Interconnected struggles: How insomnia, anxiety, and depression impact mental health

Abstract

Insomnia, anxiety, and depression have emerged as significant public mental health concerns, particularly during the coronavirus disease 2019 (COVID-19) pandemic. Early recognition and intervention, addressing COVID-19's health effects before diverse symptoms appear, will expedite recovery and significantly enhance public mental health. Li et al conducted a cross-sectional online survey to assess neuroticism, cognitive function, insomnia, and emotional disorders in adult participants, examining how these factors correlate with mental health. The study revealed that a substantial number of participants reported experiencing varying degrees of anxiety, depression, and insomnia, most of which were classified as mild. Neuroticism was found closely associated with cognitive failure and poor mental health. Furthermore, moderated mediation analysis indicated that cognitive failure mediated the relationship between insomnia and anxiety and depression, whereas neuroticism moderated the pathway. These findings suggest that improving the subjective cognitive function and emotional stability can significantly improve mental health. However, this study has several limitations, including a limited sample size, cross-sectional design, and a focus on behavioral-level data. Future research should broaden its scope to include multiple hospitals at various levels to enhance the representativeness of the study population, adopt longitudinal designs, and integrate advanced technologies such as neuroimaging to explore the neural mechanisms underlying these conditions.

Key Words: Insomnia; Anxiety; Depression; Cognitive failures; Neuroticism

Core Tip: Insomnia, anxiety, and depression have become significant public mental health concerns, particularly after the coronavirus disease 2019 (COVID-19) pandemic. However, the relationships among these conditions remain unclear, and the pandemic's impact on them is still uncertain. This editorial comments on an article from the World Journal of Psychiatry, which examined a cross-sectional online survey of adult participants to assess levels of neuroticism, cognitive function, insomnia, and emotional disorders, and explored the correlations between these factors and mental health. The editorial highlights the interconnections among insomnia, anxiety, and depression, their underlying factors, and the mediating roles of cognitive failures and neuroticism. It also reviews the strengths and limitations of the study and advocates for considering the effects of COVID-19 when treating these mental health conditions.

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic is widely recognized as a once-in-a-century global health crisis that impacts every corner of the world and facets of human life. Since its emergence, it has presented unprecedented challenges to the physical and mental well-being of individuals worldwide. The general population and those who have recovered from COVID-19 have experienced a marked increase in distress symptoms. These symptoms include physical fatigue, notable decline in sleep quality, and persistent bodily pain, which are more prevalent than those preceding the pandemic[1]. These lingering effects, collectively known as "long-term COVID" or "long COVID", are seen in approximately 10%-20% of individuals who contracted COVID-19. They encompass a wide range of symptoms that can persist for months after the initial infection. The enduring impact of the COVID-19 pandemic on human brain health requires long-term study.

The pandemic has been associated with deterioration of psychiatric symptoms. According to global burden of disease data, between 2010 and 2021, anxiety disorders and depressive disorders saw the most significant increase in age-standardized disability-adjusted life-year rates among the 25 leading level 3 causes[2]. Since the COVID-19 pandemic began, there has been a high prevalence of depression, anxiety, and insomnia. It has affected many individuals, particularly hospital staff and healthcare workers. Research shows that Healthcare workers exposed to COVID-19 are prone to psychological stress. An umbrella review of 44 meta-analyses revealed a high prevalence of mental health issues including anxiety (29.9%), depression (28.4%), and insomnia (40.0%) during the COVID-19[3]. However, there is limited confidence in the evidence for each assessed outcome. Early findings indicated that a significant number of healthcare workers experienced mood and sleep disturbances during the outbreak, underscoring the need to develop strategies to reduce mental health risks and adapt interventions to pandemic circumstances[4]. Timely identification and intervention before the emergence of various symptoms of brain disorders are vital for improving public mental health.

INTERPLAY OF INSOMNIA, ANXIETY, AND DEPRESSION

Research highlights a bidirectional relationship between insomnia, anxiety, and depression, mediated by prolonged wakefulness, negative cognitive reinforcement, and maladaptive psychological processes such as worry and rumination[5]. Li et al[6] conducted a cross-sectional online survey among adult participants to assess their level of neuroticism, cognitive function, insomnia, and emotional disorders. The study revealed a severe mental health status among the recruited participants, with a significant number of participants reporting varying degrees of anxiety, depression, and insomnia. The depression scores of participants aged 18-25 and 26-50 years were significantly higher than those of participants aged > 50 years, suggesting a higher prevalence of depression among younger individuals. These symptoms did not significantly differ according to sex, ethnicity, or educational level.

Additionally, there appears to be a substantial interplay among sleep quality, depression, and anxiety, with sleep serving as a crucial factor in regulating mood states related to depression[7]. Specifically, poor sleep quality has been linked to heightened levels of anxiety and depression[8]. Li et al[6] investigated the associations among neuroticism, cognitive failures, and mental health outcomes. Their analysis demonstrated that cognitive failures mediate the relationships between insomnia and both anxiety and depression. Additionally, neuroticism was found to moderate the initial pathway in which cognitive failures mediate the insomnia-anxiety relationship. These findings were supported by moderated mediation analyses, confirming the dual mediating role of cognitive failures in linking insomnia to anxiety and depressive symptoms[6].

There are two theories of cognitive failure. The overload theory posits that cognitive failures result from psychological fatigue and depletion of finite cognitive resources, which exhibit dual functional characteristics. In contrast, the complaint hypothesis emphasizes personality-based factors, suggesting that neurotic personality traits may amplify self-perceptions of cognitive failures. Empirical evidence indicates that insomnia severity significantly predicts both global cognitive failures and their specific dimensions[9]. Furthermore, longitudinal studies demonstrate that individuals reporting higher frequencies of cognitive failures exhibit elevated stress reactivity and greater susceptibility to anxiety and depressive disorders[10]. Li et al[6] found that neuroticism moderated the relationship between insomnia and cognitive failure. These findings indicate that neuroticism is closely associated with cognitive failure and mental health. This suggests that improving subjective cognitive function and emotional stability can significantly improve mental health.

Meanwhile, insomnia was found to be strongly associated with anxiety and depression, which aligns with existing research. All these results speculated that good sleep may reduce the formation of negative emotions. Therefore, enhancing sleep quality may exert a significant positive influence on the mitigation of depressive and anxious symptoms. Conversely, insomnia emerged as a substantial predictor of cognitive impairment in both high and low neuroticism groups, with its predictive effect on cognitive impairment being more pronounced in the low neuroticism group compared to the high neuroticism group. These findings enhance our understanding of the interactive mechanisms between perceived stress and depression and clarify the mediating role of insomnia in their association. This study offers a valuable theoretical and methodological framework for preventing depression among medical students. Liu et al[11] results suggest that improving sleep quality and reducing perceived stress may be effective strategies for decreasing depression among medical students.

LIMITATIONS AND FUTURE DIRECTIONS

However, this study has several limitations. First, this was a single-center survey using a convenience sampling method, which could have led to selection bias. We suggest that future studies be conducted in multiple hospitals at different levels to increase the representativeness of the research population. Second, as this was a cross-sectional study, it was difficult to establish causality between neuroticism, cognitive failure, and mental health indicators, indicating the need for longitudinal studies to delve deeper into these relationships. Additionally, other factors, such as inflammation and psychiatric disorders, could have contributed to the results. Evidence from longitudinal studies links elevated systemic inflammation to incident depression in post-COVID populations, highlighting the need for standardized psychopathological monitoring and translational research to identify cytokine signatures as potential theragnostic biomarkers for COVID-19-related neuropsychiatric morbidity[12]. Lastly, while many studies use psychological scales to assess brain conditions, a single index may not fully capture the complexity of brain state changes. Consequently, an increasing number of researchers are employing more advanced techniques, such as neuroimaging. Studies utilizing Peak Width of Skeletonized Mean Diffusivity (PSMD), a sensitive biomarker for small vessel disease (SVD), indicate that severe COVID-19 cases are associated with elevated PSMD index values[13]. This suggests the presence of SVD even in the absence of overt neurological symptoms.

Future investigations may profit from leveraging electrophysiological and neuroimaging techniques, along with other cutting-edge methodologies, to uncover the neural correlates of neuroticism, cognitive deficits, and overall mental health. This integrative approach would enhance our understanding of the neurobiological basis of mental health disorders. Studies have shown that the long-term prevalence of anxiety, depression, posttraumatic stress disorder, and sleep disturbances in COVID-19 survivors is comparable to general population levels[14]. Comparing mental health issues before and after COVID-19 among Chinese college students revealed characteristics of somatization within the depression-anxiety-insomnia comorbidity network[15]. Therefore, it remains uncertain whether the COVID-19 pandemic is a significant contributing factor to these psychological disorders. Nonetheless, it is crucial to consider the long-term physical and psychological effects of COVID-19 when addressing these issues. In this context, the potential long-term effects of physiological and pathological damage caused by COVID-19 should be considered when managing patients with insomnia, anxiety, and depression, particularly in cases where psychological factors were previously the only considerations for mental illnesses such as neuroticism[16]. It is crucial for the medical community and public health officials to continue monitoring and addressing the aftermath of the pandemic in order to mitigate its long-term effects on individuals and society.

CONCLUSION

The connections among insomnia, anxiety, and depression are complex, with various factors potentially influencing outcomes, particularly during the COVID-19 pandemic. Identifying mediating factors could improve our understanding of disease mechanisms and control. Addressing the health effects of COVID-19 before the onset of diverse symptoms can expedite recovery and significantly enhance public mental health. Future research should broaden its scope by including multiple hospitals at various levels to improve the representativeness of the study population, adopt longitudinal designs, and incorporate advanced technologies such as neuroimaging to explore the neural mechanisms underlying these conditions.