Track topics on Twitter Track topics that are important to you
This study will explore brain function related to depressive symptoms and will examine DNA for genes that may be involved in depressive disorders, particularly genes that regulate synthesis and metabolism of the brain neurotransmitter catecholamine. It will compare findings in patients with major depressive disorders who are in remission with those in normal, healthy volunteers.
Patients with remitted major depressive disorders and healthy normal volunteers between 18 and 60 years of age may be eligible for this study. Candidates are screened with a psychiatric and medical history, physical examination, electrocardiogram, and blood and urine tests. Participants undergo the following tests and procedures in up to eight visits to the NIH Clinical Center:
Memory Tasks and Problem Solving and Brain Imaging
Subjects are tested with measurements of intelligence or memory ability. They also undergo magnetic resonance imaging (MRI), a test that uses a magnetic field and radio waves to produce images of the brain. For this procedure, the patient lies on a table that is moved into the scanner (a narrow cylinder), and wears earplugs to muffle loud knocking and thumping sounds that occur during the scanning process. The MRI lasts about 60 minutes.
Catecholamine Depletion Study
For this study, subjects take capsules containing either AMPT (a drug that temporarily reduces brain catecholamine activity) or a placebo (lactose capsules, which do not affect brain catecholamine activity) at 9 a.m., 2 p.m., and 7 p.m. on one visit and return the next day to take additional capsules at 7 a.m. and noon. In addition to the study medication, subjects keep a low-monoamine diet (e.g., no chocolate, cheese, smoked meats, and various other foods that will be enumerated) and do not smoke, drink alcohol, or take in food or drink containing caffeine. After taking all the study capsules, the subjects have positron emission tomography (PET) and functional MRI (fMRI) scans, as follows:
- fMRI: While lying in the MRI scanner, the subject performs a monetary reward task that is somewhat like playing a computer video game for money. The amount of cash the subject can win depends on his or her performance. It is possible to lose money that was previously won, if performance declines. This portion of the study provides information on how the brain processes reward and about the role of catecholamines in this process.
- PET: The subject is injected in the arm with a gluco...
The depressive and anhedonic response precipitated by CD raises the possibility that dysfunction of the dopamine system is a stable, sometimes latent characteristic of MDD. Following this line of reasoning, central catecholamine dysfunction as evinced by CD may be equally salient in a subset of unaffected relatives who are at genetic risk for developing the disorder.
We plan to extend the phase I project to unaffected relatives of BD and MDD patients in order to evaluate sensitivity to CD as an endophenotype of MDD and BD. In order to maximize our statistical power, we will be recruiting equal numbers healthy low and high-risk relatives. Here, risk is defined on the basis of chronological age (see below for more detail).
Furthermore, it has recently become feasible to conduct genome-wide association studies and quantify the burden of risk alleles carried by an individual. Certainly, the identity of these risk alleles remains unknown or unproven. Nevertheless, Francis McMahon's group, with whom we are collaborating, have identified upwards of 20 common risk variants in two independent samples. Individuals carrying 19 or more of these risk alleles were found to be 4 times more likely to be cases than controls. This approach may provide us with another method of quantifying genetic risk.
The endophenotypic status of sensitivity to CD will be evaluated with psychometric instruments, FDG PET, and an fMRI-coupled appetitive learning task. We now have access to a high resolution PET scanner (High Resolution Research Tomograph) that will enable us to study hitherto irresolvable structures of importance such as the habenula and peri-aqueductal gray matter (PAG) in addition to previously implicated regions such as the ventral striatum and OFC. Analysis of the metabolic activity of these regions under sham and CD conditions in both remitted MDD and relatives of BD and MDD patients is of great theoretical import. So to is identifying regions of the brain involved in reward response that are selectively impacted by CD, a question that we hope to answer through the use of the fMRI-coupled appetitive learning task.
National Institutes of Health Clinical Center, 9000 Rockville Pike
National Institutes of Health Clinical Center (CC)
Published on BioPortfolio: 2014-08-27T03:54:25-0400
The goal of the study is to define and measure biological processes that contribute to the underlying pathophysiologic process of peri-partum depression to be used for identifying those at...
Depression is the most common psychiatric disorder. - 3-5% of a given population has major depression. - Less than 50% of the depressed in Denmark are diagnosed with major ...
Postpartum depression is common in mothers early after childbirth and produces harmful effects not only on mothers, but also on infants and young children. Parturietns with prenatal depres...
Microbiome studies may be highlighted as crucial in the development of depression for TBI patients. The microbiota-gut-brain connection may further provide an opportunity for microbiota ma...
Anxious depression is a particularly difficult-to-treat subtype of depression. Patients with anxious depression do not respond as well to currently available antidepressant medications. Ne...
Kinship processes contribute to the experience and interpretation of depression-generating empathy as well as silencing. We explore intersubjective experiences of depression among kin with the aim of ...
The level of physical activity (PA) and the prevalence of depression both change across the lifespan. We examined whether the association between PA and depression is moderated by age. As sense of mas...
Research linking depression to mortality among people living with HIV (PLWH) has largely focused on binary "always vs. never" characterizations of depression. However, depression is chronic, and is li...
To evaluate the psychometric properties of the Beck Depression Inventory (BDI) and Cognitive Depression Index (CDI) as a potential screening tool for major depression in haemodialysis (HD) patients.
Depression literacy refers to the ability to recognize depression and make informed decisions about its treatment. To date, relatively little research has been done to examine depression literacy in t...
Decompression external to the body, most often the slow lessening of external pressure on the whole body (especially in caisson workers, deep sea divers, and persons who ascend to great heights) to prevent DECOMPRESSION SICKNESS. It includes also sudden accidental decompression, but not surgical (local) decompression or decompression applied through body openings.
Depression in POSTPARTUM WOMEN, usually within four weeks after giving birth (PARTURITION). The degree of depression ranges from mild transient depression to neurotic or psychotic depressive disorders. (From DSM-IV, p386)
Depressive states usually of moderate intensity in contrast with major depression present in neurotic and psychotic disorders.
The prototypical tricyclic antidepressant. It has been used in major depression, dysthymia, bipolar depression, attention-deficit disorders, agoraphobia, and panic disorders. It has less sedative effect than some other members of this therapeutic group.
A propylamine formed from the cyclization of the side chain of amphetamine. This monoamine oxidase inhibitor is effective in the treatment of major depression, dysthymic disorder, and atypical depression. It also is useful in panic and phobic disorders. (From AMA Drug Evaluations Annual, 1994, p311)
Of all the types of Dementia, Alzheimer's disease is the most common, affecting around 465,000 people in the UK. Neurons in the brain die, becuase 'plaques' and 'tangles' (mis-folded proteins) form in the brain. People with Al...
DNA sequencing is the process of determining the precise order of nucleotides within a DNA molecule. During DNA sequencing, the bases of a small fragment of DNA are sequentially identified from signals emitted as each fragment is re-synthesized from a ...