Examining the evidence for a psycho-physiological model of chronic fatigue syndrome in adolescents

• Main Author: Lievesley, Kate
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2015

Introduction. The purpose of this thesis is to investigate the factors associated with predisposing, precipitating and perpetuating fatigue and disability in Chronic Fatigue Syndrome in adolescents. It presents novel evidence of psychological (including behavioural), social and physiological factors associated with adolescent Chronic Fatigue Syndrome. Methodology. In order to test a hypothesised psycho-physiological model of Chronic Fatigue Syndrome in adolescents, a cross-sectional and prospective case-control design was used. Eighty-five adolescents with Chronic Fatigue Syndrome, thirty-one adolescents with asthma and seventy-eight healthy control adolescents participated in the study. They were compared on a range of questionnaire measures at two time points. Experimental tasks were also used to test hypothesised maintaining factors for Chronic Fatigue Syndrome in adolescents derived from cognitive behavioural approaches. Physiological parameters were assessed during these tasks. Mothers of all adolescents completed questionnaire measures examining maternal distress and other psychological variables. Results. The Chronic Fatigue Syndrome group and their mothers scored significantly higher on all measures of unhelpful beliefs and behaviours in response to illness than the asthma group. Maternal distress and worse general health were also more common in the mothers of adolescents with Chronic Fatigue Syndrome. The adolescents and their parents had lower expectations of performance on the experimental tasks than the other two groups, most prominently on the exercise task. The Chronic Fatigue Syndrome group were more likely to attribute cognitive symptoms of stress to their illness rather than the stress of a speech task in comparison to the adolescents with asthma. The Chronic Fatigue Syndrome group had a significantly higher Heart Rate in anticipation of the speech and the exercise task as well as slower Heart Rate recovery compared to the other groups. The Chronic Fatigue Syndrome patients also had significantly lower Heart Rate Variability and higher Skin Conductance Response at baseline compared with the other two groups. Conclusions. This thesis confirms that cognitive, behavioural, emotional and social factors are associated with Chronic Fatigue Syndrome in adolescents. Some of these factors will need to be targeted in treatment. The differences between groups on physiological responses are consistent with the hypothesis that adolescents with Chronic Fatigue Syndrome may differ in their autonomic response to challenging situations. In particular they appear aroused in anticipation of exercise and recover more slowly from a stressful situation. The findings support the use of cognitive behavioural intervention methods in which the family is involved in assessment and treatment (Chalder et al., 2002).