Ecstasy and sleep disturbance: Progress towards elucidating a role for the circadian system

Mephedrone and MDMA: A comparative review

Mephedrone and MDMA are both constituents of party drugs, with mephedrone being relatively new compared to MDMA. This review compares current knowledge regarding the patterns of usage and neuropsychobiological effects of both mephedrone and MDMA. Both drugs share common psychoactive effects, the duration of which is significantly shorter with mephedrone use, attributing towards a pattern of binge use among users. Both drugs have also been associated with adverse health, psychiatric, and neurocognitive problems. Whilst there is extensive research into the psychobiological problems induced by MDMA, the evidence for mephedrone is comparatively limited. The adverse effect profile of mephedrone appears to be less severe than that of MDMA. Users often believe it to be safer, although both drugs have been associated with overdoses. The neurotoxic potential of mephedrone appears to be low, whereas MDMA can cause long-term damage to the serotonergic system, although this needs further investigation. The abuse liability of mephedrone is significantly greater than that of MDMA, raising concerns regarding the impact of lifetime usage on users. Given that mephedrone is relatively new, the effects of long-term exposure are yet to be documented. Future research focused on lifetime users may highlight more severe neuropsychobiological effects from the drug.

Risky Alcohol Consumption and Online Activity Levels

University students engage in risky patterns of alcohol consumption, which may affect their health and performance at university. This study provides a novel analysis which tracked students' interaction with online course materials over time, and examined associations between online activity and alcohol related harm (as indicated by the Alcohol Use Disorders Identification Test). Study 1 tracked 63 undergraduate psychology students in the second half of a semester and found risky drinking behaviors were marginally related to reductions in online study activity. Study 2 tracked 88 undergraduate psychology students in the first half of a semester. Risky drinking behaviors were associated with less online activity after midday. Students reporting more alcohol related harm were less likely to login between 7 pm and midnight, and between 1 am and 6 am. This study demonstrates a potential sensitivity of online activity levels to alcohol use.

Daily sleep quality affects drug craving, partially through indirect associations with positive affect, in patients in treatment for nonmedical use of prescription drugs

OBJECTIVE

Sleep disturbance has been identified as a risk factor for relapse in addiction to a range of substances. The relationship between sleep quality and treatment outcome has received relatively little attention in research on nonmedical use of prescription drugs (NMUPD). This study examined the within-person association between sleep quality and craving in medically detoxified patients in residence for the treatment of NMUPD.

METHOD

Participants (n=68) provided daily reports of their sleep quality, negative affect (NA), positive affect (PA), and craving for an average of 9.36 (SD=2.99) days. Within-person associations of sleep quality and craving were examined using multilevel modeling. Within-person mediation analyses were used to evaluate the mediating roles of NA and PA in the relationship between sleep quality and craving.

RESULTS

Greater cravings were observed on days of lower than usual sleep quality (γ₁₀=-0.10, p=0.003). Thirty-one percent of the overall association between sleep quality and craving was explained by PA, such that poorer sleep quality was associated with lower PA and, in turn, lower PA was associated with greater craving. No evidence emerged for an indirect association between sleep quality and craving through NA.

CONCLUSIONS

Daily fluctuations in sleep quality were associated with fluctuations in craving, an association partially explained by the association between sleep quality and daily PA. These data encourage further research on the relationship between sleep, affect, and craving in NMUPD patients, as well as in patients with other substance use disorders.

Risky drug use and effects on sleep quality and daytime sleepiness

OBJECTIVE

Sleep problems are commonly reported following alcohol and cannabis abuse, but our understanding of sleep in non-clinical drug using populations is limited. The present study examined the sleep characteristics of alcohol and cannabis users recruited from the wider community.

METHODS

Two hundred forty-eight self-identified alcohol and/or cannabis users (131 women and 117 men) with a mean age of 26.41 years completed an online study that was advertised via online forums, print media and flyers. As part of the study, participants completed validated sleep scales assessing sleep quality (Pittsburgh Sleep Quality Index) and excessive daytime sleepiness (Epworth Sleepiness Scale) in addition to validated drug scales assessing alcohol (Alcohol Use Disorders Identification Test) and cannabis (Marijuana Screening Inventory) use.

RESULTS

Problems with sleep quality were more commonly reported than were complaints of excessive daytime sleepiness. Clinically significant poor sleep quality was associated with comorbid problem alcohol and cannabis use. Women reporting problem alcohol and cannabis use had poorer sleep outcomes than men.

CONCLUSIONS

Social drug users who report risky alcohol and cannabis use also report poor sleep. Poor sleep quality likely exacerbates any drug-associated problems in non-clinical populations.

Dysfunctional overnight memory consolidation in ecstasy users

Sleep plays an important role in the consolidation and integration of memory in a process called overnight memory consolidation. Previous studies indicate that ecstasy users have marked and persistent neurocognitive and sleep-related impairments. We extend past research by examining overnight memory consolidation among regular ecstasy users (n=12) and drug naïve healthy controls (n=26). Memory recall of word pairs was evaluated before and after a period of sleep, with and without interference prior to testing. In addition, we assessed neurocognitive performances across tasks of learning, memory and executive functioning. Ecstasy users demonstrated impaired overnight memory consolidation, a finding that was more pronounced following associative interference. Additionally, ecstasy users demonstrated impairments on tasks recruiting frontostriatal and hippocampal neural circuitry, in the domains of proactive interference memory, long-term memory, encoding, working memory and complex planning. We suggest that ecstasy-associated dysfunction in fronto-temporal circuitry may underlie overnight consolidation memory impairments in regular ecstasy users.

Male and female ecstasy users: differences in patterns of use, sleep quality and mental health outcomes

BACKGROUND

Ecstasy users report a number of adverse effects following use including mood and sleep disturbances. The present study examined differences in characteristics of ecstasy use (amount, frequency of use, reported harm resulting from use) between males and females and assessed relationships between ecstasy use, sleep quality and mental health outcomes.

METHODS

An online survey of 268 ecstasy users (54.1% male, 45.9% female) was conducted. Validated sleep instruments assessing sleep quality and excessive daytime sleepiness, as well as questionnaires regarding physical and mental health (measured using the short-form health survey 12 (SF-12) and details of drug use were included.

RESULTS

Male ecstasy users reported taking larger amounts of ecstasy, but were not more frequent users compared to females. Female ecstasy users were more likely to report increased harm following ecstasy including: feelings of guilt and remorse; failing to do what was normally expected of them; and having been told by others to cut down their ecstasy use. There were interactions between amount and gender and frequency and gender in predicting use of sleep medication and daytime dysfunction. There was a positive correlation between poorer sleep quality and negative mood, although this relationship was not moderated by sex.

CONCLUSIONS

There is a significant association between sleep quality and mood disturbance in ecstasy users suggesting that these negative outcomes are co-morbid. These findings have implications for the treatment and advice given to ecstasy users who are experiencing sleep and/or mood related complaints.

MDMA induces Per1, Per2 and c-fos gene expression in rat suprachiasmatic nuclei

RATIONALE

±3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') is a psychoactive drug that has marked effects on the serotonergic system. Serotonergic agonists are known to interact with the circadian pacemaker located in the suprachiasmatic nuclei (SCN).

OBJECTIVES

Given changes reported in the behavioral activity rhythm following MDMA treatment, the effects of MDMA on core clock gene (Per1, Per2) and c-fos expression were evaluated.

METHODS

Male Long-Evans rats (n = 72) were injected once with MDMA (5 mg/kg i.p.) or saline either at the middle of their 'rest' phase (Zeitgeber Time: ZT6) or the middle of their 'active' phase (Zeitgeber Time: ZT16) and killed at 30, 60, or 120 min posttreatment for gene expression analysis in the SCN using PCR. Behavioral rhythms of a separate group of rats (n = 20) were measured following treatment at ZT16 while they were held in constant darkness for 10 days posttreatment.

RESULTS

At ZT6, c-fos mRNA was significantly induced 120 min post-MDMA treatment but there were no significant changes in Per1 or Per2 mRNA expression. At ZT16, there were significant inductions of c-fos mRNA (30 and 60 min) and Per1 and Per2 mRNA (both 60 min) post-MDMA treatment. However, no differences in behavioral activity patterns were noted following MDMA treatment at ZT16.

CONCLUSIONS

These data provide evidence that MDMA has time of day dependent actions on SCN functioning, as evident from its induction of core clock genes that are important for generating and maintaining circadian rhythmicity.