Chronic Fatigue Syndrome Epidemiology and Treatment Considerations Renee R. Taylor, Ph.D. University of Illinois at Chicago

Chronic Fatigue Syndrome Current US Case Criteria (Fukuda et al., 1994) Development sponsored by the Centers for Disease Control There have been a number of approaches to defining chronic fatigue syndrome (CFS). Three sets of diagnostic criteria currently exist: the British definition (Sharpe et al., 1989), the Australian definition (Lloyd et al., 1990), and the current US definition, developed in collaboration with the CDC (Fukuda et al., 1994). Within the US, the diagnostic criteria have undergone considerable revision and continue to undergo revision. The first US case criteria for CFS were developed in collaboration with the CDC in 1988 (Holmes et al., 1988). A central problem with CFS case criteria in general is that they have been developed based on expert consensus. Current definitions have not been supported empirically.

CFS Criteria Persistent or relapsing fatigue of 6 months or longer duration with other known medical and primary psychiatric conditions excluded by clinical diagnosis

CFS Criteria (Continued) clinically evaluated, unexplained, persistent or relapsing chronic fatigue that is of new or definite onset (i.e., not life-long) fatigue is not the result of ongoing exertion

CFS Criteria (Continued) Concurrent occurrence of four or more of the following: 1. Short term memory/concentration Persistent or recurring impairment in short term memory or concentration severe enough to cause substantial reductions in previous levels of occupational , educational, social, or personal activities

CFS Criteria (Continued) 2. sore throat 3. tender cervical or axillary lymph nodes 4. muscle pain 5. joint pain in multiple joints without joint swelling or redness

CFS Criteria (Continued) 6. headaches of a new type, pattern or severity 7. unrefreshing sleep 8. post exertional malaise lasting more than 24 hrs

History of CFS Neurasthenia coined in 1869 by George Beard. One of the most prevalent diagnoses in the late 1800’s. Herbert James Hall (a physician and one of the founders of occupational therapy) treated patients with neurasthenia. By the early 1900’s the diagnosis was used less frequently and it is possible that those with severe fatigue were considered to have depression or another psychiatric condition.

History of CFS Cluster outbreaks of unexplained fatiguing illnesses have been documented throughout the world for the past 45 years (e.g., icelandic disease, epidemic neuromyalsthenia, chronic encephalomyelitis). Patterns of associated symptoms have differed and differed from modern case criteria. Further controlled investigations of so-called cluster outbreaks were not confirmed (Fukuda et al., 1997). Anecdotally, some argue that the reason cluster outbreaks reported within the US have not been confirmed empirically is due to methodological limitations.

Conditions That Can Explain Chronic Fatigue Cancer Narcolepsy Sleep apnea Severe obesity Hypothyroidism Alcohol or substance abuse Unresolved hepatitis B or C

Conditions That Can Explain Chronic Fatigue (Continued) Lupus Tuberculosis Lyme disease Multiple sclerosis Rheumatoid arthritis Iatrogenic, e.g., medication side effects HIV/AIDS

Conditions That Can Explain Chronic Fatigue (Continued) Dementia Schizophrenia Bipolar disorder Bulimia nervosa Anorexia nervosa Major Depression with Melancholia

Possible Causes of CFS Infectious agents Immunological defects Hypothalamic-pituitary-adrenal axis dysfunction (cortisol dysregulation, hypocortisolism, dysfunction in neuroendocrine-immune communication). Orthostatic intolerance/Neurally Mediated Hypotension Biopsychosical

Findings from the Jason et al. (1999) Chicago Prevalence study Epidemiology Findings from the Jason et al. (1999) Chicago Prevalence study Jason, L.A., Richman, J.A., Rademaker, A.W., Jordan, K.M., Plioplys, A.V., Taylor, R.R., McCreedy, W., Huang, C., & Plioplys, S. (1999). A community-based study of chronic fatigue syndrome. Archives of Internal Medicine, 159, 2129-2137.

Myths about CFS Late 1980s and early 1990s Patients were thought to have “Yuppie Flu” Few minority group members Mostly women Well educated

Myths vs. Facts Myth: CFS is a relatively rare disorder Fact: CFS affects over 800,000 adults and adolescents in the United States (Jason et al., 1999)

Myths vs. Facts Myth: The highest prevalence of CFS is among young, affluent, white professionals Fact: Latinos have the highest prevalence; African Americans have the second highest

Race Latinos: 726 per 100,000 (twice that of Whites/non-Latino EuroAmericans) Whites: 318 per 100,000 African Americans: 337 per 100,000

Gender Women have a much higher rate of CFS than men 522 women per 100,000 compared to 291 men per 100,000

CFS CFS in Context Social Loss Job/Income Loss 100% report disruption in relationships Job/Income Loss 76% Unemployment Median Income Loss: $13,000 CFS in Context CFS Immunological Neurological Gastrointestinal Musculoskeletal Endocrinological Psychiatric Socio- political Stigma Mass Media CDC Misappropriating Research Funds Health Care Stigma 77% report negative interactions with health care providers

Four Models of Chronic Fatigue Syndrome Etiology PSYCHIATRIC BIOLOGIC SOCIAL - BIO- CFS is a form of Currently, no single causal agent has been identified as responsible for CFS consistently across studies. Four general models exist in the literature. The biologic and biopsychosocial models may hold the most promise in future investigations of etiology. The validity of CFS is ENVIRONMENT PSYCHOSOCIAL Relational synergy Negative contacts, somatic depression supported by Patho physiology multiple roles between all factors or hypo chondriasis

Is CFS a Distinct Entity? Findings from the Taylor et al. (2001) study Taylor, R.R., Jason, L.A., & Schoeny, M. (2001). Latent variable models of functional somatic distress in a community-based sample. Journal of Mental Health, 10, 335-349.

CFS: A Distinct Diagnostic Entity? QUESTION: Debate regarding whether CFS differs from somatic depression, somatic anxiety, fibromyalgia, and irritable bowel syndrome. Are these disorders better explained as a single unitary construct of functional somatic distress (somatoform disorders)? METHOD: Tested one-, two- and five-factor solutions using confirmatory factor analysis Used factor scores to predict actual diagnostic outcomes in logistic regression

Findings Taylor, R.R., Jason, L.A., & Schoeny, M. (2001). Latent variable models of functional somatic distress in a community-based sample. Journal of Mental Health, 10, 335-349. FINDINGS

CFS and Child Abuse?

The Current Status of Trauma Research While many have speculated that histories of childhood sexual, physical, or emotional abuse may play a role in the etiology or course of CFS, few rigorous empirical studies have been conducted.

Prior Studies Rosenthal (1996). 27 physician-diagnosed participants with CFS responded to a survey query in The CFIDS Chronicle. 100% reported a history of severe or prolonged stress or repeated traumatic events. 67% reported comorbid diagnosis of PTSD 74% felt that stress or trauma contributed to the development of CFS

Prior Studies Tiersky et al. (1998) compared the occurrence of childhood trauma in individuals with CFS and healthy controls. Individuals with CFS demonstrated a higher incidence of extreme illness or injury prior to age 17. No other significant group differences related to abuse history were found.

Prior Studies Doyle et al. (1999) conducted a large-scale study of domestic violence and sexual abuse history among women physicians. There was a significantly higher rate of CFS among physicians reporting a history of domestic violence (16.1%) as compared with physicians not reporting such history (3.5%).

Prior Studies Doyle et al. (1999) did not detect significant differences in rates of CFS among physicians reporting a lifetime history of sexual abuse.