A New York psychiatrist, Jeremy Coplan has been attempting to bridge the gap between mood and biological disorders for decades. Most studies to date have examined the overlap between mood disorders.
A large 2013 study, for instance, found that alterations in calcium channel genes increase the risk of coming down with a wide variety of psychological disorders.
In 2009 Coplan found that increased brain lactate – found in both chronic fatigue syndrome and fibromyalgia – is associated with panic-like symptoms in rats.
In 2005 he found that reduced blood flows to the frontal cortical regions of the brain induced anxiety in laboratory animals. In 2007 he noted that over or under activity of the prefrontal cortex could induce panic-like symptoms.
To test his hypothesis he gathered together a set of people with an anxiety disorder who also had a physical condition, and assessed the incidence of a wide variety of pain, muscoskeletal, immune and psychiatric conditions present.
Joint problems are common. Autoimmune processes may be present. Coplan proposed that these patients had a spectrum disorder in which five symptom/condition domains dominated.
A = Anxiety disorder (mostly panic disorder);
L = Ligamentous laxity (joint hypermobility syndrome, scoliosis, double-jointedness, mitral valve prolapse, easy bruising);
P = Pain (fibromyalgia, migraine and chronic daily headache, irritable bowel syndrome, prostatitis/cystitis);
I = Immune disorders (hypothyroidism, asthma, nasal allergies, chronic fatigue syndrome); and
M = Mood disorders (major depression, Bipolar II and Bipolar III disorder, tachyphylaxis. Two thirds of patients in the study with mood disorder had diagnosable bipolar disorder and most of those patients had lost response to antidepressants).
Ehlers Danlos Syndrome (joint hypermobility) may have driven much of Coplan’s thinking on this subject.
EDS and other genetically determined connective tissue disorders such as Marfan’s disease have been associated with a high risk of psychiatric disorders (anxiety disorders, depression, schizophrenia, autism, attention deficit/hyperactivity disorder, eating disorders, personality disorders and substance use/misuse.) Clearly some common genetic underpinning is present. Just what is not clear
In fact many of the conditions listed have a spectrum-like appearance; i.e. they often appear together and transcend disease boundaries.
A recent study, for instance, found that inflammatory disorders, “functional somatic syndromes” (i.e. ME/CFS, FM, IBS, etc.) and psychiatric disorders are also commonly found in migraine. The symptom spread in migraine, like ME/CFS and FM (and apparently anxiety, EDS, etc.) is enormous.
The authors concluded that migraine was a central sensitization disorder. A central sensitization disorder involving the immune system (the microglia) that impacts different parts of the sensory apparatus, could be present in many of these disorders.
Coplan’s experience, however, suggests that that kind of analysis is too limiting. He believes that many psychological disorders transcend the boundaries that have been imposed by researchers and vice versa. They are better viewed on a spectrum that includes both psychological and physiological component.
“Our argument is that delineations in medicine can be arbitrary and that some disorders that are viewed as multiple disparate and independent conditions may best be viewed as a single spectrum disorder with a common genetic etiology,” Dr. Coplan
A similar study of ME/CFS and FM patients would likely have similar and different findings. Joint laxity, headache, migraine, irritable bowel syndrome, hypothyroidism and depression appear to be fairly common in ME/CFS and perhaps FM. Bipolar disorder, tachyphylaxis and anxiety disorder don’t appear to be nearly as common.
Smashing boundaries between diseases is getting to be pretty common. Inflammation is now judged to play a major role not just in diseases like heart disease and diabetes but in about a third of people with depression.
Fibromyalgia is found in a significant subset of people with arthritis and other conditions.
Antidepressants don’t just help with depression but reduce pain in people without depression, improve sleep in people without depression, and reduce inflammation.