Psychological Medicine
July 1, 2007
Louisa Degenhardt, Chris Tennant, Stuart Gilmour et al.
The aim was to examine the temporal relationships over 10 months between cannabis use and symptoms of psychosis and depression in people with schizophrenia and related disorders. The design was a prospective study of 101 patients with schizophrenia and related disorders who were assessed monthly over 10 months on medication compliance, cannabis and other drug use, symptoms of depression and...
Journal watch
June 11, 2007
Barbara Geller
Researchers have reported a possible association between cannabis use and adolescent onset of schizophrenia, and magnetic resonance spectroscopy (MRS)
Biological Psychiatry
June 1, 2007
Derik Hermann, Alexander Sartorius, Helga Welzel et al.
Cannabinoids present neurotoxic and neuroprotective properties in in vitro studies, inconsistent alterations in human neuroimaging studies, neuropsychological deficits, and an increased risk for psychotic episodes. Proton magnetic resonance spectroscopy ((1)H-MRS), neuropsychological testing, and hair analysis for cannabinoids was performed in 13 male nontreatment-seeking recreational cannabis...
Adicciones
June 1, 2007
F. Árias
13 citations
Cannabis use is extremely prevalent in young people and there is controversy over the psychosocial harm of this use. One risk stands out--that of the possibility of cannabis being a risk factor of an illness as serious and incapacitating as schizophrenia. An avalanche of information has emerged recently on this subject, which it is essential to review. There are a number of cohort studies that...
Psychopharmacology
June 2007
A A Boucher, Jonathon C Arnold, L Duffy et al.
Cannabis use may precipitate schizophrenia especially if the individual has a genetic vulnerability to this mental disorder. Human and animal research indicates that neuregulin 1 (Nrg1) is a susceptibility gene for schizophrenia. The aim of this study was to investigate whether dysfunction in the Nrg1 gene modulates the behavioural effects of Delta(9)-tetrahydrocannabinol (THC), the major...
Journal of Pharmacology and Experimental Therapeutics
June 2007
Marcello Solinas, Maria Scherma, Gianluigi Tanda et al.
Systemic administration of the main active ingredient in cannabis, Delta9-tetrahydrocannabinol (THC), alters extracellular levels of acetylcholine in several brain areas, suggesting an involvement of the cholinergic system in the psychotropic effects of cannabis. Here, we investigated whether drugs acting at either nicotinic or muscarinic receptors can modulate the discriminative effects 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...
Journal of Psychoactive Drugs
June 1, 2007
Mohamed Ben Amar, Stéphane Potvin
Growing evidence supports the hypothesis that cannabis consumption is a risk factor for the development of psychotic symptoms. Nonetheless, controversy remains about the causal nature of the association. This review takes the debate further through a critical appraisal of the evidence. An electronic search was performed, allowing to identify 622 studies published until June 1st 2005....
Addiction
May 22, 2007
Roberta Pacifici, Piergiorgio Zuccaro, Magı́ Farré et al.
39 citations
ABSTRACT Aims Cell‐mediated immune function and the occurrence of mild infectious diseases was investigated. Participants Polydrug consumers of 3,4‐methylenedioxymethamphetamine (MDMA) and cannabis ( n = 37) compared to cannabis users only ( n = 23) and control group ( n = 34). Design A longitudinal prospective study with three cross‐sectional evaluations at time 0 and at 6 months and 1 year...
Psychopharmacology
May 2007
Nicole L Schramm-Sapyta, Young May Cha, Saba Chaudhry et al.
Unpleasant side effects of drugs of abuse often limit their repeated use; however, such effects may be attenuated in adolescents compared to adults. We investigated whether the anxiogenic, aversive, or locomotor effects of delta-9-tetrahydrocannabinol (THC) differ between adolescent and adult rats. We used the elevated plus maze (EPM) and light-dark tests of anxiety, the conditioned taste...
Drug and Alcohol Review
May 1, 2007
Megan A. Harvey, John D. Sellman, Richard Porter et al.
AbstractResearch indicates that cannabis continues to be a popular illegal drug internationally. Furthermore, adolescent rates of use appear to be significant. Whilst the non‐acute effect of cannabis use on adult cognition has been extensively researched, there has been less examination of adolescents. This study aimed to investigate the non‐acute relationship between cannabis and cognitive...
Human psychopharmacology
April 2007
Daniel S O'Leary, Robert I Block, Julie A Koeppel et al.
Using an attention task to control cognitive state, we previously found that smoking marijuana changes regional cerebral blood flow (rCBF). The present study measured rCBF during tasks requiring attention to left and right ears in different conditions. Twelve occasional marijuana users (mean age 23.5 years) were imaged with PET using [15O]water after smoking marijuana or placebo cigarettes as...
Journal of Pharmacology and Experimental Therapeutics
April 2007
Marcello Solinas, Gianluigi Tanda, Zuzana Justinova et al.
Anandamide is an endogenous ligand for brain cannabinoid CB(1) receptors, but its behavioral effects are difficult to measure due to rapid inactivation. Here we used a drug-discrimination procedure to test the hypothesis that anandamide, given i.v. or i.p., would produce discriminative effects like those of delta-9-tetrahydrocannabinol (THC) in rats when its metabolic inactivation was...
Addiction
March 12, 2007
James Christopher Anthony, Louisa Degenhardt
4 citations
In this issue, Hickman and colleagues [1] present estimates from a simulation exercise to project the impact of cannabis use upon the future incidence of schizophrenia in England and Wales. The projections are based upon an assumption (which the authors disclose) that cannabis smoking causes newly incident cases of schizophrenia that would never appear in the absence of cannabis smoking. It is...
Depression and Anxiety
March 7, 2007
Heather Durdle, Leslie H. Lundahl, Chris‐ellyn Johanson et al.
34 citations
Previous research has suggested that 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) users have elevated depressive symptomatology, although it is not clear whether this is due to MDMA or other drug use. This study aimed to investigate the contributions of MDMA and cannabis use to Major Depressive Disorder in MDMA users. A total of 226 MDMA users were studied. Participants (65% male) reported...
British Journal of Pharmacology
March 2007
R G Pertwee, A Thomas, L A Stevenson et al.
To follow up in vitro evidence that Delta(9)-tetrahydrocannabivarin extracted from cannabis (eDelta(9)-THCV) is a CB(1) receptor antagonist by establishing whether synthetic Delta(9)-tetrahydrocannabivarin (O-4394) and Delta(8)-tetrahydrocannabivarin (O-4395) behave as CB(1) antagonists in vivo. O-4394 and O-4395 were compared with eDelta(9)-THCV as displacers of [(3)H]-CP55940 from specific...
Neuropsychopharmacology
March 2007
Maria Ellgren, Sabrina M Spano, Yasmin L. Hurd
Cannabis use is a hypothesized gateway to subsequent abuse of other drugs such as heroin. We currently assessed whether Delta-9-tetrahydrocannabinol (THC) exposure during adolescence modulates opiate reinforcement and opioid neural systems in adulthood. Long-Evan male rats received THC (1.5 mg/kg intraperitoneally (i.p.)) or vehicle every third day during postnatal days (PNDs) 28-49. Heroin...
Current Opinion in Psychiatry
March 2007
Don H. Linszen, Therese van Amelsvoort
Cannabis use is the most commonly abused illicit substance. Its relation with psychosis remains a topic of debate. Epidemiological studies suggest that cannabis is a component cause accounting for approximately 10% of cases. An increasing number of studies have been published on neurobiological effects of cannabis and vulnerability of psychosis. Acute cannabis administration can induce memory...
Journal of Psychoactive Drugs
March 1, 2007
Casey R. Guillot
26 citations
Due to potential serotonergic deficits, 3,4-methylenedioxymethamphetamine (MDMA or Ecstasy) may cause long-term mood disruptions in recreational Ecstasy users. The purpose of this review is to evaluate the evidence for a relationship between recreational Ecstasy use and higher levels of depressive symptoms. Eleven out of 22 studies initially have reported significantly higher depression scores...
Addiction
February 10, 2007
Matthew Hickman, Peter T. Vickerman, John Macleod et al.
97 citations
AIMS: To estimate long-term trends in cannabis use and projections of schizophrenia assuming a causal relation between cannabis use and schizophrenia. METHODS: Trends in cannabis use were estimated from a national survey, 2003; and incidence of schizophrenia was derived from surveys in three English cities, 1997-99. A difference equation cohort model was fitted against estimates of...