Triple Reuptake Inhibitors: The Next Generation of Antidepressants

Depression has been associated with impaired neurotransmission of serotonergic, norepinephrinergic, and dopaminergic pathways, although most pharmacologic treatment strategies for depression enhance only serotonin and norepinephrine neurotransmission. Current drug development efforts are aimed at a new class of antidepressants which inhibit the reuptake of all three neurotransmitters in the hope of creating medications with broader efficacy and/or quicker onset of action. The current review explores limitations of presently available antidepressants and the history and premise behind the movement to devise triple reuptake inhibitors. The evidence for and against the claim that broader spectrum agents are more efficacious is discussed. Examples of triple reuptake inhibitors in development are compared, and preclinical and clinical research with these agents to date is described

DAOA Variants on Diagnosis and Response to Treatment in Patients with Major Depressive Disorder and Bipolar Disorder

OBJECTIVE: This study investigated whether selected D-amino acid oxidase activator ( DAOA) gene single nucleotide polymorphisms (SNPs; rs3916966, rs3916967, rs2391191, rs3916968, rs7139958, rs9558571, rs778293) are associated with major depressive disorder (MDD) and bipolar disorder (BD), and whether they can predict clinical outcomes in Korean in-patients treated with antidepressants and mood stabilizers, respectively. METHODS: In total, 145 patients with MDD, 132 patients with BD and 170 psychiatrically healthy controls were genotyped for the DAOA SNPs. Baseline and final clinical assessments included the Montgomery—Asberg Depression Rating Scale and Young Mania Rating Scale for patients with MDD and BD, respectively. RESULTS: There was no association between DAOA SNP genotypes or alleles with diagnosis, clinical improvement, response rates or remission rates for MDD and BD. Haplotype analyses found no association with MDD or BD diagnosis or clinical outcomes. CONCLUSIONS: The findings suggest that the DAOA SNPs investigated may not affect MDD or BD phenotype, clinical symptoms or other clinical factors, and are unlikely to be involved in MDD or BD development and treatment outcomes. Given the study's limitations, further investigation should be carried out

Publisher Correction: Enhanced clay formation key in sustaining the Middle Eocene Climatic Optimum (Nature Geoscience, (2023), 16, 8, (730-738), 10.1038/s41561-023-01234-y)

Correction to: Nature Geoscience, published online 31 July 2023. In the version of the article originally published, a reference was missing from the seventh paragraph of the “A global shift towards enhanced clay formation” section and the first paragraph of the “Further information on the successful model Scenario 8” section (in the latter instance, the reference is cited in the added text “although a global reorganisation of the silicon cycle may have also played a part”). The reference—Dunlea, A. G. et al. Cenozoic global cooling and increased seawater Mg/Ca via reduced reverse weathering. Nat. Commun. 8, 844 (2017)—has now been inserted as new ref. 54. In the “Data treatment and availability section”, the isotopic data, which can be found in the Figshare data repository at , were incorrectly said to be found in the PANGAEA data repository. These corrections have been made in the HTML and PDF versions of the article

Hierarchical dynamic causal modeling of resting-state fMRI reveals longitudinal changes in effective connectivity in the motor system after thalamotomy for essential tremor

Thalamotomy at the ventralis intermedius nucleus for essential tremor is known to cause changes in motor circuitry, but how a focal lesion leads to progressive changes in connectivity is not clear. To understand the mechanisms by which thalamotomy exerts enduring effects on motor circuitry, a quantitative analysis of directed or effective connectivity among motor-related areas is required. We characterized changes in effective connectivity of the motor system following thalamotomy using (spectral) dynamic causal modeling (spDCM) for resting-state fMRI. To differentiate long-lasting treatment effects from transient effects, and to identify symptom-related changes in effective connectivity, we subject longitudinal resting-state fMRI data to spDCM, acquired 1 day prior to, and 1 day, 7 days, and 3 months after thalamotomy using a non-cranium-opening MRI-guided focused ultrasound ablation technique. For the group-level (between subject) analysis of longitudinal (between-session) effects, we introduce a multilevel parametric empirical Bayes (PEB) analysis for spDCM. We found remarkably selective and consistent changes in effective connectivity from the ventrolateral nuclei and the supplementary motor area to the contralateral dentate nucleus after thalamotomy, which may be mediated via a polysynaptic thalamic-cortical-cerebellar motor loop. Crucially, changes in effective connectivity predicted changes in clinical motor-symptom scores after thalamotomy. This study speaks to the efficacy of thalamotomy in regulating the dentate nucleus in the context of treating essential tremor. Furthermore, it illustrates the utility of PEB for group-level analysis of dynamic causal modeling in quantifying longitudinal changes in effective connectivity; i.e., measuring long-term plasticity in human subjects non-invasively

Investigation of possible epistatic interactions between GRIA2 and GRIA4 variants on clinical outcomes in patients with major depressive disorder

Abstract OBJECTIVES: To investigate the effects of glutamate receptor, ionotropic, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) 2 (GRIA2) rs4260586 and glutamate receptor, ionotropic, AMPA 4 (GRIA4) rs10736648 single nucleotide polymorphisms (SNPs) on response to antidepressants in Korean patients with major depressive disorder (MDD), and to ascertain whether epistatic interactions might exist between these SNPs. METHODS: In this retrospective analysis, patients were assessed at hospital admission and discharge using the Montgomery-Åsberg depression rating scale (MADRS). A multiple regression model was employed to investigate the effects of the two SNP variants on clinical/sociodemographic outcomes relating to MDD. RESULTS: Out of 145 Korean patients, the presence of both GRIA2 rs4260586 and GRIA4 rs10736648 polymorphisms had no significant association with MADRS improvement scores or other clinical/sociodemographic variables. CONCLUSIONS: These data potentially suggest a lack of epistatic interaction between GRIA2 and GRIA4 variants, regarding clinical outcomes in patients with MDD. The study was limited by small sample size, use of different antidepressants and incomplete coverage of genes under investigation. Future research should include larger patient samples treated with different antidepressants, analysis of different SNPs and/or investigation of different gene-gene interactions within the glutamatergic system. KEYWORDS: AMPA 2 (GRIA2), AMPA 4 (GRIA4), Glutamate receptor, epistasis, glutamate receptor, glutamatergic, ionotropic, major depression, single nucleotide polymorphis

Genome-wide association study of antidepressant response: involvement of the inorganic cation transmembrane transporter activity pathway

Description and statistics referred to the SNPs that showed p<0.05 (response phenotype) in both the analyzed samples. (DOC 157 kb

Serotonin-Norepinephrine Reuptake Inhibitors for Pain Control: Premise and Promise

The precise mechanisms of pain perception and transmission in the central nervous system have not been fully elucidated. However, extensive data support a role for the monoamine neurotransmitters, serotonin and norepinephrine, in the modulation of pain. Experiments with animal models of pain indicate that noradrenergic interventions, and to a lesser extent serotonergic interventions, reduce pain-related behavior. This is supported by data from clinical trials in humans in which antidepressants have been shown to reduce pain and functional impairment in central and neuropathic pain conditions. These effects are particularly well-studied in trials with serotonin-norepinephrine reuptake inhibitors (SNRIs), which have provided a useful tool in the clinician’s arsenal, particularly considering the limitations of other classes of pain medications such as opioids, anti-inflammatories, and anticonvulsants (i.e., limited efficacy, safety and tolerability issues). Moreover, painful physical symptoms are frequently comorbid with major psychiatric disorders such as major depressive disorder and anxiety disorders. This paper reviewed and summarized the rationale and potential role of SNRIs for the control of pain including clinical and preclinical background. Currently evidence does not definitely support a role of the SNRIs, while limited data propose a putative promise of SNRIs in the treatment of pain related disorders including fibromyalgia and depressed patients with multiple somatic complaints. More researches are warranted to generalize currently available preliminary evidences