Michael L. Perlis

Psychophysiological insomnia: The behavioural model and a neurocognitive perspective

A number of paradoxes are apparent in the assessment and treatment of psychophysiological insomnia and sleep state misperception. Three of these paradoxes exist as discrepancies between polysomnographic (PSG) measures and the subjective impressions regarding sleep quality and quantity. The remaining incongruity exists largely within the objective domain. In the case of subjective–objective discrepancies, patients with insomnia: (1) frequently identify themselves as having been awake when awakened from PSG defined sleep; (2) tend to overestimate sleep latency and underestimate total sleep time as compared with PSG measures; (3) appear to derive more benefit from pharmacotherapy that can be explained by objective gains. The remaining paradox pertains to the observation that hypnotic medications, by and large, do not normalize sleep architecture or produce a more ‘sleep‐like’ EEG. In this paper, we review possible explanations for these various paradoxes, introduce a new perspective and suggest possible research avenues. The model introduced is based on the observation that beta and/or gamma activity (which have been found to be associated with cognitive processes) is enhanced in insomnia at or around sleep onset. We propose that this kind of high frequency EEG activity may interfere with the normal establishment of sleep onset‐related mesograde amnesia. As a result, the patient with insomnia maintains a level of information and/or memory processing that blurs the phenomenological distinction between sleep and wakefulness and influences retrospective judgments about sleep initiation and duration.

The treatments of chronic insomnia: A review of benzodiazepine receptor agonists and psychological and behavioral therapies

The present review provides an assessment of the efficacy and safety of benzodiazepine receptor agonists (BZRAs) and psychological and behavioral interventions for insomnia. These methods include relaxation techniques, sleep hygiene rules, stimulus control, sleep restriction and cognitive techniques, often also referred to as cognitive-behavioral therapy (CBT) when encompassing cognitive strategies and at least one kind of behavioral intervention. In order to provide a comprehensive assessment of the literature regarding the efficacy and safety of these standard treatments for insomnia, an integrative synthesis of the existing meta-analytic studies for each of the various treatment modalities was conducted. Where meta-analytic studies were not available, data from double-blind placebo-controlled randomized controlled trials (RCTs) were included. The summary findings from this review are (1) BZRAs and psychological and behavioral methods are effective to treat insomnia in the short-term and the latter have significantly more durable effects when active treatment is discontinued; and (2) there is only very limited evidence that BZRAs retain their efficacy during long-term treatment. The present review underscores the need for further research regarding the comparative efficacy and safety of these treatments for insomnia, how this varies with age and comorbidity, and how the various treatment modalities impact (1) daytime functioning, (2) quality of life, (3) health care utilization; and (4) pharmacoeconomics. Finally, it is particularly important that studies be conducted to determine if successful insomnia treatment influences the clinical course of the diseases that often occur co-morbidly with sleep continuity disturbance.

Insomnia as a Risk Factor for Onset of Depression in the Elderly

There are at least 9 studies that provide evidence that insomnia is a significant risk factor for recurrent and new onset major depressive disorder (MDD), two of which suggest that this association also exists specifically for the elderly. In this study, archival data from a community sample of healthy elderly participants were used to assess the extent to which insomnia predicts future illness in this age cohort. Out of the 147 participants with no prior history of mental illness, 66 participants were classified as having no insomnia, 47 had indeterminate insomnia, and 34 had persistent insomnia. Twelve participants developed MDD during the 1-year follow-up period. Two had no insomnia, 4 had indeterminate insomnia, and 6 had persistent insomnia. Persistent insomnia with onset of depression occurred only in female participants and was significantly associated with middle insomnia. These data suggest that elderly participants with persistent insomnia are at greater risk for the development of new onset depression.

Sleep quality and presleep arousal in chronic pain.

This study was designed (1) to characterize the extent and nature of sleep complaints of chronic pain patients and (2) to examine the factors that predict sleep quality. A heterogeneous sample of 51 outpatients with benign, chronic pain was recruited from newspaper and pain clinic advertisements. Patients completed a variety of self-report instruments including the Multidimensional Pain Inventory, the Pittsburgh Sleep Quality Index, the Pre-Sleep Arousal Scale, and the Beck Depression Inventory. Sleep complaints were reported by 88% of the sample. Presleep cognitive arousal, rather than pain severity, was found to be the primary predictor of sleep quality.

Neuropsychological changes and treatment compliance in older adults with sleep apnea

INTRODUCTION Apnea is a common disorder in older adults and has been shown to affect cognition. Some studies suggest that treatment for apnea improves certain cognitive deficits, but few studies have examined the relationship between compliance and cognitive improvement. We designed a study to answer the following questions about sleep apnea, cognition and treatment in older adults: (1) Which neuropsychological (NP) variables are differentially associated with measures of sleep fragmentation and oxygen desaturation? (2) Does compliant use of CPAP provide a cognitive advantage over noncompliant use? (3) Does NP performance at baseline predict compliance at 3 months? METHOD Twelve participants were recruited for the study. All had polysomnographically defined sleep apnea with an RDI of 10 or greater. All were also at least 55 years of age, had no other diagnosable sleep disorder and had no previous treatment for sleep apnea syndrome (SAS). Participants were administered a full NP battery before and 3 months after treatment with CPAP. RDI at baseline was associated with delayed verbal recall, while oxygen desaturation was associated with both delayed recall and constructional abilities. Compliant use of CPAP at 3 months was associated with greater improvements in attention, psychomotor speed, executive functioning and nonverbal delayed recall. Finally, attention measures predicted compliance at 3 months suggesting that those who were least vigilant at baseline were more likely to comply with treatment. DISCUSSION Results are discussed in terms of the relevance to targeting special populations for compliance interventions, the ways that treatment may specifically affect older adults and the possible dose-response relationship of CPAP.

Presleep cognitions in patients with insomnia secondary to chronic pain

This study had two primary objectives: (1) characterize the content of presleep cognitions of chronic pain patients and (2) evaluate the association between presleep cognitions and sleep disturbance. Thirty-one outpatients with benign chronic pain completed the Beck Depression Inventory, pain and sleep diaries and participated in an in vivo, presleep thought sampling procedure for 1 week in their homes. The three most frequently reported presleep cognitions were general pain-related thoughts (36%), thoughts about the experimental procedure (27%), and negative sleep-related thoughts (26%). Stepwise multiple regression analyses found that presleep thoughts pertaining to pain and environmental stimuli were significantly associated with sleep continuity, independent from the effects of depression and nightly pain severity. Pain severity was found to be positively associated with Wake After Sleep Onset Time. These results are consistent with cognitive-behavioral models of primary insomnia and suggest the content of presleep cognitive arousal may contribute to sleep disturbance secondary to pain.

Temporal and stagewise distribution of high frequency EEG activity in patients with primary and secondary insomnia and in good sleeper controls

In the present study, we evaluate the temporal and stagewise distribution of high frequency EEG activity (HFA) in primary and secondary insomnia. Three groups (n=9 per group) were compared: primary insomnia (PI), Insomnia secondary to major depression (MDD), and good sleeper controls (GS). Groups were matched for age, sex and body mass. Average spectral profiles were created for each sleep epoch. Grand averages were created for each NREM cycle and each stage of sleep after removing waking and movement epochs and epochs containing micro or miniarousals. It was found that HFA (in terms of relative power) tends to increase across NREM cycles, occurs maximally during stage 1 and during REM sleep, and that both these effects are exaggerated in patients with PI. In addition, HFA was found to be inversely associated with Delta activity and the three groups in our study appear to exhibit characteristic Delta/Beta patterns. Our data are consistent with the perspective that HFA is related to CNS arousal to the extent that Beta/Gamma activity occurs maximally during shallow stages of sleep and maximally in subjects with PI.

A longitudinal study of depression, pain, and stress as predictors of sleep disturbance among women with metastatic breast cancer

OBJECTIVE Sleep disturbances are common among women with breast cancer and can have serious consequences. The present study examined depression, pain, life stress, and participation in group therapy in relation to sleep disturbances in a sample of women with metastatic breast cancer. METHODS Ninety-three women with metastatic breast cancer participated in a large intervention trial examining the effect of the group therapy on their symptoms. They completed measures of depression, pain, life stress, and sleep disturbance at baseline, 4, 8 and 12 months. RESULTS The results showed that higher initial levels of depression at baseline predicted problems associated with getting up in the morning, waking up during the night, and daytime sleepiness. Increases in depression over the course of 12 months were associated with fewer hours of sleep, more problems with waking up during the night and more daytime sleepiness. Higher levels of pain at baseline predicted more problems getting to sleep. Increases in pain predicted more difficulty getting to sleep and more problems waking up during the night. Greater life stress at baseline predicted more problems getting to sleep and more daytime sleepiness. CONCLUSIONS Depression, pain, and life stress scores were each associated with different types of negative change in self-reported sleep disturbances. Depression, especially worsening depression, was associated with the greatest number of types of negative change. The relationships found between sleep disturbance and depression, pain, and life stress suggest specific ways to address the problem of sleep disturbance for women with metastatic breast cancer and show how different types of disturbed sleep may be clinical markers for depression, pain, or life stress in this population.

Improving Compliance with Nasal CPAP and Vigilance in Older Adults with OSAHS

The present study examined the efficacy of a cognitive-behavioral intervention at improving compliance with CPAP and vigilance in older adults with obstructive sleep apnea/hypopnea syndrome (OSAHS). Participants included 12 subjects who were randomized into one of two groups controlling for age, education, disease severity, and vigilance. The experimental group received two 45-min sessions designed to educate subjects on the consequences of OSAHS and the efficacy of CPAP. The control group received the same extent of therapist contact but did not receive information on OSAHS or CPAP. All subjects were administered a test of vigilance both before and after the study. Compliance data were collected using CPAP devices with internal microprocessors at were read at 1, 4, and 12 weeks after treatment initiation. The results showed that the experimental condition did not enhance compliance after 1 week of treatment but did so by the 12-week follow-up. Subjects in the experimental condition had a run time of 3.2-h per night longer than did those in the control group. Those using CPAP more regularly at 12 weeks also showed greater improvement on vigilance at follow-up. Performance on vigilance testing before the introduction of CPAP was predictive of CPAP use at 12 weeks. In conclusion, a modest cognitive-behavioral intervention may substantially increase CPAP use and vigilance in older adults.

Does REM sleep contribute to subjective wake time in primary insomnia? A comparison of polysomnographic and subjective sleep in 100 patients

Primary insomnia (PI) is characterized by low subjective sleep quality which cannot always be verified using polysomnography (PSG). To shed light on this discrepancy, subjective estimates of sleep and PSG variables were compared in patients with PI and good sleeper controls (GSC). 100 patients with PI (age: 42.57 ± 12.50 years, medication free for at least 14 days) and 100 GSC (41.12 ± 13.99 years) with a sex distribution of 46 men and 54 women in each group were included. Both PSG and questionnaire variables showed clear impairments of sleep quality in PI compared with GSC. The arousal index within total sleep time was increased, which was mainly because of a strong increase within rapid eye movement (REM) sleep. Subjectively, more PI than GSC subjects estimated wake times longer than obtained from PSG. Linear modeling analysis of subjective wake time in terms of PSG parameters revealed that in addition to PSG defined wake time, REM sleep time contributed significantly to subjective wake time. This REM sleep contribution was larger for PI than for GSC subjects. The findings suggest that REM sleep‐related processes might contribute to subjectively disturbed sleep and the perception of waking time in patients with PI.