View clinical trials related to Depressive Disorder, Major.
Filter by:The purpose of the study is to test whether oral 6(S)-5-MTHF (Deplin) is safe and effective in relieving depression when it is added to standard kinds of antidepressants called serotonin reuptake inhibitors (SSRIs).
Aripiprazole has been approved by the FDA for augmenting ineffective/partially effective oral antidepressant therapy in patients suffering from major depression. The mechanism by which this augmentation is achieved is not known. This study has been designed to test the hypothesis that the primary mechanism of action of aripiprazole (ARP) antidepressant augmentation is through the dopaminergic pathway. Two positron emission tomography (PET) scan procedures and a functional magnetic resonance imaging (fMRI) scan will be used to test this hypothesis.
In former studies of the investigators research group the investigators could also demonstrate acute inhibitory effects of the antidepressant mirtazapine on ACTH and cortisol release in normal controls (Schüle et al. 2002), most likely mediated via antagonism at central 5-HT2- and H1-receptors. In contrast to mirtazapine, serotonin or norepinephrine reuptake inhibiting antidepressants acutely stimulate ACTH and cortisol secretion (Schüle 2007). The investigators also performed a study in depressed patients who were treated either with mirtazapine or with reboxetine using serial dexamethasone/CRH tests (week 0, 1, and 5) as a parameter for HPA axis activity. Mirtazapine, but not the norepinephrine reuptake inhibitor reboxetine was able to significantly reduce HPA axis activity already within one week (Schüle et al. 2006). Mirtazapine is known to have an earlier onset of antidepressant action than do SSRIs such as sertraline (Behnke et al. 2003) or antidepressants with dual mechanism of action such as venlafaxine (Benkert et al. 2006), possibly due to its rapid inhibition of HPA axis activity in unipolar depressed patients. Since mirtazapine and quetiapine have similar effects on the HPA system in healthy male volunteers (i.e. inhibition of ACTH and cortisol secretion), a rapid attenuation of HPA axis activity is also expected during quetiapine XR treatment in depressed patients. Therefore, in the present study the investigators goal is to investigate whether quetiapine fumarate XR at a dosage of 300 mg per day has an impact on HPA axis activity in unipolar depressed patients, as measured by serial dexamethasone/CRH tests (week 0, 1, and 5) and salivary cortisol profiles and whether putative effects of quetiapine XR on the HPA system are related to its antidepressant efficacy.
The main purpose of this study is to evaluate the effect of desvenlafaxine administered as DVS SR on the pharmacokinetics of midazolam in healthy male and female subjects. The amount of drug in the body and the effect of the drug will also be evaluated.
The neuropeptide Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) and its receptors PAC1 and VPAC2 are widely expressed in the nervous system. The investigators found that PACAP treatment of neuronal cell cultures increases expression of Brain Derived Neurotrophic Factor (BDNF) that plays an important role in the etiology of psychiatric disorders and action of antidepressants. For the first time, the investigators demonstrated that treatment by Paroxetine and Citalopram significantly decreases PAC1 and VPAC2 and upregulates PACAP mRNA expression, whereas Imipramine shows an opposite effect. Moreover, PACAP, PAC1 and VPAC2 expression is highly correlated with BDNF expression. Their in vivo studies show that Imipramine reduces BDNF and increases PAC1 mRNA expression in murine hippocampus, suggesting that antidepressants may affect neuronal plasticity through PACAP-BDNF interactions. Based on their observations in experimental systems, the investigators hypothesize that PACAP signaling system may be involved in the etiology of depression and mechanism of antidepressant action. The investigators will evaluate this hypothesis by examining serum PACAP levels, effect of antidepressants on PACAP levels, and gene polymorphisms of PACAP and its receptors in major depressive disorder patients. This study will enhance the investigators' understanding of PACAP's role in the etiology of depression and antidepressant treatment and will provide a basis to evaluate PACAP pathway as a potential target for diagnostics and novel antidepressants drug discovery.
Research aimed at assessing changes in depressogenic thinking and the ability to disengage from depressogenic thinking following Mindfulness-Based Cognitive Therapy
The study involves a 32-week randomized controlled trial in primary care of a comprehensive diabetic and depression intervention in patients with type 2 diabetes and comorbid MDD, compared to a group treated with usual care for MDD plus disease self-management and measurement-based care for diabetes.
The purpose of this study is to study the effect of duloxetine treatment on (1) cognitive functions, the brain mechanisms involved with thinking, reasoning, learning, and remembering; (2) psychosocial functions, how someone interacts with his/her social environment; and (3) the relationship between these two functions, in people who have major depressive disorder, a severe form of depression.
The purpose of this study is to examine whether the speed of the clinical antidepressant action of citalopram can be accelerated by administering double doses of pindolol (15 mg/day, tid) which presumably should lead to increased 5-HT1A autoreceptor occupancy.
Objective: To study the relative balance of GABA (A) binding potential and glutamate utilization in subjects with localization-related epilepsy with and without depression, subjects with major depressive disorder alone, and in subjects with generalized epilepsy (expected not to have significant comorbid depression). Pilot data shows that GABA(A) binding potential and glutamate utilization are tightly coupled in healthy subjects particularly in the mesial temporal lobe. We hypothesize that subjects with epilepsy will not exhibit the same degree of coupling, and that subjects with both epilepsy and depression will exhibit an even more pronounced decoupling. Study Population: Subjects aged 18-55 with localization-related epilepsy with and without depression, subjects with generalized epilepsy, subjects with major depressive disorder (MDD) alone, and healthy controls. Design: This is a neuroimaging study, using positron emission tomography (PET) with [11C]flumazenil, to measure GABA(A) binding potential, and [18F]fluorodeoxyglucose, to measure glucose utilization (reflective of neuronal glutamate release) Magnetic resonance spectroscopy (MRS), will be used to measure GABA and glutamate in the mesial temporal cortex, and corroborate the PET results. Structural magnetic resonance images (MRI) will be obtained for MRS localization and partial volume correction of PET images. Outcome measures: The binding potential of GABA(A), the regional rate of glucose metabolism, and the levels of GABA and glutamate as measured by MRS. Patients will be stratified by seizure type and depression ratings. ...