Clinical implications of directly switching antidepressants in well-treated depressed patients with treatment-emergent sexual dysfunction: a comparison between vortioxetine and escitalopram.

OBJECTIVE: The objective of this work was to describe treatment-emergent sexual dysfunction (TESD) and tolerability following a switch from selective serotonin reuptake inhibitor (SSRI: citalopram, paroxetine, or sertraline) monotherapy to vortioxetine or escitalopram monotherapy in adults with well-treated major depressive disorder (MDD) and SSRI-induced sexual dysfunction. METHODS: Data were analyzed from the primary study, an 8-week, randomized, double-blind, head-to-head study in which participants with well-treated depressive symptoms but experiencing TESD with SSRIs were directly switched to flexible doses (10/20 mg) of vortioxetine or escitalopram. Sexual functioning was assessed by the Changes in Sexual Functioning Questionnaire-14 (CSFQ-14), efficacy by the Montgomery-Åsberg Depression Rating Scale scores (MADRS) and Clinicians Global Impression of Severity/Improvement (CGI-S/CGI-I), and tolerability by adverse events. Efficacy and tolerability were assessed by pre-switch SSRI therapy where possible, and by participant characteristics. RESULTS: Greater improvements in TESD were seen in the vortioxetine compared with escitalopram groups based on: participant demographics (≤45 years, women; P = 0.045), prior SSRI treatment (P = 0.044), number of prior major depressive episodes (MDEs) (1-3; P = 0.001), and duration of prior SSRI therapy (>1 year; P = 0.001). Prior SSRI treatment did not appear to influence the incidence or severity of TEAEs, except for nausea. Regardless of prior SSRI, both treatments maintained antidepressant efficacy after 8 weeks. CONCLUSION: Results suggest that vortioxetine is a safe and effective switch therapy for treating SSRI-induced sexual dysfunction in adults with well-treated MDD. Also, improvement in sexual dysfunction with vortioxetine or escitalopram may be influenced by prior SSRI usage, sex, age, and history of MDEs.

Attenuation of Cocaine-Induced Conditioned Place Preference and Motor Activity via Cannabinoid CB2 Receptor Agonism and CB1 Receptor Antagonism in Rats.

Background: Studies have shown the involvement of cannabinoid (CB) receptors in the behavioral and neurobiological effects of psychostimulants. Most of these studies have focused on the role of CB1 receptors in the psychostimulant effects of cocaine, while very few have investigated the respective role of CB2 receptors. Further studies are warranted to elucidate the extent of CB receptor involvement in the expression of cocaine-induced effects. Methods: The role of CB1 and CB2 receptors in the rewarding and motor properties of cocaine was assessed in conditioned place preference, conditioned motor activity, and open field activity in rats. Results: The CB1 receptor antagonist rimonabant (3 mg/kg) decreased the acquisition and the expression of conditioned place preference induced by cocaine (20 mg/kg). Rimonabant inhibited cocaine-elicited conditioned motor activity when administered during the expression of cocaine-induced conditioned place preference. Rimonabant decreased ambulatory and vertical activity induced by cocaine. The CB2 receptor agonist JWH-133 (10 mg/kg) decreased the acquisition and the expression of cocaine-induced conditioned place preference. JWH-133 inhibited cocaine-elicited conditioned motor activity when administered during the acquisition and the expression of cocaine-induced conditioned place preference. JWH-133 decreased ambulatory activity and abolished vertical activity induced by cocaine. The effects of JWH-133 on cocaine conditioned and stimulated responses were abolished when the CB2 receptor antagonist/inverse agonist AM630 (5 mg/kg) was preadministered. Conclusions: Cannabinoid CB1 and CB2 receptors modulate cocaine-induced rewarding behavior and appear to have opposite roles in the regulation of cocaine's reinforcing and psychomotor effects.

Efficacy, safety, and tolerability of vortioxetine for the treatment of major depressive disorder in patients aged 55 years or older.

OBJECTIVE: These post hoc analyses evaluate the efficacy, safety, and tolerability of vortioxetine versus placebo in patients aged ≥55 years with major depressive disorder (MDD). METHODS: Study-level efficacy data from 12 short-term, fixed-dose, randomized, placebo-controlled trials of vortioxetine 5-20 mg/day were assessed using a random-effects meta-analysis. Adverse events (AEs), vital signs, ECG values, liver enzymes, and body weight were pooled from the same studies. Patients had baseline Montgomery-Åsberg Depression Rating Scale (MADRS) total scores ranging from 22-30. RESULTS: 1508 patients (mean age=62.4 years; range, 55-88 years) were included. Mean differences from placebo in change from baseline to study end (6/8 weeks) in MADRS were -2.56 (5 mg, n=324, P=0.035), -2.87 (10 mg, n=222, P=0.007), -1.32 (15 mg, n=90, P=NS), and -4.65 (20 mg, n=165, P=0.012). Odds ratios for response versus placebo were 1.6 (5 mg, P=NS), 1.8 (10 mg, P=0.002), 1.2 (15 mg, P=NS), and 2.5 (20 mg, P<0.001), and for remission versus placebo were 1.5 (5 mg, P=NS), 1.5 (10 mg, P=NS), 1.4 (15 mg, P=NS), and 2.7 (20 mg, P=0.001). The proportion of patients with AEs for placebo and vortioxetine 5-20 mg was 61.5% and 62.3%, respectively, with no increase at increased doses. Vortioxetine demonstrated a placebo-level incidence of serious AEs (1.2%). AEs occurring in ≥5% of any treatment group were nausea, headache, diarrhea, dizziness, dry mouth, constipation, fatigue, vomiting, and anxiety. No clinically significant mean changes in vital signs, ECG values, liver enzymes, or body weight emerged during treatment. CONCLUSION: Vortioxetine 5-20 mg/day is efficacious and well tolerated in MDD patients aged ≥55 years, a group that is often comorbid with other conditions and treated with other medications.

Ropinirole regulates emotionality and neuronal activity markers in the limbic forebrain.

Restless legs syndrome (RLS) and Parkinson's disease (PD) are movement disorders usually accompanied by emotional and cognitive deficits. Although D3/D2 receptor agonists are effective against motor and non-motor deficits in RLS and PD, the exact behavioral and neurochemical effects of these drugs are not clearly defined. This study aimed to evaluate the effects of acute ropinirole (0, 0.1, 1 or 10 mg/kg, i.p.), a preferential D3/D2 receptor agonist, on intracranial self-stimulation (ICSS), spontaneous motor activity, anxiety- and depression-like behaviors, spatial reference and working memory in rats as well as on certain markers of neuronal activity, i.e. induction of immediate early genes, such as c-fos and arc, and crucial phosphorylations on GluA1 subunit of α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and NA1, NA2A and NA2B subunits of N-methyl-D-aspartate (NMDA) receptors. Ropinirole decreased ICSS thresholds and induced anxiolytic- and antidepressive-like effects without affecting motor activity or spatial memory. The effects on emotionality were associated with a decrease in p-Ser897-NA1 and an increase in p-Tyr1472-NA2B in the ventral striatum as well as an increased induction of c-fos messenger RNA (mRNA) in the prefrontal cortex (PFC) and decreased expression of arc mRNA in the striatum and the shell of the nucleus accumbens. Our data indicate that ropinirole significantly affects emotionality at doses (1-10 mg/kg, i.p.) that exert no robust effects on locomotion or cognition. The data reinforce the use of D3/D2 receptor agonists in the treatment of RLS and PD patients characterized by emotional deficits and suggest that altered NMDA-mediated neurotransmission in the limbic forebrain may underlie some of ropinirole's therapeutic actions.

Behavioral and neurochemical changes in mesostriatal dopaminergic regions of the rat after chronic administration of the cannabinoid receptor agonist WIN55,212-2.

BACKGROUND: The endocannabinoid system interacts extensively with other neurotransmitter systems and has been implicated in a variety of functions, including regulation of basal ganglia circuits and motor behavior. The present study examined the effects of repeated administration of the nonselective cannabinoid receptor 1 agonist WIN55,212-2 on locomotor activity and on binding and mRNA levels of dopamine receptors and transporters and GABAA receptors in mesostriatal dopaminergic regions of the rat. METHODS: Rats received systemic injections of WIN55,212-2 (0, 0.1, 0.3, or 1mg/kg, intraperitoneally) for 20 consecutive days. Locomotor activity was measured on days 1, 10, and 20. Following the last measurement, rats were euthanized and prepared for in vitro binding and in situ hybridization experiments. RESULTS: Acutely, 0.3 and 1mg/kg of WIN55,212-2 produced hypolocomotion, which was sustained for the next 2 measurements, compared to vehicle. Repeated administration of WIN55,212-2 decreased the mRNA levels of the D2 autoreceptors in substantia nigra and ventral tegmental area and increased D1 receptor mRNA and binding in nucleus accumbens. Furthermore, both dopamine receptor and transporter binding and mRNA levels were decreased in substantia nigra. Moreover, repeated administration of WIN55,212-2 decreased GABAA receptor binding levels in dorsal striatum and substantia nigra. CONCLUSIONS: Our data indicate that chronic WIN55,212-2 administration results in sustained effects on locomotor activity, similar to those observed after acute administration, and modulates the dopaminergic and GABAergic systems in a region-, dose-, and neurotransmitter-selective manner.

Modulation of neurotransmitter release in orexin/hypocretin-2 receptor knockout mice: a microdialysis study.

Orexinergic neurons are discretely localized within the lateral hypothalamus and have widespread projections to the whole brain. Here, the role of orexin/hypocretin-2 receptors (OX2) in modulating extracellular concentrations of neurotransmitters was evaluated in the hypothalamus and the prefrontal cortex (PFC) of OX2 knockout (KO) mice by using a microdialysis technique. In the hypothalamus, basal concentrations of norephinephrine (NE), acetylcholine (ACh), and histamine (Hist) were significantly higher in KO mice, whereas KCl perfusion (147 mM) resulted in significantly lesser increases in NE, ACh, and Hist release in KO compared with wild-type (WT) mice. No differences in basal concentrations or evoked release of serotonin (5-HT) or dopamine (DA) were found in the hypothalamus between genotypes. In the PFC, no differences in the basal concentrations of the studied neurotransmitters were found between genotypes. After KCl perfusion, significantly higher increases in NE, 5-HT, and DA release were found in KO compared with WT mice. No differences in the evoked release of ACh and Hist in the PFC were found between genotypes. The present results demonstrate that genetic deletion of OX2 receptors differentially modulates extracellular concentrations of distinct neurotransmitters in the somatodendritic region vs. a nerve terminal region of the orexinergic neurons. In the hypothalamus, an inhibitory role of the OX2 receptors in modulating basal concentrations of NE, ACh, and Hist was revealed, which probably accounts for the reduced responsiveness to KCl as well. In the PFC, the evoked release of the monoamines NE, 5-HT, and DA seems to be controlled negatively by OX2 receptors.

The vesicular glutamate transporter VGLUT3 synergizes striatal acetylcholine tone.

Three subtypes of vesicular transporters accumulate glutamate into synaptic vesicles to promote its vesicular release. One of the subtypes, VGLUT3, is expressed in neurons, including cholinergic striatal interneurons, that are known to release other classical transmitters. Here we showed that disruption of the Slc17a8 gene (also known as Vglut3) caused an unexpected hypocholinergic striatal phenotype. Vglut3(-/-) mice were more responsive to cocaine and less prone to haloperidol-induced catalepsy than wild-type littermates, and acetylcholine release was decreased in striatum slices lacking VGLUT3. These phenotypes were associated with a colocalization of VGLUT3 and the vesicular acetylcholine transporter (VAChT) in striatal synaptic vesicles and the loss of a synergistic effect of glutamate on vesicular acetylcholine uptake. We propose that this vesicular synergy between two transmitters is the result of the unbalanced bioenergetics of VAChT, which requires anion co-entry for continuing vesicular filling. Our study reveals a previously unknown effect of glutamate on cholinergic synapses with potential functional and pharmacological implications.

Efficacy of the atypical antipsychotic aripiprazole in d-amphetamine-based preclinical models of mania.

The atypical antipsychotic aripiprazole has been demonstrated to reduce symptoms of bipolar mania. To further profile the antimanic-like properties of aripiprazole in relevant preclinical models, we examined its efficacy in d-amphetamine-based behavioural models of acute mania in rats. The effects of acute and repeated administration of aripiprazole were assessed in the facilitation of intracranial self-stimulation (ICSS) and hyperlocomotion after acute d-amphetamine, and in the sensitized facilitation of ICSS function and hyperlocomotion after repeated d-amphetamine. Acutely, aripiprazole (0.75, 1.5 and 2.5 mg/kg i.p.) increased ICSS thresholds, attenuated the reward-facilitating effects of d-amphetamine (0.5 mg/kg i.p.), decreased motor activity and prevented d-amphetamine-induced hyperlocomotion. Co-administration of aripiprazole and d-amphetamine for 7 d resulted in aripiprazole counteracting the d-amphetamine-induced sensitization in facilitation of brain reward function and hyperlocomotion. These results indicate the efficacy of aripiprazole in d-amphetamine-based preclinical models of acute mania that are characterized by increased motivational drive and/or hyperfunction of brain reward.

Individual differences in the effects of cannabinoids on motor activity, dopaminergic activity and DARPP-32 phosphorylation in distinct regions of the brain.

This study explored the behavioural, neurochemical and molecular effects of Delta9-tetrahydrocannabinol (Delta9-THC) and WIN55,212-2, in two rat phenotypes, distinguished on the basis of their vertical activity upon exposure to a novel environment, as high responders (HR) and low responders (LR). Motor effects were assessed under habituated vs. non-habituated conditions. Dopaminergic activity and DARPP-32 phosphorylation were measured in the dorsal striatum, nucleus accumbens, prefrontal cortex and amygdala. These cannabinoids influenced motor activity in a biphasic manner, i.e. low doses stimulated, whereas high doses suppressed motor activity. Dopamine (DA) biosynthesis was increased in most brain regions studied following Delta9-THC administration mainly in HR rats, and low-dose WIN55,212-2 increased DA biosynthesis in HR rats only. Both high and low doses of Delta9-THC increased DARPP-32 phosphorylation in most brain regions studied in both phenotypes, an effect that was also observed following high-dose WIN55,212-2 administration only in the striatum. The present results provide further support for a key role of cannabinoids in the regulation of motoric responses and elements of dopaminergic neurotransmission and reveal their complex differential effects in distinct rat phenotypes, as seen with other drugs of abuse.

Effects of vortioxetine on functional capacity across different levels of functional impairment in patients with major depressive disorder: a University of California, San Diego Performance-based Skills Assessment (UPSA) analysis.

Objective: To evaluate the consistency of vortioxetine's effects on functional capacity in adults with major depressive disorder (MDD) and self-reported cognitive symptoms at different levels of functional impairment.Methods: An exploratory analysis of data from a randomized, placebo-controlled, duloxetine-referenced study (NCT01564862) involving 529 patients with moderate to severe MDD treated once-daily with vortioxetine 10/20 mg, duloxetine 60 mg, or placebo for 8 weeks. Analysis of the University of California, San Diego Performance-based Skills Assessment (UPSA) composite scores stratified patients into subgroups by baseline functional impairment and assessed clinically important differences using several cutoffs for change from baseline (CFB) (least-square means) in UPSA composite score. A path analysis was also conducted to determine the proportion of direct versus indirect effects of vortioxetine on functional capacity.Results: Vortioxetine significantly separated from placebo across different baseline levels of functional impairment, particularly at the ≤70 cutoff (mean difference = 5.9, 95% confidence interval, 1.5-10.4). A greater proportion of patients treated with vortioxetine than placebo exhibited UPSA composite score response at each threshold analyzed and were classified as responders based on UPSA CFB of ≥7 (p = 0.006) or ≥9 (p = 0.016). No significant effects were observed for duloxetine versus placebo for any baseline levels of functional impairment or response thresholds. Path analysis demonstrated that 96.9% of the effects on functional capacity can be directly attributed to the treatment effect of vortioxetine and are not mediated by improvements in depressive symptoms as measured by MADRS.Conclusion: The effects of vortioxetine on functional capacity is robust across different level of functional impairment in patients with MDD. The effect on functional capacity was largely independent of the effect on depressive symptoms. Trial Registration: ClinicalTrials.gov identifier: NCT01564862: https://clinicaltrials.gov/ct2/show/NCT01564862; European Clinical Trials Database [EudraCT] Number 2011-005298-22: https://www.clinicaltrialsregister.eu/ctr-search/trial/2011-005298-22/DE.

SAGE-217, A Novel GABAA Receptor Positive Allosteric Modulator: Clinical Pharmacology and Tolerability in Randomized Phase I Dose-Finding Studies.

BACKGROUND: SAGE-217, a novel γ-aminobutyric acid A (GABAA) receptor positive allosteric modulator, was evaluated in phase I, double-blind, placebo-controlled, single ascending dose (SAD) and multiple ascending dose (MAD) studies to assess the safety and pharmacokinetics (PK) of SAGE-217 following administration as an oral solution. METHODS: In the SAD study, subjects were randomized 6:2 to a single dose of SAGE-217 or placebo. Doses ranged from 0.25 to 66 mg across nine cohorts. In the MAD study, subjects were randomized 9:3 and received SAGE-217 (15, 30, or 35 mg) or placebo once daily for 7 days. In both studies, PK, maximum tolerated dose (MTD; against predetermined criteria), safety, and tolerability were assessed. RESULTS: A total of 108 healthy volunteers enrolled in the studies-72 subjects in the SAD study and 36 subjects in the MAD study. SAGE-217 was orally bioavailable, with a terminal-phase half-life of 16-23 h and a tmax of approximately 1 h. The MTDs for the oral solution of SAGE-217 in the SAD and MAD studies were determined to be 55 and 30 mg daily, respectively. In both studies, SAGE-217 was generally well tolerated, and no serious adverse events (SAEs) were reported. Most AEs were mild, dose-dependent, transient, occurred around the tmax, and related to drug pharmacology. CONCLUSIONS: SAGE-217 was generally well tolerated, and its PK profile was well characterized. Based on this profile, SAGE-217 has been advanced into multiple phase II clinical programs and pivotal studies of major depressive disorder and postpartum depression.

Cholinergic dysfunction in a mouse model of Alzheimer disease is reversed by an anti-A beta antibody.

Disruption of cholinergic neurotransmission contributes to the memory impairment that characterizes Alzheimer disease (AD). Since the amyloid cascade hypothesis of AD pathogenesis postulates that amyloid beta (A beta) peptide accumulation in critical brain regions also contributes to memory impairment, we assessed cholinergic function in transgenic mice where the human A beta peptide is overexpressed. We first measured hippocampal acetylcholine (ACh) release in young, freely moving PDAPP mice, a well-characterized transgenic mouse model of AD, and found marked A beta-dependent alterations in both basal and evoked ACh release compared with WT controls. We also found that A beta could directly interact with the high-affinity choline transporter which may impair steady-state and on-demand ACh release. Treatment of PDAPP mice with the anti-A beta antibody m266 rapidly and completely restored hippocampal ACh release and high-affinity choline uptake while greatly reducing impaired habituation learning that is characteristic of these mice. Thus, soluble "cholinotoxic" species of the A beta peptide can directly impair cholinergic neurotransmission in PDAPP mice leading to memory impairment in the absence of overt neurodegeneration. Treatment with certain anti-A beta antibodies may therefore rapidly reverse this cholinergic dysfunction and relieve memory deficits associated with early AD.

Biochemical and behavioral evidence for antidepressant-like effects of 5-HT6 receptor stimulation.

The primary action of several antidepressant treatments used in the clinic raises extracellular concentrations of serotonin (5-HT), which subsequently act on multiple 5-HT receptors. The present study examined whether 5-HT6 receptors might be involved in the antidepressant-like effects mediated by enhanced neurotransmission at 5-HT synapses. A selective 5-HT6 receptor antagonist, SB271046, was evaluated for its ability to counteract fluoxetine-induced biochemical and behavioral responses in mice. In addition, biochemical and behavioral effects of the 5-HT6 receptor agonist, 2-ethyl-5-methoxy-N,N-dimethyltryptamine (EMDT), were assessed in mice to ascertain whether enhancement of 5-HT6 receptor-mediated neurotransmission engenders antidepressant-like effects. SB271046 significantly counteracted the stimulatory actions of fluoxetine on cortical c-fos mRNA, phospho-Ser845-GluR1, and in the tail suspension antidepressant assay, whereas it had no effect on these parameters by itself. EMDT increased the phosphorylation states of Thr34-DARPP-32 and Ser845-GluR1, both in brain slices and in the intact brain, which were effects also seen with the antidepressant fluoxetine; as with fluoxetine, these effects were demonstrated to be independent of D1 receptor stimulation. Systemic administration of EMDT increased c-fos mRNA expression in the striatum and cerebral cortex and reduced immobility in the tail suspension test. The antidepressant-like effects of EMDT in the tail suspension test were prevented by SB271046. Our results indicate that 5-HT6 receptor stimulation may be a mechanism initiating some of the biochemical and behavioral outcomes of 5-HT reuptake inhibitors, such as fluoxetine. These findings also indicate that selective 5-HT6 receptor agonists may represent a novel antidepressant drug class.

Neurochemical and behavioral profiling of the selective GlyT1 inhibitors ALX5407 and LY2365109 indicate a preferential action in caudal vs. cortical brain areas.

Selective inhibitors of the glycine transporter 1 (GlyT1) have been implicated in central nervous system disorders related to hypoglutamatergic function such as schizophrenia. The selective GlyT1 inhibitors ALX5407 (NFPS) and LY2365109 {[2-(4-benzo[1,3]dioxol-5-yl-2-tert-butylphenoxy)ethyl]-methylamino}-acetic acid increased cerebrospinal fluid levels of glycine and potentiated NMDA-induced increases in dialysate levels of neurotransmitters in the prefrontal cortex (PFC) and the striatum. However, higher doses produced both stimulatory and inhibitory effects on motor performance and impaired respiration, suggesting significant involvement of cerebellar and brain stem areas. A dual probe microdialysis study showed that ALX5407 transiently elevated extracellular levels of glycine in the PFC with more sustained increases in the cerebellum. In support of these findings, immuno-staining with pan-GlyT1 and GlyT1a antibodies showed a higher abundance of immunoreactivity in the brain stem/cerebellum as compared to the frontal cortical/hippocampal brain areas in four different species studied, including the mouse, rat, monkey and human. In addition, the inhibitory effects of ALX5407 on cerebellar levels of cGMP in the mouse could be reversed by the glycine A receptor antagonist strychnine but not the glycine B receptor antagonist L-701324. We propose that the adverse events seen with higher doses of ALX5407 and LY2365109 are the result of high GlyT1 inhibitory activity in caudal areas of the brain with sustained elevations of extracellular glycine. High levels of glycine in these brain areas may result in activation of strychnine-sensitive glycine A receptors that are inhibitory on both motor activity and critical brain stem functions such as respiration.

Role of metabotropic glutamate receptor 5 in the procholinergic effects of neuropsychotherapeutic compounds.

We investigated the participation of the metabotropic glutamate receptor type 5 (mGluR5) in mediating increases in cortical acetylcholine (ACh) efflux elicited by established or putative neuropsychotherapeutic compounds, using in vivo microdialysis in rats. The norepinephrine transporter inhibitor atomoxetine, the cannabinoid CB1 receptor antagonist SR141716A, the dopamine D1 receptor agonist dihydrexidine, and the atypical antipsychotic clozapine increased cortical ACh (by about 2-3 fold), whereas the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) by itself had no effect. The stimulatory effects of atomoxetine, SR141716A and dihydrexidine on cortical ACh were abolished by pretreatment with MPEP. MPEP also attenuated the stimulatory effect of clozapine on ACh efflux. Thus, mGluR5 activation appears to be involved in the procholinergic effects of compounds that exhibit therapeutic properties or potential in neuropsychiatry.

In vivo neurochemical effects induced by changes in endocannabinoid neurotransmission.

Neurotropic effects of endo- and exo-cannabinoids are largely caused by their effects on classical neurotransmitter signaling. Pharmacological and molecular tools have been used to selectively target the endocannabinoid system. Endocannabinoids mostly act as retrograde messengers and, upon release from postsynaptic neurons, they modulate neurotransmitter release by activating presynaptic cannabinoid receptors. Generally, increased and decreased endocannabinoid neurotransmission results in decreases and increases in neurotransmitter release, respectively. However, net effects are often pleiotropic, probably owing to the level of regional endogenous tone, transsynaptic mechanisms and cumulative actions. Changes in classical neurotransmitter function can, in turn, modulate endocannabinoid signaling. Importantly, the endocannabinoid system can be altered in response to physiological and pathogenic events and targeted for therapeutic intervention.

Effects of Intrinsic Factors on the Clinical Pharmacokinetics of Vortioxetine.

Vortioxetine is an antidepressant agent with multimodal activity that is approved for the treatment of major depressive disorder at doses of 5 to 20 mg once daily. Vortioxetine is a medium-clearance drug that undergoes extensive metabolism via several cytochrome P450 isozymes. A series of single- and multiple-dose pharmacokinetic studies were performed to evaluate the impact of intrinsic (ie, subject-related) factors, such as age, sex, race, and renal and hepatic function, on the pharmacokinetics of vortioxetine. The point estimates on the ratios and their 90% confidence intervals (CIs) for the central values of AUC (area under the concentration-time curve) and Cmax (maximum plasma concentration) were obtained by taking the antilog of the differences and 90%CIs in the log-transformed least-squares means. The results demonstrate that there were no clinically meaningful differences (defined as exposure difference between 50% and 2-fold change) in the exposure to vortioxetine (as assessed by AUC and Cmax ) between elderly and younger subjects, men and women, and blacks and whites and among subjects with varying degrees of renal or hepatic impairment. These results suggest that no dosing adjustments of vortioxetine are required for the intrinsic factors investigated in these studies.

Functional alterations of nicotinic neurotransmission in dopamine transporter knock-out mice.

Mice lacking the dopamine (DA) transporter (DAT) gene exhibit a phenotype reminiscent of schizophrenia and attention deficit hyperactivity disorder (ADHD), including hyperDAergia, hyperactivity and deficits in cognitive performance, which are alleviated by antipsychotic agents. Numerous studies suggest a dysfunction of nicotinic neurotransmission in schizophrenia and show increased tobacco intake in schizophrenic and ADHD patients, possibly as a self-medication. Thus, we examined the potential alteration of nicotinic neurotransmission in DAT knock-out (KO) mice. We showed that constitutively hyperDAergic DAT KO mice exhibited modifications in nicotinic receptor density in an area- and subtype-dependent manner. In some DAergic areas, the small decrease in the beta2* nicotinic subunit (nAChR) density contrasted with the higher decrease and increase in the alpha6* and alpha7 nAChR densities, respectively. Mutant mice were hypersensitive to the stimulant locomotor effects of nicotine at low doses, probably due to enhanced nicotine-induced extracellular DA level. They also showed hypersensitivity to the hypolocomotion induced by nicotine. In contrast, no hypersensitivity was observed for other nicotine-induced behavioral effects, such as anxiety or motor activity in the elevated plus maze. Co-administration of nicotinic agonists at sub-active doses elicited opposite locomotor effects in wild-type and DAT KO mice, as reported previously for methylphenidate. Interestingly, such a co-administration of nicotinic agonists induced synergistic hypolocomotion in DAT KO mice. These findings show that a targeted increase of DA tone can be responsible for significant adaptations of the cholinergic/nicotinic neurotransmission. This study may provide potential leads for the use of nicotine or combined nicotinic agonists for the therapy of psychiatric disorders.

Adolescent Female Cannabinoid Exposure Diminishes the Reward-Facilitating Effects of Δ9-Tetrahydrocannabinol and d-Amphetamine in the Adult Male Offspring.

Marijuana is currently the most commonly abused illicit drug. According to recent studies, cannabinoid use occurring prior to pregnancy can impact brain plasticity and behavior in future generations. The purpose of the present study was to determine whether adolescent exposure of female rats to Δ9-tetrahydrocannabinol (Δ9-THC) induces transgenerational effects on the reward-facilitating effects of Δ9-THC and d-amphetamine in their adult male offspring. Female Sprague-Dawley rats received Δ9-THC (0.1 or 1 mg/kg, i.p.) or vehicle during postnatal days 28-50. As adults, females were mated with drug-naïve males. We then assessed potential alterations of the Δ9-THC's (0, 0.1, 0.5, and 1 mg/kg, i.p.) and d-amphetamine's (0, 0.1, 0.5, and 1 mg/kg, i.p.) reward-modifying effects using the curve-shift variant of the intracranial self-stimulation (ICSS) procedure in their adult male F1 offspring. The reward-facilitating effect of the 0.1 mg dose of Δ9-THC was abolished in the F1 offspring of females that were exposed to Δ9-THC (0.1 or 1 mg/kg), whereas the reward-attenuating effect of the 1 mg dose of Δ9-THC remained unaltered. The reward-facilitating effects of 0.5 and 1 mg of d-amphetamine were significantly decreased in the F1 offspring of females that were exposed to Δ9-THC (1 mg/kg and 0.1 or 1 mg, respectively). The present results reveal that female Δ9-THC exposure during adolescence can diminish the reward-facilitating effects of Δ9-THC and d-amphetamine in the adult male offspring. These transgenerational effects occur in the absence of in utero exposure. It is speculated that Δ9-THC exposure during female adolescence may affect neural mechanisms that are shaping reward-related behavioral responses in a subsequent generation, as indicated by the shifts in the reward-facilitating effects of commonly used and abused drugs.

Determination of a clinically important difference and definition of a responder threshold for the UCSD performance-based skills assessment (UPSA) in patients with major depressive disorder.

BACKGROUND: This article reports an evaluation of the psychometric properties and clinically important difference (CID) threshold of the UCSD Performance-Based Skills Assessment (UPSA) in major depressive disorder (MDD), using data from a large-scale study of the effects of vortioxetine on cognitive functioning and functional capacity in MDD patients. METHODS: Adults with moderate-to-severe recurrent MDD and self-reported cognitive dysfunction were randomized to 8 weeks of double-blind treatment with vortioxetine 10/20mg QD (flexible), duloxetine 60mg QD, or placebo. Pearson correlation coefficients were calculated between UPSA composite score and demographic/disease characteristics at baseline to examine construct validity. Two methods (distribution-based and anchor-based) were used to establish a CID threshold. RESULTS: A total of 602 patients were randomized; 528 comprised the full analysis set. For the entire sample mean UPSA composite scores were 77.8 at baseline and 83.9 at week 8 (mean change, +6.1). As hypothesized, at baseline, the UPSA composite score correlated with cognitive functioning (Digit Symbol Substitution Test: r=0.36, P<0.001) and workplace productivity (Work Limitations Questionnaire: r=-0.17, P=0.008), but not depressive symptoms (Montgomery-Åsberg Depression Rating Scale: r=0.02, P=0.707) or subjective cognitive dysfunction (Perceived Deficits Questionnaire: r=-0.02, P=0.698). LIMITATIONS: Two versions of the UPSA were used and no inclusion/exclusion criteria were based on the UPSA. CONCLUSIONS: These results support the construct validity of UPSA for assessing functional capacity independent of mood symptoms. The estimated CID for changes in UPSA scores was quite consistent at +6.4 points and +6.7 based on distribution-based and anchor-based methods, respectively.