The measurement of sleep onset latency in insomnia

Insomnia and quality of life of prisoners at a Nigerian maximum-security prison

PURPOSE

This study aims to determine the prevalence of insomnia as well as its association with the quality of life of the inmates in a Nigerian prison. Prisoners are a disadvantaged group of people whose needs are often unmet. Many authors have focussed on investigating the prevalence and pattern of psychiatric morbidity, as well as substance use among prisoners. However, sleep disorders, which can predispose or precipitate psychiatric disorders, have been largely neglected in research. The relationship between insomnia and quality of life (QoL) among the general population has been documented but similar investigations have yet to be conducted among the prisoner population.

DESIGN/METHODOLOGY/APPROACH

This was a cross-sectional study with 300 male prisoners at the Ibara prison, Abeokuta, Nigeria who were not diagnosed with depressive, generalized anxiety or post-traumatic stress disorders. Each respondent was interviewed with a sociodemographic proforma, Insomnia module of the Schedule for Clinical Assessment in Neuropsychiatry and the brief World Health Organisation Quality of Life questionnaire.

FINDINGS

About half of the respondents (45.7%) met diagnostic criteria for insomnia. A diagnosis of insomnia and some sleep-related variables were significantly associated with QoL.

RESEARCH LIMITATIONS/IMPLICATIONS

All the possible correlates of insomnia could not be investigated. Further research should be conducted to identify more correlates and investigate the impact of insomnia on prisoners' lives.

PRACTICAL IMPLICATIONS

Improvement of prison climate (relationships in prison, safety and order, contact with the outside world, facilities, meaningful activities and autonomy) may mitigate insomnia among prisoners. Prison psychiatry in Nigerian correctional centres should be made a priority.

SOCIAL IMPLICATIONS

The findings have brought to light the need to address the current social welfare system in place for Nigerian correctional centres.

ORIGINALITY/VALUE

The study provided information on the prevalence of insomnia and poor QoL among prisoners in a Nigerian correctional facility.

(Mis)perception of sleep in insomnia: a puzzle and a resolution

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.

Cognitive approaches to insomnia

Cognition is a broad term that refers to all mental activities and encompasses attention, perception, memory, reasoning, beliefs, attributions and expectations. The aim of the present paper is to draw together the major research findings relating to the importance of cognition in insomnia. Although the research to date has tended to focus on the role of unwanted intrusive thought (also known as worry or cognitive arousal), there is evidence that a broad range of cognitive processes are important for a full understanding of insomnia. These include beliefs, attributions, expectations, perception and attention. The treatment implications of this evidence are discussed, as are priorities for future research.

Trait anxiety and sleep-onset insomnia: evaluation of treatment using anxiety management training

OBJECTIVES

This study was initially designed to test the notion that generalized anxiety is a predominant factor in the maintenance of psychologically determined sleep-onset insomnia and that a trait anxiety reducing technique can provide significant therapeutic gains.

METHODS

Twenty participants (age 19-63) with moderate to severe sleep-onset chronic insomnia were first asked to monitor their sleep-onset latency (SOL) for a 3-week baseline period at home using a SOL clock device. Then, 10 received anxiety management training (AMT) for 9 weeks, while the remaining 10 were trained in the use of progressive relaxation (PR). All participants were measured before and after therapy using sleep laboratory recordings (three nights each), the Spielberger Trait Anxiety Inventory and the Beck Depression Inventory. Daily home sleep-onset measures with the SOL clock device were also taken during therapy.

RESULTS

There was no change in SOL over the 3-week baseline period. However, both groups experienced a significant improvement in SOL from pretreatment (end of baseline) to posttreatment periods. In the laboratory, both groups experienced a reduction in Stage 1 sleep as well as an increase in slow wave sleep (SWS) and sleep satisfaction. On the personality measures, both groups experienced a significant reduction in trait anxiety and a decrease in depression. Overall, there was no indication that one of the therapies was significantly better than the other in effecting changes.

CONCLUSION

These results suggest that both PR and AMT are efficient therapies for sleep onset insomnia and overall sleep quality. Improvements in the application of the AMT technique are proposed to maximize its usefulness.

Which hemisphere falls asleep first?

Behavioral tasks (reaction times to acoustic stimuli and finger tapping tasks) performed by normal subjects when sleepy or attempting to fall asleep have been used as indices of hemispheric asymmetries during the sleep onset period. Results show a stronger impairment of the left hemisphere (right hand) both in reacting to external stimuli and in sustaining endogenous motor programs. The left hemisphere seems to fall asleep earlier than the right hemisphere.

A home evaluation of a behavioral response measure of sleep/wakefulness

15 women and 3 men enrolled in a first-year undergraduate psychology course participated in a study concerned with evaluating the home use of a behavioral response monitor of sleep/wakefulness. The subjects, representing a range of fairly poor to good sleepers, used the device for three consecutive nights in their own homes. The 1967 Monroe Questionnaire was used to differentiate "good" sleepers from "poorer" sleepers. The behavioral response system indicated that subjects could adequately report how long they slept but consistently underestimated their number of arousals and could not reliably specify sleep-onset latency. The behavioral response measure was an effective and economical means of obtaining in-home objective sleep data and holds potential for clinical evaluation of disorders of initiating and maintaining sleep.

Computer-interfaced operant measurement in treating insomnia

A sleep assessment method consisting of a computer-interfaced hand-held microswitch and bedswitch was tested in an A-B case study with a 22-year-old male insomniac. A comprehensive stimulus control package was used as part of the treatment package (Azrin, 1977). Computer-generated and self-report data were collected and compared on sleep onset latency and time slept. Computer data also indicated time spent awake at night. Both sets of data showed that treatment was followed by clinically significant decrease in sleep onset latency and an increase in time slept. Computer data indicated a reduction in time spent awake. Twelve-month follow-up self-report data revealed continued improved sleeping.