Background: Major depressive disorder (MDD) is a psychiatric condition. People with MDD have occasional bouts of depressive symptoms; these bouts are called major depressive episodes (MDEs). Researchers want to know if people having MDEs have lower levels of an enzyme called PDE4B in their brains. Primary Objective: To determine whether PDE4B is reduced in the brains of individuals with MDD experiencing a major depressive episode (MDE). Secondary Objectives: To determine the optimal length of scanning and the retest variability and reliability of [18F]PF-06445974, and whether PDE4B binding correlates with clinical rating scales. To measure if PDE4B radioligand binding can be blocked by taking apremilast. Eligibility: People aged 18-70 years with MDD. Healthy volunteers are also needed. Design: Participants will have up to 5 clinic visits. Participants will be screened. They will have a physical exam with blood tests. They will have a test of their heart function. Some participants may have a psychiatric assessment; they will answer questions about their state of mind and related topics. Participants will have magnetic resonance imaging (MRI) of the brain. They will lie on a table that slides into a metal cylinder. Participants will have a positron emission tomography (PET) scan. A needle will be used to guide a thin plastic tube (catheter) into a vein in one arm. An experimental substance called a radioactive tracer ([18F]PF-06445974) will be injected through the catheter. Participants will lie on a table that slides into a doughnut-shaped machine. The scan will last up to 4 hours with a 15-minute break. Participants blood pressure, heart rate, and breathing will be monitored before, during, and after the PET scan. A second catheter will be inserted in the artery of the wrist so blood can be drawn during the scan. Some participants may return for a second PET scan; have a lung scan or receive apremilast. https://nimhcontent.nimh.nih.gov/start/surveys/?s=KE88DXXPLDFHHTF8

Type: Interventional

Start Date: Jun 2023

open study

Background: Negative emotional states can affect a person s behavior as they make decisions. For example, hunger may make people more impatient; they may then make riskier choices. Other negative emotional states that can change behavior include stress, pain, and sadness. By learning more about how emotions affect thinking and behavior in healthy people, researchers hope to better understand how to identify and treat people with mental disorders. Objective: To learn how negative emotions affect the brain and decision-making behavior. Eligibility: Healthy people aged 18 to 55 years. Design: Participants will have 3 clinic visits in 3 weeks. Participants will fill out questionnaires. They will be asked about their personal history, their personality, and state of mind. For 2 visits, participants will be assigned to different groups. Each group will experience 1 type of emotional stressor: Some participants will watch a video. Some will have to do arithmetic problems. Some will have heat applied to an arm or leg. Some will experience cold by immersing their hand in ice water. For a snack craving test, some will be tempted by food after a 4-hour fast. During these tests, participants will have sensors attached to their bodies. They will be videotaped. Saliva samples will be collected. After the stressors, participants will do tasks on a computer. They will need to make choices. Some participants will perform these decision-making tasks while lying in a brain scanner for functional magnetic resonance imaging. The brain scan involves lying on a table that slides into a cylinder that takes images of the brain. ...

Type: Interventional

Start Date: Jul 2023

open study

Background: About 5 million adults in the U.S. have Alzheimer s disease or another adult-onset neurodegenerative disorder. Many studies have found that inflammation in the brain contributes to these diseases. Researchers want to find a better way to measure this inflammation. Objective: To learn whether COX-1 and/or COX-2 is elevated in the brains of individuals with neurodegenerative brain disease compared to healthy volunteers. Eligibility: Adults age 18 years and older in good general health who have an adult-onset neurodegenerative dementia, such as AD, FTD, corticobasal syndrome, Huntington s disease, or MCI, ALS and healthy adult volunteers enrolled in protocols 01-M-0254 or 17-M-0181. Design: Participants will be screened with medical history, physical exam with vital signs, and lab tests. They will have a neuropsychological testing. Their heart function will be measured. Participants will have a magnetic resonance imaging (MRI) scan. The MRI scanner is a metal tube surrounded by a strong magnetic field. Participants will lie on a table that slides in and out of the tube. The machine makes noise. Participants will get earplugs. Participants will have 2 PET scans. They will be injected with the study drugs through an intravenous catheter placed in an arm vein. The PET scanner is shaped like a doughnut. Participants will lie on a bed that slides in and out of the scanner. A plastic mask will be molded to their head to keep them from moving. A thin plastic tube will be put into an artery at the wrist or elbow crease area. This will be used to draw blood during the scan. Participants will have 2-5 study visits. Participation lasts 1 week to 4 months, depending on scheduling.

Type: Interventional

Start Date: Aug 2021

open study

Background: An electroencephalogram (EEG) measures the brain s electrical activity. EEG shows that the louder the sound needed to wake a person, the deeper the person s sleep. Researchers are using functional magnetic resonance imaging (fMRI) to study people during sleep so they can view brain activity in 3D. But they still need to correlate fMRI with sound thresholds, like the EEG. Objective: To measure brain activity during sleep using fMRI and EEG. Eligibility: Healthy people ages 18 34 who can sleep on their back for several hours. Design: Participants will be screened online about their sleep and general health. At a screening visit, participants will have: Physical exam Hearing exam MRI scan. A strong magnetic field and radio waves take pictures of the brain. Participants will lie down on a bed that slides into the scanner, which is shaped like a cylinder. Participants will wear an actigraph on their wrist that records their motor activity. Participants will follow a 2-week routine. This includes regular in-to-bed and out-of-bed times and limits on alcohol, caffeine, and nicotine. During the overnight visits, participants will have: Female subjects will have a urine pregnancy test. fMRI. A coil will be placed over the head. Participants will do tasks shown on a computer screen inside the scanner. EEG. Small electrodes on the scalp will record brain waves while sleeping or doing a task in the scanner. Participants will be asked to try to sleep while researchers collect fMRI and EEG data. Participants eyes will be monitored with a video camera. Headphones will deliver sounds to wake them up throughout the night. ...

Type: Observational

Start Date: Jan 2016

open study

Background: Researchers use mixed meal tolerance tests (MMTTs) to look at how people s bodies respond to eating a meal. However, researchers do not agree on how to decide the number of calories to give in each meal. Some use fixed meals, which are the same size for everyone, and some use adjusted meals, based on the size of the person s body. Researchers want to know which MMTT is best to use for future research. Objective: To learn how fixed vs adjusted meals affect blood glucose levels in healthy people. Eligibility: Healthy people aged 18 years or older. Design: Participants will have 3 or 4 clinic visits of up to 8 hours in 8 weeks. Participants will have baseline tests: Their height, weight, and waist size will be measured. They will have an oral glucose tolerance test: A needle attached to a tube (IV) will be inserted into a vein in the arm. They will have a sugary drink. Blood samples will be taken from the tube at intervals up to 3 hours after the drink. They will have a body scan. Participants will have 2 MMTT visits. One will include a fixed meal and one will include an adjusted meal. They will have tests at both visits: Resting metabolic rate: A clear hood will be placed over the participant s head while they rest for 20 minutes. This will measure the oxygen they breathe in and out. MMTT. Participants will have 5 minutes to drink a liquid meal. Blood samples will be taken at intervals for the next 4 hours....

Type: Interventional

Start Date: Aug 2024

open study

Background: - Atopic dermatitis, or eczema, is a chronic skin disorder. Patients sometimes have infections with S. aureus bacteria. Researchers want to study how eczema treatments affect the number and the type of bacteria on the skin. Objectives: - To study the effect of eczema treatments on skin bacteria. Eligibility: - Individuals between 2 and 25 years of age who have moderate to severe atopic dermatitis. - Healthy volunteers between 18 and 40 years of age with no history of eczema. Design: - Participants will be screened with a physical exam and medical history. Research samples will be collected. Skin biopsies may also be performed. - All participants will be assigned to one of several study groups. - Healthy volunteers must not have taken antibiotics in the year before the start of the study. - All participants will have regular study visits during their 1-year participation. More research samples will be collected at these visits. - Healthy volunteers may be asked to come in for a one-time follow up after the 1 year mark.

Type: Interventional

Start Date: Sep 2012

open study

The goal of this study is to understand factors that contribute to delayed sleep wake phase disorder (DSWPD). The investigators will examine whether patients with DSWPD exhibit alterations in circadian rhythms and sensitivity to light compared to healthy controls. The investigators will also test a new method of predicting circadian rhythms form a blood sample.

Type: Interventional

Start Date: Apr 2024

open study

The swallowing muscles are prone to decreased strength and function as part of the natural aging process which can lead to difficulty swallowing, malnutrition, and frailty. Exercise and nutrition are powerful stimulators of muscular change. The proposed research will investigate the effectiveness of a 12-week proactive regimen of swallowing exercises (with or without daily protein supplement drinks) to improve the composition, force, and physiology of the swallowing muscles and explore the relationship to overall health and physical function in 80 community-dwelling older adults. Each participant will serve as their own control for 12 weeks before being randomized to complete swallowing exercises alone or swallowing exercises with protein drinks.

Type: Interventional

Start Date: May 2024

open study

This study aims to illuminate the biological underpinnings of negative symptoms in schizophrenia-particularly motivational impairments-by probing the link between systemic inflammation and neural activity in reward-related brain circuits. The primary goal of this study is to determine: - Ventral Striatum Activation: Assess how reward anticipation engages the ventral striatum in individuals with schizophrenia, both before and after an anti-inflammatory intervention. - Anterior Insula Activation: Examine how increasing effort demands modulate activity in the anterior insula under the same conditions.

Type: Interventional

Start Date: Apr 2024

open study

Background: - Like other complex diseases, autoimmune diseases are the result of numerous causes, including genetic and environmental factors. Some researchers believe that people who are susceptible to autoimmune disorders develop them when the body reacts to environmental or other factors by creating white blood cells that attack the body s own tissues, which then progresses to autoimmune diseases. These immune-triggered disorders can overlap with one another to some extent, but most autoimmune diseases have certain distinct triggers. - The autoimmune disorder myositis weakens the muscles and may cause other health problems. Environmental exposures associated with myositis include ultraviolet radiation, stressful life events and muscle overexertion, collagen implants, infections such as retroviruses and streptococci bacteria, and certain drugs and chemicals. Some individuals with myositis also produce proteins in the blood called autoantibodies that react with certain parts of the person s own cells, called synthetases, which are involved in making new proteins. A syndrome called the anti-synthetase syndrome, which includes myositis and lung disease, is associated with having the anti-synthetase autoantibodies. Researchers are interested in studying differences in environmental exposures in individuals with myositis. This study is being conducted to determine if persons with the anti-synthetase syndrome have had different environmental exposures before disease onset compared with other patients with myositis who do not have this syndrome and also compared with healthy volunteers. Objectives: - To determine whether selected infectious and noninfectious environmental exposures are more common in individuals who have myositis with the anti-synthetase syndrome, compared with healthy volunteers. Eligibility: - Individuals who have been diagnosed with myositis (with or without anti-synthetase autoantibodies), and healthy volunteers without autoimmune disorders. Design: - Participants will be screened with a full medical history and physical examination, and will provide blood, urine and house dust samples. - Participants will complete questionnaires about their medical history and the types of exposures they have had at work, at home, and elsewhere. Participants who have myositis will also be asked about certain infections, heavy exercise or physical exertion, sun exposure, tobacco and alcohol use, and stressful events prior to being diagnosed with the disease. Healthy volunteers will be asked about the same exposures before the date of diagnosis of disease of the myositis subject to which they have been matched. - Participants will receive a kit that contains instructions and a filter to be put onto their vacuum cleaner to collect house dust in the bedroom. This dust will be kept for possible future analyses of infectious or toxic agents based on the other results from the study. - Individuals with myositis will have other tests as clinically indicated, including lung function tests and imaging studies.

Type: Observational

Start Date: Feb 2011

open study

Several studies have reported that diabetic subjects have lower plasma vitamin C concentrations than non-diabetic subjects. Although urinary vitamin C loss in diabetic subjects was reported to be increased in two studies, these are difficult to interpret due to lack of controlled vitamin C intake, inadequate sampling, lack of control subjects, or methodology uncertainties in vitamin C assay and sample processing. Consequently, it is unclear whether diabetic subjects truly have both low plasma and high urine vitamin C concentrations. We propose that low plasma vitamin C concentrations in diabetic subjects are due in part to inappropriate renal loss of vitamin C in these subjects but not in healthy controls. We will study nondiabetic controls and cohorts with diabetes. Vitamin C concentrations in plasma, RBCs, and urine will be measured in outpatients. In those willing to be admitted to the Clinical Center, we will measure vitamin C pharmacokinetics to determine the relative bioavailability for vitamin C in individuals with and without abnormal urinary loss of vitamin C (or renal leak). Single nucleotide polymorphisms (SNPs) will be determined in genomic DNA responsible for the two proteins mediating sodium dependent vitamin C transport, SVCT1 and SVCT2. We will also explore mechanisms underlying abnormal urinary vitamin C loss....

Type: Observational

Start Date: Apr 2006

open study

Latino caregivers of individuals with Alzheimer's disease and related dementias experience high levels of stress burden and depressive symptoms and are underrepresented in caregiver intervention research. Tele Savvy is an evidence based caregiver education program that focuses on developing caregiver mastery skills. This study aims to culturally adapt the Tele Savvy intervention for Latino caregivers and evaluate its preliminary efficacy in a Stage 1b single arm clinical trial. The intervention is delivered remotely and includes weekly group sessions and asynchronous instructional videos. Primary outcomes focus on caregiver mastery with secondary outcomes including stress burden depressive symptoms and self efficacy.

Type: Interventional

Start Date: Apr 2026

open study