0494 Ability to Discontinue Chronic Hypnotic Use: An Update

Introduction

Physicians prescribing hypnotics remain concerned regarding patient’s inability to discontinue hypnotics after chronic use. That concern has never been directly tested in a controlled prospective study using self-administration choice procedures. This is an update on results from an on-going “blinded” clinical trial in which insomnia subjects are instructed to stop taking their study medication after 6 months of nightly use.

Methods

DSM-V diagnosed insomnia subjects, aged 23-61 yrs, (n=31, 26 females), with disturbed sleep (i.e., polysomnographic sleep efficiency of ≤85%), no other sleep disorder, unstable medical or psychiatric diseases or drug dependency completed the trial. Participants were randomized to zolpidem XR (12.5 mg), eszopiclone (3 mg), or placebo nightly for 6 months (blinded groups A: n=11, B: n=9, C: n=11). After 6 months, nightly use, over a 2-week choice period, they were instructed to discontinue hypnotic use, but if necessary, to self-administer either 1, 2, or 3 capsules of their assigned medication (zolpidem XR 6.25 mg, 6.25 mg, placebo; eszopiclone 2 mg, 1 mg, placebo as capsules 1, 2 and 3 respectively; or 3 placebos).

Results

The number of capsules taken declined from week 1 to 2 (p< .001). Over the 2 weeks 15 participants took 0 (48%), 12 ≤ 6 (39%) and 4 ≥10 total capsules (1 each took 42, 19, 13, and 10). Among those taking capsules, most took one capsule per night and 6 took > 1 capsule. Those 4 taking ≥ 10 were younger (p<.05), but did not differ in screening sleep efficiency or blinded treatment group. Importantly 1 subject took every capsule available.

Conclusion

The majority (87%) of the participants discontinued 6-month nightly hypnotic use (i.e. took ≤ 6 total capsules) and among those taking capsules the rate declined from week 1 to 2. Age may help identify the few with difficulty discontinuing.

Support

NIDA, grant#: R01DA038177 awarded to Dr. Roehrs

0497 Rebound Insomnia During Discontinuation of Chronic Hypnotic Use

Introduction

Rebound insomnia refers to worsened sleep relative to baseline on 1-2 nights after discontinuation of active hypnotic medication. Rebound is typically assessed using a placebo substitution. We assessed rebound in an on-going “blinded” clinical trial in which people with insomnia are instructed to discontinue their study medication (i.e., no-pill) after 6 months of nightly use.

Methods

DSM-V diagnosed people with insomnia (n=31, 26 females), aged 26-61 yrs, with a polysomnographic sleep efficiency of ≤85%, no other sleep disorders, unstable medical or psychiatric diseases or drug dependency completed the clinical trial. Participants were randomized to zolpidem XR (12.5 mg), eszopiclone (3 mg) or placebo nightly for 6 months (blinded groups A: n=11, B: n=9, C: n=11). After 6 months, over a 2-week choice period, they were given the instruction to discontinue their nightly hypnotic use with an opportunity, if necessary, to self-administer either 1, 2, or 3 capsules of their assigned medication (zolpidem XR 6.25 mg, 6.25 mg, placebo; eszopiclone 2 mg, 1 mg, placebo as capsules 1, 2 and 3 respectively; or 3 placebos). On baseline and the14 discontinuation nights, sleep was recorded and scored by actigraphy for sleep efficiency (SE), sleep latency (LAT) and wake after sleep onset (WASO).

Results

Relative to the baseline night, on the first discontinuation night there was no difference in SE, LAT, and WASO. Fifteen subjects stopped taking study medication when told to discontinue and 16 subjects took study medication on one night or more. While not differing on baseline or night 1, on night 14 the last study night the medication users had a lower SE (75.9 vs 87.7 %, p<.0.004) and a longer LAT (61.5 vs 14.5 min, p<0.05).

Conclusion

Difficulty discontinuing hypnotic use is not specifically related to rebound insomnia. We reported in a companion abstract those with insomnia and hyperarousal, defined by MSLT, are those with difficulty discontinuing hypnotic use and as shown here slept poorly on the last study night.

Support

NIDA, grant#: R01DA038177 awarded to Dr. Roehrs

0492 Sleep and Hyperarousal: Inability to Discontinue Chronic Hypnotic Use

Introduction

Inability to discontinue chronic hypnotic use by people with insomnia remains a clinical concern. Sleep and hyperarousal was examined in an on-going “blinded” clinical trial in which people with insomnia are instructed to discontinue their study medication after 6 months of nightly use.

Methods

DSM-V diagnosed people with insomnia (n=31, 26 females), aged 23-61 yrs, with a polysomnographic sleep efficiency (SE) of ≤85% on a 8-hr polysomnogram, no other sleep disorders, unstable medical or psychiatric diseases or drug dependency have completed the clinical trial. Participants were randomized to zolpidem XR (12.5 mg), eszopiclone (3 mg) or placebo nightly for 6 months (blinded groups A: n=11, B: n=9, C: n=11). After 6 months, over a 2-week choice period, they were given the instruction to discontinue their nightly hypnotic use with an opportunity, if necessary, to self-administer either 1, 2, or 3 capsules of their assigned medication (zolpidem XR 6.25 mg as capsule 1, 6.25 mg as capsule 2, placebo as capsule 3; eszopiclone 2 mg, 1 mg, and placebo as capsules 1, 2 and 3 respectively; or 3 placebos.

Results

Fifteen subjects stopped taking study medication when told to discontinue. The other 16 subjects who took study medication (users) had longer MSLT (a measure of hyperarousal) sleep latency (16.2 vs 8.3 min) than non-users (p<.001) at baseline. At baseline users and non-users had similarly disturbed nocturnal sleep: SE 73.4 vs 73.9 %, with sleep latencies of 54 vs 40 min and wake time after sleep onset of 90 vs 104 min.

Conclusion

Hyperarousal, defined by MSLT and high diurnal urinary cortisol levels, has been found in some people with insomnia. High MSLTs were previously associated with dose escalation in a chronic zolpidem use study. These emerging data would suggest high MSLT may also be predictive of difficulty discontinuing hypnotic use.

Support

NIDA, grant#: R01DA038177 awarded to Dr. Roehrs

0496 Self-Reported Sleep During Discontinuation of Chronic Hypnotic Use

Introduction

Inability to discontinue chronic hypnotic use by people with insomnia remains a clinical concern. Self-reported sleep in an on-going “blinded” clinical trial in which people with insomnia are instructed to discontinue their study medication after 6 months of nightly use was examined and compared to objective actigraphic recordings of their sleep.

Methods

DSM-V diagnosed people with insomnia (n=31, 26 females), aged 26-61 yrs, with a polysomnographic sleep efficiency of ≤85%, no other sleep disorders, unstable medical or psychiatric diseases or drug dependency completed the clinical trial. Participants were randomized to zolpidem XR (12.5 mg), eszopiclone (3 mg) or placebo nightly for 6 months (blinded groups A: n=11, B: n=9, C: n=11). After 6 months, over a 2-week choice period, they were given the instruction to discontinue their nightly hypnotic use with an opportunity, if necessary, to self-administer either 1, 2, or 3 capsules of their assigned medication (zolpidem XR 6.25 mg, 6.25 mg, placebo; eszopiclone 2 mg, 1 mg, placebo as capsules 1, 2 and 3 respectively; or 3 placebos). On post-sleep questionnaires they reported sleep latency (LAT), wake after sleep onset (WASO), and sleep quality (Q:1-5; best - worst).

Results

15 subjects stopped taking study medication when told to discontinue. The 16 subjects who took study medication had shorter LAT on nights they took capsules then on nights they did not (31 vs 38 min, p<.03), less WASO (22 vs 44 min, p<.02) and better Q (2.3 vs 3.2, p<.002). In contrast, actigraphic recordings of sleep showed no differences in LAT, WASO, or SE.

Conclusion

For subjects who took study medication during the nights they were instructed to discontinue, they reported better sleep than on the nights they used no medication, although objectively their sleep did not differ.

Support

NIDA, grant#: R01DA038177 awarded to Dr. Roehrs

How representative are insomnia clinical trials?

OBJECTIVES

To address the question of how representative subjects studied in hypnotic clinical trials are of the broader insomnia population, this study assessed initial contact rates and reasons for inclusion and exclusion during recruitment to an efficacy trial and to a safety trial of Food & Drug Administration (FDA) approved hypnotics.

METHODS

Otherwise heathy persons meeting Diagnostic Statistical Manual, Fourth Edition, Revised (DSM-IVR) criteria for insomnia were recruited. In one study, persons 32-65 yrs, were invited to a 12 month trial of nightly use of zolpidem or placebo. In the other, persons 21-64 yrs with driver's licenses were recruited to test the effects of a hypnotic on live on-the-road driving ability. In both studies screening was conducted through an initial telephone interview followed by a clinic visit.

RESULTS

In the United States (US) study 13% (n = 410) of 3180 initial contacts and in the Netherlands (NL) study 67% (n = 53) of the 79 initial contacts proceeded to the clinic visit. Of those at clinic 25% of US and 37% of NL participants failed to meet additional insomnia criteria. Mental health exclusions accounted for 24% of US and 23% of NL participants and medical problems accounted for 23% of US and 9% NL exclusions. Finally 20% of US and 26% of NL participants were excluded for drug use/abuse histories. After all screening 4% of the initial US contacts and 0% of the NL contacts entered the study.

CONCLUSIONS

These data suggest persons entering insomnia hypnotic clinical trials are a highly selected sample that is unlikely to be representative of the broad insomnia population or the population of potential medication users.

The status of sleep abnormalities as a diagnostic test for major depressive disorder

BACKGROUND

Psychiatry lags other fields in development of diagnostic tests.

METHODS

A literature review and meta-analysis was conducted to ascertain if polysomnographic abnormalities (REM density, REM latency, sleep efficiency, slow wave sleep, stage 1 and stage 2 sleep) warrant additional effort to develop them into a clinical diagnostic test for major depressive disorder (MDD). The 31 publications meeting inclusion criteria were then classified into one of three progressive steps using guidelines for evaluating the clinical usefulness of a diagnostic test.

RESULTS

Most of the abnormalities found in MDD patients, when compared to healthy controls, occurred in the expected direction with moderate effect sizes but with substantial publication bias and heterogeneity. Eleven studies compared abnormalities in MDD to other psychiatric disorders (step 2a), and four studies provided data on the sensitivity or specificity of the findings in differentiating among the psychiatric disorders that frequently appear on the same differential diagnostic list as MDD (step 2b). No multicenter trial has been conducted prospectively to test the clinical utility of the diagnostic test (step 3).

LIMITATIONS

Only published articles in the English language were used.

CONCLUSIONS

Sleep studies for the detection of MDD appear replicable with a moderate effect size. However, additional step 1 studies are needed to define the sensitivity and specificity. The heterogeneity of sleep recording, scoring techniques, and MDD must also be addressed.

Medical comorbidity affects antidepressant treatment response in patients with melancholic depression

BACKGROUND

This study aimed at the impact of medical comorbidity (MC) on response to antidepressant treatment over 6 weeks in diagnostic subtypes of patients with major depressive episode (MDE).

METHODS

In a clinical sample of 241 admitted patients with MDE, MC was assessed by medical specialists and weekly response to antidepressant treatment was assessed with the Hamilton Depression Scale (HAM-D 21).

RESULTS

Over 6 weeks of treatment, patients with melancholic depression and MC had poorer treatment response on the HAM-D scale and a worse functional outcome (GAF) as opposed to their counterparts without MC, which was first detected after 4 weeks of treatment (p = 0.02). More specifically, subjects with melancholic depression and cardiovascular or endocrinological MC showed significantly poorer treatment response over 6 weeks. Interestingly, these effects were not related to various antidepressant treatment regimens.

CONCLUSIONS

MC has a negative impact on treatment response in patients with melancholic depression.

Effects of zaleplon or triazolam with or without ethanol on human performance

Objectives and background: Given that non-selective gamma-aminobutyric acid (GABA) agonist hypnotics impair performance and potentiate the disruptive effects of ethanol, this study was done to determine the performance-impairing and ethanol-potentiating effects of zaleplon, a new selective GABA agonist hypnotic.Methods: Eighteen healthy men (12) and women (six), 31.5+/-5.6 years old, were studied. Each underwent six treatments of 2 days in duration, presented in a Latin square design with 2-12 recovery days between. The treatments were: placebo-placebo; placebo-ethanol; triazolam-placebo; triazolam-ethanol; zaleplon-placebo; and zaleplon-ethanol; with triazolam (0.25 mg) or placebo administered at 08:30 h, zaleplon (10 mg) or placebo at 09:00 h, and ethanol (0.75 g/kg) or placebo consumed from 09:30 h. Performance tests were completed each day at 10:30, 12:00 and 14:30 h.Results: Breath ethanol concentration (BrEC), tested 0.5, 2.0, 4.5 and 6 h post consumption, did not differ among treatments and peaked at 0.052%, declining to 0.037, 0.009 and 0.001%. Triazolam with and without ethanol impaired digit symbol substitution, symbol copying, simple and complex reaction times and divided attention performance relative to placebo-placebo treatment. It did so consistently at 10:30 and 12:00 h, and less consistently at 14:30 h. Zaleplon without ethanol impaired only digit symbol substitution and divided attention tracking, and only at 10:30 h. Zaleplon with ethanol impaired most measures at 10:30 and 12:00 h, but not at 14:30 h. Zaleplon without ethanol consistently differed from triazolam without ethanol in the extent of performance impairment. Zaleplon with ethanol began to differ from triazolam with ethanol in performance impairment on the 12:00 and 14:30 h test sessions. Ethanol itself impaired most measures at 10:30 h, fewer at 12:00 h and none at 14:30 h. All active drug treatments increased self-rated sleepiness compared with placebo-placebo. Triazolam without ethanol produced greater self-rated sleepiness than zaleplon without ethanol. The addition of ethanol to both drugs generally produced comparable levels of self-rated sleepiness.Conclusions: In an absolute sense, zaleplon produced less performance impairment and a shorter period of ethanol potentiation than triazolam.

Treatment regimen and hypnotic self-administration

RATIONALE AND OBJECTIVES

Previous studies have shown that insomniacs self-administer hypnotics at high nightly rates. This study determined whether prior experience with different treatment regimens (i.e., instructions and capsule availability) would alter the previously observed high hypnotic self-administration rates.

METHODS

Sixty-four healthy men and women with (n = 32) and without (n = 32) insomnia, 21-55 years, self administered placebo or triazolam (0.25 mg) after different prior treatment regimens. They received one of three different treatment regimens enforced for 11 nights: a capsule each night, a capsule as needed, or a capsule every third night. On 14 subsequent nights they choose to self-administer a capsule or not, placebo during 1 week and triazolam (0.25 mg) the other (counterbalanced in order).

RESULTS

Insomniacs self-administered more capsules than normals and triazolam was self-administered more than placebo. For both groups, treatment regimen had a minimal effect on capsule self-administration. During the treatment phase, triazolam improved self-ratings of sleep relative to placebo. During the choice phase, nightly variations in self-rated sleep predicted self-administration of a capsule on the following night, regardless of whether the capsule was active drug or placebo.

CONCLUSIONS

The data of this study are consistent with the view that hypnotic self-administration by insomniacs is therapy-seeking behavior and not drug abuse.

Sleep physiology and pathophysiology

Sleep is a complex, highly organized state that is fundamental to life. And yet, many functions of sleep remain to be discovered and understood. The past 50 years of modern sleep research clearly indicate what sleep is not--simply a resting brain, as popular notions and behavioral observations might suggest. This review will describe normal sleep physiology and its regulation as well as the major disorders of sleep and their underlying pathophysiology.

Alexithymia and polysomnographic measures of sleep in healthy adults

OBJECTIVE

This study examined associations between alexithymia and objective characteristics of sleep (latencies, stages, and amount and patterning of REM sleep) that may contribute to subjective reports of poor sleep quality and impaired dream recall among alexithymic people.

METHODS

Fifty healthy, normally sleeping adults from the community completed the 20-item Toronto Alexithymia Scale and slept uninterrupted for one night in the laboratory while polysomnography was conducted. Various measures of sleep latency, sleep stages, and REM sleep-related variables were obtained, and analyses correlated these sleep measures with alexithymia, controlling for age, sex, and level of depressed affect.

RESULTS

Higher alexithymia scores were significantly related to increased stage 1 (light) sleep and decreased stage 3/4 (deep) sleep. Alexithymia was unrelated to overall sleep efficiency or percentage of stage 2 sleep. Alexithymia was related to more frequent REM episodes and more stage 1 sleep during and immediately after REM episodes but was unrelated to the absolute amount of REM sleep. Alexithymia was also related to an earlier onset of the first REM episode.

CONCLUSIONS

Alexithymia is associated with more light sleep and less deep sleep, which may contribute to subjective reports of poor sleep and increased sleepiness, fatigue, and somatic symptoms. Although alexithymia is not associated with an overall reduction of REM sleep, the increased frequency of episodes of REM that are interrupted and followed by light sleep rather than complete awakenings may contribute to limited dream recall.

Sleep, sleepiness, and alcohol use

The study of alcohol's effects on sleep dates back to the late 1930s. Since then, an extensive literature has described alcohol's effects on the sleep of healthy, nonalcoholic people. For example, studies found that in nonalcoholics who occasionally use alcohol, both high and low doses of alcohol initially improve sleep, although high alcohol doses can result in sleep disturbances during the second half of the nocturnal sleep period. Furthermore, people can rapidly develop tolerance to the sedative effects of alcohol. Researchers have investigated the interactive effects of alcohol with other determinants of daytime sleepiness. Such studies indicate that alcohol interacts with sleep deprivation and sleep restriction to exacerbate daytime sleepiness and alcohol-induced performance impairments. Alcohol's effects on other physiological functions during sleep have yet to be documented thoroughly and unequivocally.

Effects of sleep loss on waking actigraphy

STUDY OBJECTIVES

To assess the effect of sleep loss and the effect of a sedating drug on waking actigraphy

DESIGN

N/A SETTING: N/A PARTICIPANTS: Seventeen healthy volunteers, aged 19-35 yrs

INTERVENTIONS

Four night-day treatments presented in a Latin Square Design: placebo-8 hr time-in-bed (TIB), placebo-4 hr TIB, placebo-0 hr TIB, and diphenhydramine 50 mg-8 hr TIB.

MEASUREMENTS AND RESULTS

After the appropriate TIB, medication was administered at 09:00 hr, the Multiple Sleep Latency Test at 09:30, 11:30, 13:30, 15:30, and 17:30 hr, and a 45 min performance battery at 10:30, 14:30, and 16:30 hr. Each day the volunteers wore actigraphs from 0700-1800 hrs. Decreasing TIB was associated with decreased daily mean sleep latency on the MSLT with 4 and 0 hrs differing from 8 hrs and each other. Daytime activity also was reduced by the reduced prior TIB. Increased inactivity relative to the 8 hr TIB developed between the 4 hr and 0 hr TIBs, with 4 hrs differing from 0 hrs, but not 8 hrs. Diphenhydramine 50 mg reduced mean daily sleep latency and increased percent inactive time relative to placebo. On the MSLT diphenhydramine was intermediate to 4 hr and 0 hr TIB and on actigraphy it was similar to 0 hr TIB.

CONCLUSIONS

The difference in the effect of diphenhydramine on these actigraphy and MSLT may reflect the different sensitivities of the measures.

Sleep-wake state and memory function

Facility of memory formation and retrieval is affected by sleep-wake state. This paper discusses memory function while individuals are awake, but sleepy, at the transitions in state (i.e., wake to sleep and sleep to wake), and in REM and NREM sleep. The basal state of arousal at the time of memory function seems to be critical and the sleepy state, state transitions, and NREM sleep seem to define a continuum of arousal with respect to memory function. While different memory systems have been described, the effect of sleep-wake state on memory systems appears to be non-specific. Finally there is a shift in neurobiology from the NREM to REM state and memory function also appears to change in REM sleep.

Sleep organization and regulation

Sleep is a vital, complex state with as yet unknown functions. It is active and highly organized and is regulated by homeostatic, circadian, and ultradian processes. It consists of two distinct sleep states, rapid eye movement (REM) and non-rapid eye movement (NREM), both of which have a dramatic impact on many aspects of physiology and behavior. The significance and consequences of the REM-NREM organization of sleep are not known. On the other hand, the sleep state and its organization are quite fragile and dynamic. Any number of factors can disrupt sleep and its expression, and its nature changes over the life span. What is certain is that any reduction and/or disruption of sleep hinders an organism's ability to navigate through the waking state.

Effects of sleep deprivation on daytime sleepiness in primary insomnia

STUDY OBJECTIVES

This study investigated changes in MSLT scores and recovery sleep following total sleep deprivation in subjects with insomnia as compared to normal sleepers.

DESIGN

Matched-groups design.

SETTING

A sleep disorders center in a large medical center.

PARTICIPANTS

Ten individuals with psychophysiological insomnia and ten age- and sex-matched normal sleepers served as subjects.

INTERVENTIONS

Subjects underwent total sleep deprivation after baseline polysomnography and MSLT. A post-deprivation MSLT was obtained, as well as polysomnography on the recovery night and an MSLT after the recovery night.

MEASUREMENTS AND RESULTS

Both groups showed significant decreases in MSLT scores following total sleep deprivation, as compared to baseline. Both groups had significantly shorter scores on a nighttime MSLT compared to a daytime MSLT. The insomnia group also showed a significant increase in total sleep time on the recovery night compared to baseline.

CONCLUSIONS

The MSLT is sensitive to changes in sleepiness associated with total sleep deprivation in individuals with primary insomnia.

The effects of cocaine on mood and sleep in cocaine-dependent males

The effects of cocaine use and withdrawal on mood and sleep were examined. Three cocaine-dependent men lived in an inpatient facility for approximately 4 weeks, which included an initial abstinence phase (8-10 days), a cocaine administration phase (5 days), and a 2nd abstinence phase (14-16 days). During the 2nd phase, cocaine was administered intranasally a few hours before bedtime. During the day, mood and daytime sleepiness were measured, and sleep was monitored each night. Cocaine produced typical changes in mood and blood pressure, and sleep was severely disrupted. Following Phase 2, there were no changes in mood that was indicative of an abstinence syndrome, although, initially, daytime sleepiness increased. After 2 weeks, sleep architecture remained different from age-matched controls. This study is the first to measure changes in sleep architecture polysomnographically following a period of controlled cocaine use.

The effects of cocaine on mood and sleep in cocaine-dependent males

The effects of cocaine use and withdrawal on mood and sleep were examined. Three cocaine-dependent men lived in an inpatient facility for approximately 4 weeks, which included an initial abstinence phase (8-10 days), a cocaine administration phase (5 days), and a 2nd abstinence phase (14-16 days). During the 2nd phase, cocaine was administered intranasally a few hours before bedtime. During the day, mood and daytime sleepiness were measured, and sleep was monitored each night. Cocaine produced typical changes in mood and blood pressure, and sleep was severely disrupted. Following Phase 2, there were no changes in mood that was indicative of an abstinence syndrome, although, initially, daytime sleepiness increased. After 2 weeks, sleep architecture remained different from age-matched controls. This study is the first to measure changes in sleep architecture polysomnographically following a period of controlled cocaine use.

Repeated nocturnal sleep latencies in narcoleptic, sleepy and alert subjects

OBJECTIVES

The purpose of this study was to assess nocturnal sleep latencies among narcoleptics.

METHODS

Thirteen narcoleptics and matched sleepy and alert controls participated in this study. Subjects were awakened three times on each of two experimental nights. The latencies to sleep and rapid eye movement sleep were evaluated at the beginning of the night and following each experimental awakening.

RESULTS

The alert group (AG) had a significantly longer mean nocturnal sleep latency than the narcoleptic (NG) and sleepy groups (SG). The sleep latencies at 23:00 and 01:10 h were significantly longer than the latencies at 03:10 and 05:10 h. The interaction between group and time of night demonstrated longer latencies at 23:00 and 03:10 h for the AG when compared to the SG and the NG. At 01:10 and 05:10 h all groups had comparable latencies. The number of subjects in the NG who had multiple sleep onset REM periods (SOREMPs) was significantly higher than in either the AG or the SG.

CONCLUSIONS

Narcoleptics were found to have a heightened propensity to fall asleep and increased number of SOREMPs during nocturnal sleep opportunities. These characteristics are consistent with the daytime polysomnographic findings known in this patient population.

Sleepiness and the reinforcing and subjective effects of methylphenidate

On 4 days, 6 volunteers received 10 mg methylphenidate or placebo at 0900 after 4 or 8 hr time in bed (TIB) and then on 4 days after 4 or 8 hr TIB chose their preferred capsule. On sampling days, 4 hr TIB increased multiple sleep latency test (MSLT) scores and Fatigue scale scores on the Profile of Mood States (POMS). In both TIBs, the drug increased the MSLT and POMS Vigor and Tension scale scores. It reduced POMS Fatigue scores and improved divided attention performance to a greater extent after 4 versus 8 hr. Drug was chosen on 88% of days after 4 hr, but only 29% of days after 8 hr. Preference for the drug depends on sleepiness and is mediated by performance-enhancing and fatigue-altering effects.

The detection of brief daytime sleep episodes

INTRODUCTION

In the present study we evaluated the characteristics of sleep-onset detection (during daytime nap opportunities) as a function of differing sleep lengths among healthy, asymptomatic subjects.

METHODS

Twenty subjects were randomized into a Latin square design in which each subject received 1, 5, 10, and 20 minutes of sleep during an MSLT. Subjects were asked after each nap if they fell asleep. The rate of sleep detection was analyzed as a function of sleep duration.

RESULTS

Three subjects detected sleep onset after 1 minute of sleep, 7 subjects after 5 minutes of sleep, 10 subjects after 10 minutes of sleep, and 14 after 20 minutes of sleep (chi 2 = 9.63, p < .05).

CONCLUSIONS

The present data indicate the importance of sleep duration in an individual's ability to detect the occurrence of sleep. Importantly, only three subjects detected sleep after 1 minute of sleep, emphasizing the dangerous nature of brief sleep episodes in the context of public safety.

Psychometric evaluation of daytime sleepiness and nocturnal sleep onset scales in a representative community sample

BACKGROUND

The public health importance of daytime sleepiness as a risk factor for accidents, interpersonal problems, and decreased productivity has been recognized. However, epidemiologic research on this topic has been limited by the reliance on laboratory measures (i.e., the Multiple Sleep Latency Test-MSLT). Two scales, daytime sleepiness and nocturnal sleep onset, have been identified from the self-report Sleep-Wake Activity Inventory (SWAI) in a clinic sample and validated against the MSLT. This study evaluates the replicability of the two scales in a population sample and assesses potential thresholds in scale scores that distinguish normal from pathologic levels of daytime sleepiness and difficulty falling asleep.

METHODS

The sample consisted of 2181 subjects 18-45 years old in the Detroit metropolitan area. All sleep characteristic information covered the 2 weeks prior to interview. Split-half sample factor analyses were conducted to assess replicability of the results. Distribution of scale scores and their relation to construct validity variables were used to evaluate possible thresholds.

RESULTS

A two-factor model appeared to best account for the variation among the 12 items from the SWAI. The two factors accounted for 50% of the variance in both split-half sample analyses. The revised eight-item daytime sleepiness and two-item nocturnal sleep onset scales showed good and fair internal consistency respectively across both split-half samples. There appeared to be a "natural break" in daytime sleepiness scale scores that was associated with a substantial and consistent change in number of hours slept. No breaks appeared in nocturnal sleep onset scores.

CONCLUSIONS

This study replicated the results of the clinic-based study and suggested a potentially useful diagnostic threshold for self-report excessive daytime sleepiness. Epidemiology of sleep depends on the ability to move from the laboratory to population surveys in reliable and valid ways. Development of self-report is a step in that direction.

Ethanol as a hypnotic in insomniacs: self administration and effects on sleep and mood

The purpose of this study was to assess the effects of low ethanol doses on sleep and mood and to assess its reinforcing effects used as a hypnotic. Twenty healthy adults, aged 21-45 yrs, all moderate social drinkers, were studied: eleven subjects had insomnia and nine were normal sleepers, as documented by clinical polysomnography. On two sampling nights each, ethanol (0.5 g/kg) or placebo was administered before sleep in color-coded cups presented in three doses (0.2, 0.2, and 0.1 g/kg) separated by 15 min. On three subsequent nights subjects chose their preferred presleep beverage (0.2 g/kg ethanol or placebo) based on cup color and were given an opportunity for 3 additional refills (0.2 g/kg each) of the chosen beverage at 15 min intervals, yielding a total possible dose of 0.8 g/kg. Insomniacs chose ethanol 67% of nights and normals 22%. Insomniacs chose significantly more ethanol refills than normals for an average nightly dose of 0.45 g/kg and normals took significantly more placebo refills. On the sampling nights 0.5 g/kg ethanol reduced REM sleep for both groups for the 8-hr sleep period and in insomniacs increased stage 3-4 sleep and reduced stage 1 sleep during the first half of the night to the level seen in the normals. Other sleep variables were not altered in either group or halves of the night. Presleep improvements in the Profile of Mood States tension and concentration factors were also associated with ethanol administration. Thus, acutely, both sleep and mood effects appear to be associated with the reinforcing effects of ethanol as a hypnotic for insomniacs.

The effects of REM sleep deprivation on the level of sleepiness/alertness

STUDY OBJECTIVES

The purpose of this study was to evaluate the effects of acute REM deprivation on daytime sleepiness/alertness, as measured by the MSLT.

PARTICIPANTS

Twenty-six healthy, normal volunteers (14 males and 12 females) participated in this study. Participating subjects were in good physical and psychological health and were asymptomatic as to sleep/wake complaints.

INTERVENTIONS

Subjects spent 5 nights and 5 days in the laboratory. The first night and day were utilized for screening purposes. The remaining stay in the laboratory consisted of a baseline night and day, 2 deprivation nights and days, and a recovery night and day. Each night, a nocturnal polysomnogram was employed to monitor subjects' sleep. Each day, subjects underwent an MSLT to evaluate their sleepiness/alertness. Subjects were randomized into REM-deprivation (RD) and yoked-control (YC) groups. On deprivation nights, RD subjects were awakened each time they entered stage REM sleep, and the YC subjects were awakened concomitantly with the RD subjects, assuming they were not in stage REM sleep.

RESULTS

The REM-deprived subjects did not demonstrate any changes in MSLT scores across experimental days. In contrast, the YC subjects documented significantly lower MSLT scores on deprivation days due to decreased total sleep time.

CONCLUSION

The REM-deprivation procedure antagonized the effects of sleep loss on daytime sleepiness, resulting in increased alertness for RD subjects compared to YC subjects. The mechanism by which REM deprivation exerts its alerting effects is unknown and will require future research.

The perception of sleep as a function of the level of daytime sleepiness among patients with obstructive sleep apnea

Subjective estimates of sleep onset among patients with a variety of sleep disorders have been shown to be inaccurate. This inability in perceiving sleep onset is potentially dangerous for this population, in particular, for individuals who are required to drive long distances or operate heavy machinery as part of their daily activities. This study evaluated the perception of sleep among 237 consecutive patients diagnosed with obstructive sleep apnea. Patients completed an overnight sleep-laboratory evaluation followed by an objective evaluation of sleep propensity. The latter was done using the Multiple Sleep Latency Test (MSLT). Patients with an accurate perception of having slept on the MSLT were found to have shorter sleep latencies when compared with those with an inaccurate perception of their sleep. The results of this study suggest that the rapidity with which sleep is manifested is an important contributor to the accurate perception of sleep.

Epidemiology of alcohol and medication as aids to sleep in early adulthood

STUDY OBJECTIVES

In a representative sample of adults 18-45 years of age, this study addressed three questions about the use of sleep aids in the general population: (1) what are the past-year prevalences of the use of alcohol, over-the-counter medication and prescription medication to facilitate sleep? (2) among those who use these substances for sleep problems, what are the patterns of use? and (3) are there social factors, independent of sleep characteristics, that increase the likelihood of alcohol and medication use to aid sleep?

DESIGN

The 1996 Detroit Area Survey was a random-digit-dial, computer-assisted survey of a representative sample of 2,181 adults ages 18-45 in the Detroit primary metropolitan statistical area. Eligible household response rate was 86.8%.

RESULTS

In the general population, use of alcohol and medication as sleep aids in the past year was found to be fairly common: 13% used alcohol, 18% used medications and 5% used both. The prevalence of any substance use to aid sleep was 26%. The duration of use was short for the majority of users, less than 1 week. However, duration of use was greater for the majority of those using prescription sleep aids. A substantial minority of users report regular use lasting longer than 1 month: 15%, 9%, and 36% for alcohol, OTC medications, and prescription medications, respectively. Both sociodemographic and sleep characteristics were associated with alcohol and medication use to aid sleep. Difficulty falling asleep was the factor most strongly associated with use of substances to improve sleep. Sex, race/ethnicity, work shift, marital status and education were also significantly associated with one or more types of sleep aid use adjusting for difficulty falling asleep.

Alerting effects of methylphenidate under basal and sleep-deprived conditions

Six men and 3 women on each of 4 days received 10 mg of methylphenidate or placebo (2 times a day) at 0800 and 1200 after 8 hr or 0 hr of sleep. Sleep latency was measured by the Multiple Sleep Latency Test (MSLT) at 0930, 1130, 1330, 1530, and 1730. Participants also completed divided-attention and auditory vigilance tasks at 1000 and 1400 and the Profile of Mood States (POMS) and the Addiction Research Center Inventory (ARCI) after the 0930 and 1330 latency tests. The drug increased mean latency on the MSLT in both sleep conditions. Performance only showed drug effects after prior sleep deprivation. On the POMS, the drug increased Vigor and reduced Fatigue and Depression scale scores, primarily after sleep deprivation. The drug increased the ARCI Amphetamine and Morphine-Benzedrine scores only in the basal state. The ARCI Pentobarbital score was increased by sleep deprivation and decreased by the drug.

Hypnotic self administration: forced-choice versus single-choice

Twenty-four men and women with insomnia, age 21-50 years, self administered hypnotics under a single-choice with placebo, single-choice with triazolam (0.25 mg), or forced-choice of placebo versus triazolam (0.25 mg) paradigm. Subjects received 4- sampling nights of placebo or triazolam in the single-choice conditions or 2 nights of each in the forced-choice condition. Then on 7 choice nights they could self administer a capsule, or not, in the single-choice conditions, or were required to choose one of two color-coded capsules in the forced-choice condition. In the single-choice conditions, subjects chose placebo 80% of nights and triazolam 77% of nights, while in the forced-choice condition triazolam was chosen on 86% of nights. Thus, the self administration of triazolam did not vary significantly between single or forced choice conditions, but that of placebo did. Placebo rate was high when it was the only alternative, but low when competing with triazolam. On sampling nights, compared to placebo, triazolam produced a significant increase in total sleep time, a reduction in latency to sleep, wake after sleep onset, and percentage stage 1 sleep. Triazolam, relative to placebo, also improved mood in the morning on some sampling nights. For subjects choosing capsules < 100% of opportunities (n = 14), on nights a capsule was chosen versus nights none was chosen (regardless of whether placebo or triazolam was the choice), self-ratings 30 min before bedtime on the Profile of Mood States vigor scale were significantly higher.

Minimal rebound insomnia after treatment with 10-mg zolpidem

This study examined rebound insomnia after discontinuation of chronic use of zolpidem (10 mg), a short elimination half-life imidazopyridine. The zolpidem group was bracketed by a placebo group and a positive control group taking 0.5 mg of triazolam (twice the recommended dose), which is known to produce rebound insomnia. Ninety-nine patients with sleep complaints that were polysomnographically documented participated in the study. After randomization, patients completed a 2-night, single-blind, placebo baseline period, a 28-night double-blind treatment phase, and a 3-night, single-blind, placebo substitution period. Polysomnographic and subjective sleep variables indicated a lack of rebound insomnia for the zolpidem group. The positive triazolam control group had rebound insomnia only on the first discontinuation night. There was no significant correlation between rebound insomnia and the level of initial insomnia, the degree of response to treatment in week 4, or the amount of tolerance that developed during drug use. During the 4-week treatment period, efficacy diminished for both drugs. From these data, it cannot be determined whether the lack of rebound insomnia with zolpidem is a result of drug dose or some property of the drug such as receptor selectivity.

The alerting effects of short and long naps in narcoleptic, sleep deprived, and alert individuals

Eleven narcoleptic patients and 22 age- and gender-matched normal controls participated in a study to determine the alerting effects of differing nap lengths. All narcoleptic patients had been previously diagnosed [mean sleep latency on the multiple sleep latency test (MSLT) < or = 5 minutes with two or more sleep-onset rapid eye movement periods (SOREMPs)]. Healthy, normal subjects with a mean sleep latency on the screening MSLT > or = 8 minutes were randomly assigned to one of two groups (i.e. sleep-deprived and alert). All subjects completed two experimental night and days with at least 5 days between sessions. On the evening prior to each experimental day, narcoleptic and alert subjects spent 8 hours in bed and sleep-deprived subjects spent 0 hours in bed. The following day, all subjects underwent one of two napping conditions, 15 or 120 minutes in bed. Both naps were terminated at noon. Every subject underwent both conditions and the order of conditions was counterbalanced. From 1215 to 1355 hours all subjects underwent a modified MSLT. At 1500 hours, the subjects had a 1-hour nap. The results showed that the 120-minute nap condition was more beneficial than the 15-minute nap. Narcoleptic and sleep deprived subjects were shown to have comparable levels of sleepiness on the modified MSLT. However, a differential response pattern on their latency to sleep was noted on the 1-hour nap. Sleep-deprived subjects were shown to be differentially more alert following a 120-minute nap opportunity. In contrast, for narcoleptic patients the beneficial effects of the nap were lost when tested 3 hours later. These results show that narcoleptic patients benefit from a longer nap but that these benefits are short-lived.

The frequency of multiple sleep onset REM periods among subjects with no excessive daytime sleepiness

The multiple sleep latency test (MSLT) is a valuable tool in the assessment of excessive daytime sleepiness (EDS). Additionally, multiple sleep onset rapid eye movement periods (SOREMPs) are a frequent occurrence in patients with narcolepsy. To date, however, few studies have evaluated the frequency of SOREMPs in a population of healthy control subjects. Subjects participating in a variety of sleep studies were screened with a nocturnal clinical polysomnogram, followed by the MSLT. Subjects were required to be drug free and have no sleep-related symptoms or medical or psychiatric conditions. Of the 139 subjects who were screened, 24 (17%) had two or more SOREMPs. These individuals were more likely to be male, younger, and sleepier than those with one or zero SOREMPs. The etiology of two or more SOREMPs in healthy controls was not apparent from the clinical or polysomnographic evaluation. Although it is possible that these findings are early signs of narcolepsy, subjects reported being free of any sleep-related complaints. Further investigations into the determinants of multiple SOREMPs and their reliability among asymptomatic populations are warranted.

Hypnotic self administration and dose escalation

The dependence liability of benzodiazepines in the context of their use as hypnotics (i.e. by insomnia patients as pre-sleep medications) is unresolved. A recent study found that insomniacs self administer capsules at bedtime at a high rate, with triazolam (0.25 mg) taken as often as placebo. This study sought to determine if differential self administration would develop when multiple capsules are available nightly. Eighteen men and women, age 21-45 years, with insomnia complaints (nine with objective sleep disturbance and nine without) were studied, 1 week with placebo and 1 week with triazolam (0.25 mg). The two conditions were administered double-blind and presented in a counter-balanced order with a week between conditions. In each condition, after 3 consecutive sampling nights of the available single capsule for that condition, subjects could self administer 0-3 capsules before bed on the 4 subsequent nights. Triazolam was self administered as many nights as placebo, but the number of placebo capsules self administered was twice that of triazolam capsules. The objective insomniacs self administered more capsules than the subjective insomniacs and neither group differentially choose triazolam over placebo. The number of triazolam capsules taken nightly was stable and the number of placebo capsules variable. It is concluded that insomniacs show no short-term escalation of triazolam dose, but do choose an increased and variable number of placebos, a pattern which is interpreted as being insomnia relief-seeking behavior.

A two-week sleep extension in sleepy normals

Thirty-four healthy, normal young men and women (21-35 years), with no sleep complaints and a normal screening polysomnogram, some with short (< or = 6-minute) and some with long (> or = 16-minute) average daily sleep latencies on a screening multiple sleep latency test, were studied on two baseline nights (8 hours) and in the "sleepy" group, for 14 consecutive nights of extended (10-hour) or habitual (7.8 +/- 0.7-hour) bedtimes. The screening differences between the groups in average daily sleep latency were consistently seen on the two further baseline nights and days. The extension of bedtime in sleepy subjects was followed by an increase in average daily sleep latency relative to randomly chosen sleepy subjects maintained on their habitual sleep schedule for the 14 nights. The increase in average daily sleep latency was associated with a gradual reduction in sleep efficiency over the 14 nights. Some (36%) of the sleepy subjects did not have increased average sleep latencies during the 10-hour bedtime extension. Those showing no increase in average daily sleep latency had an immediate drop in sleep efficiency when the bedtime was increased to 10 hours, suggesting they were unable to sleep longer during the extension. Their short average daily sleep latency was a result of causes other than chronic insufficient sleep.

The reliability of the diagnostic features in patients with narcolepsy

This study determined the test-retest reliability of the polysomnographic findings in narcolepsy. The diagnosis of narcolepsy was based on clinical symptoms and polysomnographic signs. Control subjects were screened before participation and were split based on their screening multiple sleep latency test (MSLT) into high- and low-MSLT groups. Subjects completed two polysomnographic evaluations with at least 5 days between laboratory tests. Narcoleptics had lower sleep efficiencies and high stage 1% when compared to the low MSLT control group. They had more awakenings and less stage 2% than the control groups. Narcoleptics had a shorter latency to 1 when compared to the high-MSLT group but comparable to that of the low-MSLT group. Narcoleptics had a higher number of sleep-onset rapid eye movement periods (SOREMPs) than both control groups. The MSLT scores were stable across the two evaluations and showed a statistically significant correlation. Twenty-eight of the 30 narcoleptic subjects had two or more SOREMPs on reevaluation. None of the controls had multiple SOREMPs. Thus, multiple SOREMPs were shown to be a reliable finding in patients with narcolepsy.

Nocturnal sleep latencies among alert, alert-deprived and sleepy subjects

Twenty-seven healthy, asymptomatic subjects participated in a study to determine repeated nocturnal sleep latencies as a function of level of daytime sleepiness. Subjects were screened polysomnographically and were determined to be free of any sleep pathology. Nine subjects had a screening multiple sleep latency test (MSLT) of < or = 5 min and 18 had a MSLT of > or = 10 min. Subjects were assigned to 3 groups, sleepy (MSLT < or = 5 min), alert, and alert sleep-deprived groups (MSLT > or = 10 min). Repeated nocturnal latencies to sleep were determined at 2300, 0110, 0310 and 0510 h on 2 nights with at least 5 days between nights. The results showed a main effect of group on the repeated nocturnal sleep latencies. Post-hoc tests demonstrated longer repeated nocturnal latencies among alert subjects compared to the sleepy and alert sleep-deprived subjects. The latter two groups had comparable sleep latencies. A significant main effect of time of night was also shown. The 0510 h latency was significantly shorter than the latencies at 2300 and 0110 h. The 0310 h latency was significantly shorter than the 0110 h latency and comparable to the 2300 and 0510 h latency. Significant correlations were found between daytime MSLT, repeated nocturnal sleep latencies, and nocturnal sleep time. These results show systematic differences in repeated nocturnal sleep latencies among sleep and alert subjects and extend the already described characteristics of these subjects by comparing them to a group of alert sleep-deprived subjects.

Phase advance in moderately sleepy and alert normals

Phase advanced sleep (by 4 hours) was studied in 28 healthy, normal men and women, aged 21-50 years, without nocturnal sleep or daytime sleepiness complaints. Eleven subjects (6 men and 5 women) with moderately short (< or = 10 minutes) average daily sleep latencies on the multiple sleep latency test (MSLT) were compared to 17 (11 men and 6 women) with relatively long (> or = 12 minutes) latencies. Nocturnal sleep on both a baseline and a shift night differed between the groups. The moderately "sleepy" group had shorter sleep latencies and less wakefulness during sleep than the moderately "alert" group. The phase advanced sleep schedule reduced sleep efficiency in both groups, but the moderately sleepy group showed a lessened effect of the shift. Additionally, sleep efficiency was reduced in the moderately sleepy group only during the first 2 hours of the sleep period, while sleep efficiency was uniformly disturbed in the moderately alert group throughout the night during the phase advance.

Auditory awakening thresholds in sleepy and alert individuals

Twenty-seven healthy men and women with regular sleep-wake habits (and no habitual napping) participated in a study to determine the relation between auditory awakening thresholds (AAT) and multiple sleep latency test (MSLT) scores. Subjects were free of any sleep complaints and were screened polysomnographically. Nine subjects had a screening MSLT of < or = 5 minutes (sleepy group), and 18 subjects had an MSLT of > or = 10 minutes. Subjects were assigned to three groups: a sleepy group, alert group and an alert sleep-deprived group. Subjects underwent 2 nights of AAT testing with at least 5 days in between each study night. AATs were determined at 0100, 0300, 0500 and 0730 hours. There were a total of 209 available AAT determinations, with a comparable number of trials across the groups. Because 68% of AAT determinations were done out of stage 2 non-rapid eye movement (NREM) sleep, the thrust of the analysis was based on the results of this stage of sleep. The AATs were averaged across the two experimental nights. Trials 1 and 2 (first half of the night) and 3 and 4 (second half of the night) were averaged for each subject. There was no main effect of group on AATs. However, there was a significant main effect of time and a significant group by time interaction. The former indicated an overall decline in AATs across the night. More importantly, the three groups had comparable AAT levels during the first half of the night:. Sleepy and alert-deprived subjects, however, failed to show a decline in AATs, whereas the alert group showed a significant decline in the second half of the night. This differential rate of decline in AATs is suggested to be related to the differences in sleep homeostasis among alert and sleepy individuals.