Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
May 2011
Amy L Bauernfeind, Mary S Dietrich, Jennifer U Blackford et al.
The serotonergic neurotoxin, 3,4-methylenedioxymethamphetamine (MDMA/Ecstasy), is a highly popular recreational drug. Human recreational MDMA users have neurocognitive and neuropsychiatric impairments, and human neuroimaging data are consistent with animal reports of serotonin neurotoxicity. However, functional neuroimaging studies have not found consistent effects of MDMA on brain...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
March 2011
Yen F Tai, Rosa Hoshi, Catherine M Brignell et al.
Ecstasy (±3,4-methylenedioxymethamphetamine, MDMA) is a popular recreational drug with known serotonergic neurotoxicity. Its long-term effects on dopaminergic function are less certain. Studying the long-term effects of ecstasy is often confounded by concomitant polydrug use and the short duration of abstinence. We used (18)F-dopa positron emission tomography (PET) to investigate the long-term...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
October 2010
Colm M P O'Tuathaigh, Magdalena Hryniewiecka, Aine Behan et al.
Cannabis use confers a two-fold increase in the risk for psychosis, with adolescent use conferring even greater risk. A high-low activity catechol-O-methyltransferase (COMT) polymorphism may modulate the effects of adolescent Δ-9-tetrahydrocannabinol (THC) exposure on the risk for adult psychosis. Mice with knockout of the COMT gene were treated chronically with THC (4.0 and 8.0 mg/kg over 20...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
January 2010
Yoko Nawata, Takato Hiranita, Tsuneyuki Yamamoto
(+/-)-3,4-Methylenedioxymethamphetamine (MDMA, 'Ecstasy') abusers have persistent neuropsychiatric deficits including memory impairments after the cessation of abuse. On the other hand, cannabinoid CB(1) receptors have been implicated in learning/memory, and are highly expressed in the hippocampus, a region of the brain believed to have an important function in certain forms of learning and...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
February 2009
Matthijs G. Bossong, Bart N M Van Berckel, Ronald Boellaard et al.
The influence of cannabis on mental health receives growing scientific and political attention. An increasing demand for treatment of cannabis dependence has refueled the discussion about the addictive potential of cannabis. A key feature of all addictive drugs is the ability to increase synaptic dopamine levels in the striatum, a mechanism involved in their rewarding and motivating effects....
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
October 2008
Tiziana Rubino, Daniela Vigano', Natalia Realini et al.
Few and often contradictory reports exist on the long-term neurobiological consequences of cannabinoid consumption in adolescents. The endocannabinoid system plays an important role during the different stages of brain development as cannabinoids influence the release and action of different neurotransmitters and promote neurogenesis. This study tested whether long-lasting interference by...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
October 2008
Elena H Chartoff, David Potter, Diane Damez-Werno et al.
Stress and chronic exposure to drugs of abuse can trigger addictive and depressive disorders. Both stimuli increase activity of dynorphin, a neuropeptide that acts at kappa-opioid receptors (KORs). In humans, KOR agonists cause dysphoria, raising the possibility that dynorphin modulates the depressive-like effects of stress and chronic drug use. We examined if KOR activation alters sensitivity...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
September 2008
Deepak Cyril D'Souza, Mohini Ranganathan, Gabriel Braley et al.
Cannabis is one of the most widely used illicit substances and there is growing interest in the association between cannabis use and psychosis. Delta-9-Tetrahydrocannabinol (Delta-9-THC) the principal active ingredient of cannabis has been shown to induce psychotomimetic and amnestic effects in healthy individuals. Whether people who frequently use cannabis are either protected from or are...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
August 2008
Michael A. Benneyworth, Randy L Smith, Elaine Sanders‐bush
Recent clinical studies in schizophrenic patients show that a selective agonist of group II metabotropic glutamate (mGlu) receptors has robust efficacy in treating positive and negative symptoms. Group II mGlu receptor agonists also modulate the in vivo activity of psychotomimetic drugs, reducing the ability of psychotomimetic hallucinogens to increase glutamatergic transmission. The use of...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
April 2008
Brian J. Piper, Joseph B. Fraiman, Cullen B Owens et al.
High or repeated doses of the recreational drug 3,4-methylenedioxymethamphetamine (MDMA, or 'Ecstasy') produce long-lasting deficits in several markers of serotonin (5-HT) system integrity and also alter behavioral function. However, it is not yet clear whether MDMA-induced serotonergic neurotoxicity is responsible for these behavioral changes or whether other mechanisms are involved. The...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
October 1, 2007
Martina Ballmaier, Marco Bortolato, Cristina Rizzetti et al.
Clinical and laboratory findings suggest that cannabinoids and their receptors are implicated in schizophrenia. The role of cannabinoids in schizophrenia remains however poorly understood, as data are often contradictory. The primary aim of this study was to investigate whether the cannabinoid CB1 receptor antagonists rimonabant and AM251 are able to reverse deficits of sensorimotor gating...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
June 2007
Margaret Haney
In non-human animals, opioid antagonists block the reinforcing and discriminative-stimulus effects of Delta(9)-tetrahydrocannabinol (THC), while in human marijuana smokers, naltrexone (50 mg) enhances the reinforcing and subjective effects of THC. The objective of this study was to test a lower, more opioid-selective dose of naltrexone (12 mg) in combination with THC. The influence of...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
July 2006
Michael John Morgan, Lara Chiara Impallomeni, Alessandro Pirona et al.
Ecstasy (MDMA; 3,4-methylenedioxymethamphetamine) has a well-recognized neurotoxic effect on central serotonergic (5-HT) systems in animals, and there is some evidence of persistent serotonergic dysregulation in human ecstasy users. Serotonin is believed to mediate impulsive behavior and effective decision-making. Thus, the aim of the present study was to investigate impulsive behavior and...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
February 2006
Euphrosyne Gouzoulis‐mayfrank, Karsten Heekeren, Anna Neukirch et al.
Patients with schizophrenia exhibit disturbances of orienting of attention. However, findings have been inconsistent. Pharmacologic challenges with hallucinogens have been used as models for psychosis. The NMDA antagonist state (PCP, ketamine) resembles undifferentiated psychoses with positive and negative symptoms, while the 5-HT(2A) agonist state (LSD, dimethyltryptamine (DMT)) is thought to...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
February 2006
Annis O. Mechan, Jie Yuan, George Hatzidimitriou et al.
A large body of data indicates that (+/-)3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') can damage brain serotonin neurons in animals. However, the relevance of these preclinical data to humans is uncertain, because doses and routes of administration used in animals have generally differed from those used by humans. Here, we examined the pharmacokinetic profile of MDMA in squirrel monkeys...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
August 2005
June M Young, Iain S. Mcgregor, Paul E Mallet
3,4-Methylenedioxymethamphetamine (MDMA, 'Ecstasy') and cannabis are two of the most commonly used illicit drugs in the western world, and are often used in combination. Very little research has examined their effect on cognitive function or behavior when combined, The present study used a double Y-maze task to examine the acute effect of MDMA and delta9-tetrahydrocannabinol (THC, the principal...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
June 2005
Grégory Conductier, Cyril Crosson, René Hen et al.
3,4-Methylenedioxy-N-methamphetamine (MDMA or 'ecstasy') is a psychoactive substance, first described as an appetite suppressant in humans, inducing side effects and even death. MDMA increases serotonin (5-HT) levels, and 5-HT inhibits food intake, but the 5-HT receptors involved in MDMA-induced changes in feeding behavior are unknown. We examined whether a systemic MDMA injection would reduce...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
August 2004
Deepak Cyril D'Souza, Edward Perry, Lisa Macdougall et al.
Recent advances in the understanding of brain cannabinoid receptor function have renewed interest in the association between cannabinoid compounds and psychosis. In a 3-day, double-blind, randomized, and counterbalanced study, the behavioral, cognitive, and endocrine effects of 0, 2.5, and 5 mg intravenous delta-9-tetrahydrocannabinol (Delta-9-THC) were characterized in 22 healthy individuals,...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
June 1, 2004
Janne Damm Andersen, Bruno Pouzet
It has been suggested that perinatal treatment with the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist phencyclidine (PCP) induces transient neurodegeneration in the limbic and cortical structures of rats. Since dysfunction of these structures is associated with cognitive deficits in patients with schizophrenia, we studied the effects of subchronic treatment with PCP in...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
May 2004
Boris B. Quednow, Kai‐uwe Kühn, Klaus Hoenig et al.
Chronic administration of 3,4-methylenedioxymethamphetamine (MDMA) is associated with long-term depletion of serotonin (5-HT) and loss of 5-HT axons in the brains of rodents and nonhuman primates. Despite the broad database concerning the selective serotonergic neurotoxicity of recreational MDMA consumption by humans, controversy still exists with respect to the question of whether the...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
July 2003
Jennifer McDonald, Laura Schleifer, Jerry B Richards et al.
This study investigated the acute effects of delta(9)-tetrahydrocannabinol (THC) on four behavioral measures of impulsivity in recreational marijuana users. Although impulsive behavior has been studied using several different measures of impulsivity, few studies have utilized more than one of these measures on a single cohort. In this study, 37 healthy men and women participated in three...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
February 1, 2003
Susan M Cochran, Matthew D Kennedy, Clare E McKerchar et al.
Numerous human imaging studies have revealed an absolute or relative metabolic hypofunction within the prefrontal cortex, thalamus and temporal lobes of schizophrenic patients. The former deficit correlates with cognitive deficits and negative symptoms, whereas the latter correlates with positive symptomologies. There is also general consensus that schizophrenia is associated with decreased...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
2003
Andrea Balla, Henry Sershen, Michael Serra et al.
Functional dopaminergic hyperactivity is a key feature of schizophrenia. Etiology of this dopaminergic hyperactivity, however, is unknown. We have recently demonstrated that subchronic phencyclidine (PCP) treatment in rodents induces striatal dopaminergic hyperactivity similar to that observed in schizophrenia. The present study investigates the ability of PCP to potentiate amphetamine-induced...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
November 2001
Carl L. Hart, W Van Gorp, M Haney et al.
Although the ability to perform complex cognitive operations is assumed to be impaired following acute marijuana smoking, complex cognitive performance after acute marijuana use has not been adequately assessed under experimental conditions. In the present study, we used a within-participant double-blind design to evaluate the effects acute marijuana smoking on complex cognitive performance in...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
October 1, 2001
Adrienne C. Lahti, M A Weiler, B A Tamara Michaelidis et al.
This study evaluates the effects of ketamine on healthy and schizophrenic volunteers (SVs) in an effort to define the detailed behavioral effects of the drug in a psychosis model. We compared the effects of ketamine on normal and SVs to establish the comparability of their responses and the extent to which normal subjects might be used experimentally as a model. Eighteen normal volunteers (NVs)...