Active clinical trials for "Marijuana Abuse"

The objective of the current study is to prospectively assess the effect of cannabis on pain and functional outcomes in a large group of patients with chronic pain.

Marijuana (Cannabis sativa) is the most widely used illicit drug worldwide, with 17.4 million Americans reporting past month use in 2010 and 4.6 million meeting criteria for dependence, underscoring the public health importance of understanding the biological implications of use. How heavy cannabis use affects brain structure and cognitive performance in late life is unknown. The ongoing maturation in the adolescent brain, including the developmental circuitry underlying memory performance and executive control puts the adolescent brain at high risk for detrimental effects of heavy cannabis use. With the aging of the 'baby boomer' generation, many people who used cannabis heavily as adolescents are now entering their senior years when age-related cognitive decline may begin. Cannabis use doubled in less than a decade during the 1970's when 38% of those surveyed in the U.S. Survey on Drug Abuse reported using cannabis and 12% of those users reported using cannabis more than 20 times a month. Understanding how heavy, early cannabis use may affect neurobiological and cognitive outcomes is of high importance for this aging population, which is already at risk for memory and cognitive deficits in aging. Because cannabis use appears to have a primary effect within the hippocampus, the main structure for memory and the structure affected most by age-related memory impairments and pre-clinical Alzheimer's disease, we expect that the effects of chronic cannabis use may be greatest during aging. To our knowledge, no study has investigated the long-term effects of adolescent cannabis use on hippocampal morphology and cognitive performance in an aging population. Investigators will investigate hippocampal integrity and cognitive performance using high-resolution magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) and neuropsychological testing in an aging population of subjects (55-70 years old) who used cannabis more than 20 times a month for at least a year during adolescence. Investigators will compare data collected from heavy cannabis users to subjects who did not use cannabis but are matched for age, gender, education, light tobacco and light alcohol use. Finally, because family history and genetic risk are known to accelerate hippocampal morphology and memory decline in aging, the investigators will investigate whether possession of the APOE ε4 variant in heavy cannabis users is synergistically related to thinner hippocampal cortex and white matter deficits.

This study aims to determine if a marijuana (MJ) Approach Avoidance Task (AAT) intervention reduces cannabis use compared to a control condition containing no active components of AAT. Adolescent heavy MJ users (N=40, ages 16-21) will be randomly assigned to MJ-AAT (n=20) or control condition (MJ-Sham, n=20) for three weeks. The MJ-AAT includes six sessions designed to reduce action tendencies to approach marijuana. The MJ-Sham includes six MJ-AAT-sham conditions. Substance use and cognitive assessment will identify changes in MJ use patterns and mechanisms of treatment outcomes. Additionally, using an functional magnetic resonance imaging marijuana cue reactivity task, we will determine differences in neural response in reward regions before and after 3 weeks of either AAT or sham treatment.

The purpose of this study is to explore sex differences in cognitive functioning and responses to marijuana-related items, and to determine whether stress impacts these measures. Hypothesis 1: Attentional bias will be greater for marijuana cues in male marijuana-dependent subjects relative to female marijuana-dependent or non-dependent male controls. Hypothesis 2: Marijuana-dependent females will exhibit greater stress-induced changes in attentional bias and cognitive functioning than marijuana-dependent males.

Background: - Individuals with schizophrenia or schizoaffective disorders have a high prevalence of cannabis use. Understanding some of the environmental factors that maintain cannabis use, such as socially triggered cravings, is a critical step in improving treatment for cannabis dependence. In recent years, virtual reality has been studied to determine whether it can be used to induce craving by using life-like cue settings. Researchers are interested in using virtual reality systems to study cannabis cravings in individuals with schizophrenia. Objectives: - To determine if virtual reality cues will elicit cannabis craving in persons with schizophrenia who have a history of cannabis use. Eligibility: - Individuals between 18 and 50 years of age who have been diagnosed with schizophrenia or schizoaffective disorders, are on a stable antipsychotic medication, and who have a lifetime history of at least 50 cannabis uses and average cannabis use of once per month. Design: This study involves an initial screening visit, a study visit, and a followup visit. Participants will be screened with a medical history and physical examination, and will complete questionnaires about their history of marijuana and other drug use. Participants will also learn how to use the virtual reality equipment at this visit. During the study visit, participants will respond to marijuana cues using the virtual reality system while researchers monitor their heart rate, blood pressure, and sweat levels. At the followup visit, participants will complete questionnaires about their mood and any cravings for marijuana.

The purpose of the proposed study to examine the links among stress, craving for marijuana, and marijuana reminders, or "cues". In this study, an agent called yohimbine will be used to produce stress-like responses. Yohimbine is known to cause stress response in studies of alcohol and other substance use disorders. This study intends to show it can be used to cause stress in marijuana users as well.

This study investigates the effects of repeated NAC administration on glutamate concentrations in the anterior cingulate cortex (ACC), on neurocognitive functioning, and on neuro-inflammatory parameters in adult cannabis-dependent individuals.

Driving is a set of complex tasks and requires use of multiple cognitive domains, including attention, planning, and memory. In laboratory studies, the main psychoactive component in cannabis, delta-9-tetrahydrocannabinol (THC), was shown to impair short-term memory, attention, reaction time, tracking, and coordination, resulting, for instance, in significantly more deviations from the lane and increased break latency. Surveys and epidemiological studies suggest that cannabis consumption is associated with increased risks of collision. The current study aims to evaluate individual driving behavior and performance on various neurocognitive tests and their correlated neural networks while under the influence of cannabis and while sober. The investigators will use the STISIM driving simulator, which is fully MRI compatible, to study brain activation, while participants are performing various driving maneuvers. The goals of the study are: identify driving performance and patterns in brain activation associated with cannabis exposure and compare them to brain patterns of the same participants while sober; compare participant's performance on cognitive tasks while under the influence of cannabis and sober; look for correlations between concentration of cannabinoids in the participants' blood and their driving performance and performance on cognitive tasks; correlate demographic variables and personal history (e.g. tolerance to drug) with performance and brain activation while driving under the influence of cannabis.

Medical Marijuana is used widely, and its effects on the visual system and the function of the retina have not been investigated thoroughly. Some evidence suggests that cannabinoids may be beneficial in certain degenerative diseases of the retina. The purpose of the study is To determine whether cannabis derivatives affect the visual functions in healthy adults To examine the effect of cannabis derivatives on the retina of retinitis pigmentosa patients

This study will examine how medical cannabis use affects neuropathic pain, inflammation and adverse events in people living with HIV (PLWH) with neuropathic pain. We will study how varying ratios of THC and CBD in medical cannabis impact neuropathic pain, inflammation and adverse events.