Publications by authors named "Marco Riebel"
Neurosteroids and translocator protein 18 kDa (TSPO) ligands as novel treatment options in depression.
Eur Arch Psychiatry Clin Neurosci
July 2024
Article Synopsis
- The GABA system, specifically 3α-reduced steroids like allopregnanolone, has gained attention for treating anxiety and depression, particularly postpartum depression, with recent FDA approvals marking significant progress.
- Brexanolone, an intravenous form of allopregnanolone, and zuranolone, an oral option, are both FDA-approved for postpartum depression, although zuranolone's approval for major depressive disorder is still pending due to insufficient efficacy data.
- Side effects of these treatments include somnolence, dizziness, and headache, and current research is exploring alternatives like etifoxine, a TSPO ligand, which is already available in France for anxiety and may have potential antidepressant properties.
TSPO ligands are promising alternatives to benzodiazepines in the treatment of anxiety, as they display less pronounced side effects such as sedation, cognitive impairment, tolerance development and abuse potential. In a randomized double-blind repeated-measures study we compare a benzodiazepine (alprazolam) to a TSPO ligand (etifoxine) by assessing side effects and acquiring resting-state fMRI data from 34 healthy participants after 5 days of taking alprazolam, etifoxine or a placebo. To study the effects of the pharmacological interventions in fMRI in detail and across different scales, we combine in our study complementary analysis strategies related to whole-brain functional network connectivity, local connectivity analysis expressed in regional homogeneity, fluctuations in low-frequency BOLD amplitudes and coherency of independent resting-state networks.
View Article and Find Full Text PDFBackground: Recent developments suggest that neurosteroids may achieve rapid antidepressant effects. As such, neurosteroidogenesis mediated by the translocator protein 18 kDa (TSPO) might constitute a promising option for the treatment of depression. Therefore, the current clinical trial aims to get the first evidence of whether TPSO ligands promote rapid antidepressant effects.
View Article and Find Full Text PDFIntroduction: In contrast to other sensory domains, detection of primary olfactory processes using functional magnetic resonance imaging has proven to be notably challenging with conventional block designs. This difficulty arises from significant habituation and hemodynamic responses in olfactory areas that do not appear to align with extended boxcar functions convolved with a generic hemodynamic response model. Consequently, some researchers have advocated for a transition to event-related designs, despite their known lower detection power compared to block designs.
View Article and Find Full Text PDFArticle Synopsis
- Neurosteroids, particularly etifoxine, are being researched for treating affective disorders and are thought to stimulate the production of neurosteroids in the body.
- A crossover study involving 36 healthy male volunteers compared the effects of etifoxine, alprazolam, and a placebo using stool sample analysis to assess gut microbiome changes.
- Results showed that while etifoxine treatment led to a reduction in certain beneficial bacterial species, changes in microbiome diversity were more likely influenced by individual differences rather than the treatments themselves.
Introduction: There is a need for novel anxiolytics with improved side effect profiles compared to benzodiazepines. A promising candidate with alternative pharmacodynamics is the translocator protein ligand, etifoxine.
Methods: To get further insight into its mechanisms of action and side effects compared to the benzodiazepine alprazolam, we performed a double-blind, placebo-controlled, repeated-measures study in 36 healthy male subjects.