect people of any age.

According to the results of the study, 41% of parents polled reported that their child felt tired and had no energy during the prior month-with 40.8% of those children being girls and 30.6% boys. Based on the parent reports, there was a 4.17% overall prevalence of CFS lasting more than 3 months, and 2.76% lasting more than 6 months, and prevalence was higher in girls. When compared to data self-reported by the children, researchers adjusted those prevalence rates to 2.02% for cases lasting more than 3 months, and 1.46% for cases lasting more than 6 months.

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Depressive symptoms were reported in more than 67% of children with CFS, compared to 15.3% without, and researchers report that children with CFS had an 11-fold higher odds of depressive symptoms than their peers.

Over-reporting of CFS can be attributed to depression, according to the report, but even when those cases were eliminated from the study, CFS was more common than previously thought.

Chronic fatigue syndrome diagnoses confirmed by physicians are less prevalent than those that are self-reported, with prevalence in this study group ranging between 0.1% and 0.5%. The study attributes this discrepancy to barriers to care.

“Pediatricians need to consider the possibility of CFS in children who are not attending school full-time,” researchers note, drawing a correlation between missed school and a possible CFS diagnosis. “This finding is particularly true for children from disadvantaged backgrounds because families that experience early family adversity may be less likely to overcome barriers to accessing specialist care.”

According to the CDC, CFS is mostly likely to develop in children and especially adolescents after acute flu-like or mononucleosis-like illness, but it can also develop gradually.

NEXT: Making the diagnosis

Diagnosis is typically made by ruling out other conditions that can cause fatigue, according to CDC. Chronic fatigue syndrome should be considered when fatigue occurs in the absence of other medical conditions, persists for 6 months or more, and is not relieved by rest. A diagnosis of CFS in the United States should also include 1 of the 4 following symptoms: muscle or joint aches, sore throat, tender cervical or axillary lymph nodes, post-exertional malaise and fatigue, pain, and memory or concentration problems.

Physicians should also consider exploring a CFS diagnosis if a child is often absent from school, has cognitive problems, or difficulties in completing school assignments, according to CDC.

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A 2012 study on CFS revealed that 55% of children reported a decline in their academic performance since the onset of their illness, and 80% reported a decline in extracurricular activity participation.

To confirm a suspected diagnosis, pediatricians should review the patient’s complete medical history and medications, a full physical and mental status assessment, and laboratory tests to rule out other conditions that could cause the presenting symptoms.

Diagnosis can be difficult, according to CDC, in part because children and adolescents are not often able to accurately describe their symptoms, CFS is unpredictable and its symptoms are common to a host of other illnesses, and there is no lab test that can confirm a CFS diagnosis.

Management of CFS can be difficult, but options focus on treating the most disruptive symptoms such as difficulty sleeping, pain, and lightheadedness, says CDC.

Sleep disturbances in children and adolescents should be based on non-pharmacologic interventions like establishing regular bedtimes routines, avoiding daytime naps, creating an environment supportive to sleep, and exercise earlier in the day, CDC advises.

In addressing pain, CDC says physicians should be cautious about prescribing medications and try to identify the origin of the pain. Counseling or cognitive therapies can be used to treat CFS, particular with depression and anxiety symptoms. Some children with depression and anxiety may also benefit from medications, CDC says, but some side effects of these medications actually have the potential to worsen CFS.

Other physical symptoms, like orthostatic intolerance, can be treated with dietary changes and the use of compression garments, CDC notes, and lifestyle modifications.

Crawley says she hopes the new report will help to bring CFS to the attention of pediatricians.

“Awareness needs to be raised to ensure that families of children affected by CFS can access specialist medical care and that pediatricians and those looking after children

are trained in the identification and management of CFS,” the study notes. “Future research should examine the type of fatigue experienced by children, and its different phenotypes, and investigate potentially important etiologic factors that might explain the association of fatigue with family adversity. Further research is also needed to investigate the extent to which psychological problems and life difficulties predate or follow CFS.”