Sleep amphetamine effects in MBDS and normal subjects

The acute effects of psychoactive drugs on emotional episodic memory encoding, consolidation, and retrieval: A comprehensive review

Psychoactive drugs modulate learning and emotional processes in ways that could impact their recreational and medical use. Recent work has revealed how drugs impact different stages of processing emotional episodic memories, specifically encoding (forming memories), consolidation (stabilizing memories), and retrieval (accessing memories). Drugs administered before encoding may preferentially impair (e.g., GABAA sedatives including alcohol and benzodiazepines, Δ9-tetrahydrocannabinol or THC, ketamine), enhance (e.g., dextroamphetamine and dextromethamphetamine), or both impair and enhance (i.e., ± 3,4-methylenedioxymethylamphetamine or MDMA) emotionally negative and positive compared to neutral memories. GABAA sedatives administered immediately post-encoding (during consolidation) can preferentially enhance emotional memories, though this selectivity may decline or even reverse (i.e., preferential enhancement of neutral memories) as the delay between encoding and retrieval increases. Finally, retrieving memories under the effects of THC, dextroamphetamine, MDMA, and perhaps GABAA sedatives distorts memory, with potentially greater selectively for emotional (especially positive) memories. We review these effects, propose neural mechanisms, discuss methodological considerations for future work, and speculate how drug effects on emotional episodic memory may contribute to drug use and abuse.

Effect of illicit recreational drugs upon sleep: cocaine, ecstasy and marijuana

The illicit recreational drugs cocaine, ecstasy and marijuana have pronounced effects upon sleep. Administration of cocaine increases wakefulness and suppresses REM sleep. Acute cocaine withdrawal is often associated with sleep disturbances and unpleasant dreams. Studies have revealed that polysomnographically assessed sleep parameters deteriorate even further during sustained abstinence, although patients report that sleep quality remains unchanged or improves. This deterioration of objective sleep measures is associated with a worsening in sleep-related cognitive performance. Like cocaine, 3,4-methylenedioxymethamphetamine (MDMA; "ecstasy") is a substance with arousing properties. Heavy MDMA consumption is often associated with persistent sleep disturbances. Polysomnography (PSG) studies have demonstrated altered sleep architecture in abstinent heavy MDMA users. Smoked marijuana and oral Delta-9-tetrahydrocannabinol (THC) reduce REM sleep. Moreover, acute administration of cannabis appears to facilitate falling asleep and to increase Stage 4 sleep. Difficulty sleeping and strange dreams are among the most consistently reported symptoms of acute and subacute cannabis withdrawal. Longer sleep onset latency, reduced slow wave sleep and a REM rebound can be observed. Prospective studies are needed in order to verify whether sleep disturbances during cocaine and cannabis withdrawal predict treatment outcome.

Sleep in children with attention-deficit hyperactivity disorder: a meta-analysis of polysomnographic studies

The links between sleep and attention-deficit hyperactivity disorder (ADHD) have been a topic for intense ongoing research and clinical interest. Previous narrative literature reviews conveyed a consensus that parents of children with ADHD are more likely to report sleep problems in their children in comparison to parents of control children. However, when objective measures are considered the results appear to be more complex and inconsistent. This review is based on a meta-analysis of relevant polysomnographic studies. We assessed measures related to sleep architecture, breathing disorders, and periodic limb movements in sleep (PLMS), and the role of potential moderators such as age, gender, and other methodological factors. The meta-analysis revealed only one significant combined effect that indicates that children with ADHD are more likely than controls to suffer from PLMS. Factors such as age, gender, inclusion of adaptation night, and comorbidity appear to play a moderating role in the associations between sleep characteristics and ADHD. To provide new insight regarding the links between sleep and ADHD research in this field should adopt new strict guidelines and consider the role of multiple pertinent moderating factors.

[Sleep disorders in children with attention-deficit hyperactivity disorder--results of a polysomnographic study]

OBJECTIVES

We report results of a polysomnographic study carried out with children aged 6 to 12 years with either ADHD or a sleep disorder. The study focussed on whether the sleep structure and architecture of n = 36 ADHD children with and without sleep disorders differed from that of either n=15 children with sleep disorders or n=87 children without sleep disorders. Moreover, we assessed whether there was an increased risk for co-morbid sleep-related breathing disorders among ADHD children.

METHODS

All children underwent polysomnography in a paediatric clinic. Principal variables of the sleep structure and architecture as well as cardiorespirographic measures were analysed.

RESULTS

Our findings demonstrate that sleep problems in children with ADHD seem to be unspecific concurrent symptoms since the sleep structure of sleep-disordered ADHD children and children with sleep disorders was similar. Only minor differences were found between non-sleep-disturbed ADHD children and healthy children without sleep problems.

CONCLUSIONS

We conclude that sleep problems in ADHD are independent co-morbid symptoms without any pathogenetic relationship to vigilance functions in ADHD. The cardiorespirographic analyses showed that a subgroup of ADHD children with sleep problems may be at increased risk for co-morbid sleep-related breathing disorder. This finding is potentially important for differential diagnostic considerations in ADHD.

Sleep disturbances in children with attention deficit hyperactivity disorder

The objective of the study was to compare polysomnographic patterns in two groups of preadolescent children with attention deficit hyperactivity disorder (ADHD) (a sleep clinic referral sample and a community sample) with control children. A prospective and observational study in the sleep clinic and the community was undertaken. Forty-seven ADHD children referred to the sleep clinic (ADHDcl), 53 ADHD children from a community survey (ADHDcom), and 49 control children underwent overnight polysomnography. Significant differences between the groups were observed for rapid-eye-movement (REM) sleep latency and percentage, and periodic limb movement index with associated arousals (PLMa). REM sleep latency was shorter in controls than ADHDcl and ADHDcom (p < 0.01) and REM% was highest in controls and lowest in ADHDcl (p < 0.001). PLMa was higher in ADHDcl than the other groups (p < 0.001), but there were no differences in PLMa between ADHDcom and controls. ADHD children display significant alterations in their sleep patterns, and ADHDcl are more likely to have an elevated PLMa than ADHDcom. In addition, REM sleep is affected by ADHD. We postulate that ADHDcl may represent a subset of children with ADHD at high risk for hyperactivity during sleep.

Responses to methylphenidate in Attention-Deficit/Hyperactivity Disorder and normal children: update 2002

Since the positive effects of stimulants on disruptive behavior were described (Bradley & Bowen, 1941), further pediatric studyhas been limited almost exclusively to samples of hyperkinetic school-age children. Because these agents normally were viewed as arousing in their effects on the central nervous system, but were calming in their therapeutic effects on these children, stimulant effects on Attention Deficit Disorder (ADD) were interpreted as being 'paradoxical.' Investigation of effects in normal children and adolescents and in those with disorders unrelated to Attention-Deficit/Hyperactivity Disorder (ADHD), as well as in young adult samples, however, indicate that stimulants appear to have similar behavioral effects in normal and in hyperactive children. This brief report is an update (as of August 2002) on studies of stimulants in ADHD and normal children, with particular focus on MPH.

[Sleep disorders in hyperkinetic children--correlation with arousal disorders, differential diagnosis and comorbidity]

OBJECTIVES

Sleep disorders are frequently observed in Attention Deficit-Hyperactivity Disorder (ADHD). At the same time, however, there is little evidence of their prevalence and their specific characteristics. Also unclear is a possible pathogenetic relationship between disturbed sleep and the core symptoms of ADHD. There are still very few findings on the role of comorbid internal and neurological disorders like sleep apnea and restless legs syndrome in the differential diagnosis of ADHD.

METHODS

We present an overview of the current literature, describing the most important results concerning sleep disorders in ADHD.

RESULTS

A principal goal of future assessments is to ascertain whether sleep problems in children with ADHD represent unspecific concurrent symptoms or whether they play a substantial role in the pathogenesis of ADHD.

CONCLUSIONS

Moreover a possibly increased risk of comorbid sleep-disordered breathing disorder might be an important issue in the differential diagnostic considerations with regard to ADHD.

Sleep disturbances associated with attention deficit hyperactivity disorder: the impact of psychiatric comorbidity and pharmacotherapy

OBJECTIVE

To estimate the relative risk of sleep problems associated with attention deficit hyperactivity disorder (ADHD), its pharmacotherapy, and its comorbid psychopathology.

METHOD

Standard sleep questionnaires were used to assess sleep problems and characteristics in ADHD (n = 122) and non-ADHD (n = 105) comparison youths.

RESULTS

ADHD was associated with 10 of 19 sleep problems assessed. However, after controlling for psychiatric comorbidity and pharmacotherapy with stimulants, the majority of these differences were no longer evident. Rather, treatment with stimulants and comorbidity with anxiety and behavior disorders were significantly associated with sleep disturbances. Positive family history of ADHD was associated with none of the sleep problems assessed here after adjusting for age, psychiatric comorbidity, and treatment with anti-ADHD medication.

CONCLUSIONS

Although subjective sleep difficulties are common in ADHD youths, they are frequently accounted for by comorbidity and pharmacotherapy. Furthermore, the lack of an association between a positive family history of ADHD and sleep difficulties suggests that ADHD is not a misdiagnosis of the consequences of disruption of normal sleep.

Periodic limb movement disorder and restless legs syndrome in children with attention-deficit hyperactivity disorder

Sleep disruption can lead to symptoms of attention-deficit hyperactivity disorder (ADHD) in children. Since periodic limb movement disorder and/or restless legs syndrome can cause sleep disruption, we assessed whether these two specific sleep disorders are likely to occur in children with ADHD. We asked a series of 69 consecutive parents of children with ADHD questions about the symptoms of periodic limb movement disorder. Based on a positive response to these periodic limb movement disorder queries, 27 children underwent all-night polysomnography. Eighteen children (aged 2 to 15 years) of the 27 (26% of the 69 children with ADHD) had 5 or more periodic leg movements in sleep per hour of sleep and had complaints of sleep disruption, thus fulfilling the criteria for periodic limb movement disorder. A comparably age- and sex-matched group of children referred to a sleep laboratory for sleep complaints but without ADHD showed only a 5% prevalence (2 of 38 subjects) of periodic leg movements in sleep (P=.017). Eight of the 18 children with ADHD and periodic limb movement disorder and one of the two control patients with periodic limb movement disorder had both a personal and parental history of restless legs syndrome symptomatology. This study further documents the occurrence of periodic limb movement disorder and restless legs syndrome in children and is the first large-scale study establishing a possible comorbidity between ADHD and periodic limb movement disorder. We propose that the sleep disruption associated with periodic limb movement disorder and restless legs syndrome and the motor restlessness of restless legs syndrome while awake could contribute to the inattention and hyperactivity seen in a subgroup of ADHD-diagnosed children.

Sleep disturbances in children with attention-deficit/hyperactivity disorder

OBJECTIVE

To evaluate the relationship between sleep disturbances and attention-deficit/hyperactivity disorder (ADHD).

METHOD

Empirical research published since 1970 on sleep disturbances in children with ADHD was systematically reviewed. A "box-score" approach was used to examine consistency of findings across the studies, which used different outcome measures.

RESULTS

Although subjective accounts of sleep disturbances in ADHD were prevalent, objective verification of these disturbances was less robust. The only consistent objective findings were that children with ADHD displayed more movements during sleep but did not differ from normal controls in total sleep time. An additional finding was that stimulant medication led to changes in the children's sleep (e.g., prolonged sleep latency, increased length of onset to first rapid eye movement cycle), but these changes were believed to be nonpathological.

CONCLUSIONS

The exact nature of the sleep problems in children with ADHD remains to be determined. Many of the relevant issues have not been adequately addressed. Factors such as poorly defined diagnostic groups, small sample sizes, few studies, and methodological and procedural limitations make it difficult to determine the relationship between ADHD and sleep problems.

Sleep EEG effects of 3,4-methylenedioxyethamphetamine (MDE; "eve") in healthy volunteers

3,4-methylenedioxyethamphetamine (MDE; "Eve") exerts similar psychotropic effects in humans as 3,4-methylenedioxymethamphetamine (MDMA; "Ecstasy") and is less toxic in animal studies. We conducted a double-blind, placebo-controlled, cross-over sleep electroencephalogram (EEG) study with healthy volunteers. One hundred forty milligrams of MDE or placebo were administered PO in six subjects at 11 PM. Sleep EEG was registered from 11 PM-7 AM the next morning. All subjects had a normal sleep onset latency. They all awoke 60 to 120 min after administration of MDE and stayed awake for at least 150 min (total sleep time, TST MDE < placebo and intermittent time awake MDE > placebo: p < 0.001). After again falling asleep rapid eye movement (REM) sleep was totally suppressed (REM during time in bed, TIB MDE < placebo: p < 0.001). A cyclic alternation of relatively long periods of slow wave sleep (SWS) with periods of light sleep occurred in three subjects during the second part of the night (stage 4 in second part of night MDE > placebo: p = 0.16). The effects of MDE on sleep variables largely demonstrate the stimulant, amphetamine-like properties of MDE.

Hypnopolygraphic alterations in Attention Deficit Disorder (ADD) children

The sleep pattern of 13 prepubertal children, nonmedicated, rigourously diagnosed as Attention Deficit Disorder (ADD) was recorded for two consecutive nights. Analyses of sleep pattern variables revealed a marked reduction of sleep onset latency (p less than .01), a great number of nocturnal awakenings (p less than .01), and a high increase of Delta sleep percentage (p less than .01) for the ADD children compared to normals. In addition, the two subtypes of the disorder--ADD with hyperactivity (ADD/H) and ADD without hyperactivity (ADD/WO) or ADD undifferentiated--showed distinct hypnopolygraphic correlates. Those ADD/H children had a greater sleep fragmentation and a lesser degree of sleep efficiency. These findings would support the hypothesis that ADD is related to a deficient control of arousal level and, on the other hand, suggest that ADD/H and ADD/WO are different clinical entities.

A function for REM sleep: regulation of noradrenergic receptor sensitivity

We hypothesize that REM sleep serves to upregulate and/or prevent downregulation of brain norepinephrine (NE) receptors. This hypothesis is based on the following observations: (1) NE neurons of the locus coeruleus (LC) are tonically active in waking and non-REM sleep, but the entire population of LC NE neurons is inactive during REM sleep. (2) Continuous presence of NE or adrenoceptor agonists downregulates NE receptors, while a reduction in NE availability upregulates these receptors. (3) The effects of REM sleep deprivation are similar to those of NE receptor downregulation. Recent biochemical studies of NE receptor sensitivity provide strong experimental support for this hypothesis. The functional consequence of enhanced NE receptor 'tone' brought about by REM sleep would be improved signal processing in diverse brain systems, thus endowing the organism with a selective advantage. This hypothesis makes a number of specific predictions which can be tested with currently available techniques, and suggests new ways of understanding the evolution and postnatal development of REM sleep.

Absence of REM rebound after barbiturate withdrawal

Administration of three different barbiturates reduced rapid eye movement (REM) sleep. Drug withdrawal led to a return to baseline REM] values without significant overshoot. Similar results are observed with administration of benzodiazepines in pharmacologically equivalent dosages; therefore, a distinction between these two drug classes on the basis of withdrawal effects on the sleep electroencephalogram appears unwarranted. Further investigation is required determine why high REM levels are sometimes associated with the withdrawal of sedative-hypnotic agents.