Neural Substrates of Emotion: Impact of Cocaine Dependence

• Status: Completed
• Trial end date: 2020-07-27
• Target enrollment: 0
• Participant gender: All

Summary

Over one million individuals in the United States meet criteria for cocaine use disorders. Relapse rates are highest among cocaine-dependent (CD) populations. Social stress is a significant risk factor for relapse. Data from human neuroimaging studies suggest that "top-down" prefrontal cortical inhibition of amygdala activity controls emotional responses to social stimuli. A growing literature suggests that hypoactivity in the medial prefrontal cortex coupled with increases in amygdala activity underscore the vulnerability of CD individuals to relapse. Neuroimaging studies of corticolimbic network activity (functional connectivity) have been conducted in CD subjects at rest. Compared with healthy controls, CD subjects exhibited lower corticolimbic connectivity and the degree of corticolimbic uncoupling was associated with time to relapse. Studies measuring corticolimbic connectivity during exposure to a social stress task in CD subjects could provide critical insight into the neurobiologic mechanisms that underscore the sensitivity of CD individuals to social stress. Moreover interventions that improve corticolimbic connectivity in CD subjects may be effective therapeutic strategies for preventing relapse in CD populations. Oxytocin (OT) is an anxiolytic neuropeptide that attenuates amygdala responses to aversive social cues. In order to better understand the neurobiologic mechanisms that control emotion-related behavior in CD populations, we propose a double-blind placebo (PBO) controlled study using blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) to measure (1) corticolimbic functional connectivity during the Montreal Imaging Stress Task (MIST) and (2) amygdala activity in response to an implicit facial affect recognition paradigm in groups of CD individuals (CD n=80) and healthy non-dependent controls (HC, n=80). Prior to the scanning session, participants will receive either intranasal OT (24 IU) or PBO spray (n=40 per treatment group). The order of the tasks will be counterbalanced.

• Phase: Phase 2
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Medical University of South Carolina
• Treatments: Cocaine; Oxytocin

Criteria

General Inclusion/Exclusion Criteria Inclusion Criteria

1. Age 18-65.

2. Subjects must be able to provide informed consent and function at an intellectual level sufficient to allow accurate completion of all assessment instruments.

3. Subjects must consent to remain abstinent from all drugs of abuse (except nicotine) for the three-day period immediately prior to the study visit.

4. Subjects must consent to random assignment.

5. Subjects must have a negative breathalyzer, urine drug screen at the study visit.

6. Subjects must consent to the study visit which includes an outpatient visit to the ASD and completing one functional magnetic resonance imaging (fMRI) scanning session.

Exclusion Criteria

1. Subjects with evidence of or a history of significant hematological, endocrine, cardiovascular, pulmonary, renal, gastrointestinal, or neurological disease including diabetes.

2. Subjects with a history of or current psychotic disorder or bipolar affective disorder.

3. Subjects with current major depressive disorder or post-traumatic stress disorder.

4. Subjects taking any psychotropic medications, including SSRI's or other antidepressants, opiates or opiate antagonists. Subjects taking trazodone or non-benzodiazepene hypnotics for sleep will be included.

5. Women who are pregnant, nursing or of childbearing potential and not practicing an effective means of birth control.

6. Subjects who have a BMI that procludes them from fitting comfortably in the scanner.

7. Persons with ferrous metal implants or pacemaker.

8. Subjects that are claustrophobic.

9. Subjects with significant psychiatric or medical problems that would impair participation or limit ability to complete the scanning session.

10. Subjects that require maintenance or acute treatment with any psychoactive medication including anti-seizure medications which could potentially interfere with fMRI data acquisition.

Group - Specific Inclusion/Exclusion Criteria Individuals with Cocaine Dependence Inclusion Criteria

1. Subjects must meet DSM-5 criteria for current (three months prior to study visit) moderate to severe cocaine use disorder. Individuals may meet criteria for mild marijuana use disorder, but they must not meet criteria for substance use disorder for any other substance (except nicotine) within the 60 days prior to study participation. Due to the high comorbidity of alcohol and cocaine use disorder individuals with alcohol use disorder will be included in the study if they do not require medically supervised detoxification.

Exclusion Criteria 1. Subjects meeting DSM-5 criteria for substance use disorder (other than nicotine, cocaine, marijuana or alcohol) within the 60 days prior to study participation.

Healthy Controls Inclusion Criteria

1. As above. Exclusion Criteria

1. Subjects meeting DSM-5 criteria for current or lifetime substance use disorder on any drugs of abuse (except nicotine and marijuana.

2. Subjects meeting DSM-5 criteria for marijuana use disorder within the last year.

3. Subjects with current major depression or post-traumatic stress disorder (past month)