Reward-related brain response and craving correlates of marijuana cue exposure: a preliminary study in treatment-seeking marijuana-dependent subjects.

Objective: : Determining the brain substrates underlying the motivation to abuse addictive drugs is critical for understanding and treating addictive disorders. Laboratory neuroimaging studies have demonstrated differential activation of limbic and motivational circuitry (eg, amygdala, hippocampus, ventral striatum, insula, and orbitofrontal cortex) triggered by cocaine, heroin, nicotine, and alcohol cues. The literature on neural responses to marijuana cues is sparse.

Effects of varenicline on smoking cue–triggered neural and craving responses.

Context: Varenicline, an effective smoking cessation medication, functions as an α4β2 nicotinic acetylcholine receptor partial agonist. It indirectly affects the dopaminergic reward system by reducing withdrawal symptoms during abstinence and by decreasing the reinforcement received from nicotine while smoking. We hypothesize that varenicline would have a third mechanism to blunt responses to smoking cues in the reward-related ventral striatum and medial orbitofrontal cortex and would be associated with a reduction in smoking cue–elicited craving.

Identifying risk factors for marijuana use among veterans affairs patients.

Objectives: Cannabis is the most widely used drug in the United States, and its use carries negative health consequences; however, universal screening for cannabis use is cumbersome. If data commonly collected in the primary care setting (eg, use of alcohol, smoking status, and depression symptoms) could predict cannabis use, then providers can implement targeted marijuana screening in high-risk groups.

Methods: We reviewed Behavioral Health Laboratory data collected between 2003 and 2006 from 5512 patients referred by Veterans Affairs primary care clinics for potential mental health needs.

Atomoxetine for treatment of marijuana dependence: a report on the efficacy and high incidence of gastrointestinal adverse events in a pilot study.

Marijuana users consistently demonstrate impairments in attention, executive function and response inhibition, which resemble deficits seen in attention deficit hyperactivity disorder (ADHD). We hypothesized that targeting the cognitive deficits associated with chronic marijuana use through ADHD medications may help identify a therapeutic agent for marijuana dependence. Thirteen subjects participated in an 11-week open label study to determine the feasibility, safety and tolerability of atomoxetine for individuals seeking treatment for marijuana dependence.

Normal sleep and circadian rhythms: neurobiologic mechanisms underlying sleep and wakefulness.

Sleep is a vital, highly organized process regulated by complex systems of neuronal networks and neurotransmitters. Sleep plays an important role in the regulation of central nervous system and body physiologic functions. Sleep architecture changes with age and is easily susceptible to external and internal disruption.