Medicinal THC (Dronabinol) Impairs on-the-Road Driving Performance of Occasional and Heavy Cannabis Users but Is Not Detected in Standardized Field Sobriety Tests.

Medicinal THC (dronabinol) impairs on-the-road driving performance of occasional and heavy cannabis users but is not detected in Standardized Field Sobriety Tests.

Filed under: Addiction Rehab

Addiction. 2012 May 4;
Bosker WM, Kuypers KP, Theunissen EL, Surinx A, Blankespoor RJ, Skopp G, Jeffery WK, Walls HC, van Leeuwen CJ, Ramaekers JG

AIMS: The acute and chronic effects of dronabinol (medicinal tetrahydrocannabinol) on actual driving performance and the Standard Field Sobriety Test (SFST) were assessed. It was hypothesized that occasional users would be impaired on these tests and that heavy users would show less impairment due to tolerance. DESIGN, SETTING AND PARTICIPANTS: Double-blind, placebo-controlled, randomized, 3-way cross-over study. Twelve occasional and twelve heavy cannabis users (14 males/ 10 females) received single doses of placebo, 10 and 20 mg dronabinol. MEASUREMENTS: Standard deviation of lateral position (SDLP; i.e. weaving) is the primary measure of road tracking control. Time to speed adaptation (TSA) is the primary reaction time measure in the car-following test. Percentage of impaired individuals on the SFST and subjective high on a visual analogue scale were secondary measures. FINDINGS: Superiority tests showed that SDLP (p=0.008) and TSA (p=0.011) increased after dronabinol in occasional users. Equivalence tests demonstrated that dronabinol-induced increments in SDLP, were bigger than impairment associated with BAC of 0.5 mg/mL in occasional and heavy users, although the magnitude of driving impairment was generally less in heavy users. The SFST did not discriminate between conditions. Levels of subjective high were comparable in occasional and heavy users. CONCLUSIONS: Dronabinol (medicinal tetrahydrocannabinol) impairs driving performance in occasional and heavy users in a dose-dependent way, but to a lesser degree in heavy users possibly due to tolerance. The Standard Field Sobriety Test is not sensitive to clinically relevant driving impairment caused by oral tetrahydrocannabinol.
HubMed – addiction

Structural characterization of the binding mode of smoking cessation drugs to nicotinic acetylcholine receptors through the study of ligand complexes with acetylcholine binding protein.

Filed under: Addiction Rehab

J Biol Chem. 2012 May 2;
Rucktooa P, Haseler CA, van Elk R, Smit AB, Gallagher T, Sixma TK

Smoking cessation is an important aim in public health worldwide since tobacco smoking causes many preventable deaths. Addiction to tobacco smoking results from the binding of nicotine to nicotinic acetylcholine receptors (nAChRs) in the brain, in particular the ?4?2 receptor. One way to aid smoking cessation is by the use of nicotine replacement therapies or partial nAChR agonists like cytisine or varenicline. Here we present the co-crystal structures of cytisine and varenicline in complex with Aplysia californica acetylcholine binding protein (AcAChBP), and use these as models to investigate binding of these ligands binding to nAChRs. This analysis of the binding properties of these two partial agonists provides insight into differences with nicotine binding to nAChRs. A mutational analysis reveals that the residues conveying subtype selectivity in nAChRs reside on the binding site complementary face and include features extending beyond the first shell of contacting residues.
HubMed – addiction

Dopaminergic mechanisms of individual differences in human effort-based decision-making.

Filed under: Addiction Rehab

J Neurosci. 2012 May 2; 32(18): 6170-6
Treadway MT, Buckholtz JW, Cowan RL, Woodward ND, Li R, Ansari MS, Baldwin RM, Schwartzman AN, Kessler RM, Zald DH

Preferences for different combinations of costs and benefits are a key source of variability in economic decision-making. However, the neurochemical basis of individual differences in these preferences is poorly understood. Studies in both animals and humans have demonstrated that direct manipulation of the neurotransmitter dopamine (DA) significantly impacts cost/benefit decision-making, but less is known about how naturally occurring variation in DA systems may relate to individual differences in economic behavior. In the present study, 25 healthy volunteers completed a dual-scan PET imaging protocol with [(18)F]fallypride and d-amphetamine to measure DA responsivity and separately completed the effort expenditure for rewards task, a behavioral measure of cost/benefit decision-making in humans. We found that individual differences in DA function in the left striatum and ventromedial prefrontal cortex were correlated with a willingness to expend greater effort for larger rewards, particularly when probability of reward receipt was low. Additionally, variability in DA responses in the bilateral insula was negatively correlated with willingness to expend effort for rewards, consistent with evidence implicating this region in the processing of response costs. These findings highlight the role of DA signaling in striatal, prefrontal, and insular regions as key neurochemical mechanisms underlying individual differences in cost/benefit decision-making.
HubMed – addiction

New Drug Rehab Referrals Site Makes Itself Available For Help For Those Addicted

Filed under: Addiction Rehab

New site will provide free counseling to addicts and loved ones of those with substance abuse issues as well as referrals to drug rehab centers nationwide. by Dena Goad Oklahoma – A new web-site has just launched which promises to help anyone in need …
Read more on OfficialWire (press release)

Related Addiction Rehab Information…