Pharmacological effects of Lu AA21004: a novel multimodal compound for the treatment of major depressive disorder

Sedative and hypnotic effects of Polygala tenuifolia willd. saponins on insomnia mice and their targets

ETHNOPHARMACOLOGICAL RELEVANCE

Polygala tenuifolia Willd. has been widely used in the treatment of cancer, forgetfulness, depression and other diseases.

AIM OF REVIEW

The purpose of this study was to investigate the sleep-enhancing effect and mechanism of P. tenuifolia saponins (PTS).

MATERIALS AND METHODS

The total saponin (YZ-I) and purified saponin (YZ-II) fractions were extracted and ICR mice model of insomnia was established by p-chlorophenylalanine (PCPA) induction to observe anxiety and depression behaviors. Effects of YZ-I and YZ-II on the levels of neurotransmitters, hormones, and inflammation cytokines were detected by ELISA, RT-qPCR and western blotting.

RESULTS

The results showed that YZ-I and YZ-II reduced the immobility time of mice and prolonged the sleep time of mice and significantly increased the concentrations of 5-HT, NE, PGD2, IL-1β and TNF-α. YZ-I and YZ-II regulated GABAARα2, GABAARα3, GAD65/67, 5-HT1A and 5-HT2A, while regulated the levels of inflammatory cytokines such as DPR, PGD2, iNOS and TNF-α to exert sedative and hypnotic effects.

CONCLUSION

PTS are mainly achieved sedative and hypnotic effects by altering serotonergic, GABAergic and immune systems, but the effects and mechanisms of action of YZ-I were different from YZ-II.

Reproductive toxicity of JJH201501 in rats: Perinatal study

INTRODUCTION

In this study, JJH201501 was examined for reproductive toxicity during the perinatal period to support its safety as a novel serotonergic agent (5-HT) antidepressant. Pregnant Sprague-Dawley rats (F0, n = 24/group) were continuously exposed to 0 (control), 6, 18, and 60 mg/kg body weight/day of JJH201501 by intragastric administration from gestation day 15 to lactation day 21.

METHODS

During this period, maternal toxicity was evaluated based on clinical signs, body weight, feed intake, delivery condition, litter parameters, and necropsy, with body weight, sex ratios, malformation incidence, physical, and neurodevelopmental assessments conducted on all offspring rats. Ten pups (male:female 1:1) from each dam within each dose group on postnatal day 4 (PND4) were randomly selected. One pair was evaluated for behavior evaluations (F1a) after PND35, one for reproduction performance (F1b) after 10 weeks, and three for organ weight and deformities (F1c) on PND35. After successful mating, F1b male rats were weighed and dissected to assess reproductive organ weight and sperm motility. Pregnant F1b rats were weighed and monitored for food intake twice weekly until laparotomy on GD14, which recorded live/dead fetuses, resorptions, implantations, corpora lutea, and uterine weight. Some statistical differences were found between the JJH-treated and control groups in maternal weight, food consumption, and F1 body weight and water maze performance.

RESULTS

Autopsy results showed that JJH201501 had a low cardiac index effect in F0, with no significant histopathological changes detected. Only one F1 offspring died in the high-dose group throughout the experiment. Due to the lack of dose-dependent effects and the consistent growth pattern of these alterations, the study findings do not suggest any toxicological significance for the observed results.

CONCLUSION

In conclusion, the no-observed-adverse-effect level of JJH201501 for perinatal rats is about 60 mg/kg b.w./day.

Clinical benefits of vortioxetine 20 mg/day in patients with major depressive disorder

BACKGROUND

Vortioxetine has demonstrated dose-dependent efficacy in patients with major depressive disorder (MDD), with the greatest effect observed with vortioxetine 20 mg/day. This analysis further explored the clinical relevance of the more rapid and greater improvement in depressive symptoms observed with vortioxetine 20 mg/day vs 10 mg/day.

METHODS

Analysis of pooled data from six short-term (8-week), randomized, placebo-controlled, fixed-dose studies of vortioxetine 20 mg/day in patients with MDD (N = 2620). Symptomatic response (≥50% decrease in Montgomery-Åsberg Depression Rating Scale [MADRS] total score), sustained symptomatic response, and remission (MADRS total score ≤10) were assessed by vortioxetine dosage (20 or 10 mg/day).

RESULTS

After 8 weeks, 51.4% of patients receiving vortioxetine 20 mg/day had achieved symptomatic response vs 46.0% of those receiving vortioxetine 10 mg/day (P < .05). Significantly more patients achieved symptomatic response vs placebo from week 2 onwards for vortioxetine 20 mg/day and from week 6 onwards for vortioxetine 10 mg/day (both P ≤ .05). Sustained response was achieved from week 4 for 26.0% of patients receiving vortioxetine 20 mg/day vs 19.1% of those receiving vortioxetine 10 mg/day (P < .01), increasing to 36.0% and 29.8%, respectively, over the 8-week treatment period (P < .05). At week 8, 32.0% of patients receiving vortioxetine 20 mg/day were in remission vs 28.2% of those receiving vortioxetine 10 mg/day (P = .09). Rates of adverse events and treatment withdrawal were not increased during the week following vortioxetine dose up-titration to 20 mg/day.

CONCLUSION

Vortioxetine 20 mg/day provides more rapid and more sustained symptomatic response than vortioxetine 10 mg/day in patients with MDD, without compromising tolerability.

The 5-HT7 receptor system as a treatment target for mood and anxiety disorders: A systematic review

BACKGROUND

Preclinical animal and preliminary human studies indicate that 5-HT7 antagonists have the potential as a new treatment approach for mood and anxiety disorders. In this systematic review, we aimed to review the relationship between the 5-HT7 receptor system and mood and anxiety disorders, and to explore the pharmacology and therapeutic potential of medications that target the 5-HT7 receptor for their treatment.

METHODS

Medline, Cochrane Library, EMBASE, PsycINFO databases, the National Institute of Health website Clinicaltrials.gov, controlled-trials.com, and relevant grey literature were used to search for original research articles, and reference lists of included articles were then hand searched.

RESULTS

Sixty-four studies were included in the review: 52 animal studies and 12 human studies. Studies used a variety of preclinical paradigms and questionnaires to assess change in mood, and few studies examined sleep or cognition. Forty-four out of 47 (44/47) preclinical 5-HT7 modulation studies identified potential antidepressant effects and 20/23 studies identified potential anxiolytic effects. In clinical studies, 5/7 identified potential antidepressant effects in major depressive disorder, 1/2 identified potential anxiolytic effects in generalized anxiety disorder, and 3/3 identified potential antidepressant effects in bipolar disorders.

CONCLUSION

While there is some evidence that the 5-HT7 receptor system may be a potential target for treating mood and anxiety disorders, many agents included in the review also bind to other receptors. Further research is needed using drugs that bind specifically to 5-HT7 receptors to examine treatment proof of concept further.

Effectiveness of vortioxetine in patients with major depressive disorder and early-stage dementia: The MEMORY study

BACKGROUND

Depression and dementia are highly prevalent in older adults and often co-occur. This Phase IV study investigated the effectiveness and tolerability of vortioxetine in improving depressive symptoms, cognitive performance, daily and global functioning and health-related quality of life (HRQoL) in patients with major depressive disorder (MDD) and comorbid early-stage dementia.

METHODS

Patients (n = 82) aged 55-85 years with a primary diagnosis of MDD (onset before age 55 years) and comorbid early-stage dementia (diagnosed ≥6 months before screening and after onset of MDD; Mini-Mental State Examination-2 total score, 20-24) received vortioxetine for 12 weeks (initiated at 5 mg/day and up-titrated to 10 mg/day at day 8, with flexible dosing thereafter [5-20 mg/day]). The primary endpoint was change from baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) total score at week 12.

RESULTS

Significant improvement in depressive symptom severity was seen from week 1 onwards (P < 0.0001). At week 12, the least-square mean (standard error) change in MADRS total score from baseline was -12.4 (0.78). Significant improvements in cognitive performance were observed (from week 1 for the Digit Symbol Substitution Test and week 4 for the Rey Auditory Verbal Learning Test). Patients also experienced significant improvements in daily and global functioning, and HRQoL. Vortioxetine was well tolerated. From week 4 onwards, more than 50 % of patients were receiving 20 mg/day.

LIMITATIONS

Open-label study.

CONCLUSIONS

Vortioxetine demonstrated effectiveness in clinically significantly improving depressive symptoms, cognitive performance, daily and global functioning, and HRQoL in patients with MDD and comorbid early-stage dementia treated for 12 weeks.

TRIAL REGISTRATION

ClinicalTrials.gov/ct2/show/NCT04294654.

Recent Developments in Pharmacotherapy of Depression: Bench to Bedside

For the last 70 years, we did not move beyond the monoamine hypothesis of depression until the approval of the S-enantiomer of ketamine, an N-methyl-D-aspartate (NMDA) receptor blocker and the first non-monoaminergic antidepressant characterized by rapid antidepressant and antisuicidal effects. A similar profile has been reported with another NMDA receptor antagonist, dextromethorphan, which has also been approved to manage depression in combination with bupropion. More recently, the approval of a positive allosteric modulator of GABA-A receptors, brexanolone, has added to the list of recent breakthroughs with the relatively rapid onset of antidepressant efficacy. However, multiple factors have compromised the clinical utility of these exciting discoveries in the general population, including high drug acquisition costs, mandatory monitoring requirements, parenteral drug administration, lack of insurance coverage, indirect COVID-19 effects on healthcare systems, and training gaps in psychopharmacology. This narrative review aims to analyze the clinical pharmacology of recently approved antidepressants and discuss potential barriers to the bench-to-bedside transfer of knowledge and clinical application of exciting recent discoveries. Overall, clinically meaningful advances in the treatment of depression have not reached a large proportion of depressed patients, including those with treatment-resistant depression, who might benefit the most from the novel antidepressants.

Catecholaminergic and Cholinergic Systems Mediate Beneficial Effect of Vortioxetine on Diabetes-Induced Neuropathic Pain

The therapeutic potential of vortioxetine on mechanical hyperalgesia/allodynia was investigated in rats with streptozotocin-induced diabetes, and its possible mechanism of action was elucidated in this study. The obtained findings demonstrated that subacute vortioxetine treatment (5 and 10 mg/kg for 2 weeks) increased the reduced paw-withdrawal thresholds of diabetic rats both in the Randall-Selitto and Dynamic plantar tests. Moreover, the falling latencies of animals did not change in the Rota-rod assessments. These results suggest that vortioxetine administration significantly improved diabetes-induced hyperalgesia and allodynia responses in the rats without affecting their motor coordination. The vortioxetine (5 mg/kg)-induced antihyperalgesic and antiallodynic effects were reversed by AMPT, yohimbine, ICI 118,551, sulpiride and atropine pre-treatments, suggesting the involvement of the catecholaminergic system, α₂- and β₂-adrenoceptors, D_2/3 dopaminergic receptors and cholinergic muscarinic receptors in the exhibited pharmacological activity, respectively. Moreover, the data from the immunohistochemical studies indicated that the inhibition of c-Fos overexpression in dorsal horn neurons also mediates the beneficial effect of this drug. Vortioxetine induced no difference in plasma glucose levels in diabetic rats. If clinical studies confirm these findings, the concomitant beneficial effect of vortioxetine on mood disorders and its neutral activity profile on glycemic control may make it an alternative drug for the treatment of neuropathic pain.

Epilepsy and Attention Deficit Hyperactivity Disorder: Connection, Chance, and Challenges

Comorbidities are common in children with epilepsy, with nearly half of the patients having at least one comorbidity. Attention deficit hyperactivity disorder (ADHD) is a psychiatric disorder characterized by hyperactivity and inattentiveness level disproportional to the child’s developmental stage. The burden of ADHD in children with epilepsy is high and can adversely affect the patients’ clinical outcomes, psychosocial aspects, and quality of life. Several hypotheses were proposed to explain the high burden of ADHD in childhood epilepsy; the well-established bidirectional connection and shared genetic/non-genetic factors between epilepsy and comorbid ADHD largely rule out the possibility of a chance in this association. Stimulants are effective in children with comorbid ADHD, and the current body of evidence supports their safety within the approved dose. Nonetheless, safety data should be further studied in randomized, double-blinded, placebo-controlled trials. Comorbid ADHD is still under-recognized in clinical practice. Early identification and management of comorbid ADHD are crucial to optimize the prognosis and reduce the risk of adverse long-term neurodevelopmental outcomes. The identification of the shared genetic background of epilepsy and ADHD can open the gate for tailoring treatment options for these patients through precision medicine.

YY1 (Yin-Yang 1), a transcription factor regulating systemic inflammation, is involved in cognitive impairment of depression

AIM

Clinical and preclinical studies suggest that alterations in the peripheral and brain immune system are associated with the pathophysiology of depression, also leading to changes in local glucose metabolism in the brain. Here, the authors identified Yin-Yang 1 (YY1), a transcription factor closely associated with central and peripheral inflammation.

METHODS

Plasma levels of YY1, interleukin (IL) 6, and IL-1β in major depressive disorder (MDD) were collected before and after treatment with vortioxetine, and correlation with clinical and cognitive scores was studied. Chronic unpredictable mild stress was treated with vortioxetine. Micropositron emission tomography (microPET) was used to analyze glucose metabolism and mRNA, and the protein level of the YY1-nuclear factor κB (NF-κB)-IL-1β inflammatory pathway were measured in related brain regions.

RESULTS

Plasma levels of YY1 and IL-1β were significantly increased in MDD and decreased after treatment with vortioxetine. Meanwhile, the level of YY1 in plasma was negatively correlated with cognitive functions in patients with MDD and positively correlated with the level of IL-1β in plasma. Compared with the control group, in chronic unpredictable mild stress rats, (microPET) analysis showed that the decrease of glucose metabolism in the hippocampus, entorhinal cortex, amygdala, striatum, and medial prefrontal cortex was reversed after treatment. mRNA and protein level of related molecular in YY1-NF-κB-IL-1β inflammatory pathway decreased in the hippocampus and was reversed by vortioxetine.

CONCLUSION

The current study suggests that the YY1-NF-κB-IL-1β inflammatory pathway may play an essential role in both mood changes and cognitive impairment in depression, and may be associated with changes in glucose metabolism in emotion regulation and cognition. These findings provide new evidence for the inflammatory mechanisms of depression.

The clinical utility of newer antidepressant agents: Understanding the role in management of MDD

Whereas MDD is characterized in part by changes in mood, other symptoms can also cause significant impairment, including sexual dysfunction, cognitive impairment, and fatigue. Newer antidepressants are explored with the goal of more optimally treating these non–mood-related symptoms of MDD. The 3 oral antidepressants that have been FDA-approved most recently include vortioxetine, vilazodone, and levomilnacipran. Unique features of these antidepressants are explored through 3 patient cases.

The molecular pathophysiology of depression and the new therapeutics

Major depressive disorder (MDD) is a highly prevalent and disabling disorder. Despite the many hypotheses proposed to understand the molecular pathophysiology of depression, it is still unclear. Current treatments for depression are inadequate for many individuals, because of limited effectiveness, delayed efficacy (usually two weeks), and side effects. Consequently, novel drugs with increased speed of action and effectiveness are required. Ketamine has shown to have rapid, reliable, and long-lasting antidepressant effects in treatment-resistant MDD patients and represent a breakthrough therapy for patients with MDD; however, concerns regarding its efficacy, potential misuse, and side effects remain. In this review, we aimed to summarize molecular mechanisms and pharmacological treatments for depression. We focused on the fast antidepressant treatment and clarified the safety, tolerability, and efficacy of ketamine and its metabolites for the MDD treatment, along with a review of the potential pharmacological mechanisms, research challenges, and future clinical prospects.

Inhibitory Effectiveness in Delayed-Rectifier Potassium Current Caused by Vortioxetine, Known to Be a Novel Antidepressant

Vortioxetine (VOR) is recognized to exert antidepressant actions. However, whether this drug modifies ionic currents in excitable cells remains unclear. The aim of this study was to explore the electrophysiological effects of VOR and other related compounds in pituitary GH₃ cells and in Neuro-2a cells. VOR suppressed the delayed-rectifier K⁺ current (I_K(DR)) in a concentration-, time-, and state-dependent manner. Effective IC₅₀ values needed to inhibit peak and sustained I_K(DR) were computed to be 31.2 and 8.5 μM, respectively, while the K_D value estimated from minimal binding scheme was 7.9 μM. Cell exposure to serotonin (10 μM) alone failed to alter I_K(DR), while fluoxetine (10 μM), a compound structurally similar to VOR, mildly suppressed current amplitude. In continued presence of VOR, neither further addition of propranolol nor risperidone reversed VOR-mediated inhibition of I_K(DR). Increasing VOR concentration not only depressed I_K(DR) conductance but also shifted toward the hyperpolarized potential. As the VOR concentration was raised, the recovery of I_K(DR) block became slowed. The I_K(DR) activated by a downsloping ramp was suppressed by its presence. The inhibition of I_K(DR) by a train pulse was enhanced during exposure to VOR. In Neuro-2a cells, this drug decreased I_K(DR). Overall, inhibitory effects of VOR on ionic currents might constitute another underlying mechanism of its actions.

Vortioxetine Treatment for Depression in Alzheimer's Disease: A Randomized, Double-blind, Placebo-controlled Study

OBJECTIVE

Vortioxetine, a new antidepressant, has been demonstrated to have effects on depression and cognitive function. This study aimed to investigate the anti-depressive efficacy of vortioxetine through a well-designed double- blind, placebo-controlled study in Alzheimer's disease (AD) patients, and to confirm the presence of secondary benefits, including the improvement of cognitive function and activities of daily living (ADL).

METHODS

The present study included 100 AD patients with depression who were assigned randomly to 12 weeks of daily treatment with either vortioxetine or placebo. The primary efficacy measure was the change in the Cornell Scale for Depression in Dementia score from baseline to 12 weeks. Several secondary efficacy measures were evaluated, including the Korean version of the Short form of Geriatric Depression Scale and several cognitive function domains. The safety and tolerability of vortioxetine were also assessed. We performed modified intention-to-treat analysis using mixed modeling (the Mixed Models for Repeated Measures).

RESULTS

There was no statistically significant difference between the two groups in terms of depressive symptoms, cognitive functions, and ADL. Further, the percentage of adverse events and drug discontinuation between the vortioxetine and placebo groups was similar.

CONCLUSION

Our results suggest that vortioxetine might not be effective in reducing depressive symptoms or cognitive impairment in AD patients with depression. However, general drug tolerance and patient safety were similar to those of placebo. Thus, additional studies are needed to replicate the effectiveness and tolerability of vortioxetine in AD patients with depression.

Effectiveness of vortioxetine in patients with major depressive disorder comorbid with generalized anxiety disorder: Results of the RECONNECT study

BACKGROUND

Major depressive disorder (MDD) and generalized anxiety disorder (GAD) are frequently comorbid.

AIMS

To assess the effectiveness of vortioxetine in patients with MDD and comorbid GAD.

METHODS

Open-label, 8-week study (NCT04220996) in 100 adult outpatients with severe MDD and severe comorbid GAD receiving vortioxetine as first treatment for the current depressive episode or switching to vortioxetine due to inadequate response to another drug for depression. Vortioxetine starting dosage was 10 mg/day, with forced up-titration to 20 mg/day after 1 week. Response was defined as ⩾50% decrease in Montgomery-Åsberg Depression Rating Scale (MADRS) and/or Hamilton Anxiety Rating Scale (HAM-A) total score from baseline; remission defined as MADRS and/or HAM-A total score ⩽10.

RESULTS

Clinically meaningful and statistically significant improvements from baseline in symptoms of depression and anxiety, and overall functioning and health-related quality of life, were observed after 8 weeks' vortioxetine treatment (all changes p < 0.0001 vs baseline). At week 8, rates of MADRS response and remission were 61% and 35%, respectively. Corresponding rates of HAM-A response and remission were 55% and 42%. Response on both the MADRS and HAM-A scales was achieved by 52% of patients; 31% achieved remission on both scales. Vortioxetine dose up-titration was well tolerated; no unexpected adverse events were reported.

CONCLUSION

Vortioxetine demonstrates effectiveness in significantly reducing symptoms of both depression and anxiety in patients with severe MDD comorbid with severe GAD. Findings support increasing vortioxetine dosage to 20 mg/day early in the course of therapy, and show that this may be achieved without compromising tolerability.

PET as a Translational Tool in Drug Development for Neuroscience Compounds

In central nervous system drug discovery programs, early development of new chemical entities (NCEs) requires a multidisciplinary strategy and a translational approach to obtain proof of distribution, proof of occupancy, and proof of function in specific brain circuits. Positron emission tomography (PET) provides a way to assess in vivo the brain distribution of NCEs and their binding to the target of interest, provided that radiolabeling of the NCE is possible or that a suitable radioligand is available. PET is therefore a key tool for early phases of drug discovery programs. This review will summarize the main applications of PET in early drug development and discuss the usefulness of PET microdosing studies performed with direct labelling of the NCE and PET occupancy studies. The purpose of this review is also to propose an alignment of the nomenclatures used by drug metabolism and pharmacokinetic scientists and PET imaging scientists to indicate key pharmacokinetic parameters and to provide guidance in the performance and interpretation of PET studies.

Vortioxetine ameliorates motor and cognitive impairments in the rotenone-induced Parkinson's disease via targeting TLR-2 mediated neuroinflammation

Parkinson's disease (PD) is characterized by motor and non-motor symptoms associated with dopaminergic and non-dopaminergic injury. Vortioxetine is a multimodal serotonergic antidepressant with potential procognitive effects. This study aimed to explore the effects of vortioxetine on motor functions, spatial learning and memory, and depression-like behavior in the rotenone-induced rat model of PD. Male Sprague-Dawley rats were daily administered with the rotenone (2 mg·kg^-1, s.c.) and/or vortioxetine (10 mg·kg^-1, s.c.) for 28 days. Motor functions (rotarod, catalepsy, open-field), depression-like behaviors (sucrose preference test), anxiety (elevated plus maze), and spatial learning and memory abilities (novel object recognition and Morris water maze) were evaluated in behavioral tests. Then immunohistochemical, neurochemical, and biochemical analysis on specific brain areas were performed. Vortioxetine treatment markedly reduced rotenone-induced neurodegeneration, improved motor and cognitive dysfunction, decreased depression-like behaviors without affecting anxiety-like parameters. Vortioxetine also restored the impaired inflammatory response and affected neurotransmitter levels in brain tissues. Interestingly, vortioxetine was thought to trigger a sort of dysfunction in basal ganglia as evidenced by increased Toll-like receptor-2 (TLR-2) and decreased TH immunoreactivity only in substantia nigra tissue of PD rats compared to the control group. The present study indicates that vortioxetine has beneficial effects on motor dysfunction as well as cognitive impairment associated with neurodegeneration in the rotenone-induced PD model. Possible mechanisms underlying these beneficial effects cover TLR-2 inhibition and neurochemical restoration of vortioxetine.

New Drugs to Treat ADHD: Opportunities and Challenges in Research and Development

Since the landmark MTA (Multimodal Treatment of ADHD) trial unequivocally demonstrated the efficacy of methylphenidate, catecholaminergic drugs, especially stimulants, have been the therapeutic mainstay in treatment of Attention-Deficit Hyperactivity Disorder (ADHD). We review the new drugs which have entered the ADHD formulary. The lessons learned from drug-candidates that have succeeded in clinical trials together with those that have not have also been considered. What emerges confirms and consolidates the hypothesis that clinically effective ADHD drugs indirectly or directly increase catecholaminergic neurotransmission in the prefrontal cortex (PFC). Attempts to enhance catecholaminergic signalling through modulatory neurotransmitter systems or cognitive-enhancing drugs have all failed. New drugs approved for ADHD are catecholaminergic reuptake inhibitors and releasing agents, or selective noradrenaline reuptake inhibitors. Triple reuptake inhibitors with preferential effects on dopamine have not been successful. The substantial number of failures probably accounts for a continued focus on developing novel catecholaminergic and noradrenergic drugs, and a dearth of drug-candidates with novel mechanisms entering clinical development. However, substantial improvements in ADHD pharmacotherapy have been achieved by the almost exclusive use of once-daily medications and prodrugs, e.g. lisdexamfetamine and Azstarys^®, which improve compliance, deliver greater efficacy and reduce risks for diversion and abuse.

Astroglial Serotonin Receptors as the Central Target of Classic Antidepressants

Major depressive disorder (MDD) presents multiple clinical phenotypes and has complex underlying pathological mechanisms. Existing theories cannot completely explain the pathophysiological mechanism(s) of MDD, while the pharmacology of current antidepressants is far from being fully understood. Astrocytes, the homeostatic and defensive cells of the central nervous system, contribute to shaping behaviors, and regulating mood and emotions. A detailed introduction on the role of astrocytes in depressive disorders is thus required, to which this chapter is dedicated. We also focus on the interactions between classic antidepressants and serotonin receptors, overview the role of astrocytes in the pharmacological mechanisms of various antidepressants, and present astrocytes as targets for the treatment of bipolar disorder. We provide a foundation of knowledge on the role of astrocytes in depressive disorders and astroglial 5-HT_2B receptors as targets for selective serotonin reuptake inhibitors in vivo and in vitro.

Vortioxetine as an analgesic in preclinical inflammatory pain models: Mechanism of action

Vortioxetine is a novel atypical antidepressant with multimodal activity that has recently demonstrated efficacy against neuropathic pain. There is no published data about its analgesic properties in models characterized by peripheral inflammation and consequent pain pathway sensitization, nor data on its mechanism of antinociceptive action. This study aimed to investigate vortioxetine's antinociceptive/antihyperalgesic effects in trigeminal, visceral, and somatic inflammatory pain models, and provide evidence on its mechanism of action in the modulation of trigeminal nociception. Vortioxetine's effects on the nociceptive behavior in orofacial formalin test (OFT) and acetic acid-writhing test in mice and on mechanical hyperalgesia in carrageenan-induced paw inflammation in rats were examined following peroral single administration. The involvement of serotonergic/adrenergic/cholinergic/cannabinoid/adenosine receptors was evaluated in OFT by intraperitoneally treating mice with an appropriate antagonist immediately after vortioxetine application. We used antagonists of 5-HT_1B/1D serotonergic (GR 127935), α₁ -adrenergic (prazosin), α₂ -adrenergic (yohimbine), β₁ -adrenergic (metoprolol), muscarinic (atropine), α₇ nicotinic (methyllycaconitine), CB₁ /CB₂ cannabinoid (AM251 and AM630), and adenosine A₁ (DPCPX) receptors. Vortioxetine dose-dependently reduced pain behavior in OFT and acetic acid writhing test, as well as inflammatory hyperalgesia in paw pressure test. All examined antagonists except prazosin dose-dependently inhibited vortioxetine's antinociceptive effects. In conclusion, vortioxetine exerted analgesic efficacy in trigeminal, visceral, and somatic inflammatory pain. The effect is at least in part mediated by 5-HT_1B/1D serotonergic, α₂ /β₁ -adrenergic, muscarinic and nicotinic cholinergic, CB₁ /CB₂ cannabinoid, and adenosine A₁ receptors. These findings contribute to better understanding of the analgesic effect of vortioxetine and suggest its potential usefulness for inflammatory pain treatment.

Vortioxetine Add-On to Methylphenidate for the Treatment of Symptoms of Sickness Behavior in Attention-Deficit Hyperactivity Disorder: Report of Two Cases

Youth with Attention-Deficit Hyperactivity Disorder (ADHD) may suffer from comorbid difficulties, such as anxiety–depressive symptoms, social withdrawal, and somatic complaints. Although stimulants remain the ADHD cornerstone treatment, mental fatigue, school problems and low self-esteem may persist, often being the most unacceptable symptoms for these patients. We present two cases of adolescents (14 and 15 years old) with methylphenidate-treated ADHD, where cognitive fatigability, depressive thoughts, anxiety, irritability, and poor social relationships remained. Based on clinical observation and the completion of parent and child rating scales, the aforementioned manifestations appeared to progressively reduce by the time of the subsequent control visits planned 1, 3, and 5 months after, following the use of vortioxetine (up to 10 mg/day) as add-on therapy to methylphenidate. No significant side effects were reported in both cases in a follow-up period of 3 months, also supporting the stability of the observed clinical improvement. Vortioxetine monotherapy has already been tested for the treatment of anxiety–depressive symptoms in youth, as well as ADHD in adulthood. The cases presented here suggest that vortioxetine could also be an effective option for ADHD treatment in childhood and adolescence, warranting further investigation of its potential benefits as both a monotherapy and adjunctive therapy to stimulants.

5-HT Receptors and the Development of New Antidepressants

Serotonin modulates several physiological and cognitive pathways throughout the human body that affect emotions, memory, sleep, and thermal regulation. The complex nature of the serotonergic system and interactions with other neurochemical systems indicate that the development of depression may be mediated by various pathomechanisms, the common denominator of which is undoubtedly the disturbed transmission in central 5-HT synapses. Therefore, the deliberate pharmacological modulation of serotonergic transmission in the brain seems to be one of the most appropriate strategies for the search for new antidepressants. As discussed in this review, the serotonergic system offers great potential for the development of new antidepressant therapies based on the combination of SERT inhibition with different pharmacological activity towards the 5-HT system. The aim of this article is to summarize the search for new antidepressants in recent years, focusing primarily on the possibility of benefiting from interactions with various 5-HT receptors in the pharmacotherapy of depression.

5-HT1A Serotonergic, α-Adrenergic and Opioidergic Receptors Mediate the Analgesic Efficacy of Vortioxetine in Mice

Vortioxetine is a multimodal antidepressant drug that affects several brain neurochemicals and has the potential to induce various pharmacological effects on the central nervous system. Therefore, we investigated the centrally mediated analgesic efficacy of this drug and the mechanisms underlying this effect. Analgesic activity of vortioxetine (5, 10 and 20 mg/kg, p.o.) was examined by tail-clip, tail-immersion and hot-plate tests. Motor performance of animals was evaluated using Rota-rod device. Time course measurements (30-180 min) showed that vortioxetine (10 and 20 mg/kg) administrations significantly increased the response latency, percent maximum possible effect and area under the curve values in all of the nociceptive tests. These data pointed out the analgesic effect of vortioxetine on central pathways carrying acute thermal and mechanical nociceptive stimuli. Vortioxetine did not alter the motor coordination of mice indicating that the analgesic activity of this drug was specific. In mechanistic studies, pre-treatments with p-chlorophenylalanine (serotonin-synthesis inhibitor), NAN-190 (serotonin 5-HT_1A receptor antagonist), α-methyl-para-tyrosine (catecholamine-synthesis inhibitor), phentolamine (non-selective α-adrenoceptor blocker), and naloxone (non-selective opioid receptor blocker) antagonised the vortioxetine-induced analgesia. Obtained findings indicated that vortioxetine-induced analgesia is mediated by 5-HT_1A serotonergic, α-adrenergic and opioidergic receptors, and contributions of central serotonergic and catecholaminergic neurotransmissions are critical for this effect.

Therapy response prediction in major depressive disorder: current and novel genomic markers influencing pharmacokinetics and pharmacodynamics

Major depressive disorder is connected with high rates of functional disability and mortality. About a third of the patients are at risk of therapy failure. Several pharmacogenetic markers especially located in CYP450 genes such as CYP2D6 or CYP2C19 are of relevance for therapy outcome prediction in major depressive disorder but a further optimization of predictive tools is warranted. The article summarizes the current knowledge on pharmacogenetic variants, therapy effects and side effects of important antidepressive therapeutics, and sheds light on new methodological approaches for therapy response estimation based on genetic markers with relevance for pharmacokinetics, pharmacodynamics and disease pathology identified in genome-wide association study analyses, highlighting polygenic risk score analysis as a tool for further optimization of individualized therapy outcome prediction.

Vortioxetine ameliorates anhedonic-like behaviour and promotes strategic cognitive performance in a rodent touchscreen task

Depression-associated cognitive impairments are among the most prevalent and persistent symptoms during remission from a depressive episode and a major risk factor for relapse. Consequently, development of antidepressant drugs, which also alleviate cognitive impairments, is vital. One such potential antidepressant is vortioxetine that has been postulated to exhibit both antidepressant and pro-cognitive effects. Hence, we tested vortioxetine for combined antidepressant and pro-cognitive effects in male Long-Evans rats exposed to the chronic mild stress (CMS) paradigm. This well-established CMS paradigm evokes cognitive deficits in addition to anhedonia, a core symptom of depression. Learning and memory performance was assessed in the translational touchscreen version of the paired-associates learning task. To identify the mechanistic underpinning of the neurobehavioural results, transcriptional profiling of genes involved in the stress response, neuronal plasticity and genes of broad relevance in neuropsychiatric pathologies were assessed. Vortioxetine substantially relieved the anhedonic-like state in the CMS rats and promoted acquisition of the cognitive test independent of hedonic phenotype, potentially due to an altered cognitive strategy. Minor alterations in gene expression profiling in prefrontal cortex and hippocampus were found. In summary, our findings suggest that vortioxetine exhibits an antidepressant effect as well as behavioural changes in a translational learning task.

Multiple facets of serotonergic modulation

The serotonergic system of the central nervous system (CNS) has been implicated in a broad range of physiological functions and behaviors, such as cognition, mood, social interaction, sexual behavior, feeding behavior, sleep-wake cycle and thermoregulation. Serotonin (5-hydroxytryptamine, 5-HT) establishes a plethora of interactions with neurochemical systems in the CNS via its numerous 5-HT receptors and autoreceptors. The facets of this control are multiple if we consider the molecular actors playing a role in the autoregulation of 5-HT neuron activity including the 5-HT_1A, 5-HT_1B, 5-HT_1D, 5-HT_2B, 5-HT₇ receptors as well as the serotonin transporter. Moreover, extrinsic loops involving other neurotransmitters giving the other 5-HT receptors the possibility to impact 5-HT neuron activity. Grasping the complexity of these interactions is essential for the development of a variety of therapeutic strategies for cognitive defects and mood disorders. Presently we can illustrate the plurality of the mechanisms and only conceive that these 5-HT controls are likely not uniform in terms of regional and neuronal distribution. Our understanding of the specific expression patterns of these receptors on specific circuits and neuronal populations are progressing and will expand our comprehension of the function and interaction of these receptors with other chemical systems. Thus, the development of new approaches profiling the expression of 5-HT receptors and autoreceptors should reveal additional facets of the 5-HT controls of neurochemical systems in the CNS.

Serotonin/dopamine interaction: Electrophysiological and neurochemical evidence

The interaction between serotonin (5-HT) and dopamine (DA) in the central nervous system (CNS) plays an important role in the adaptive properties of living animals to their environment. These are two modulatory, divergent systems shaping and regulating in a widespread manner the activity of neurobiological networks and their interaction. The concept of one interaction linking these two systems is rather elusive when looking at the mechanisms triggered by these two systems across the CNS. The great variety of their interacting mechanisms is in part due to the diversity of their neuronal origin, the density of their fibers in a given CNS region, the distinct expression of their numerous receptors in the CNS, the heterogeneity of their intracellular signaling pathway that depend on the cellular type expressing their receptors, and the state of activity of neurobiological networks, conditioning the outcome of their mutual influences. Thus, originally conceptualized as inhibition of 5-HT on DA neuron activity and DA neurotransmission, this interaction is nowadays considered as a multifaceted, mutual influence of these two systems in the regulation of CNS functions. These new ways of understanding this interaction are of utmost importance to envision the consequences of their dysfunctions underlined in several CNS diseases. It is also essential to conceive the mechanism of action of psychotropic drugs directly acting on their function including antipsychotic, antidepressant, antiparkinsonian, and drug of abuse together with the development of therapeutic strategies of Alzheimer's diseases, epilepsy, obsessional compulsive disorders. The 5-HT/DA interaction has a long history from the serendipitous discovery of antidepressants and antipsychotics to the future, rationalized treatments of CNS disorders.

Effects of Subchronic Administrations of Vortioxetine, Lurasidone, and Escitalopram on Thalamocortical Glutamatergic Transmission Associated with Serotonin 5-HT7 Receptor

The functional suppression of serotonin (5-HT) type 7 receptor (5-HT7R) is forming a basis for scientific discussion in psychopharmacology due to its rapid-acting antidepressant-like action. A novel mood-stabilizing atypical antipsychotic agent, lurasidone, exhibits a unique receptor-binding profile, including a high affinity for 5-HT7R antagonism. A member of a novel class of antidepressants, vortioxetine, which is a serotonin partial agonist reuptake inhibitor (SPARI), also exhibits a higher affinity for serotonin transporter, serotonin receptors type 1A (5-HT1AR) and type 3 (5-HT3R), and 5-HT7R. However, the effects of chronic administration of lurasidone, vortioxetine, and the selective serotonin reuptake inhibitor (SSRI), escitalopram, on 5-HT7R function remained to be clarified. Thus, to explore the mechanisms underlying the clinical effects of vortioxetine, escitalopram, and lurasidone, the present study determined the effects of these agents on thalamocortical glutamatergic transmission, which contributes to emotional/mood perception, using multiprobe microdialysis and 5-HT7R expression using capillary immunoblotting. Acute local administration of a 5-HT7R agonist and antagonist into the mediodorsal thalamic nucleus (MDTN) enhanced and reduced thalamocortical glutamatergic transmission, induced by N-methyl-D-aspartate (NMDA)/glutamate receptor inhibition in the reticular thalamic nucleus (RTN). Acute local administration of a relevant therapeutic concentration of vortioxetine and lurasidone into the MDTN suppressed the thalamocortical glutamatergic transmission via 5-HT7R inhibition, whereas that of escitalopram activated 5-HT7R. Subchronic administration of effective doses of vortioxetine and lurasidone (for 7 days) reduced the thalamocortical glutamatergic transmission, but escitalopram did not affect it, whereas subchronic administration of these three agents attenuated the stimulatory effects of the 5-HT7R agonist on thalamocortical glutamatergic transmission. Subchronic administration of effective doses of vortioxetine, lurasidone, and escitalopram downregulated the 5-HT7R expression of the plasma membrane in the MDTN; the 5-HT7R downregulation induced by vortioxetine and lurasidone was observed at 3 days, but that induced by escitalopram required a longer duration of 7 days. These results indicate that chronic administration of vortioxetine, escitalopram, and lurasidone generate downregulation of 5-HT7R in the thalamus; however, the direct inhibition of 5-HT7R associated with vortioxetine and lurasidone generates more rapid downregulation than the indirect elevation of the extracellular serotonin level via serotonin transporter inhibition by escitalopram.

Role of central serotonin and noradrenaline interactions in the antidepressants' action: Electrophysiological and neurochemical evidence

The development of antidepressant drugs, in the last 6 decades, has been associated with theories based on a deficiency of serotonin (5-HT) and/or noradrenaline (NA) systems. Although the pathophysiology of major depression (MD) is not fully understood, numerous investigations have suggested that treatments with various classes of antidepressant drugs may lead to an enhanced 5-HT and/or adapted NA neurotransmissions. In this review, particular morpho-physiological aspects of these systems are first considered. Second, principal features of central 5-HT/NA interactions are examined. In this regard, the effects of the acute and sustained antidepressant administrations on these systems are discussed. Finally, future directions including novel therapeutic strategies are proposed.

Efficacy of Vortioxetine on Anhedonia: Results from a Pooled Analysis of Short-Term Studies in Patients with Major Depressive Disorder

PURPOSE

Anhedonia is a core symptom of major depressive disorder (MDD), which has important functional consequences for the patient. This post hoc analysis investigated the relationship between anhedonia and functioning in patients with MDD treated with vortioxetine.

PATIENTS AND METHODS

We conducted a pooled analysis of all 11 short-term, double-blind, randomized, placebo-controlled studies of vortioxetine (fixed dose, 5-20 mg/day) in patients with MDD which included Montgomery-Åsberg Depression Rating Scale (MADRS) and Sheehan Disability Scale (SDS) assessments. A short-term, randomized, active-controlled trial of flexible-dose treatment with vortioxetine (10-20 mg/day) versus agomelatine (25-50 mg/day) was also analyzed. Mean changes from baseline to study endpoint in MADRS total, MADRS anhedonia subscale, SDS total, and SDS social-functioning scores were analyzed by a mixed model for repeated measures. The relationship between treatment effects on anhedonia and functioning was investigated using path analysis.

RESULTS

A total of 4988 patients with MDD were included in the placebo-controlled studies and 495 in the active-comparator study. Significant dose-dependent improvements in overall depressive symptoms, anhedonia, and measures of functioning were seen in vortioxetine-treated patients compared with those who received placebo or agomelatine. Results of the path analysis for the placebo-controlled studies suggested that the effect on functioning was mostly driven by the effect of treatment on MADRS anhedonia factors.

CONCLUSION

Vortioxetine showed significant short-term efficacy against anhedonia in this large population of patients with MDD. In the placebo-controlled studies, improvements in functioning associated with vortioxetine appeared to be mostly driven by the effect of treatment on MADRS anhedonia factors.

Vortioxetine as a new frontier in the treatment of chronic neuropathic pain: a review and update

Chronic neuropathic pain (CNP) is a disabling medical condition that impairs the health-related quality-of-life of affected patients. A high prevalence of anxiety, depression, sleep disturbance and cognitive impairment has frequently been reported in association with CNP, making the management of this disease complex and often multidisciplinary. Dual-acting agents such as selective serotonin and noradrenalin reuptake inhibitors (SNRIs) are considered particularly useful in the modulation of pain and in treatment of the mood disorders frequently associated with CNP. Recent evidence suggests that the top-down inhibitory control of pain involves the engagement and enhancement of descending endogenous opioidergic, cannabinoid and serotonergic systems, with the effect of serotonin being particularly related to the receptor subtypes that are preferentially activated; indeed serotonin induces analgesia via activation of 5-HT7 receptors and hyperalgesia via activation of 5-HT3 receptors. Vortioxetine (VO) is a novel multimodal serotonergic antidepressant with a unique mechanism of action. It has been demonstrated recently in experimental and clinical studies to have efficacy on pain hypersensitivity and on mood disorders. This drug inhibits the serotonin transporter with a high affinity, antagonises the 5-HT3, 5-HT1D and 5HT7 serotonin receptors, and activates the 5-HT1A and 5-HT1B receptors. In clinical studies, VO has proved effective at a dose of 10-20 mg/daily in short- and long-term treatment of patients with chronic orofacial pain, demonstrating a higher rate of clinical response and remission, a better acceptability, safety rate and tolerability, and a lower latency of action compared with other antidepressants. In the light of these recent findings, VO may be considered as a new pharmacological treatment also in relation to various types of CNP, particularly in elderly patients with concomitant mood disorders and cognitive impairment. The purpose of this review is to provide an up-to-date overview of the pharmacology and clinical applications of VO and to highlight its potential therapeutic properties and advantages in the management of CNP.

International Union of Basic and Clinical Pharmacology. CX. Classification of Receptors for 5-hydroxytryptamine; Pharmacology and Function

5-HT receptors expressed throughout the human body are targets for established therapeutics and various drugs in development. Their diversity of structure and function reflects the important role 5-HT receptors play in physiologic and pathophysiological processes. The present review offers a framework for the official receptor nomenclature and a detailed understanding of each of the 14 5-HT receptor subtypes, their roles in the systems of the body, and, where appropriate, the (potential) utility of therapeutics targeting these receptors. SIGNIFICANCE STATEMENT: This review provides a comprehensive account of the classification and function of 5-hydroxytryptamine receptors, including how they are targeted for therapeutic benefit.

Vortioxetine versus other antidepressants in the treatment of burning mouth syndrome: An open-label randomized trial

OBJECTIVES

This randomized open-label trial compared the efficacy and tolerability of vortioxetine (15 mg/daily) with different antidepressants in the treatment of patients with burning mouth syndrome (BMS).

METHODS

One and hundred fifty BMS patients were randomized into five groups and treated with either vortioxetine, paroxetine (20 mg/daily), sertraline (50 mg/daily), escitalopram (10 mg/daily) or duloxetine (60 mg/daily). The Visual Analogue Scale (VAS), Total Pain Rating Index (T-PRI), Hamilton Rating Scales for Depression (HAM-D) and Anxiety (HAM-A), and Clinical Global Impression Improvement (CGI-I) and Efficacy scales (CGI-E) were performed at baseline and after 2, 4, 6, and 12 months of treatment. Any adverse events (AEs) were tabulated for each group. Descriptive statistics, including the Kruskal-Wallis non-parametric test and the Friedman non-parametric test for median comparisons between different times, were used.

RESULTS

All the antidepressants (AD) were associated with a significant decrease in the VAS, T-PRI, HAM-A, HAM-D, CGI-I, and CGI-E scores in the long-term (p < .001). However, the response rate of the vortioxetine group showed a significant reduction after six months. The medians, after 6 months, were as follows: VAS 0.0; T-PRI 2.0; HAM-A 7.0; HAM-D 7.0; CGI-I 1.0; and CGI-E 1.0 with a lower incidence of AEs (p < .019).

CONCLUSION

Vortioxetine was efficacious with a shorter latency of action and fewer AEs compared with other ADs.

Analysis of Density Changes of Selected Brain Receptors After a 14-Day Supply of Chromium(III) and Evaluation of Chromium(III) Affinity to Selected Receptors and Transporters

Chromium(III) is one of the most controversial biometals. Although, it is no longer on the list of minerals necessary for the proper functioning of the human body, and its pharmacological effect is still under discussion. One of the purposes of Cr(III) administration is to use it in patients with mood disorders and it is strictly related to its pharmacological, not dietary effect. This is because its high doses are necessary to obtain the results and additionally, no deficiencies in human population have been noted. In this study, the affinity of chromium(III) to selected receptors and transporters in the rat brain was evaluated, and the effect of the 14-day administration of this metal was assessed on the density of selected receptors. All analyses were performed in vitro using radioligand binding assays, and the results indicated lack of affinity to β₁ and α₁ receptors and serotonin transporter (SERT), furthermore very weak affinity to the 5-HT_1A receptor (30% inhibition at 10^-4 and 10^-5 M). Analysis of the α₁ and β₁ adrenergic receptor density indicated lack of any adaptive effects after 14 days of Cr(III) administration through intraperitoneal injections (doses 6 and 12 mg/kg). The antidepressant activity of chromium(III) indicated in clinical trials concerned patients with atypical, seasonal, or dystonic symptoms. This effect, as it seems based on the presented results, does not depend on direct affinity to serotonin receptors and transporter nor is the result of adaptive changes in the adrenoreceptor system.

Central 5-HT receptors and their function; present and future

Since our review of central 5-HT receptors and their function twenty years ago, no new 5-HT receptor has been discovered and there is little evidence that this situation will change in the near future. Nevertheless, over this time significant progress has been made in our understanding of the properties of these receptors and in the clinical translation of this information, and some of these developments are highlighted herein. Such highlights include extensive mapping of 5-HT receptors in both animal and human brain, culminating in readily-accessible brain atlases of 5-HT receptor distribution, as well as emerging data on how 5-HT receptors are distributed within complex neural circuits. Also, a range of important pharmacological and genetic tools have been developed that allow selective 5-HT receptor manipulation, in cells through to whole organism models. Moreover, unexpected complexity in 5-HT receptor function has been identified including agonist-dependent signalling that goes beyond the pharmacology of canonical 5-HT receptor signalling pathways set down in the 1980s and 1990s. This new knowledge of 5-HT signalling has been extended by the discovery of combined signalling of 5-HT and co-released neurotransmitters, especially glutamate. Another important advance has been the progression of a large number of 5-HT ligands through to experimental medicine studies and clinical trials, and some such agents have already become prescribed therapeutic drugs. Much more needs to be discovered and understood by 5-HT neuropharmacologists, not least how the diverse signalling effects of so many 5-HT receptor types interact with complex neural circuits to generate neurophysiological changes which ultimately lead to altered cognitions and behaviour. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.

Vortioxetine Subchronically Activates Serotonergic Transmission via Desensitization of Serotonin 5-HT1A Receptor with 5-HT3 Receptor Inhibition in Rats

Vortioxetine is a novel, multimodal antidepressant with unique targets, including the inhibition of the serotonin transporter (SET), of serotonin 5-HT₃ (5-HT3R), and of 5-HT₇ (5-HT7R) receptors and partial agonism to serotonin 5-HT_1A (5-HT1AR) receptors in humans. Vortioxetine has a lower affinity to 5-HT1AR and 5-HT7R in rats compared with humans, but several behavior studies have demonstrated its powerful antidepressant-like actions. In spite of these efforts, detailed effects of the subchronic administration of vortioxetine on serotonergic transmission remain to be clarified. This study examined the mechanisms underlying the clinical effects of vortioxetine by measuring the releases of 5-HT and GABA in the medial prefrontal cortex (mPFC) of freely moving rats compared with the selective SET inhibitor, escitalopram. Inhibition of 5-HT3R in the mPFC enhanced regional 5-HT release via GABAergic disinhibition. Activation of somatodendritic 5-HT1AR in the dorsal raphe nucleus (DRN) and presynaptic 5-HT1AR in the mPFC inhibited 5-HT release in the mPFC. Escitalopram subchronically activated mesocortical serotonergic transmission via desensitization of 5-HT1AR in the mPFC and DRN and of 5-HT3R in the mPFC; however, vortioxetine also subchronically activated mesocortical serotonergic transmission via desensitization of 5-HT1AR in the mPFC and DRN but not of 5-HT3R in the mPFC. These demonstrations, the desensitization of 5-HT1AR with the inhibition of 5-HT3R (without 5-HT3R desensitization), at least partially, contribute to the multimodal antidepressant action of vortioxetine in rats.

New Somatic Treatments for Child and Adolescent Depression

PURPOSE OF REVIEW

Depression is a common clinical problem in youth, with prevalence increasing significantly during the adolescent period. Although several evidence-based treatments are currently available for treating depression in adults, only a subset of these have been investigated in a pediatric sample. Unfortunately, even well-established, first-line interventions do not lead to sufficient treatment response for many children and adolescents suffering from depression. However, recent research has been conducted in the area of somatic treatments for youth with depression. This review focuses on current (past three years, including published results and ongoing studies) research on somatic treatments for adolescent depression in the following categories: psychopharmacology, nutraceuticals, interventions implicating motor and sensory systems, and neuromodulation.

FINDINGS

Results from recent randomized, controlled trials testing psychopharmacological options suggest that while antidepressants that have been recently approved for adult patients are safe and tolerable in children and adolescents, none have yet outperformed performed placebo in efficacy. Nutraceuticals, motor-sensory interventions, and neuromodulation techniques, present safe and promising results, but few have been tested against controls to support effectiveness over current treatment options.

SUMMARY

This review of research on pediatric depression treatment from the past 3 years highlights some disappointments (negative results following some of the well-designed clinical trials) and gaps (preliminary studies in need of follow up with robust methodology) but also some promising directions in research of the efficacyof these treatments in a pediatric sample. We offer suggestions for future research including consideration of treatment timing, sequencing, the role of symptom severity in directing treatment selection, the potential value of combined treatments, consideration of how to best account for high placebo response rates, and the incorporation of neurobiological assessments to examine mechanisms and biomarker predictors of treatment response.

Vortioxetine versus sertraline in metabolic control, distress and depression in Mexican patients with type 2 diabetes

Background

Depression in patients with type 2 diabetes (T2D) is often undiagnosed and remains untreated, leading to poor therapy adherence and ill health-related outcomes. We evaluated the effect of vortioxetine versus sertraline in the treatment of depression, distress and metabolic control in subjects with T2D and depression.

Methods

Participants were selected from the Clinic for Diabetes, diagnosed with depression when the score was ≥14 in the Hamilton Depression Rating Scale, and verified by a psychiatrist in agreement with the DSM-5 instrument (Diagnostic and Statistical Manual of Mental Disorders, fifth edition). The criteria for recruitment also included glycosylated hemoglobin ≥7.5%, 18 to 60 years of age, and written informed consent. Pharmacological treatment for depression was assigned randomly: vortioxetine (10 mg/day) or sertraline (75 mg/day) for 8 weeks. Biochemical parameters, anthropometric measures and depression symptoms were evaluated after antidepressant treatment. This was a randomized singled-blind study.

Results

Subjects that met the inclusion criteria were 50, of which only 21 patients with T2D and depression finished the treatment. Vortioxetine and sertraline showed partial remission of depression. Vortioxetine showed a major effect size in glycosylated hemoglobin and a moderate effect size on weight loss, fasting plasma glucose (FPG), cholesterol and triacylglycerol levels. On the other hand, patients treated with sertraline presented a slight increase in body weight, body mass index (BMI), and in all biochemical markers.

Conclusions

Vortioxetine may ameliorate depressive symptoms and metabolic control in patients with T2D and depression. Trial registration number: NCT03978286.

Vortioxetine Reduces Marble Burying but Only Transiently Enhances Social Interaction Preference in Adult Male BTBR T+Itpr3tf/J Mice

Vortioxetine is a multimodal antidepressant with agonist activity at serotonin (5-HT)_1A and 5-HT_1B receptors that blocks the 5-HT transporter (SERT). Previously in male BTBR T⁺Itpr3^tf/J (BTBR) mice, the 5-HT_1A partial agonist buspirone and SERT blocker fluoxetine enhanced social interaction but did not reduce marble burying. We hypothesized that vortioxetine through its actions at SERT and 5-HT_1A could improve BTBR sociability and via 5-HT_1B could reduce burying better than sertraline, a selective SERT blocker. Vortioxetine (5-10 mg/kg) or sertraline (2 mg/kg) was administered 30 min presociability and 75 min prior to marble burying tests. Vortioxetine (10 mg/kg) occupancy (%) was 84 ± 1 for SERT, 31 ± 12 for 5-HT_1A, and 80 ± 5 for 5-HT_1B in brain at 110 min postinjection, and serum oxytocin was 24% lower (p < 0.01) in vortioxetine-treated mice. Vortioxetine reduced novel object investigation, whereas sertraline enhanced overall sociability. However, the vortioxetine-induced increase in social sniffing was transient, as it was lost with 60-120 min presociability test delays in subsequent experiments. Vortioxetine and sertraline both reduced BTBR marble burying. Based on vortioxetine occupancy, actions at SERT and/or 5-HT_1B are more likely to underlie its behavioral effects than 5-HT_1A. Overall, vortioxetine has great potential for suppressing restrictive-repetitive behaviors, but it appears less promising as a sociability enhancer.

Effect of clinically relevant doses of vortioxetine and citalopram on serotonergic PET markers in the nonhuman primate brain

Vortioxetine is a multimodal antidepressant approved for treatment of major depressive disorder. Preclinical studies have demonstrated that the mechanism of action of vortioxetine might be different from selective serotonin reuptake inhibitors (SSRIs), including larger serotonin (5-HT) release and direct modulation of several 5-HT receptors. In the current positron emission tomography (PET) study, we evaluated the mechanism of action of vortioxetine by comparing its effect to the SSRI citalopram on the binding of [¹¹C]AZ10419369 to the 5-HT_1B receptor in the nonhuman primate brain. Initially, the 5-HT transporter (5-HTT) binding of vortioxetine was determined by [¹¹C]MADAM PET measurements before and after administration of vortioxetine (0.1-3.0 mg/kg) and data were used to confirm clinically relevant dosing in subsequent PET measurements with [¹¹C]AZ10419369. The 5-HT_1B receptor binding was significantly decreased after 0.3 mg/kg of citalopram in the dorsal raphe nucleus (5%), as well as after 0.3 mg/kg of vortioxetine in six brain regions (~25%) or 1.0 mg/kg of vortioxetine in all 12 examined regions (~48%). Moreover, there was no effect of 1.0 mg/kg of vortioxetine on the binding of [¹¹C]Cimbi-36 to the 5-HT_2A receptor, which has comparable sensitivity to 5-HT release as [¹¹C]AZ10419369 binding. In conclusion, at clinically relevant doses, vortioxetine induced larger reductions in [¹¹C]AZ10419369 binding than citalopram. These observations suggest that vortioxetine binds to the 5-HT_1B receptor at clinically relevant doses. Future studies are warranted to evaluate the role of the 5-HT_1B receptor in the therapeutic effects of vortioxetine and as a potential target for the development of novel antidepressant drugs.

Fluoxetine and Vortioxetine Reverse Depressive-Like Phenotype and Memory Deficits Induced by Aβ1-42 Oligomers in Mice: A Key Role of Transforming Growth Factor-β1

Depression is a risk factor for the development of Alzheimer’s disease (AD), and the presence of depressive symptoms significantly increases the conversion of mild cognitive impairment (MCI) into AD. A long-term treatment with antidepressants reduces the risk to develop AD, and different second-generation antidepressants such as selective serotonin reuptake inhibitors (SSRIs) are currently being studied for their neuroprotective properties in AD. In the present work, the SSRI fluoxetine and the new multimodal antidepressant vortioxetine were tested for their ability to prevent memory deficits and depressive-like phenotype induced by intracerebroventricular injection of amyloid-β (1-42) (Aβ_1-42) oligomers in 2-month-old C57BL/6 mice. Starting from 7 days before Aβ injection, fluoxetine (10 mg/kg) and vortioxetine (5 and 10 mg/kg) were intraperitoneally injected daily for 24 days. Chronic treatment with fluoxetine and vortioxetine (both at the dose of 10 mg/kg) was able to rescue the loss of memory assessed 14 days after Aβ injection by the passive avoidance task and the object recognition test. Both antidepressants reversed the increase in immobility time detected 19 days after Aβ injection by forced swim test. Vortioxetine exerted significant antidepressant effects also at the dose of 5 mg/kg. A significant deficit of transforming growth factor-β1 (TGF-β1), paralleling memory deficits and depressive-like phenotype, was found in the hippocampus of Aβ-injected mice in combination with a significant reduction of the synaptic proteins synaptophysin and PSD-95. Fluoxetine and vortioxetine completely rescued hippocampal TGF-β1 levels in Aβ-injected mice as well as synaptophysin and PSD-95 levels. This is the first evidence that a chronic treatment with fluoxetine or vortioxetine can prevent both cognitive deficits and depressive-like phenotype in a non-transgenic animal model of AD with a key contribution of TGF-β1.