Chronic Fatigue and Personality: A Twin Study of Causal Pathways and Shared Liabilities

Abstract

Background The etiology of chronic fatigue syndrome (CFS) remains unknown. Personality traits influence well-being and may play a role in CFS and unexplained chronic fatigue. Purpose To examine the association of emotional instability and extraversion with chronic fatigue and CFS in a genetically informative sample. Methods We evaluated 245 twin pairs for two definitions of chronic fatigue. They completed the Neuroticism and Extraversion subscales of the NEO-FFI. Using a co-twin control design, we examined the association between personality and chronic fatigue. Results Higher emotional instability was associated with both definitions of chronic fatigue and was confounded by shared genetics. Lower extraversion was also associated with both definitions of fatigue, but was not confounded by familial factors. Conclusions Both emotional instability and extraversion are related to chronic fatigue and CFS. Whereas emotional instability and chronic fatigue are linked by shared genetic mechanisms, the relationship with extraversion may be causal and bi-directional.

Widespread Psychosocial Difficulties in Men and Women With Urologic Chronic Pelvic Pain Syndromes: Case-control Findings From the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network

“…Patients with UCPPS evidenced higher scores on Negative Emotionality and lower scores on Extraversion compared to HC. Negative Emotionality (formerly referred to as Neuroticism) reflects a general propensity to increased stress responses and has been associated with development of IBS [21], CFS [22] and other pain problems [23, 24]. A pattern of high negative emotionality and low extroversion has recently been found in a longitudinal study to be the personality pattern most associated with long term poor health [25] and low resilience.…”

“…Since personality traits are thought to reflect life-long individual characteristics, these data are consistent with a model of development of psychosocial problems that hypothesizes some personality traits, especially negative emotionality and to a lesser extent low extraversion (indicating an inhibited personality), may be important mediators of who will develop significant chronic symptoms in the face of physical or environmental stressors, and who may be less resilient to recovery from these stressors. It is also possible that common physiological mechanisms may underlie both trait psychological characteristics and a vulnerability to chronic pain or inflammation [22, 26]. Furthermore, early adversity is known to profoundly alter biologic mechanisms related to later health vulnerabilities and outcomes [27].…”

T. Egeland og medarbeidere svarer:

“…Visse personlighetstrekk, blant annet perfeksjonisme, antas å øke sykdomsrisikoen (6)(7)(8) . Imidlertid knytter det seg flere metodeproblemer til studier av personlighetstrekk og årsakssammen-henger ved CFS/ME.…”

Efficacy of rintatolimod in the treatment of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME)

“…The etiologic/pathogenic basis for CFS/ ME is unknown and may be multifactoral with a variety of microbes, hormonal, and immunological abnormalities linked to its pathogenesis [ 4 – 6 ]. Moreover, CFS/ME may have a familial component [ 7 ] and be dependent on genetic signatures [ 8 – 10 ]. Recently discovered time-dependent plasma immune signatures indicate a dynamic and evolving pathogenesis [ 11 ].…”