Publications by authors named "Phillip B Chappell"

This single-center, randomized, 3-way crossover thorough QT study evaluated the effect of steady-state supratherapeutic venlafaxine (Effexor) on cardiac repolarization. Fifty-four healthy adults received double-blinded extended-release venlafaxine 450 mg/d and placebo and open-label positive-control moxifloxacin 400 mg. The postdose QT intervals corrected for heart rate using the Fridericia formula (QTcF) were assessed on day 14 with an analysis of covariance using a mixed-effects model.

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Objective: Disruptive mood dysregulation disorder (DMDD) was introduced in DSM-5 to distinguish a subset of chronically irritable youth who may be incorrectly diagnosed and/or treated for pediatric bipolar disorder (BPD). This study characterized the rate of new treatment episodes and treated prevalence of BPD and DMDD from a longitudinal electronic health record database and examined the impact of DMDD on prescription trends.

Method: A retrospective cohort study using 2008-2018 Optum electronic health record data was conducted.

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The effect of steady-state supratherapeutic sertraline (Zoloft) on QT interval was assessed in a single-center, randomized, 3-way crossover, double-blind, placebo- and moxifloxacin-controlled thorough QT study. Healthy adults received sertraline 400 mg/day, moxifloxacin 400 mg, and placebo, with a washout period (≥14 days) between treatments. A 12-lead electrocardiogram was recorded in triplicate before dosing and at selected time points up to 72 hours after dosing.

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Objective: To assess efficacy and safety of adjunctive ziprasidone in subjects with bipolar depression treated with lithium, lamotrigine, or valproate.

Method: 298 adult outpatients with bipolar I disorder (DSM-IV criteria) were randomized to receive ziprasidone, 20-80 mg twice a day, or placebo twice a day for 6 weeks plus their preexisting mood stabilizer. The primary efficacy variable was change in Montgomery-Asberg Depression Rating Scale (MADRS) total scores from baseline to 6 weeks.

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A number of studies have reported decreased human lumbar cerebrospinal fluid (CSF) concentrations of the major serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA), following chronic administration of selective serotonin reuptake inhibitors (SSRIs). This decrease has been thought to be a consequence of elevated extracellular serotonin and to be mediated through terminal autoreceptor feedback inhibition of serotonin turnover. We wished to study the previously unexamined acute effects of SSRI administration on human CSF 5-HIAA.

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