Acute effects of MDMA (3,4-methylenedioxymethamphetamine) on EEG oscillations: alone and in combination with ethanol or THC (delta-9-tetrahydrocannabinol)

Item does not contain fulltextRATIONALE: Typical users of 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") are polydrug users, combining MDMA with alcohol or cannabis [most active compound: delta-9-tetrahydrocannabinol (THC)]. OBJECTIVES: The aim of the present study was to investigate whether co-administration of alcohol or THC with MDMA differentially affects ongoing electroencephalogram (EEG) oscillations compared to the administration of each drug alone. METHODS: In two separate experiments, 16 volunteers received four different drug conditions: (1) MDMA (100 mg); (2) alcohol clamp (blood alcohol concentration = 0.6 per thousand) or THC (inhalation of 4, 6 and 6 mg, interval of 1.5 h); (3) MDMA in combination with alcohol or THC; and (4) placebo. Before and after drug administration, electroencephalography was recorded during an eyes closed resting state. RESULTS: Theta and alpha power increased after alcohol intake compared to placebo and reduced after MDMA intake. No interaction between alcohol and MDMA was found. Significant MDMA x THC effects for theta and lower-1-alpha power indicated that the power attenuation after the combined intake of MDMA and THC was less than the sum of each drug alone. For the lower-2-alpha band, the intake of MDMA or THC alone did not significantly affect power, but the intake of combined MDMA and THC significantly decreased lower-2-alpha power. CONCLUSIONS: The present findings indicate that the combined intake of MDMA and THC, but not of MDMA and alcohol, affects ongoing EEG oscillations differently than the sum of either one drug alone. Changes in ongoing EEG oscillations may be related to the impaired task performance that has often been reported after drug intake

Involvement of the endocannabinoid system in reward processing in the human brain

Rationale Disturbed reward processing in humans has been associated with a number of disorders, such as depression, addiction, and attention-deficit hyperactivity disorder. The endocannabinoid (eCB) system has been implicated in reward processing in animals, but in humans, the relation between eCB functioning and reward is less clear. Objectives The current study uses functional magnetic resonance imaging (fMRI) to investigate the role of the eCB system in reward processing in humans by examining the effect of the eCB agonist Δ9-tetrahydrocannabinol (THC) on reward-related brain activity. Methods Eleven healthy males participated in a randomized placebo-controlled pharmacological fMRI study with administration of THC to challenge the eCB system. We compared anticipatory and feedback-related brain activity after placebo and THC, using a monetary incentive delay task. In this task, subjects are notified before each trial whether a correct response is rewarded (“reward trial”) or not (“neutral trial”). Results Subjects showed faster reaction times during reward trials compared to neutral trials, and this effect was not altered by THC. THC induced a widespread attenuation of the brain response to feedback in reward trials but not in neutral trials. Anticipatory brain activity was not affected. Conclusions These results suggest a role for the eCB system in the appreciation of rewards. The involvement of the eCB system in feedback processing may be relevant for disorders in which appreciation of natural rewards may be affected such as addiction

Delta-9-tetrahydrocannabinol, neural oscillations above 20 Hz and induced acute psychosis

Rationale: An acute challenge with delta-9-tetrahydrocannabinol (THC) can induce psychotic symptoms including delusions. High electroencephalography (EEG) frequencies, above 20 Hz, have previously been implicated in psychosis and schizophrenia. Objectives: The objective of this study is to determine the effect of intravenous THC compared to placebo on high-frequency EEG. Methods: A double-blind cross-over study design was used. In the resting state, the high-beta to low-gamma magnitude (21–45 Hz) was investigated (n=13 pairs+4 THC only). Also, the event-related synchronisation (ERS) of motor-associated high gamma was studied using a self-paced button press task (n=15). Results: In the resting state, there was a significant condition × frequency interaction (p=0.00017), consisting of a shift towards higher frequencies under THC conditions (reduced high beta [21–27 Hz] and increased low gamma [27–45 Hz]). There was also a condition × frequency × location interaction (p=0.006), such that the reduction in 21–27-Hz magnitude tended to be more prominent in anterior regions, whilst posterior areas tended to show greater 27–45-Hz increases. This effect was correlated with positive symptoms, as assessed on the Positive and Negative Syndrome Scale (PANSS) (r=0.429, p=0.042). In the motor task, there was a main effect of THC to increase 65–130-Hz ERS (p=0.035) over contra-lateral sensorimotor areas, which was driven by increased magnitude in the higher, 85–130-Hz band (p=0.02) and not the 65–85-Hz band. Conclusions: The THC-induced shift to faster gamma oscillations may represent an over-activation of the cortex, possibly related to saliency misattribution in the delusional state

Cannabis and creativity: highly potent cannabis impairs divergent thinking in regular cannabis users

Stress-related psychiatric disorders across the life spa

Inhibition of THC-induced effects on the central nervous system and heart rate by a novel CB1 receptor antagonist AVE1625

CB1 antagonists such as AVE1625 are potentially useful in the treatment of obesity, smoking cessation and cognitive impairment. Proof of pharmacological action of AVE1625 in the brain can be given by antagonising the effects of delta-9-tetrahydrocannabinol (THC), a CB1/CB2 agonist. Inhibition of THC-induced effects by AVE1625 was observed on Visual Analogue Scales 'alertness', 'feeling high', 'external perception', 'body sway' and 'heart rate'. Even the lowest dose of AVE1625 20 mg inhibited most of THC-induced effects. AVE1625 did not have any effect on psychological and behavioural parameters or heart rate by itself. After THC and AVE1625 administration, changes on electroencephalography were observed. This study shows a useful method for studying the effects of CB1 antagonists. AVE1625 penetrates the brain and antagonises THC-induced effects with doses at or above 20 mg.Stress-related psychiatric disorders across the life spa

Effects of ¿9-Tetrahydrocannabinol Administration on human encoding and recall memory function: a pharmacological fMRI study

Deficits in memory function are an incapacitating aspect of various psychiatric and neurological disorders. Animal studies have recently provided strong evidence for involvement of the endocannabinoid (eCB) system in memory function. Neuropsychological studies in humans have shown less convincing evidence but suggest that administration of cannabinoid substances affects encoding rather than recall of information. In this study, we examined the effects of perturbation of the eCB system on memory function during both encoding and recall. We performed a pharmacological MRI study with a placebo-controlled, crossover design, investigating the effects of ¿9-tetrahydrocannabinol (THC) inhalation on associative memory-related brain function in 13 healthy volunteers. Performance and brain activation during associative memory were assessed using a pictorial memory task, consisting of separate encoding and recall conditions. Administration of THC caused reductions in activity during encoding in the right insula, the right inferior frontal gyrus, and the left middle occipital gyrus and a network-wide increase in activity during recall, which was most prominent in bilateral cuneus and precuneus. THC administration did not affect task performance, but while during placebo recall activity significantly explained variance in performance, this effect disappeared after THC. These findings suggest eCB involvement in encoding of pictorial information. Increased precuneus activity could reflect impaired recall function, but the absence of THC effects on task performance suggests a compensatory mechanism. These results further emphasize the eCB system as a potential novel target for treatment of memory disorders and a promising target for development of new therapies to reduce memory deficits in human

Surinabant, a selective cannabinoid receptor type 1 antagonist, inhibits 9-tetrahydrocannabinol-induced central nervous system and heart rate effects in humans

Stress-related psychiatric disorders across the life spa

CCR5 Delta 32 genotype is associated with outcome in type 2 diabetes mellitus

Aims: To test whether the genetic variant CCR5 Delta 32 in the CC-chemokine receptor 5, which is known to lead to CCR5 deficiency, is associated with mortality in type 2 diabetes patients. Methods: We examined the effect of presence or absence of the CCR5 Delta 32 on overall and cardiovascular mortality risk in the Zwolle outpatient Diabetes project Integrating Available Care (ZODIAC) cohort, a type 2 diabetes patient cohort. Results: We studied 756 patients with a mean duration of follow-up of 5.4 (+/- 1.4) years. 194 patients died during follow up of which 83 were cardiovascular deaths. 144 subjects (19%) carried the CCR5 Delta 32 deletion. CCR5 Delta 32 carriers had an adjusted hazard ratio of 0.62 (95%CI: 0.40-0.96; p = 0.03) for all-cause mortality and 0.63 (95%CI: 0.33-1.19; p = 0.16) for cardiovascular mortality. Conclusions: The presence of CCR5 Delta 32 is associated with better survival in type 2 diabetes patients. These data suggest that it is worthwhile to explore the protective potential of pharmacological blockade of CCR5 in type 2 diabetic patients. (C) 2009 Elsevier Ireland Ltd. All rights reserved