Journal of Psychopharmacology
May 2009
J G Ramaekers, G Kauert, E L Theunissen et al.
Performance impairment during Delta(9)-tetrahydrocannabinol (THC) intoxication has been well described in occasional cannabis users. It is less clear whether tolerance develops to the impairing effects of THC in heavy users of cannabis. The aim of the present study was to assess neurocognitive performance during acute THC intoxication in occasional and heavy users. Twenty-four subjects (12...
Psychopharmacology
April 2009
Lance R Mcmahon
Anandamide and Delta(9)-tetrahydrocannabinol (Delta(9)-THC) sometimes produce different discriminative stimulus effects and, therefore, appear to differ in their mechanism of action. In order to understand the widespread use of cannabis and the therapeutic potential of cannabinoids, mechanisms responsible for behavioral effects need to be identified. Drug discrimination was used to compare the...
Molecular Pharmacology
April 2009
Alan M Roloff, Stanley A Thayer
Delta(9)-tetrahydrocannabinol (THC), the principal psychoactive ingredient in marijuana, acts as a partial agonist on presynaptic cannabinoid type 1 (CB1) receptors to inhibit neurotransmitter release. Here, we report that THC inhibits excitatory neurotransmission between cultured rat hippocampal neurons in a manner highly sensitive to stimulus rate. THC (1 microM) inhibited excitatory...
Psychopharmacology
April 2009
Joshua A Lile, Thomas H Kelly, David J Pinsky et al.
Preclinical evidence suggests that non-cannabinoid neurotransmitter systems are involved in the behavioral and physiological effects of cannabinoids, but relatively little research has been conducted in humans. The aims of this study were to assess whether oral Delta(9)-tetrahydrocannabinol (Delta(9)-THC) would function as a discriminative stimulus in humans and to examine the substitution...
Archives of General Psychiatry
April 1, 2009
Sagnik Bhattacharyya, Paolo Fusar‐poli, Stefan Borgwardt et al.
250 citations
CONTEXT: Cannabis sativa use can impair verbal learning, provoke acute psychosis, and increase the risk of schizophrenia. It is unclear where C. sativa acts in the human brain to modulate verbal learning and to induce psychotic symptoms. OBJECTIVES: To investigate the effects of 2 main psychoactive constituents of C. sativa, Delta9-tetrahydrocannabinol (Delta9-THC) and cannabidiol, on regional...
Pharmacology, Biochemistry, and Behavior
March 2009
Ronald L Cowan, James M. Joers, Mary S Dietrich
Impaired verbal memory is common in MDMA (Ecstasy) polydrug users. The contributions of Ecstasy or polydrug exposure to reduced verbal memory are unclear, as is the neural basis for this cognitive deficit. Ecstasy users have reduced gray matter in brain regions mediating verbal memory (BA 18, 21 and 45). N-acetylaspartate (NAA) as a neuronal marker and myoinositol (mI) as a glial marker are...
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....
European Addiction Research
2009
Derik Hermann, Tagrid Leménager, Jan Gelbke et al.
It is unclear whether impairment in decision making, measured by the Iowa Gambling Task (IGT), in addiction is substance-induced or the consequence of personality structure. Analysis of the IGT, the Tridimensional Personality Questionnaire (TPQ) and cannabinoids in hair and urine were performed in 13 cannabis users and matched controls. Hair Delta(9)-tetrahydrocannabinol (THC) correlated...
European Psychiatry
2009
M. Di Forti
Epidemiological studies have reported that the increased risk of developing psychosis in cannabis users is dose related. In addition, experimental research has shown that the active constituent of cannabis responsible for its psychotogenic effect is Delta-9-Tetrahydrocannabinol (THC) (Murray et al, 2007). Recent evidence has suggested an increased in potency (% TCH) in the cannabis seized in...
Frontiers in Human Neuroscience
2009
Else-Marie Løberg
83 citations
People with schizophrenia frequently report cannabis use, and cannabis may be a risk factor for schizophrenia, mediated through effects on brain function and biochemistry. Thus, it is conceivable that cannabis may also influence cognitive functioning in this patient group. We report data from our own laboratory on the use of cannabis by schizophrenia patients, and review the existing literature...