Monday, 13 January 2020

Comorbidity: Symptoms, conditions, behaviour and treatments

Title of publication

Comorbidity: Symptoms, conditions, behaviour and treatments (edited book).


Brown, R. F., & Thorsteinsson, E. B. (Eds.). (2020). Comorbidity: Symptoms, conditions, behaviour and treatments (1 ed.): Palgrave Macmillan.


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.


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.

Monday, 2 December 2019

Workplace incivility and outcomes in Australian and Singaporean employees

Title of publication

Workplace incivility and work outcomes: Cross-cultural comparison between Australian and Singaporean employees


Workplace incivility is a common issue experienced by employees around the globe. However, research has found cultural variability in how workplace incivility is perceived and interpreted. Studies have shown that employees from high power distance societies tend to be more accepting of workplace mistreatment than employees from low power distance societies. Adopting Conservation of Resources (COR) theory and national culture as theoretical frameworks, we tested a moderated mediation model that linked the experience of workplace incivility, burnout/exhaustion, job satisfaction and work withdrawal between Australian and Singaporean white-collar employees. Data were collected through an online survey of 301 Australian and 303 Singaporean employees. Results indicated that workplace incivility contributed to burnout/exhaustion, which in turn predicted employees’ job dissatisfaction and work withdrawal. Specifically, Australians were more negatively affected by workplace incivility than Singaporeans. The findings suggest the need to consider employees’ national culture/ethnicity when examining relationships between mistreatment in different workplaces and the outcomes.


Loh, J., Thorsteinsson, E. B., & Loi, N. (2019 first online). Workplace incivility and work outcomes: Cross-cultural comparison between Australian and Singaporean employees. Asia Pacific Journal of Human Resources

Adolescents' sleep difficulty: Trends in the Nordic countries 2002-2014

Title of publication

Trends in sleeping difficulty among adolescents in five Nordic countries 2002-2014


Sleep has been found to be an important factor in adolescents’ mental and physical health. The aim of the present study was to examine trends in sleep difficulty (i.e., difficulty falling asleep more often than once a week) in the Nordic countries among 11- to 15-year-olds. We analysed Nordic data from the Health Behaviour in School-aged Children study (HBSC), which is conducted every four years, looking specifically at trends in sleep difficulty over a 12-year period from 2002 to 2014. The participants were aged 11 to 15 years. The total number of participants across these years was 113,447. A large percentage (17% to 31% in 2014) of adolescents in the Nordic countries experience sleep difficulty, and these difficulties increased from 2002 to 2014 in Denmark, Finland, Iceland, and Sweden. Only in Norway was there a decrease, mainly due to a reduction in sleep difficulty among 11-year-old boys and girls from 2010 to 2014. Sleep difficulty among boys and girls are prevalent and generally on the rise in the Nordic countries with the exception of Norway.


Thorsteinsson, E. B., Potrebny, T., Arnarsson, Á. M., Tynjälä, J., Välimaa, R., & Eriksson, C. (2019). Trends in sleeping difficulty among adolescents in five Nordic countries 2002-2014. Nordisk välfärdsforskning | Nordic Welfare Research, 4, 77-87.

Poor sleep quality is predicted by stress, anxiety, depression, and rumination with all of these factors contributing to fatigue

Title of publication

Modelling the effects of stress, anxiety, and depression on rumination, sleep, and fatigue in a nonclinical sample


Background: Stress and affective distress (e.g., anxiety, depression) have previously been shown to predict sleep quality, and all the factors have been shown to predict fatigue severity. However, few prior studies have examined the likely indirect mediational relationships between stress, affective distress, and poor sleep quality in predicting fatigue severity, and the potential role played by ruminative thinking. Thus, the relationship between stress, anxiety, depression, sleep, rumination, and fatigue was modelled using Structural Equation Modelling. Method: A short questionnaire asked 229 participants about their recent experiences of stress, affective distress, rumination, sleep and fatigue in a community sample. Results: High stress, anxiety, and depression was related to more ruminative thinking, which in turn was related to poor sleep quality; and sleep quality predicted worse fatigue. Conclusion: Results suggest that rumination parsimoniously explains the tendency of stress and affective distress to contribute to poor sleep quality, and together with poor sleep, it may also contribute to worse fatigue in some individuals.


Thorsteinsson, E. B., Brown, R. F., & Owens, M. T. (2019). Modelling the effects of stress, anxiety, and depression on rumination, sleep, and fatigue in a nonclinical sample. The Journal of Nervous and Mental Disease, 207, 355-359.

Intervention, health education, and schizophrenia literacy

Title of publication

Schizophrenia literacy: The effects of an educational intervention on populations with and without prior health education


Background: Mental health literacy is an important predictor of appropriate help-seeking behaviour. Aims: This study investigated (a) the effects of an educational intervention on schizophrenia mental health literacy, beliefs about causes, discrimination, treatment, and attitudes that promote recognition, and (b) whether schizophrenia literacy would be higher in people with prior education in a health-related area than people without such education. Method: A randomised control design tested the effects of an educational intervention on schizophrenia literacy relative to a control group. Participants (N = 260; mean age = 31.18 years, SD = 11.43, female = 78.8%) answered a mental health literacy questionnaire, based on a vignette of a person with schizophrenia, before and after watching either an educational video on schizophrenia or a control video. Results: The intervention significantly increased schizophrenia identification and literacy, reduced personal stigma, and increased perceived discrimination in society. The health background group reported significantly greater schizophrenia identification than the no health background group. Participants thought help should be sought from health care professionals and through psychotherapy, close friends and physical activity. Conclusions: Targeted education can significantly improve the ability to identify schizophrenia which may have positive implications for reducing the time individuals take to seek help.

Videos used

Experimental condition video

Control condition video


Thorsteinsson, E. B., Bhullar, N., Williams, E., & Loi, N. M. (2019). Schizophrenia literacy: The effects of an educational intervention on populations with and without prior health education. Journal of Mental Health, 28, 229-237.

School stress among adolescents in the Nordic countries: Trends 2002-2014

Title of publication

Trends in perceived school stress among adolescents in five Nordic countries 2002-2014


Associations between school-related stress and poor health, risk behaviours and low well-being are well documented. The aim of this paper was to estimate trends of perceived school stress experienced by boys and girls of different ages in the Nordic countries, and to describe trends in school stress between the Nordic countries. Nordic data from the Health Behaviour in School-aged Children study (HBSC) between 2002 and 2014 were used. The participants were aged 11–16 years. School stress was measured by a single item; “How pressured do you feel by schoolwork?” The participants answering “some” or “a lot” were categorised as reporting school stress.  Sweden, Norway and Denmark had lower prevalence of school stress compared to Finland and Iceland. There was an increase in Iceland, Finland and Denmark, whereas adolescents from Sweden showed a decreasing trend. In Norway, the level was stable. Boys showed a marginal decline in school stress whereas girls showed an increase, and school stress increased by age for the whole period. It is a challenge for the public education systems in the Nordic countries to develop policies and practices that provide children with the necessary tools to achieve knowledge and skill, and at the same minimise stress in school.


Löfstedt, P., Charli, E., Potrebny, T., Välimaa, R., Thorsteinsson, E. B., Due, P., Damsgaard, M. T., Suominen, S., Rasmussen, M., & Torsheim, T. (2019). Trends in perceived school stress among adolescents in five Nordic countries 2002-2014. Nordisk välfärdsforskning | Nordic Welfare Research, 4, 101-112.

Wednesday, 27 November 2019

Attraction oriention and substance use: European adolescents

Title of publication

Romantic attraction and substance use in 15-year-old adolescents from eight European countries


Sexual minority youth are at higher risk of substance use than heterosexual youth. However, most evidence in this area is from North America, and it is unclear whether the findings can be generalized to other cultures and countries. In this investigation, we used data from the 2014 Health Behaviour in School-aged Children (HBSC) study to compare substance use in same- and both-gender attracted 15-year-old adolescents from eight European countries (n = 14,545) to that of their peers who reported opposite-gender attraction or have not been romantically attracted to anyone. Both-gender attracted, and to a lesser extent, same-gender attracted adolescents were significantly more likely to smoke cigarettes, consume alcohol, get drunk and use cannabis, or be involved in multiple substance use in the last 30 days compared to their opposite-gender attracted peers. Those adolescents who have not been in love had significantly lower odds for substance use than all other youth. The pattern of results remained the same after adjusting for country, gender and family affluence. These findings are compatible with the minority stress and romantic stress theories. They suggest that sexual minority stigma (and love on its own) may contribute to higher substance use among adolescents in European countries.


Költő, A., Cosma, A., Young, H., Moreau, N., Pavlova, D., Tesler, R., Thorsteinsson, E. B., Vieno, A., Saewyc, E. M., & Gabhainn, S. N. (2019). Romantic attraction and substance use in 15-year-old adolescents from eight European countries. International Journal of Environmental Research and Public Health, 16, Article 3063.

Comorbidity: Symptoms, conditions, behaviour and treatments

Title of publication Comorbidity: Symptoms, conditions, behaviour and treatments (edited book).