4 Clinical Trials for Intermittent Explosive Disorder
The goal of this experimental medicine clinical trial is to test the hypothesis that nitrous oxide inhalation will result in a change in neurocircuit function in healthy controls and in individuals with impulsive aggressive tendencies. The main question aims to answer are: Does Nitrous Oxide normalize brain circuit function in impulsively aggressive individuals 24 hours after inhalation. Participants will undergo a 60 minute inhalation session with 50% Nitrous Oxide (or room air at another session) and then undergo an fMRI scan 24 hours later. Researchers will compare healthy controls and impulsively aggressive individuals to see if Nitrous Oxide can normalize the function of cortico-limbic circuits in the latter group.
The investigators are studying how certain drugs can reduce anger outbursts in people with anger problems. In this study the investigators seek to determine if a single 34 mg (two 17 mg tablets) oral dose of the 5-HT2a receptor blocker, pimavanserin, will reduce aggressive responding in individuals with impulsive aggression (Intermittent Explosive Disorder: IED) on a laboratory task that assesses aggression (Taylor Aggression Paradigm: TAP). We will also be examining how this drug impacts hostile social cognition e.g., hostile attribution). If pimvanserin reduces aggression in this study a next step would be a placebo-controlled treatment trial of pimavanserin in study participants with IED. Participation will first involve a remote (e.g., TEAMS) screening session. If potential study participants appear eligible they will come into the lab for an in-person session where participants will complete interviews and questionnaires and have a medical evaluation (including a physical exam, electrocardiogram, and screens for alcohol and drug use). During the next study session, participants will complete a diagnostic interview and a series of questionnaires, all of which can all take place on-line. During the next two sessions (which will be in-person) participants will undergo two (2) study sessions during which study participants will be given a study drug (orally). The drug given, pimavanserin, is currently available and is known to block serotonin receptors thought to be involved in regulating anger. After participants take the study drug, study participants will complete questionnaires and computer tasks for assessment of aggression and of hostile social cognition. Each of these two in-person study sessions will take at least eight (8) hours. A final on-line session will be done to make certain the investigators have all the data required by the study protocol.
From a psychoevolutionary perspective, anger is a universal emotion that can serve the function of making us aware of wrongdoing and motivating us to undo/correct the wrongdoing. However, it is well recognized in clinical psychology that anger can be maladaptive, often causing distress and impairment in various areas of day-to-day life; untreated maladaptive anger has been found to raise the risk of certain physical health problems e.g., hypertension and coronary heart disease. At the very extreme, rage has been implicated in aggression and violence. Not surprisingly, there has been a widespread quest for anger treatments or what is popularly called "anger management". One treatment approach that has received increasing empirical support is Cognitive Behavioral Affective Therapy (CBAT), which has been applied to patients with chemical dependence and individuals with chronic pain. To extend this programmatic line of research, the proposed research aims to evaluate the efficacy of CBAT in reducing multiple (psychometric and self-monitored) measures of anger within a community sample.
Alcohol intoxication is responsible for a large proportion of violent crime/assault and personal injury in our society. While a number of variables have been associated with alcohol-related aggression, high trait aggression and impaired executive function have been identified as key factors. Both Alcohol Use Disorder (AUD) and Impulsive Aggression behavior (AGG) are related to impaired social-emotional information processing (SEIP) whereby social threat cues, especially ones that are ambiguous in nature, lead to hostile attribution and negative emotional response to the "other" and, then, aggression against the "other". Thus, understanding the underlying neuroscience of SEIP under the influence of alcohol will be critical to identifying targets for intervention to reduce alcohol-related aggressive behavior. In addition to potential pharmacologic and cognitive-behavioral based interventions, such interventions may also involve the rehabilitation of aberrant neuronal circuits underlying social cognitive function through neuroplasticity-based remediation exercises. This study is designed to see how brain activation of cortico-limbic circuits involving social-emotional information processing, analyzed by fMRI Imaging, are impacted by alcohol administration in those with and without aggressive disorders and with and without alcohol use disorder.