Title of publication
Comorbidity: Symptoms, conditions, behaviour and treatments (edited book).
https://www.palgrave.com/gp/book/9783030325442
Citation:
Brown, R. F., & Thorsteinsson, E. B. (Eds.). (2020).
Comorbidity: Symptoms, conditions, behaviour and treatments (1 ed.): Palgrave Macmillan.
https://doi.org/10.1007/978-3-030-32545-9
About
This book introduces a new theory on the substantial comorbidity that exists between many illnesses and disorders and concurrent symptoms such as pain, impaired sleep and fatigue. The specific illnesses and disorders discussed include obesity, diabetes mellitus type-II, medical illnesses including cardiovascular disease and sleep-disordered breathing, insomnia, disordered eating such as binge-eating disorder and night-eating syndrome, affective distress (anxiety and depression), and comorbidities that are linked to eating disorders such as anorexia nervosa and bulimia nervosa. The book posits that the comorbidities are the result of a complex bio-psycho-behavioral mechanism that includes circadian rhythm dysfunction. It examines the statistical and methodological (e.g. measurement) problems that can complicate the understanding of comorbidity and explores a broad range of novel, existing, and repurposed therapy approaches that could have utility in treating comorbid disorders.
This book will be of great value to academics as well as practitioners working in the field of psychiatry, health psychology and medicine more broadly.
Link
https://link.springer.com/book/10.1007/978-3-030-32545-9#about
Table of contents
Chapter 1. Comorbidity: What Is It and Why Is It Important?
Comorbidity refers to any distinct clinical entity that coexists with or occurs during the clinical course of another illness or condition. In other words, it refers to the co-occurrence of two or more distinct illnesses, disorders or conditions in a single individual. As a result of the comorbidity, some disorders tend to occur together more often than they occur alone. For example, anxiety, depressed mood and impaired sleep often co-occur, and in this instance, the co-occurrence appears to be the rule rather than the exception.
Chapter 2. Models of Comorbidity
Most existing theories of disease comorbidity provide only a broad overview of the manner in which comorbidity is likely to arise, although these broad overarching theories have, for the most part, not been tested empirically. Further, there are few comorbidity theories that are comprehensive yet specific enough to help guide the exploration of the relationships between specific comorbid disorders and the likely role played by intervening factors. As a result, we know little about the extent to which comorbidity is relevant to our understanding of single disorders and conditions; the mechanisms likely to underpin the development of the comorbidities; and the nature of the interactions between specific risk factors and comorbid disorders.
Chapter 3. Overweight/Obesity and Concurrent Disorders, Symptoms, Behaviour, and Body Temperature
Overweight/obesity tends to co-occur with disturbed sleep and disordered eating (e.g. binge-eating, night-eating), although the precise mechanism/s underpinning the relationships is unclear. However, overweight/obese people are more likely to eat late at night than normal-weight people, thus, late night-eating (or binge-eating, which often occurs at night) may at least partly explain the observed relationship between overweight/obesity and impaired sleep in affected individuals. For example, night-eating and binge-eating are related to impaired sleep (e.g. longer sleep onset latency) and weight gain in obese people, and clinically, obese people are at an increased risk of a binge eating disorder and/or night eating syndrome diagnosis. A similar profile of sleep deficits is evident in overweight/obese people, binge-eaters, and night-eaters, and impaired sleep (e.g. longer sleep onset latency, shorter sleep duration) is associated with overweight/obesity, night-eating, and binge-eating. Thus, it is possible that the sleep problems experienced by overweight/obese people are at least in part due to the indirect effects of late night-eating and/or binge-eating on sleep, although it is less clear exactly how this might occur. Several psychological and biological mechanisms are examined as potential explanations of the relationship between disordered eating, overweight/obesity, and impaired sleep, including an elevated nocturnal body temperature.
Chapter 4. Overview of the Comorbidity Between Medical Illnesses and Overweight/Obesity
Overweight and obesity are major contributors to the total global burden of chronic diseases due to the consequences of their associated comorbid conditions which can affect all systems of the body. These comorbidities are often considered to be consequence of the excess weight with unidirectional causality; however, causality is almost certainly multidirectional with roles for both physical and psychological factors. In this chapter, an overview of overweight- and obesity-related medical illnesses, categorised according to the body systems affected, is provided. Some focus is directed towards the role of the metabolic syndrome in these illnesses. The importance of causality of comorbid conditions at early, middle and late stages of disease is emphasised, as interventions targeting causalities at each of these times are likely to have the greatest impact on lessening the burden of overweight and obesity on affected individuals.
Chapter 5. Comorbid Eating Disorders
Anorexia nervosa is defined by persistent restriction of energy intake, intense fear and rumination about gaining weight, and disturbance in self-perceived weight or shape, which results in behaviour that prevents weight gain or results in weight loss.
Chapter 6. Comorbid Psychiatric Illnesses
Comorbidity among psychiatric illnesses is common, as is comorbidity between psychiatric and physical illnesses. Current knowledge of psychiatric comorbidity points to several possible underlying factors, notably an overlap in their definitions and symptoms; unidirectional and bidirectional causation; disordered sleep; and a range of shared risk factors. Psychiatric illness may lead to poorer self-care and sleep problems, whereas being physically ill may impact upon an individual’s psychological wellbeing. An integration of the various causal models that have been proposed to explain the comorbidities is discussed, incorporating different socio-psychological and biological factors to explain the development of depression and anxiety. These issues are detailed in the following chapter with a focus on depression. Implications for treatment are also discussed.
Chapter 7. Arousal States, Symptoms, Behaviour, Sleep and Body Temperature
Autonomic arousal (or affective states, e.g. stress, anxiety), symptoms (e.g. fatigue, pain), sleep-disrupting behaviour (e.g. physical inactivity, electronic device use, TV watching, shift work) and medications are linked to impaired sleep and, in many cases, overweight/obesity. Further, in many cases, the phenomena are linked to an elevated BT, and in some cases, a high nocturnal BT, although there is a lack of specific research pertaining to nocturnal BT and the relationship between BT and chronic pain. A relative hyperthermia at night is known to interfere with sleep onset, possible via a phase-shift in the sleep-wake cycle. However, an elevated BT can additionally lead to activation of the inflammatory response system (e.g. cytokine secretion), which may represent another possible mechanism by which the aforementioned states, symptoms, disorders and behaviour can develop.
Chapter 8. Design, Statistical and Methodological Considerations: Comorbidity
Research of disease comorbidity and symptom co-occurrence raises several issues relating to study design and analytical techniques that require careful consideration. In this chapter, we first address methodological issues that are of particular relevance in comorbidity research, including symptom overlap and the resultant double counting of symptoms; the pitfalls and advantages of removing overlapping scale items; and the utility of creating latent variables or ‘symptom groups’. We then discuss the advantages and limitations of employing various study designs in the context of comorbidity research and make recommendations for maximising the scientific rigour of statistical analyses whilst ensuring that ethical standards are met. Finally, we highlight analytical techniques that are relatively novel and/or less commonly utilised in studies of comorbidity, and how these techniques might advance research in this field.
Chapter 9. Typing It All Together
Comorbidity is common, affecting one-third or more of the global population; and recent co-prevalence estimates suggest that its presence is increasing. It is associated with substantial chronic illness burden, disability, high mortality, and high ongoing costs to the individual and the community, reflecting its substantial impact within and beyond the health care system. Thus, unravelling the causes of comorbidity currently ranks among the top priorities in clinical practice. However, there are currently few protocols and clinical practice guidelines that can be used to assist clinicians in treating comorbid conditions in a coordinated way. Instead, the guidelines and protocols have tended to focus on single disorders and they generally fail to take comorbidities into account. This has resulted in the comorbid disorders being treated as if they are isolated clinical entities, with each condition managed separately, often by different clinicians. Therefore, there is a clear need to develop new clinical practice guidelines and therapeutic approaches that do take comorbidity into account; especially in patients with highly prevalent and highly comorbid disorders.
