View clinical trials related to Amphetamine Abuse.
Filter by:Illicit use of the psychostimulant "Ecstasy" (3,4-methylenedioxymethamphetamine, MDMA) is considered a major public health issue. In Switzerland, MDMA and congeners are - after cannabis and cocaine - number three in the ranking of the most popular illicit drugs. Worldwide, Ecstasy is estimated to be even the second most popular illicit drug, used by millions of regular users. On the basis of animal data, it is likely that MDMA at high or cumulative doses damages serotonin (5-HT) neurons in the human brain. However, because of a multitude of methodological problems and a limited number of studies conducted in human subjects, no firm conclusions can yet be established whether chronic MDMA exposure produces a long lasting 5-HT deficiency syndrome, with consequent neuropsychiatric risks. To further address the putative neurotoxicity of MDMA in the human brain, we propose that novel functional assays of serotonergic neurotransmission may be useful to clarify this issue. We suggest that a 5-HT challenge study using positron emission tomography (PET) in conjunction with the 5-HT releaser dexfenfluramine [(+)FEN] may test the functional integrity of the 5-HT system in the living human brain. Specifically, in a placebo-controlled study, the 5-HT release capacity of serotonergic neurons shall be investigated by assessing [18F]-altanserin binding to 5-HT2A receptors following (+)FEN challenge in former and continuing MDMA users, and age and sex-matched MDMA-naïve controls. (+)FEN is a potent serotonin releaser without relevant affinity for 5-HT, dopamine (DA) or norepinephrine (NE) receptors, and devoid of acute adverse effects in man. This makes (+)FEN an ideal pharmacological probe to explore functional integrity of serotonin neurotransmission. A second aim of our investigation is to detect possible impairments of cognitive functions and to study their relationship to serotonin neurotransmission as indexed by PET. In the course of the neuroimaging study, the investigators therefore also measure cognitive (e.g. attention, visual and working memory, learning, executive function) and affective functions (e.g. anxiety, impulsivity), suspected to be altered due to chronic MDMA use. Using correlational analyses, the investigators aim to determine if circumscribed regions of altered 5-HT function are associated with specific impairments in cognitive and/or behavioural parameters. We hypothesize that (+)FEN-evoked 5-HT release will discernibly alter availability of 5-HT2A receptors to [18F]-altanserin, with a pattern revealing the spatially heterogeneous vulnerability of 5-HT innervations to MDMA. The investigators predict that [18F]-altanserin volume of distribution (DV) will decline following (+)FEN challenge to a lesser extent in current MDMA users compared to MDMA-naïve control subjects. On the basis of animal data and recent neuroimaging studies in humans, the investigators hypothesize that functional recovery in former MDMA users will be manifest by a normalization or overshoot of the 5-HT release capacity. Our methodology will allow us to quantitatively assess serotonergic functions in the living human brain. The novel combination of (+)FEN-induced release of 5-HT from intracellular storage vesicles and subsequent PET assessment of competitively altered [18F]-altanserin binding at postsynaptic 5-HT2A receptors will provide a more direct biological marker of in vivo serotonin function than has been hitherto available. By applying this new pharmacological challenge/PET neuroimaging approach to groups of current and former users of MDMA, the investigators shall be able to gain important new insight in the debated functional consequences of MDMA use, especially concerning the controversy about the reversibility of 5-HT changes following cessation of MDMA use. Successful completion of this project should have useful implications for public education and harm reduction with respect to MDMA use, and may also facilitate the development of possible treatment options for chronic MDMA users.
Bipolar disorder (BD) is a common and severe psychiatric illness. Drug and alcohol abuse are very common in people with BD and other mood disorders and are associated with increased rates of hospitalization, violence towards self and others, medication non-adherence and cognitive impairment. However, few studies have investigated the treatment of dual-diagnosis patients as substance use is frequently an exclusion criterion in clinical trials of patients with BD. To address this need, we have developed a research program that explores the pharmacotherapy of people with BD and substance related-disorders. A potentially very interesting treatment for BD is citicoline. Some data suggest that this supplement may stabilize mood, decrease drug use and craving, and improve memory. We found promising results with citicoline in patients with BD and cocaine dependence. In recent years the use of amphetamine and methamphetamine has become an important public health concern. However, virtually no research has been conducted on the treatment of amphetamine abuse. We propose a double-blind placebo controlled prospective trial of citicoline in a group of 60 depressed outpatients with bipolar disorder, depressed phase or major depressive disorder and amphetamine abuse/dependence, to explore the safety and tolerability of citicoline, and its efficacy for mood symptoms, stimulant use and craving and its impact on cognition. Our goal is to determine which symptoms (e.g. mood, cognition, substance use) citicoline appears to be most effective and estimate effect sizes for future work.