Table 5.

Symptom comparison between depression/anxiety disorders and ME/CFS in children and adolescents.

Symptoms	Depression/anxiety disorders	ME/CFS	Comments
Fatigue, lack of energy, difficulty sleeping, cognitive problems, weight gain, or loss	Yes	Yes	These symptoms occur in both conditions. In ME/CFS, fatigue tends to fluctuate during the day and from day-to-day
Absence from school	Yes	Yes	ME/CFS is the most common medical cause of prolonged absence from school
Depression, feeling sad for no apparent reason	Yes	Sometimes	Young patients with ME/CFS might be sad, discouraged and fed up. Clinical depression is more likely in those who encounter disbelief in the reality of their illness
Anxiety	Yes	Sometimes	In young patients with ME/CFS, anxiety can be associated with having an undiagnosed illness, ignorance about ME/CFS, and/or skepticism about the reality of the illness from family members, physicians, or staff at school. Panic attacks are occasionally seen. There is a higher degree of anxiety in young patients with co-morbid OI and joint hypermobility
Feelings of worthlessness, guilt, low self-esteem	Yes	No	Occasionally, young patients with ME/CFS feel guilty because the illness has caused family disruption. These feelings are secondary to the illness
Anhedonia (lack of interest and/or pleasure in activities previously enjoyed)	Yes	No	Young patients with ME/CFS often wish to engage in previous activities but are physically unable to do so. They might still enjoy previous activities even when the activities exceed their energy limits. Patients with depressive illness do not wish to engage in, or enjoy previous activities, but are physically able to do so
Severe depression with suicidal thinking	Yes	No	Severe depression with suicidal thinking is not present in ME/CFS without co-morbid major depressive disorder
Lack of interest in friendships/relationships	Yes	No	Young patients with ME/CFS often want to socialize, but are physically and cognitively unable to do so. Patients with depressive illness often do not wish to socialize
Post-exertional symptom worsening	No	Yes	This is a hallmark of ME/CFS. Patients with Depression/Anxiety often feel better after exertion.
Orthostatic intolerance (OI)	Occasionally	Sometimes	Much more common in young patients with ME/CFS
Hypersensitivities to light noise, odors, and medications	No	Sometimes	Common in young patients with ME/CFS. Can contribute to feeling anxious and overwhelmed
Difficulty with thermoregulation, low body temperature, and intolerance to heat and cold	No	Sometimes	Common in young patients with ME/CFS