Chronic fatigue syndrome (CFS), Myalgic Encephalomyelitis (ME) and Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) refer to a debilitating illness without a universally accepted or well-understood etiology.
Some experts have suggested that there are multiple pathways to the development
of ME and CFS, which may also indicate multiple onset patterns. Due to unanswered questions regarding etiology, the onset of ME and CFS is considered a key area of inquiry.
Case criteria for ME and CFS and much of the academic literature suggest that patients typically experience one of two possible onset patterns: sudden or gradual. Many experts consider the mode of ME and CFS onset an important factor for differentiating patients on key dimensions including etiology, health status, prognosis, and psychiatric comorbidity.
Previous literature has suggested a link between sudden ME and CFS onset and a viral/infectious etiology, lower psychopathology, and worse health outcomes. However, other studies have found opposite or inconclusive findings. In order to replicate and build on previous research, the current study is an investigation of whether mode of onset
differentiates individuals with ME and CFS on etiology, psychopathology, and
It was hypothesized that individuals with sudden onsets would more likely report that a virus/infection preceded their illness, attribute their illness to physical causes, evidence lower lifetime psychiatric comorbidity, report poorer physical functioning, and have better mental health outcomes compared to the gradual onset group. Hypotheses were tested using multivariate analyses of variance (MANOVA) and the Pearson’s chi-squared test of independence.
Results revealed that mode of illness onset did not differentiate individuals on key factors
related to etiology, psychopathology, and prognosis.
The lack of a universal definition for mode of illness onset is likely contributing to the inconsistencies in the percentage of sudden versus gradual ME and CFS onsets reported in the literature. Given the ambiguous etiology, complex symptom profile, and heterogeneous onset patterns associated with ME and CFS, it would be useful to better define onset. An in-depth investigation of ME and CFS onset can provide insight into early symptoms, onset duration, and the progression of functional disability. Few studies have utilized qualitative inquiry to understand the patient’s perspective of onset.
Based on previous research documenting the rich information that can be gained from personal illness narratives, the second phase of the study involved phone interviews with
individuals with ME and CFS. A qualitative descriptive approach was used to gain rich descriptions of illness onset from the patients’ point of view. Overall, qualitative findings revealed detailed descriptions of ME and CFS onset experiences.
Major themes that emerged from the data included: onset/illness progression patterns, illness causes, methods of adapting and coping, hardworking and active lives prior to onset, healthy lives prior to onset, prior health problems, comorbid health conditions, emotional responses to onset, exertional effects, the illness as life limiting, stress, traumatic experiences, lack of support, support, and treatment limitations.
A closer examination of the onset/illness progression patterns that emerged from the data provided evidence that individuals with ME and CFS experience complex onset patterns. Furthermore, the study findings suggest that the method of categorizing individuals into sudden versus gradual onset groups may not be useful as it fails to capture the more nuanced and varied onset experiences.
Prospective research studies that capture the onset period as it is developing could lead to improvements in the way we define and assess ME and CFS onset, and may also lead to methods for early detection, prevention, and individualized treatment approaches for this multifaceted and debilitating illness.
Onset Patterns of Chronic Fatigue Syndrome and Myalgic Encephalomyelitis: A Mixed Method Approach, by Meredyth Evans (2015) DePaul University, College of Science and Health Theses and Dissertations, Paper 117