This study is enrolling emerging adults (ages 18-25) with cannabis use disorder (CUD) to examine sex differences in (a) cannabis withdrawal symptoms during short-term cannabis abstinence, (b) cannabidiol (CBD) versus placebo effects on stress reactivity during short-term cannabis abstinence, and (c) the relationship between stress reactivity and time to cannabis relapse after short-term cannabis abstinence. The proposed study is designed to reveal sex differences and guide the development of tailored treatments that address factors disproportionately affecting emerging adult females with CUD.

Participants will complete an assessment visit to determine eligibility. Eligible participants will be scheduled for their next visit and will be instructed to abstain from cannabis use for 3 days. Participants will be set up with a phone application (app) and given instructions on its use. This app will send twice daily, random surveys everyday throughout study participation with questions about cannabis use, cravings, and overall mood. Participants will also complete twice daily saliva samples.

At the end of the 3 days, participants will return to the clinic for their second visit. Participants will complete a urine and blood sample at each visit. After eating a snack, participants will receive one dose of CBD (800mg) or placebo and then participate in a stress task. Upon completion of the stress task, participants will complete 3 saliva samples and then be discharged after evaluation by research staff. After the completion of Visit 2, participants will continue to complete twice daily surveys for 10 days. The study will last approximately 14 days.

There are risks involved with participating in this study, including risks associated with CBD, risks associated with the stress task and study procedures, emotional distress from answering personal questions, and loss of confidentiality. There is a risk of experiencing cannabis withdrawal symptoms during the 3-day period of cannabis abstinence. Some potential risks related to CBD include dry mouth, diarrhea, reduced appetite, drowsiness, and fatigue. There is a risk of loss of confidentiality, but the researchers will code the samples and research information to protect privacy. There are no direct benefits to the participant, but we hope the knowledge gained will help us inform future clinical strategies to address cannabis use in emerging adults.

Persistent smell loss that can include diminished or distorted smell function is a common symptom of long COVID syndrome. There are limited treatment options for long COVID-related smell loss. Our study aims to determine the efficacy of two at-home treatments, smell training and non-invasive trigeminal nerve stimulation. This study requires participants to conduct daily at-home treatment sessions, attend three in-person study visits at the MUSC Department of Psychiatry and Behavioral Sciences, and complete electronic questionnaires over the 12-week trial, and again at the six-month timepoint. Participants in this trial may benefit directly with an improvement in sense of smell. However, participation may also help society more generally, as this study will provide new information about long COVID-related smell loss and its treatment.

EEG Substudy:

Long COVID syndrome has been associated with cognitive impairment and may be related to affected emotional regulation. This study will use a electroencephalography (EEG) to examine how the body and brain responses to emotional cues in participants who are currently undergoing treatment for COVID-related smell loss. Participation will aid in the understanding of how emotional processing in long COVID is impacted by treatment for related smell loss.

Blood Analysis Substudy:
Alzheimer's Disease can be precedented by other clinical disorders or neuropsychiatric symptoms. Due to the cognitive deficits that can affect those with Long COVID, this sub study will use a blood sample to investigate if there are blood based biomarkers for Alzheimer's in those who report Long COVID symptoms.

This study is an open-label study that will evaluate SAGE-718 on the cognitive effects in subject with early manifest Huntington's Disease (HD). The subject will be on study drug for a year. At clinic visits, participants will take the IP under staff supervision, followed by assessments of cognitive function, health-related function and quality of life, and neuropsychiatric symptoms.

This study is designed to collect saliva and blood samples from subjects going through the Lung Cancer Screening Program to compare biomarker test results to develop lung cancer clinical risk prediction models further. Also, this study will store blood samples in a biorepository.

This study is designed to collect saliva and blood samples from subjects going through the Lung Cancer Screening Program to compare biomarker test results to develop lung cancer clinical risk prediction models further. Also, this study will store blood samples in a biorepository.

This study is designed to collect saliva and blood samples from subjects going through the Lung Cancer Screening Program to compare biomarker test results to develop lung cancer clinical risk prediction models further. Also, this study will store blood samples in a biorepository.

This study is designed to collect saliva and blood samples from subjects going through the Lung Cancer Screening Program to compare biomarker test results to develop lung cancer clinical risk prediction models further. Also, this study will store blood samples in a biorepository.

This study is designed to collect saliva and blood samples from subjects going through the Lung Cancer Screening Program to compare biomarker test results to develop lung cancer clinical risk prediction models further. Also, this study will store blood samples in a biorepository.

This study is designed to collect saliva and blood samples from subjects going through the Lung Cancer Screening Program to compare biomarker test results to develop lung cancer clinical risk prediction models further. Also, this study will store blood samples in a biorepository.

In this study, we will recruit cirrhotic patients who are undergoing endocscopic procedures as part of their standard of care. Their endoscopies will reveal whether they have portal hypertensive gastropathy. After the procedure, we will ask the patients to provide us with a stool sample, which we will assess for occult GI bleeding. For those patients who DO NOT have occult GI bleeding, they will be contacted every 6 months for 2 years to check whether they have developed GI bleeding.