Background. This paper reviews and integrates the growing literature concerning the prevalence of and risk factors for suicidality in chronic pain. Method. A series of systematic searches in MEDLINE and PsychINFO identified 12 relevant articles examining suicide, suicide attempts, and suicidal ideation in chronic pain. A selection of theoretical and empirical work identifying psychological processes that have been implicated in both the pain and suicide literature and which may be related to increased suicidality was also reviewed. Results. Relative to controls, risk of death by suicide appeared to be at least doubled in chronic pain patients. The lifetime prevalence of suicide attempts was between 5% and 14% in individuals with chronic pain, with the prevalence of suicidal ideation being ~20%. Eight risk factors for suicidality in chronic pain were identified, including the type, intensity and duration of pain and sleep-onset insomnia co-occuring with pain, which appeared to be pain-specific. Helplessness and hopelessness about pain, the desire for escape from pain, pain catastrophizing and avoidance, and problem-solving deficits were highlighted as psychological processes relevant to the understanding of suicidality in chronic pain. Conclusions. Programmatic research is urgently required to investigate the role of both general and pain-specific risk factors for suicidality, to examine how the psychological processes mentioned above mediate or exacerbate suicidality, and to develop enhanced interventions for pain patients at risk.

Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not universal). Resolving this puzzle has clinical, theoretical, and public health importance. There are implications for assessment, definition, and treatment. Moreover, solving the puzzle creates an opportunity for real-world applications of theories from clinical, perceptual, and social psychology as well as neuroscience. Herein we evaluate 13 possible resolutions to the puzzle. Specifically, we consider the possible contribution, to misperception, of (1) features inherent to the context of sleep (e.g., darkness); (2) the definition of sleep onset, which may lack sensitivity for insomnia patients; (3) insomnia being an exaggerated sleep complaint; (4) psychological distress causing magnification; (5) a deficit in time estimation ability; (6) sleep being misperceived as wake; (7) worry and selective attention toward sleep-related threats; (8) a memory bias influenced by current symptoms and emotions, a confirmation bias/belief bias, or a recall bias linked to the intensity/recency of symptoms; (9) heightened physiological arousal; (10) elevated cortical arousal; (11) the presence of brief awakenings; (12) a fault in neuronal circuitry; and (13) there being 2 insomnia subtypes (one with and one without misperception). The best supported resolutions were misperception of sleep as wake, worry, and brief awakenings. A deficit in time estimation ability was not supported. We conclude by proposing several integrative solutions.

Summary: Given the suggestion of a reciprocal relationship between sleep and pain and the recognition of sleep as an important parameter in determining quality of life, there is increasing research interest in sleep disturbance linked to chronic pain. The present study aimed to provide an estimate of the prevalence of ‘clinical insomnia’ in patients attending a specialist pain clinic and identify factors associated with it. Seventy chronic back pain patients and 70 gender‐ and age‐matched pain‐free controls completed a set of questionnaires measuring sleep (Insomnia Severity Index; ISI), pain (Short‐Form McGill Pain Questionnaire) and a selection of general and specific psychological variables (Hospital Anxiety and Depression Scale, Short Health Anxiety Inventory). Scores suggestive of clinical insomnia (ISI ≥ 15) were noted in 53% of chronic pain patients, when compared with only 3% in pain‐free controls. Significant positive correlations with insomnia severity were detected for all six variables of interest (pain intensity, sensory pain ratings, affective pain ratings, general anxiety, general depression and health anxiety). Affective pain ratings and health anxiety were the best predictors of insomnia severity in this sample, accounting for 30% of the total variance, even when present pain intensity was controlled for. Affective pain remained as a significant predictor of insomnia severity when both the effect of pain intensity and the effects of anxiety and depression were controlled for. Future research should consider investigating the role of pain appraisal and health anxiety in the development and manifestation of insomnia concomitant to chronic pain.

Emerging longitudinal research has highlighted poor sleep as a risk factor of a range of adverse health outcomes, including disabling pain conditions. In establishing the causal role of sleep in pain, it remains to be clarified whether sleep deterioration over time is a driver of pain and whether sleep improvement can mitigate pain-related outcomes. A systematic literature search was performed using PubMed MEDLINE, Ovid EMBASE, and Proquest PsycINFO, to identify 16 longitudinal studies involving 61,000 participants. The studies evaluated the effect of sleep changes (simulating sleep deterioration, sleep stability, and sleep improvement) on subsequent pain-related outcomes in the general population. A decline in sleep quality and sleep quantity was associated with a two- to three-fold increase in risk of developing a pain condition, small elevations in levels of inflammatory markers, and a decline in self-reported physical health status. An exploratory meta-analysis further revealed that deterioration in sleep was associated with worse self-reported physical functioning (medium effect size), whilst improvement in sleep was associated with better physical functioning (small effect size). The review consolidates evidence that changes in sleep are prospectively associated with pain-related outcomes and highlights the need for further longitudinal investigations on the long-term impact of sleep improvements.

Two experiments were conducted to investigate the effect of presleep arousal on sleep perception. Experiment 1 examined the link between presleep cognitive arousal and distorted perception of sleep and compared the relative effect of anxious and neutral cognitive arousal on sleep perception. Experiment 2 compared the relative effect of anxious cognitive arousal and physiological arousal on sleep perception. Participants completed a nap session. Just prior to the nap, the participants were randomly assigned to 1 of 3 groups to receive different arousal manipulations. They were then allowed to go to sleep and were asked to report their sleep perception upon waking. Sleep laboratory. Fifty-four healthy good sleepers in each experiment. N/A. Self-reported sleep, actigraphy-defined sleep, and the discrepancy between them were indexed. In Experiment 1, participants who were experimentally manipulated to experience anxious cognitive arousal during the presleep period reported longer sleep-onset latency. Both the Anxious Cognitive Arousal Group and the Neutral Cognitive Arousal Group exhibited a greater discrepancy between self-reported and actigraphy-defined sleep, relative to participants who received no manipulation. In Experiment 2, participants who were experimentally manipulated to experience anxious cognitive arousal or physiological arousal during the presleep period reported longer sleep-onset latency and shorter total sleep time, and both groups exhibited a greater discrepancy between the self-reported and actigraphy-defined sleep, relative to participants who received no manipulation. Results suggest that both presleep cognitive arousal and presleep physiological arousal contribute to distorted perception of sleep.