Bruce M. Carruthers

In general, fatigue is not as severe in depression as in ME/CFS. Joint and muscle pains, recurrent sore throats, tender lymph nodes, various cardiopulmonary symptoms (55), pressure headaches, prolonged post-exertional fatigue, chronic orthostatic intolerance, tachycardia, irritable bowel syndrome, bladder dysfunction, sinus and upper respiratory infections, new sensitivities to food, medications and chemicals, and atopy, new premenstrual syndrome, and sudden onset are commonly seen in ME/CFS, but not in depression. ME/CFS patients have a different immunological profile (56), and are more likely to have a down- regulation of the pituitary/adrenal axis (57). Anhedonia and self- reproach symptoms are not commonly seen in ME/CFS unless a concomitant depression is also present (58). The poor concentra- tion found in depression is not associated with a cluster of other cognitive impairments, as is common in ME/CFS. EEG brain mapping (59,60) and levels of low molecular weight RNase L (21,26) clearly distinguish ME/CFS from depression.

ME/CFS is not synonymous with depression or other psychiatric ill- nesses. The belief by some that they are the same has caused much con- fusion in the past, and inappropriate treatment.Nonpsychotic depression (major depression and dysthymia), anxiety disorders and somatization disorders are not diagnostically exclusionary, but may cause significant symptom overlap. Careful attention to the timing and correlation of symptoms, and a search for those characteris- tics of the symptoms that help to differentiate between diagnoses may be informative, e.g., exercise will tend to ameliorate depression whereas excessive exercise tends to have an adverse effect on ME/CFS patients.