In an interview published in InFocus, the pain specialist Dr. Alan Spanos, reported that patients with other conditions are often misdiagnosed as having fibromyalgia.

Other conditions frequently labeled as fibromyalgia include: prolong post-infectious pain and exhaustion; postpartum and other types of depression with widespread pain and fatigue; chronic encephalopathy; multiple regional musculoskeletal pain disorder; diffuse hyperalgesia (extreme pain) of unknown cause; central sleep order with diffuse pain; and mixed borderline endocrine disorder with pain and fatigue.

Dr. Spanos reports that the concept of evidence-based medicine has led to treatments that are often worse than those used in the past. For example, once patients are diagnosed with fibromyalgia (a condition over diagnosed far too often) they are typically given prescriptions for the long-term use of Lyrica because of one study showing that this medication might work. 

Similarly, because of one study showing symptoms of ADHD can occur in fibromyalgia, patients are often given prescriptions for stimulants such as Provigil,  a drug recently found to have a potential for abuse.

Furthermore, because many physicians consider fibromyalgia a psychosomatic disorder, they avoid using effective pain medications or acupuncture for pain and fail to investigate nutritional deficiencies, hormonal problems, or neurological conditions. 

Source:
Are Fibromyalgia Patients Being Wrongly Diagnosed, In Focus, Public of the American Autoimmune and Related Diseases Association, March 2009.