Publications by authors named "Peter van der Ark"

The antidepressant efficacy and safety of seltorexant monotherapy in major depressive disorder (MDD) was investigated in a placebo-controlled, placebo lead-in, randomized, double-blind, phase 1b study. Participants were randomized to receive seltorexant (20 mg or 40 mg) or placebo. The treatment effect was assessed by changes in the Hamilton Rating Scale for Depression-17 item (HDRS) from treatment-period baseline to week 5 in lead-in placebo non-responders ("enriched" intent-to-treat analysis set).

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Article Synopsis
  • The study evaluated the effectiveness of aticaprant, a medication for major depressive disorder (MDD), in adults who had not adequately responded to previous antidepressant treatment.
  • After a placebo lead-in period, participants received either aticaprant 10 mg or placebo for 6 weeks, with results showing a significant reduction in depression scores for those taking aticaprant compared to the placebo group.
  • Common side effects of aticaprant included headache, diarrhea, and nasopharyngitis, but overall, the treatment was deemed safe, suggesting potential for further research in larger trials.
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JNJ-54175446 is a selective purine P2X7 receptor (P2X7R) antagonist that attenuates microglial IL-1β/IL-18 release. In healthy volunteers, JNJ-54175446 suppressed peripheral interleukin (IL)-1β release, and attenuated dexamphetamine-induced improvements of mood and (visuo)motor performance in a human dexamphetamine-challenge paradigm. In depression, P2X7R inhibition may dampen immune-related dysregulation of mood.

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Background: Alzheimer's disease cerebrospinal fluid (CSF) biomarkers amyloid-β 1-42 (Aβ42), total tau (T-tau), and phosphorylated tau 181 (P-tau181) are widely used. However, concentration gradient of these biomarkers between intraventricular (V-CSF) and lumbar CSF (L-CSF) has been demonstrated in idiopathic normal pressure hydrocephalus (iNPH), potentially affecting clinical utility.

Objective: Here we aim to provide conversion factors for clinical and research use between V-CSF and L-CSF.

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Introduction: The lack of ideal measurement of treatment efficacy is a well acknowledged problem in the epilepsy community, both in clinical care and clinical trials. Whilst still the current gold-standard, self-reported seizure frequency significantly underestimates the true number of seizures and does not account for any other at least equally important outcome parameters, such as neurodevelopment and cognition. With the rise of disease modifying treatments, the need for more reliable endpoints in practice and clinical trials becomes more pressing.

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Background: Longitudinal changes in cerebrospinal fluid (CSF) biomarkers are seldom studied. Furthermore, data on biomarker gradient between lumbar (L-) and ventricular (V-) compartments seems to be discordant.

Objective: To examine alteration of CSF biomarkers reflecting Alzheimer's disease (AD)-related amyloid-β (Aβ) aggregation, tau pathology, neurodegeneration, and early synaptic degeneration by CSF shunt surgery in idiopathic normal pressure hydrocephalus (iNPH) in relation to AD-related changes in brain biopsy.

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JNJ-42165279 is a selective inhibitor of fatty acid amide hydrolase (FAAH), the enzyme responsible for the degradation of fatty acid amides (FAA) including anandamide (AEA), palmitoylethanolamide (PEA), and N-oleoylethanolamide (OEA). We assessed the efficacy, safety, tolerability, pharmacokinetics, and pharmacodynamics of treatment with JNJ-42165279 in subjects with social anxiety disorder (SAD). This was a multicenter, double-blind, placebo-controlled study randomizing subjects to 12 weeks of treatment with either JNJ-42165279 (25 mg daily) or placebo (PBO).

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In the original Article, Tables two and three had formatting issues which affected their clarity. This has been corrected in the PDF and HTML versions of this Article.

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Excessive arousal has a role in the pathophysiology of major depressive disorder (MDD). Seltorexant (JNJ-42847922/MIN-202) is a selective antagonist of the human orexin-2 receptor (OX2R) that may normalize excessive arousal and thereby attenuate depressive symptoms. In this study, the effects of night-time arousal suppression on depressive symptoms were investigated.

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Background: Insomnia is common in patients with major depressive disorder. Although antidepressants improve mood, insomnia often persists as a result of physiological hyperarousal. The orexin-2 receptor is increasingly being recognized as a new target for the treatment of persistent insomnia in major depressive disorder .

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Background: Pharmacokinetics, pharmacodynamics and general safety and tolerability of JNJ-42847922, a selective orexin-2 receptor antagonist, were assessed in healthy subjects.

Methods: Five consecutive cohorts of healthy subjects were enrolled and received doses of 5-60 mg orally once daily over 10 days of JNJ-42847922 ( n=6) or placebo ( n=2). Concentrations of drug in plasma and urine were measured over 24 h after dosing on Days 1, 5 and 10.

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Background: Detection of pathological tau aggregates could facilitate clinical diagnosis of Alzheimer's disease (AD) and monitor drug effects in clinical trials. S-[18F]THK-5117 could be a potential tracer to detect pathological tau deposits in brain. However, no previous study have correlated S-[18F]THK-5117 uptake in PET with brain biopsy verified tau pathology in vivo.

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Background: Seltorexant is a potent and selective antagonist of the orexin-2 receptor that is being developed for the treatment of insomnia and major depressive disorder.

Aims: The primary objective was to investigate the effect of seltorexant on sleep efficiency after single and multiple dose administration in subjects with insomnia disorder without psychiatric comorbidity. Secondary objectives included evaluation of total sleep time, latency to persistent sleep, and wake after sleep onset.

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Inhibition of fatty acid amide hydrolase (FAAH) potentiates endocannabinoid activity and is hypothesized to have therapeutic potential for mood and anxiety disorders and pain. The clinical profile of JNJ-42165279, an oral selective FAAH inhibitor, was assessed by investigating the pharmacokinetics, pharmacodynamics, safety, and binding to FAAH in the brain of healthy human volunteers. Concentrations of JNJ-42165279 (plasma, cerebrospinal fluid (CSF), urine) and fatty acid amides (FAA; plasma, CSF), and FAAH activity in leukocytes was determined in a phase I multiple ascending dose study.

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Background: The effect of intranasal esketamine on cognitive functioning in healthy participants is assessed in this study.

Methods: Twenty-four participants (19-49 years) were randomized to one of two treatment sequences in which either esketamine 84 mg or placebo was intranasally administered in a double-blind, two-period crossover design. Primary measures included five tests of Cogstate computerized test battery assessed at 1 h predose and 40 min, 2, 4, and 6 h postdose.

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Rationale: The purpose of this study is to evaluate the single dose effect of intranasal esketamine (84 mg) compared to placebo on on-road driving performance. Mirtazapine (oral, 30 mg) was used as a positive control, as this antidepressant drug is known to negatively affect driving performance.

Methods: Twenty-six healthy volunteers aged 21 to 60 years were enrolled in this study.

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Background: Corticotropin-releasing factor receptor type 1 (CRF(1)) antagonists have been proposed as therapeutic agents in the treatment of mood and anxiety disorders although clinical evidence supporting their development and understanding of a dose-response relationship has been lacking.

Methods: We tested two doses of the CRF(1) antagonist R317573 for effects on regional cerebral glucose metabolism (rCMglu) using [(18)F] fluoro-2-deoxy-D: -glucose (FDG) positron emission tomography (PET) following single-dose challenges in a double-blind, placebo-controlled, cross-over design, in 12 healthy male volunteers.

Results: Single 30- and 200-mg doses of R317573 resulted in dose-related changes in rCMglu.

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Background: Preoperative epoetin-alpha administration is said to have a limited effect in patients with chronic inflammatory diseases such as rheumatoid arthritis (RA), due to lower iron availability. We studied the effects of preoperative epoetin-alpha treatment in orthopedic surgery patients in a daily life setting in which iron supplementation was assured, and compared the effects in RA and non-RA patients.

Methods: In an open, naturalistic, randomized controlled trial, 695 orthopedic surgery patients with preoperative hemoglobin (Hb) values of 10-13 g/dL, either with RA (113) or without RA (582), received either preoperative epoetin-alpha treatment added to standard care, or standard care alone.

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