Brain research. Cognitive brain research
April 2005
Staci A Gruber, Deborah A Yurgelun-Todd
Neuropsychological investigations of substance abusers have reported impairments on tasks mediated by the frontal executive system, including functions associated with behavioral inhibition and decision making. The higher order or executive components which are involved in decision making include selective attention and short term storage of information, inhibition of response to irrelevant...
Biological Psychiatry
March 15, 2005
Deepak Cyril D'Souza, Walid Michel Abi-Saab, Steven Madonick et al.
Recent advances in the neurobiology of cannabinoids have renewed interest in the association between cannabis and psychotic disorders. In a 3-day, double-blind, randomized, placebo-controlled study, the behavioral, cognitive, motor, and endocrine effects of 0 mg, 2.5 mg, and 5 mg intravenous Delta-9-tetrahydrocannabinol (Delta-9-THC) were characterized in 13 stable, antipsychotic-treated...
Psychopharmacology
March 2005
Stephen A Varvel, E Anum, F Niyuhire et al.
The results of recent in vitro studies have underscored the important role that activation of CB(1) receptors has on GABAergic activity in brain areas associated with memory. The primary purpose of this study was to test the hypothesis that the memory disruptive effects of Delta(9)-tetrahydrocannabinol (Delta(9)-THC) in vivo are mediated through GABAergic systems. Conversely, we also evaluated...
Journal of Psychopharmacology
March 1, 2005
David M. Semple, Andrew M. McIntosh, Stephen M. Lawrie
Various lines of evidence suggest an association between cannabis and psychosis. Five years ago, the only significant case-control study addressing this question was the Swedish Conscript Cohort. Within the last few years, other studies have emerged, allowing the evidence for cannabis as a risk factor to be more systematically reviewed and assessed. Using specific search criteria on Embase,...
Medical journal, Armed Forces India
February 2005
S Chaudhury, S Sudarsanan, S K Salujha et al.
Cannabis abuse has been associated with psychiatric disorders. The pattern of cannabis use and incidence of cannabis dependence and cannabis psychosis among 471 consecutive patients admitted to a tertiary care psychiatric center was investigated. Cannabis use was reported by 67 (14.23%) patients of whom 42 (8.92%) were occasional users, 18 (3.82%) were classified as frequent users while 7...
Drug and Alcohol Dependence
January 7, 2005
John A Matochik, Dana A Eldreth, Jean Lud Cadet et al.
Marijuana is the most widely used illicit substance in the United States; however, previous imaging studies have not detected altered brain structure in marijuana users compared to non-users. Voxel-based morphometry was used to investigate possible differences in brain tissue composition in a group of 11 heavy marijuana users and a group of 8 non-users. All participants were male. Statistical...
Journal of the experimental analysis of behavior
January 2005
Scott D Lane, Don R Cherek, Lori M Lieving et al.
It has long been known that acute marijuana administration impairs working memory (e.g., the discrimination of stimuli separated by a delay). The determination of which of the individual components of memory are altered by marijuana is an unresolved problem. Previous human studies did not use test protocols that allowed for the determination of delay-independent (initial discrimination) from...
Drug and Alcohol Review
December 1, 2004
BOB Green, David J. Kavanagh, Ross McD. Young
Abstract: Psychoses are relatively low prevalence disorders that have a disproportionately negative impact on individuals and society. Cannabis use is one factor that can exacerbate the negative consequences associated with psychotic disorders. Relatively few studies have examined the effects or reasons for using cannabis self‐reported by individuals with psychosis. The present study is the...
Drug and Alcohol Review
November 30, 2004
Wayne Hall, Louisa Degenhardt, Maree Teesson
105 citations
This paper evaluates three hypotheses about the relationship between cannabis use and psychosis in the light of recent evidence from prospective epidemiological studies. These are that: (1) cannabis use causes a psychotic disorder that would not have occurred in the absence of cannabis use; (2) that cannabis use may precipitate schizophrenia or exacerbate its symptoms; and (3) that cannabis use...
Neuroimage
November 2004
Dana A Eldreth, John A Matochik, Jean L Cadet et al.
We used PET (15)O and a modified version of the Stroop task to determine if 25-day abstinent heavy marijuana (MJ) users have persistent deficits in executive cognitive functioning (ECF) and brain activity. Performance on a modified version of the Stroop task and brain activity was compared between 25-day abstinent, heavy marijuana users (n = 11), and a matched comparison group (n = 11). The...