Mechanisms of action of antidepressants: from neurotransmitter systems to signaling pathways

Optimally combining transcranial magnetic stimulation with antidepressants in major depressive disorder: A systematic review and Meta-analysis

There is a critical knowledge gap in optimally combining transcranial magnetic stimulation (TMS) and antidepressants to treat patients with major depressive disorder (MDD). TMS is effective in treating MDD in patients who have failed at least one antidepressant trial, with accelerated protocols showing faster remission in treatment-resistant depression (TRD). Although clinicians routinely augment antidepressants with TMS, there is a knowledge gap in stopping versus continuing antidepressants or the dosing strategies when starting or tapering TMS. These considerations are important when considering maintenance TMS (delivered alone or in combination with suitable antidepressants) to maintain remission in MDD after the index course of TMS. As the first step towards filling this knowledge gap, we reviewed randomized controlled trials (RCTs) and open-label trials from 2 databases (PubMed/Medline and EMBASE) that compared active TMS combined with a pre-specified antidepressant dosed in the same manner for adults with MDD versus sham TMS combined with the same antidepressant as in the active arm. All studies were published between January 1, 2000, and December 31, 2023. We excluded case reports, case series, and clinical studies that augmented TMS with antidepressants and vice versa. We found 10 RCTs (n = 654 participants) and performed a meta-analysis. This showed active TMS combined with pre-specified antidepressants had greater efficacy for MDD treatment than sham TMS combined with the same antidepressants as in the active arm (Hedge's g = 1; 95 % CI [0.27, 1.73]). The review and meta-analysis indicate greater short-term efficacy in combining antidepressants with TMS from the get-go in MDD. Given the increasing role of accelerated TMS protocols in expediting remission in MDD and the results of our meta-analysis, we advocate for RCTs examining the short-term and long-term effects of various antidepressant classes on these TMS protocols in MDD. This can also optimize and individualize maintenance TMS protocols to prevent relapse in MDD.

Lycium barbarum polysaccharides attenuate nonylphenol and octylphenol-induced oxidative stress and neurotransmitter disorders in PC-12 cells

Nonylphenol (NP) and octylphenol (OP) are environmental contaminants with potential endocrine disrupting effects. However, there is limited research on the mechanisms and intervention of combined NP and OP exposure-induced neurotoxicity. This study aims to explore the cytotoxicity of combined NP and OP exposure and evaluate the potential of Lycium barbarum polysaccharides (LBP) in mitigating the aforementioned toxicity. In present study, LBP (62.5, 125 and 250 µg/mL) were applied to intervene rat adrenal pheochromocytoma (PC-12) cells treated with combined NP and OP (NP: OP = 4:1, w/w; 1, 2, 4 and 8 µg/mL). The results showed that NP and OP induced oxidative stress, disrupted the 5-hydroxytryptamine (5-HT) and cholinergic systems in PC-12 cells. Additionally, they activated the p38 protein kinase (p38) and suppressed the expression of silent information regulation type 1 (SIRT1), monoamine oxidase A (MAOA), phosphorylated cyclic-AMP response binding protein (p-CREB), brain-derived neurotrophic factor (BDNF) and phosphorylated tropomyosin-related kinase receptor type B (p-TrkB). However, N-acetyl-L-cysteine (NAC) treatment counteracted the changes of signalling molecule p38, SIRT1/MAOA and CREB/BDNF/TrkB pathways-related proteins induced by NP and OP. LBP pretreatment ameliorated combined NP and OP exposure-induced oxidative stress and neurotransmitter imbalances. Furthermore, the application of LBP and administration of a p38 inhibitor both reversed the alterations in the signaling molecule p38, as well as the proteins associated to the SIRT1/MAOA and CREB/BDNF/TrkB pathways. These results implied that LBP may have neuroprotective effects via p38-mediated SIRT1/MAOA and CREB/BDNF/TrkB pathways.

Treating Depression in Dementia Patients: A Risk or Remedy-A Narrative Review

BACKGROUND

The diagnosis of depression in dementia patients leads to an increase in the burden of the disease. To treat depression in this patient group, antidepressants are frequently used; however, there is not any proof of their therapeutic effectiveness, and their use may be potentially harmful. This narrative review aims to summarize the existing evidence regarding the role of antidepressants in treating depression in dementia patients.

MAIN TEXT

A search was conducted in the PubMed, Excerpta Medica database (EMBASE), and Cochrane databases for randomized controlled trials and meta-analyses wherein antidepressants were given to dementia sufferers to address depression. Fifteen randomized controlled trials and seven meta-analyses were identified. Most well-designed blinded placebo-controlled trials reported a lack of effectiveness of antidepressants in treating depression in dementia patients. Among the seven metanalyses, two reported good efficacy of Selective serotonin reuptake inhibitors (SSRIs). However, two major Cochrane reviews reported little or no effectiveness and increased side effects of antidepressants in dementia patients.

CONCLUSION

There is robust evidence regarding the lack of efficacy of antidepressants in treating depression in dementia patients. However, further well-designed Randomized controlled trials (RCTs,) using scales with good validity and reliability to diagnose depression in dementia patients, sufficient sample sizes, and detailed adverse effect profiles may help determine the rationale for their use.

Multi-frequency electromagnetic radiation induces anxiety in mice via inflammation in the cerebral cortex

Modern life is filled with radiofrequency electromagnetic radiation (RF-EMR) in various frequency bands, while the health risks are not clear. In this study, mice were whole-body exposed to 0.9/1.5/2.65 GHz radiofrequency radiation at 4 W/kg for 2 h per day for 4 weeks to investigate the emotional effects. It was found that the mice showed anxiety but no severe depression. The ELISA results showed a significant decrease in amino acid neurotransmitters (GABA, DA, 5-HT), although acetylcholine (ACH) levels were not significantly altered. Furthermore, Western blot results showed that BDNF, TrkB, and CREB levels were increased in the cerebral cortex, while NF-κB levels were decreased. In addition, pro-inflammatory factors (IL-6, IL-1β, TNF-α) were significantly elevated, and anti-inflammatory factors (IL-4, IL-10) tended to decrease. In conclusion, multi-frequency electromagnetic radiation induces an inflammatory response through the CREB-BDNF-TrkB and NF-κB pathways in the cerebral cortex and causes a decrease in excitatory neurotransmitters, which ultimately causes anxiety in mice.

Preoperative Intrathecal Morphine is Associated With Reduced Postoperative Pain, Agitation, and Delirium In Living Donor Kidney Transplantation Recipients

BACKGROUND

Postoperative delirium after organ transplantation can lead to increased length of hospital stay and mortality. Because pain is an important risk factor for delirium, perioperative analgesia with intrathecal morphine (ITM) may mitigate postoperative delirium development. We evaluated if ITM reduces postoperative delirium incidence in living donor kidney transplant (LDKT) recipients.

METHODS

Two hundred ninety-six patients who received LDKT between 2014 and 2018 at our hospital were retrospectively analyzed. Recipients who received preoperative ITM (ITM group) were compared with those who did not (control group). The primary outcome was postoperative delirium based on the Confusion Assessment Method for Intensive Care Unit results during the first 4 postoperative days.

RESULTS

Delirium occurred in 2.6% (4/154) and 7.0% (10/142) of the ITM and control groups, respectively. Multivariable analysis showed age (odds ratio [OR]: 1.07, 95% CI: 1.01-1.14; P = .031), recent smoking (OR: 7.87, 95% CI: 1.43-43.31; P = .018), preoperative psychotropics (OR: 23.01, 95% CI: 3.22-164.66; P = .002) were risk factors, whereas ITM was a protective factor (OR: 0.23, 95% CI: 0.06-0.89; P = .033).

CONCLUSIONS

Preoperative ITM showed an independent association with reduced post-LDKT delirium. Further studies and the development of regional analgesia for delirium prevention may enhance the postoperative recovery of transplant recipients.

Major depressive disorder: hypothesis, mechanism, prevention and treatment

Worldwide, the incidence of major depressive disorder (MDD) is increasing annually, resulting in greater economic and social burdens. Moreover, the pathological mechanisms of MDD and the mechanisms underlying the effects of pharmacological treatments for MDD are complex and unclear, and additional diagnostic and therapeutic strategies for MDD still are needed. The currently widely accepted theories of MDD pathogenesis include the neurotransmitter and receptor hypothesis, hypothalamic-pituitary-adrenal (HPA) axis hypothesis, cytokine hypothesis, neuroplasticity hypothesis and systemic influence hypothesis, but these hypothesis cannot completely explain the pathological mechanism of MDD. Even it is still hard to adopt only one hypothesis to completely reveal the pathogenesis of MDD, thus in recent years, great progress has been made in elucidating the roles of multiple organ interactions in the pathogenesis MDD and identifying novel therapeutic approaches and multitarget modulatory strategies, further revealing the disease features of MDD. Furthermore, some newly discovered potential pharmacological targets and newly studied antidepressants have attracted widespread attention, some reagents have even been approved for clinical treatment and some novel therapeutic methods such as phototherapy and acupuncture have been discovered to have effective improvement for the depressive symptoms. In this work, we comprehensively summarize the latest research on the pathogenesis and diagnosis of MDD, preventive approaches and therapeutic medicines, as well as the related clinical trials.

Nitrogen-containing heterocyclic compounds: A ray of hope in depression?

Depression is not similar to daily mood fluctuations and temporary emotional responses to day-to-day activities. Depression is not a passing problem; it is an ongoing problem. It deals with different episodes consisting of several symptoms that last for at least 2 weeks. It can be seen for several weeks, months, or years. At its final stage, or can say, in its worst condition, it can lead to suicide. Antidepressants are used to inhibit the reuptake of the neurotransmitters by some selective receptors, which increase the concentration of specific neurotransmitters around the nerves in the brain. Drugs that are currently being used for the management of various types of depression include selective serotonin reuptake inhibitors, tricyclic antidepressants, atypical antidepressants, serotonin, noradrenaline reuptake inhibitors, etc. In this review, we have outlined different symptoms, causes, and recent advancements in nitrogen-containing heterocyclic drug candidates for the management of depression. This article highlights the various structural features along with the structure-activity relationship (SAR) of nitrogen-containing heterocyclics that play a key role in binding at target sites for potential antidepressant action. The in silico studies were carried out to determine the binding interactions of the target ligands with the receptor site to determine the potential role of substitution patterns at core pharmacophoric features. This article will help medicinal chemists, biochemists, and other interested researchers in identifying the potential pharmacophores as lead compounds for further development of new potent antidepressants.

Molecular mechanisms of cholinergic neurotransmission in visceral smooth muscles with a focus on receptor-operated TRPC4 channel and impairment of gastrointestinal motility by general anaesthetics and anxiolytics

Acetylcholine is the primary excitatory neurotransmitter in visceral smooth muscles, wherein it binds to and activates two muscarinic receptors subtypes, M2 and M3, thus causing smooth muscle excitation and contraction. The first part of this review focuses on the types of cells involved in cholinergic neurotransmission and on the molecular mechanisms underlying acetylcholine-induced membrane depolarisation, which is the central event of excitation-contraction coupling causing Ca2+ entry via L-type Ca2+ channels and smooth muscle contraction. Studies of the muscarinic cation current in intestinal myocytes (mICAT) revealed its main molecular counterpart, receptor-operated TRPC4 channel, which is activated in synergy by both M2 and M3 receptors. M3 receptors activation is of permissive nature, while activation of M2 receptors via Gi/o proteins that are coupled to them plays a direct role in TRPC4 opening. Our understanding of signalling pathways underlying mICAT generation has vastly expanded in recent years through studies of TRPC4 gating in native cells and its regulation in heterologous cells. Recent studies using muscarinic receptor knockout have established that at low agonist concentration activation of both M2 receptor and the M2/M3 receptor complex elicits smooth muscle contraction, while at high agonist concentration M3 receptor function becomes dominant. Based on this knowledge, in the second part of this review we discuss the cellular and molecular mechanisms underlying the numerous anticholinergic effects on neuroactive drugs, in particular general anaesthetics and anxiolytics, which can significantly impair gastrointestinal motility. This article is part of the Special Issue on "Ukrainian Neuroscience".

Global Neuropsychopharmacological Prescription Trends in Adults with Schizophrenia, Clinical Correlates and Implications for Practice: A Scoping Review

It is important to examine the psychotropic prescription practices in schizophrenia, as it can inform regarding changing treatment choices and related patient profiles. No recent reviews have evaluated the global neuropsychopharmacological prescription patterns in adults with schizophrenia. A systematic search of the literature published from 2002 to 2023 found 88 empirical papers pertinent to the utilization of psychotropic agents. Globally, there were wide inter-country and inter-regional variations in the prescription of psychotropic agents. Overall, over time there was an absolute increase in the prescription rate of second-generation antipsychotics (up to 50%), mood stabilizers (up to 15%), and antidepressants (up to 17%), with an observed absolute decrease in the rate of antipsychotic polypharmacy (up to 15%), use of high dose antipsychotic (up to 12% in Asia), clozapine (up to 9%) and antipsychotic long-acting injectables (up to 10%). Prescription patterns were mainly associated with specific socio-demographic (such as age), illness (such as illness duration), and treatment factors (such as adherence). Further work, including more evidence in adjunctive neuropsychopharmacological treatments, pharmaco-economic considerations, and examination of cohorts in prospective studies, can proffer insights into changing prescription trends relevant to different treatment settings and predictors of such trends for enhancement of clinical management in schizophrenia.

Photoactivatable Agonist-Antagonist Pair as a Tool for Precise Spatiotemporal Control of Serotonin Receptor 2C Signaling

Orthogonal recreation of the signaling profile of a chemical synapse is a current challenge in neuroscience. This is due in part to the kinetics of synaptic signaling, where neurotransmitters are rapidly released and quickly cleared by active reuptake machinery. One strategy to produce a rapid rise in an orthogonally controlled signal is via photocaged compounds. In this work, photocaged compounds are employed to recreate both the rapid rise and equally rapid fall in activation at a chemical synapse. Specifically, a complementary pair of photocages based on BODIPY were conjugated to a 5-HT2C subtype-selective agonist, WAY-161503, and antagonist, N-desmethylclozapine, to generate "caged" versions of these drugs. These conjugates release the bioactive drug upon illumination with green light (agonist) or red light (antagonist). We report on the synthesis, characterization, and bioactivity testing of the conjugates against the 5-HT2C receptor. We then characterize the kinetics of photolysis quantitatively using HPLC and qualitatively in cell culture conditions stimulating live cells. The compounds are shown to be stable in the dark for 48 h at room temperature, yet photolyze rapidly when irradiated with visible light. In live cells expressing the 5-HT2C receptor, precise spatiotemporal control of the degree and length of calcium signaling is demonstrated. By loading both compounds in tandem and leveraging spectral multiplexing as a noninvasive method to control local small-molecule drug availability, we can reproducibly initiate and suppress intracellular calcium flux on a timescale not possible by traditional methods of drug dosing. These tools enable a greater spatiotemporal control of 5-HT2C modulation and will allow for more detailed studies of the receptors' signaling, interactions with other proteins, and native physiology.

Involvement of brain-derived neurotrophic factor signaling in the pathogenesis of stress-related brain diseases

Neurotrophins including brain-derived neurotrophic factor, BDNF, have critical roles in neuronal differentiation, cell survival, and synaptic function in the peripheral and central nervous system. It is well known that a variety of intracellular signaling stimulated by TrkB, a high-affinity receptor for BDNF, is involved in the physiological and pathological neuronal aspects via affecting cell viability, synaptic function, neurogenesis, and cognitive function. As expected, an alteration of the BDNF/TrkB system is suspected to be one of the molecular mechanisms underlying cognitive decline in cognitive diseases and mental disorders. Recent evidence has also highlighted a possible link between the alteration of TrkB signaling and chronic stress. Furthermore, it has been demonstrated that downregulation of the BDNF/TrkB system and chronic stress have a role in the pathogenesis of Alzheimer's disease (AD) and mental disorders. In this review, we introduce current evidence showing a close relationship between the BDNF/TrkB system and the development of cognition impairment in stress-related disorders, and the possible contribution of the upregulation of the BDNF/TrkB system in a therapeutic approach against these brain diseases.

Medication and Road Test Performance Among Cognitively Healthy Older Adults

Importance

Older adults are increasingly prescribed medications that have adverse effects. Prior studies have found a higher risk of motor vehicle crashes to be associated with certain medication use.

Objective

To determine whether specific medication classes were associated with performance decline as assessed by a standardized road test in a community sample of cognitively healthy older adults, to evaluate additional associations of poor road test performance with comorbid medical conditions and demographic characteristics, and to test the hypothesis that specific medication classes (ie, antidepressants, benzodiazepines, sedatives or hypnotics, anticholinergics, antihistamines, and nonsteroidal anti-inflammatory drugs or acetaminophen) would be associated with an increase in risk of impaired driving performance over time.

Design, Setting, and Participants

This was a prospective cohort study of 198 cognitively healthy adults 65 years and older with a valid driver's license who were followed up annually, with rolling enrollment. Data were collected from participants in St Louis, Missouri, and neighboring Illinois who were enrolled in the Knight Alzheimer's Disease Research Center. Data were collected from August 28, 2012, to March 14, 2023, and analyzed from April 1 to 25, 2023. Participants with healthy cognition, defined as a Clinical Dementia Rating score of 0 at baseline and subsequent visits, who had available clinical, neuropsychological, road tests, and self-reported medication data were included.

Exposure

Potentially driver-impairing medication use.

Main Outcomes and Measures

The primary outcome measure was performance on the Washington University Road Test (pass or marginal/fail). Multivariable Cox proportional hazards models were used to evaluate associations between potentially driver-impairing medication use and road test performance.

Results

Of the 198 included adults (mean [SD] baseline age, 72.6 [4.6] years; 87 female [43.9%]), 70 (35%) received a marginal/fail rating on the road test over a mean (SD) follow-up of 5.70 (2.45) years. Any use of antidepressants (adjusted hazard ratio [aHR], 2.68; 95% CI, 1.69-4.71), serotonin and norepinephrine reuptake inhibitors (aHR, 2.68; 95% CI, 1.54-4.64), sedatives or hypnotics (aHR, 2.70; 95% CI, 1.40-5.19), or nonsteroidal anti-inflammatory drugs (aHR, 2.72; 95% CI, 1.31-5.63) was associated with an increase in risk of receiving a marginal/fail rating on the road test compared with control individuals. Conversely, participants taking lipid-lowering agents had a lower risk of receiving a marginal/fail rating compared to control individuals. There were no statistically significant associations found between anticholinergic or antihistamines and poor performance.

Conclusions and Relevance

In this prospective cohort study, specific medication classes were associated with an increase in risk of poor road test performance over time. Clinicians should consider this information and counsel patients accordingly when prescribing these medications.

Antidepressants in pregnancy: applying causal epidemiological methods to understand service-use outcomes in women and long-term neurodevelopmental outcomes in exposed children

Background

Antidepressants are commonly prescribed during pregnancy, despite a lack of evidence from randomised trials on the benefits or risks. Some studies have reported associations of antidepressants during pregnancy with adverse offspring neurodevelopment, but whether or not such associations are causal is unclear.

Objectives

To study the associations of antidepressants for depression in pregnancy with outcomes using multiple methods to strengthen causal inference.

Design

This was an observational cohort design using multiple methods to strengthen causal inference, including multivariable regression, propensity score matching, instrumental variable analysis, negative control exposures, comparison across indications and exposure discordant pregnancies analysis.

Setting

This took place in UK general practice.

Participants

Participants were pregnant women with depression.

Interventions

The interventions were initiation of antidepressants in pregnancy compared with no initiation, and continuation of antidepressants in pregnancy compared with discontinuation.

Main outcome measures

The maternal outcome measures were the use of primary care and secondary mental health services during pregnancy, and during four 6-month follow-up periods up to 24 months after pregnancy, and antidepressant prescription status 24 months following pregnancy. The child outcome measures were diagnosis of autism, diagnosis of attention deficit hyperactivity disorder and intellectual disability.

Data sources

UK Clinical Practice Research Datalink.

Results

Data on 80,103 pregnancies were used to study maternal primary care outcomes and were linked to 34,274 children with at least 4-year follow-up for neurodevelopmental outcomes. Women who initiated or continued antidepressants during pregnancy were more likely to have contact with primary and secondary health-care services during and after pregnancy and more likely to be prescribed an antidepressant 2 years following the end of pregnancy than women who did not initiate or continue antidepressants during pregnancy (odds ratioinitiation 2.16, 95% confidence interval 1.95 to 2.39; odds ratiocontinuation 2.40, 95% confidence interval 2.27 to 2.53). There was little evidence for any substantial association with autism (odds ratiomultivariableregression 1.10, 95% confidence interval 0.90 to 1.35; odds ratiopropensityscore 1.06, 95% confidence interval 0.84 to 1.32), attention deficit hyperactivity disorder (odds ratiomultivariableregression 1.02, 95% confidence interval 0.80 to 1.29; odds ratiopropensityscore 0.97, 95% confidence interval 0.75 to 1.25) or intellectual disability (odds ratiomultivariableregression 0.81, 95% confidence interval 0.55 to 1.19; odds ratiopropensityscore 0.89, 95% confidence interval 0.61 to 1.31) in children of women who continued antidepressants compared with those who discontinued antidepressants. There was inconsistent evidence of an association between initiation of antidepressants in pregnancy and diagnosis of autism in offspring (odds ratiomultivariableregression 1.23, 95% confidence interval 0.85 to 1.78; odds ratiopropensityscore 1.64, 95% confidence interval 1.01 to 2.66) but not attention deficit hyperactivity disorder or intellectual disability; however, but results were imprecise owing to smaller numbers.

Limitations

Several causal-inference analyses lacked precision owing to limited numbers. In addition, adherence to the prescribed treatment was not measured.

Conclusions

Women prescribed antidepressants during pregnancy had greater service use during and after pregnancy than those not prescribed antidepressants. The evidence against any substantial association with autism, attention deficit hyperactivity disorder or intellectual disability in the children of women who continued compared with those who discontinued antidepressants in pregnancy is reassuring. Potential association of initiation of antidepressants during pregnancy with offspring autism needs further investigation.

Future work

Further research on larger samples could increase the robustness and precision of these findings. These methods applied could be a template for future pharmaco-epidemiological investigation of other pregnancy-related prescribing safety concerns.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (15/80/19) and will be published in full in Health Technology Assessment; Vol. 27, No. 15. See the NIHR Journals Library website for further project information.

Critical appraisal and systematic review of genes linked with cocaine addiction, depression and anxiety

Recent lifestyle changes have resulted in tremendous peer pressure and mental stress, and increased the incidences of chronic psychological disorders; like addiction, depression and anxiety (ADA). In this context, the stress-tolerance levels vary amongst individuals and genetic factors play prominent roles. Vulnerable individuals may often be drawn towards drug-addiction to combat stress. This systematic review critically appraises the relationship of various genetic factors linked with the incidences of ADA development. For coherence, we focused solely on cocaine as a substance of abuse in this study. Online scholarly databases were used to screen pertinent literature using apt keywords; and the final retrieval included 42 primary-research articles. The major conclusion drawn from this systematic analysis states that there are 51 genes linked with the development of ADA; and 3 (BDNF, PERIOD2 and SLC6A4) of them are common to all the three aspects of ADA. Further, inter-connectivity analyses of the 51 genes further endorsed the central presence of BDNF and SLC6A4 genes in the development of ADA disorders. The conclusions derived from this systematic study pave the way for future studies for the identification of diagnostic biomarkers and drug targets; and for the development of novel and effective therapeutic regimens against ADA.

Electromagnetic field exposure affects the calling song, phonotaxis, and level of biogenic amines in crickets

The electromagnetic field (EMF) is ubiquitous in the environment, constituting a well-known but poorly understood stressor. Few studies have been conducted on insect responses to EMF, although they are an excellent experimental model and are of great ecological importance. In our work, we tested the effects of EMF (50 Hz, 7 mT) on the cricket Gryllus bimaculatus: the male calling song pattern, female mate choice, and levels of biogenic amines in the brain. Exposure of males to EMF increased the number and shortened the period of chips in their calling song (by 2.7% and 5% relative to the control song, respectively), but not the sound frequency. Aged (3-week-old) females were attracted to both natural and EMF-modified male signals, whereas young (1-week-old, virgin) females responded only to the modified signal, suggesting its higher attractance. Stress response of males to EMF may be responsible for the change in the calling song, as suggested by the changes in the amine levels in their brains: an increase in dopamine (by 50% relative to the control value), tyramine (65%), and serotonin (25%) concentration and a decrease in octopamine level (by 25%). These findings indicate that G. bimaculatus responds to EMF, like stressful conditions, which may change the condition and fitness of exposed individuals, disrupt mate selection, and, in consequence, affect the species' existence.

Do antidepressants prevent transition to psychosis in individuals at clinical high-risk (CHR-P)? Systematic review and meta-analysis

BACKGROUND

Emerging meta-analytical evidence indicates that baseline exposure to antipsychotics in individuals at clinical high-risk for psychosis (CHR-P) is associated with a higher risk of an imminent transition to psychosis. Despite their tolerability profile and potential beneficial effects, baseline exposure to antidepressants (AD) in CHR-P has surprisingly received far less attention as a potential risk modulator for transition to psychosis. The current systematic review and meta-analysis were performed to fix such a knowledge gap.

METHODS

Systematic scrutiny of Medline and Cochrane library, performed up to 1 August 2021, searching for English-language studies on CHR-P reporting numeric data about the sample, the transition outcome at a predefined follow-up time and raw data on AD baseline exposure in relation to such outcome.

RESULTS

Of 1942 identified records, 16 studies were included in the systematic review and meta-analysis. 26% of the participants were already exposed to AD at baseline; at the end of the follow-up 13.5% (95% CI 10.2-17.1%) of them (n = 448) transitioned to psychosis against 21.0% (18.9 to 23.3%) of non-AD exposed CHR-P (n = 1371). CHR-P participants who were already under AD treatment at baseline had a lower risk of transition than non-AD exposed CHR-P. The RR was 0.71 (95% CI 0.56-0.90) in the fixed-effects model (z = -2.79; p = 0.005), and 0.78 (0.58-1.05) in the random-effects model (z = -1.77; p = 0.096; tau-squared = 0.059). There was no relevant heterogeneity (Cochran's Q = 18.45; df = 15; p = 0.239; I2 = 18.7%).

CONCLUSIONS

Ongoing AD exposure at inception in CHR-P is associated to a reduced risk of transition to psychosis at follow up.

Eight-week antidepressant treatment changes intrinsic functional brain topology in first-episode drug-naïve patients with major depressive disorder

BACKGROUND

A recent study revealed disrupted topological organization of whole-brain networks in patients with major depressive disorder (MDD); however, these results were mostly driven by recurrent MDD patients, rather than first-episode drug-naïve (FEDN) patients. Furthermore, few longitudinal studies have explored the effects of antidepressant therapy on the topological organization of whole-brain networks.

METHODS

We collected clinical and neuroimaging data from 159 FEDN MDD patients and 152 normal controls (NCs). A total of 115 MDD patients completed an eight-week antidepressant treatment procedure. Topological features of brain networks were calculated using graph theory-based methods and compared between FEDN MDD patients and NCs, as well as before and after treatment.

RESULTS

Decreased global efficiency, local efficiency, small-worldness, and modularity were found in pretreatment FEDN MDD patients compared with NCs. Nodal degrees, betweenness, and efficiency decreased in several networks compared with NCs. After antidepressant treatment, the global efficiency increased, while the local efficiency, the clustering coefficient of the network, the path length, and the normalized characteristic path length decreased. Moreover, the reduction rate of the normalized characteristic path length was positively correlated with the reduction rate of retardation factor scores.

LIMITATIONS

The interaction effects of groups and time on the topological features were not explored because of absence of the eighth-week data of NC group.

CONCLUSIONS

The topological architecture of functional brain networks is disrupted in FEDN MDD patients. After antidepressant therapy, the global efficiency shifted toward recovery, but the local efficiency deteriorated, suggesting a correlation between recovery of retardation symptoms and global efficiency.

Prenatal exposure to sertraline, associated or not with stress, can negatively program somatic and neurobehavioral development of female rats, and dysregulate reproductive function in adulthood

Selective serotonin reuptake inhibitors (SSRIs) are prescribed to pregnant women for treating mental illnesses. Among the drugs of this class, sertraline (ST) is the antidepressant therapy recommended most frequently. Therefore, this study aimed to evaluate the impact of gestational ST treatment on reproductive parameters and toxicological target organs of rat female offspring, as well as on somatic, reflex and neurobehavioral development, in a model of maternal adversity. Pregnant Wistar rats received vehicle (filtered water) or ST hydrochloride (20 mg/Kg/day diluted in vehicle) by oral gavage, associated or not with restraint stress for 1 h/day from gestational days 13-20. F1 female offspring was evaluated on reproductive parameters, body weight and somatic and reflex milestones from postnatal day (PND) 1. On PNDs 25 and 72, the elevated-plus-maze test was performed, while toxicological target organs were evaluated on PNDs 42 and 80. In utero exposure to ST, regardless of exposure to stress, reduced body weight at birth and affected the somatic development and estrous cycle. The absolute and relative thyroid weights were increased in Stress/ST group during puberty and adulthood, while the percentage of ovarian structures and the absolute uterine weight were altered in this group on PND 80. Prenatal exposure only to ST reduced initial body weight gain, delayed fur development and increased anxiety-like behavior on PND 25. Thus, this experimental study suggests that intrauterine exposure to ST disrupts the fetal environment and can negatively program serotonin-regulated processes. Furthermore, it impacts thyroid weight when associated with stress.

Role of the Intestinal Microbiota in the Genesis of Major Depression and the Response to Antidepressant Drug Therapy: A Narrative Review

A major depressive disorder is a serious mental illness characterized by a pervasive low mood that negatively concerns personal life, work life, or education, affecting millions of people worldwide. To date, due to the complexity of the disease, the most common and effective treatments consist of a multi-therapy approach, including psychological, social, and pharmacological support with antidepressant drugs. In general, antidepressants are effective in correcting chemical imbalances of neurotransmitters in the brain, but recent evidence has underlined the pivotal role of gut microbiota (GM) also in the regulation of their pharmacokinetics/pharmacodynamics, through indirect or direct mechanisms. The study of these complex interactions between GM and drugs is currently under the spotlight, and it has been recently named "pharmacomicrobiomics". Hence, the purpose of this review is to summarize the contribution of GM and its metabolites in depression, as well as their role in the metabolism and activity of antidepressant drugs, in order to pave the way for the personalized administration of antidepressant therapies.

Novel antidepressant drugs: Beyond monoamine targets

Treatment of major depressive disorder (MDD) including treatment-resistant depression (TRD) remains a major unmet need. Although there are several classes of dissimilar antidepressant drugs approved for MDD, the current drugs have either limited efficacy or are associated with undesirable side effects and withdrawal symptoms. The efficacy and side effects of antidepressant drugs are mainly attributed to their actions on different monoamine neurotransmitters (serotonin, norepinephrine, and dopamine). Development of new antidepressants with novel targets beyond the monoamine pathways may fill the unmet need in treatment of MDD and TRD. The recent approval of intranasal Esketamine (glutamatergic agent) in conjunction with an oral antidepressant for the treatment of adult TRD patients was the first step toward expanding beyond the monoamine targets. Several other glutamatergic (AXS-05, REL-1017, AV-101, SLS-002, AGN24175, and PCN-101) and GABAergic (brexanolone, zuranolone, and ganaxolone) drugs are currently in different stages of clinical development for MDD, TRD and other indications. The renaissance of psychedelic drugs and the emergence of preliminary positive clinical trial results with psilocybin, Ayahuasca, 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), and lysergic acid diethylamide (LSD) may pave the way towards establishing this class of drugs as effective therapies for MDD, TRD and other neuropsychiatric disorders. Going beyond the monoamine targets appears to be an effective strategy to develop novel antidepressant drugs with superior efficacy, safety, and tolerability for the improved treatment of MDD and TRD.

The gut-microbiota-brain axis in a Spanish population in the aftermath of the COVID-19 pandemic: microbiota composition linked to anxiety, trauma, and depression profiles

The prevalence of anxiety and depression soared following the COVID-19 pandemic. To effectively treat these conditions, a comprehensive understanding of all etiological factors is needed. This study investigated fecal microbial features associated with mental health outcomes (symptoms of anxiety, depression, or posttraumatic stress disorder (PTSD)) in a Spanish cohort in the aftermath of the COVID-19 pandemic. Microbial communities from stool samples were profiled in 198 individuals who completed validated, self-report questionnaires. 16S ribosomal RNA gene V3-4 amplicon sequencing was performed. Microbial diversity and community structure were analyzed, together with relative taxonomic abundance. In our cohort of N=198, 17.17% reported depressive symptoms, 37.37% state anxiety symptoms, 40.90% trait anxiety symptoms, and 8.08% PTSD symptoms, with high levels of comorbidity. Individuals with trait anxiety had lower Simpson's diversity. Fusicatenibacter saccharivorans was reduced in individuals with comorbid PTSD + depression + state and trait anxiety symptoms, whilst an expansion of Proteobacteria and depletion of Synergistetes phyla were noted in individuals with depressive symptoms. The relative abundance of Anaerostipes was positively correlated with childhood trauma, and higher levels of Turicibacter sanguinis and lower levels of Lentisphaerae were found in individuals who experienced life-threatening traumas. COVID-19 infection and vaccination influenced the overall microbial composition and were associated with distinct relative taxonomic abundance profiles. These findings will help lay the foundation for future studies to identify microbial role players in symptoms of anxiety, depression, and PTSD and provide future therapeutic targets to improve mental health outcomes.

Genome-wide Mendelian randomization identifies actionable novel drug targets for psychiatric disorders

Psychiatric disorders impose tremendous economic burden on society and are leading causes of disability worldwide. However, only limited drugs are available for psychiatric disorders and the efficacy of most currently used drugs is poor for many patients. To identify novel therapeutic targets for psychiatric disorders, we performed genome-wide Mendelian randomization analyses by integrating brain-derived molecular quantitative trait loci (mRNA expression and protein abundance quantitative trait loci) of 1263 actionable proteins (targeted by approved drugs or drugs in clinical phase of development) and genetic findings from large-scale genome-wide association studies (GWASs). Using transcriptome data, we identified 25 potential drug targets for psychiatric disorders, including 12 genes for schizophrenia, 7 for bipolar disorder, 7 for depression, and 1 (TIE1) for attention deficit and hyperactivity. We also identified 10 actionable drug targets by using brain proteome data, including 4 (HLA-DRB1, CAMKK2, P2RX7, and MAPK3) for schizophrenia, 1 (PRKCB) for bipolar disorder, 6 (PSMB4, IMPDH2, SERPINC1, GRIA1, P2RX7 and TAOK3) for depression. Of note, MAPK3 and HLA-DRB1 were supported by both transcriptome and proteome-wide MR analyses, suggesting that these two proteins are promising therapeutic targets for schizophrenia. Our study shows the power of integrating large-scale GWAS findings and transcriptomic and proteomic data in identifying actionable drug targets. Besides, our findings prioritize actionable novel drug targets for development of new therapeutics and provide critical drug-repurposing opportunities for psychiatric disorders.

Dihydromyricetin Attenuates Depressive-like Behaviors in Mice by Inhibiting the AGE-RAGE Signaling Pathway

Depression is a complex mental disorder, affecting approximately 280 million individuals globally. The pathobiology of depression is not fully understood, and the development of new treatments is urgently needed. Dihydromyricetin (DHM) is a natural flavanone, mainly distributed in Ampelopsis grossedentata. DHM has demonstrated a protective role against cardiovascular disease, diabetes, liver disease, cancer, kidney injury and neurodegenerative disorders. In the present study, we examined the protective effect of DHM against depression in a chronic depression mouse model induced by corticosterone (CORT). Animals exposed to CORT displayed depressive-like behaviors; DHM treatment reversed these behaviors. Network pharmacology analyses showed that DHM's function against depression involved a wide range of targets and signaling pathways, among which the inflammation-linked targets and signaling pathways were critical. Western blotting showed that CORT-treated animals had significantly increased levels of the advanced glycation end product (AGE) and receptor of AGE (RAGE) in the hippocampus, implicating activation of the AGE-RAGE signaling pathway. Furthermore, enzyme-linked immunosorbent assay (ELISA) detected a marked increase in the production of proinflammatory cytokines, interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNFα) in the hippocampus of CORT-treated mice. DHM administration significantly counteracted these CORT-induced changes. These findings suggest that protection against depression by DHM is mediated by suppression of neuroinflammation, predominantly via the AGE-RAGE signaling pathway.

Selective Serotonin Reuptake Inhibitors and Associated Bleeding Risks: A Narrative and Clinical Review

Major Depressive Disorder (MDD) is a major cause of disability worldwide and is associated with serious lasting impairment. A leading hypothesis of the pathophysiology of MDD is the monoamine deficiency hypothesis which suggests that depression is caused by depletion of serotonin, norepinephrine, or dopamine in the central nervous system. Serotonin is the most widely studied neurotransmitter in the pathophysiology of depression, with studies showing that reduced central serotonin synthesis leads to depressive symptoms in individuals at risk for depression. Selective Serotonin Reuptake Inhibitors (SSRI) inhibit serotonin reuptake and subsequently increase the amount of serotonin available in synapses. Common side effects of SSRIs include increased suicidality of patients under the age of 25, sexual dysfunction, anxiety, dizziness, weight gain, gastrointestinal distress, and headache. Other side effects include prolonging the QT interval, coagulopathy, and the risk of serotonin syndrome, as well as SSRI discontinuation syndrome. Sites of increased bleeding related to SSRI use have been reported to occur in the upper gastrointestinal tract, as well as intracranially. Based on the current literature, three studies have found that SSRIs are not associated with increased bleeding and/or increased perioperative risk, while others have demonstrated that SSRIs are associated with an increased risk in perioperative use. The inhibition of serotonin reuptake can affect platelet aggregation since platelets also express the serotonin transporter. SSRIs can result in decreased storage of serotonin in platelet dense granules. Increased serotonin can also increase gastric acid secretion, which increases the risk for ulceration. SSRIs in combination with NSAIDs also show a significantly increased risk of upper GI bleeding. Some studies show an increased bleeding risk from 30% to 70% when taking a combination of vitamin K antagonists and SSRIs in hospitalized patients. Related to the high prevalence of conditions that are treated with SSRIs, the bleeding risk associated with this class of medication merits further study.

Monoamine Neurotransmitters Control Basic Emotions and Affect Major Depressive Disorders

Major depressive disorder (MDD) is a common and complex mental disorder, that adversely impacts an individual’s quality of life, but its diagnosis and treatment are not accurately executed and a symptom-based approach is utilized in most cases, due to the lack of precise knowledge regarding the pathophysiology. So far, the first-line treatments are still based on monoamine neurotransmitters. Even though there is a lot of progress in this field, the mechanisms seem to get more and more confusing, and the treatment is also getting more and more controversial. In this study, we try to review the broad advances of monoamine neurotransmitters in the field of MDD, and update its effects in many advanced neuroscience studies. We still propose the monoamine hypothesis but paid special attention to their effects on the new pathways for MDD, such as inflammation, oxidative stress, neurotrophins, and neurogenesis, especially in the glial cells, which have recently been found to play an important role in many neurodegenerative disorders, including MDD. In addition, we will extend the monoamine hypothesis to basic emotions; as suggested in our previous reports, the three monoamine neurotransmitters play different roles in emotions: dopamine—joy, norepinephrine—fear (anger), serotonins—disgust (sadness). Above all, this paper tries to give a full picture of the relationship between the MDD and the monoamine neurotransmitters such as DA, NE, and 5-HT, as well as their contributions to the Three Primary Color Model of Basic Emotions (joy, fear, and disgust). This is done by explaining the contribution of the monoamine from many sides for MDD, such the digestive tract, astrocytes, microglial, and others, and very briefly addressing the potential of monoamine neurotransmitters as a therapeutic approach for MDD patients and also the reasons for its limited clinical efficacy, side effects, and delayed onset of action. We hope this review might offer new pharmacological management of MDD.

The Microbiota–Gut–Brain Axis in Psychiatric Disorders

Modulating the gut microbiome and its influence on human health is the subject of intense research. The gut microbiota could be associated not only with gastroenterological diseases but also with psychiatric disorders. The importance of factors such as stress, mode of delivery, the role of probiotics, circadian clock system, diet, and occupational and environmental exposure in the relationship between the gut microbiota and brain function through bidirectional communication, described as “the microbiome–gut–brain axis”, is especially underlined. In this review, we discuss the link between the intestinal microbiome and the brain and host response involving different pathways between the intestinal microbiota and the nervous system (e.g., neurotransmitters, endocrine system, immunological mechanisms, or bacterial metabolites). We review the microbiota alterations and their results in the development of psychiatric disorders, including major depressive disorder (MDD), schizophrenia (SCZ), bipolar disorder (BD), autism spectrum disorder (ASD), and attention-deficit hyperactivity disorder (ADHD).

Platycladus orientalis seed extract as a potential triple reuptake MAO inhibitor rescue depression phenotype through restoring monoamine neurotransmitters

ETHNOPHARMACOLOGY RELEVANCE

Platycladus orientalis seeds are recorded in traditional Chinese medicine (TCM) formulations for modulation of mood and physical activity in "Shen Nong Ben Cao Jing" and "Compendium of Materia Medica" and so on. Recently, we identified its extracting components and looked for the potentials in treatment for depression by improving the function of monoamine neurotransmitters.

AIM OF THE STUDY

We investigated the mechanism of action of the seed extracts of P. orientalis (S4) to rescue depressive behavior in a chronic, unpredicted, mild stress (CUMS)-induced model in rats.

MATERIALS AND METHODS

We used ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry to analyze the chemical constituents in S4. An assay platform in zebrafish and molecular docking were used to analyze if S4 regulated rest/wake behavior and predict the biological targets which correlated with monoamine neurotransmitters. Depressive-behavior tests (body weight, sucrose preference test, tail-suspension test, forced-swimming test) were carried in the CUMS model. After behavior tests and killing, rat brains were separated into the hippocampus, frontier cortex and dorsal raphe nucleus. The main monoamine neurotransmitters and their metabolite concentrations in these three brain regions were measured by rapid resolution liquid chromatography coupled with triple quadrupole tandem mass spectrometry.

RESULTS

Forty-one compounds were identified in S4, including fatty acids, terpenoids, amino acids, plant sterols and flavonoids. S4 could increase the total rest time and decrease the waking activity of zebrafish. S4 showed high correlation with adrenaline agonists, 5-hydroxytryptamine (5-HT) reuptake inhibitors and dopamine agonists. CUMS-group rats, compared with controls, had significantly decreased body weight and preference for sucrose water, whereas the immobility time in the tail-suspension test and forced-swimming test was increased. S4 could significantly rescue the increased levels of 5-HT, noradrenaline and dopamine in the prefrontal cortex and dorsal raphe nucleus.

CONCLUSIONS

We demonstrated that S4 was a potential inhibitor of MAO reuptake that could rescue depression in a CUMS-model rats by restoring monoamine neurotransmitters in different encephalic regions.

Alterations in Astrocytic Regulation of Excitation and Inhibition by Stress Exposure and in Severe Psychopathology

Dysregulation of excitatory and inhibitory signaling is commonly observed in major psychiatric disorders, including schizophrenia, depression, and bipolar disorder, and is often targeted by psychological and pharmacological treatment methods. The balance of excitation and inhibition is highly sensitive to severe psychological stress, one of the strongest risk factors for psychiatric disorders. The role of astrocytes in regulating excitatory and inhibitory signaling is now widely recognized; however, the specific involvement of astrocytes in the context of psychiatric disorders with a history of significant stress exposure remains unclear. In this review, we summarize how astrocytes regulate the balance of excitation and inhibition in the context of stress exposure and severe psychopathology, with a focus on the PFC, a brain area highly implicated in psychopathology. We first focus on preclinical models to demonstrate that the duration of stress (particularly acute vs chronic stress) is key to shaping astrocyte function and downstream behavior. We then provide a hypothesis for how astrocytes are involved in stress-associated cortical signaling imbalance, discuss how this directly contributes to phenotypes of psychopathologies, and provide suggestions for future research. We highlight that astrocytes are a key target to understand and treat the dysregulation of cortical signaling associated with stress-related psychiatric disorders.

The role of mGlu2/3 receptor antagonists in the enhancement of the antidepressant-like effect of ketamine

MGlu_2/3 receptor antagonists produce antidepressant-like effects in animal models of depression. A number of mechanisms responsible for these actions are convergent to the mechanism of the fast antidepressant-like effect of ketamine. Furthermore, the data indicate that ketamine effect is related to the action of mGlu₂ receptors and may be reduced by their agonists. The above facts became the basis for the hypothesis that the antidepressant effect of low doses of ketamine might be enhanced by coadministration of a mGlu₂ receptor antagonist. This strategy was aimed not only at enhancing the therapeutic effect of ketamine but also at reducing the risk of undesirable effects by lowering its therapeutic dose. It is known that ketamine, effective in relieving depressive symptoms in patients suffering from treatment-resistant depression (TRD), is burdened with a number of side effects, which may be particularly dangerous in psychiatric patients. Data have confirmed that subeffective doses of ketamine and its enantiomer, (R)-ketamine, coadministered with an mGlu_2/3 receptor antagonist, induce antidepressant-like effects in the screening tests and in the chronic-stress-induced model of depression. At the same time, these drug combinations did not cause undesirable effects characteristic of higher doses of ketamine and (S)-ketamine, including those related to psychostimulatory effects. Further research is required to prove whether this strategy will also be effective in depressive patients.

Pathophysiology of Depression: Stingless Bee Honey Promising as an Antidepressant

Depression is a debilitating psychiatric disorder impacting an individual’s quality of life. It is the most prevalent mental illness across all age categories, incurring huge socio-economic impacts. Most depression treatments currently focus on the elevation of neurotransmitters according to the monoamine hypothesis. Conventional treatments include tricyclic antidepressants (TCAs), norepinephrine–dopamine reuptake inhibitors (NDRIs), monoamine oxidase inhibitors (MAOIs), and serotonin reuptake inhibitors (SSRIs). Despite numerous pharmacological strategies utilising conventional drugs, the discovery of alternative medicines from natural products is a must for safer and beneficial brain supplement. About 30% of patients have been reported to show resistance to drug treatments coupled with functional impairment, poor quality of life, and suicidal ideation with a high relapse rate. Hence, there is an urgency for novel discoveries of safer and highly effective depression treatments. Stingless bee honey (SBH) has been proven to contain a high level of antioxidants compared to other types of honey. This is a comprehensive review of the potential use of SBH as a new candidate for antidepressants from the perspective of the monoamine, inflammatory and neurotrophin hypotheses.

Current and Possible Future Therapeutic Options for Huntington’s Disease

Huntington’s disease (HD) is an autosomal neurodegenerative disease that is characterized by an excessive number of CAG trinucleotide repeats within the huntingtin gene ( HTT). HD patients can present with a variety of symptoms including chorea, behavioural and psychiatric abnormalities and cognitive decline. Each patient has a unique combination of symptoms, and although these can be managed using a range of medications and non-drug treatments there is currently no cure for the disease. Current therapies prescribed for HD can be categorized by the symptom they treat. These categories include chorea medication, antipsychotic medication, antidepressants, mood stabilizing medication as well as non-drug therapies. Fortunately, there are also many new HD therapeutics currently undergoing clinical trials that target the disease at its origin; lowering the levels of mutant huntingtin protein (mHTT). Currently, much attention is being directed to antisense oligonucleotide (ASO) therapies, which bind to pre-RNA or mRNA and can alter protein expression via RNA degradation, blocking translation or splice modulation. Other potential therapies in clinical development include RNA interference (RNAi) therapies, RNA targeting small molecule therapies, stem cell therapies, antibody therapies, non-RNA targeting small molecule therapies and neuroinflammation targeted therapies. Potential therapies in pre-clinical development include Zinc-Finger Protein (ZFP) therapies, transcription activator-like effector nuclease (TALEN) therapies and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated system (Cas) therapies. This comprehensive review aims to discuss the efficacy of current HD treatments and explore the clinical trial progress of emerging potential HD therapeutics.

The role of cytochromes P450 in metabolism of selected antidepressants and anxiolytics under psychological stress

In today's modern society, it seems to be more and more challenging to cope with life stresses. The effect of psychological stress on emotional and physical health can be devastating, and increased stress is associated with increased rates of heart attack, hypertension, obesity, addiction, anxiety and depression. This review focuses on the possibility of an influence of psychological stress on the metabolism of selected antidepressants (TCAs, SSRIs, SNRIs, SARIs, NDRIs a MMAs) and anxiolytics (benzodiazepines and azapirone), as patients treated with antidepressants and/or anxiolytics can still suffer from psychological stress. Emphasis is placed on the drug metabolism mediated by the enzymes of Phase I, typically cytochromes P450 (CYPs), which are the major enzymes involved in drug metabolism, as the majority of psychoactive substances are metabolized by numerous CYPs (such as CYP1A2, CYP2B6, CYP2C19, CYP2C9, CYP2A6, CYP2D6, CYP3A4). As the data on the effect of stress on human enzymes are extremely rare, modulation of the efficacy and even regulation of the biotransformation pathways of drugs by psychological stress can be expected to play a significant role, as there is increasing evidence that stress can alter drug metabolism, hence there is a risk of less effective drug metabolism and increased side effects.

Antidepressant treatment effects on hippocampal protein turnover: Molecular and spatial insights from mass spectrometry

A major challenge in managing depression is that antidepressant drugs take a long time to exert their therapeutic effects. For the development of faster acting therapies, it is crucial to get an improved understanding of the molecular mechanisms underlying antidepressant mode of action. Here, we used a novel mass spectrometry-based workflow to investigate how antidepressant treatment affects brain protein turnover at single cell and subcellular resolution. We combined stable isotope metabolic labeling, quantitative Tandem Mass Spectrometry (qTMS) and Multi-isotope Imaging Mass Spectrometry (MIMS) to simultaneously quantify and image protein synthesis and turnover in hippocampi of mice treated with the antidepressant paroxetine. We identified changes in turnover of individual hippocampal proteins that reveal altered metabolism-mitochondrial processes and report on subregion-specific turnover patterns upon paroxetine treatment. This workflow can be used to investigate brain protein turnover changes upon pharmacological interventions at a resolution and precision that has not been possible with other methods to date. Our results reveal acute paroxetine effects on brain protein turnover and shed light on antidepressant mode of action. This article is protected by copyright. All rights reserved.

Optimized Clinical Strategies for Treatment-Resistant Depression: Integrating Ketamine Protocols with Trauma- and Attachment-Informed Psychotherapy

Strategically timed trauma- and attachment-informed psychotherapy to address underlying emotional wounds, paired with ketamine administered in precision-calibrated doses to ensure high-entropy brain states, may be key to improving the quality and duration of ketamine’s therapeutic efficacy for treatment-resistant depression. This approach optimizes the opportunities for change created by ketamine’s known effects as a rapid antidepressant that stimulates synaptogenesis, normalizes neural connectivity and coherence, enhances neuroplasticity, reduces inflammation, and induces high-entropy brain states with associated subjective psychedelic experiences. Ketamine, a non-selective N-methyl-D-aspartate (NMDA) receptor antagonist is a safe, effective, fast-acting dissociative anesthetic that, as a standalone treatment, also exhibits rapid sustained antidepressant effects, even in many patients with treatment-resistant depression. A prior history of developmental trauma and attachment injuries are known primary factors in the etiology of treatment resistance in depression and other mental disorders. Thus, the adjunct of targeted psychotherapy attuned to trauma and attachment injuries may enhance and prolong ketamine efficacy and provide an opportunity for lasting therapeutic change. Psychotherapy engagement during repeated ketamine sessions for patient safety and integration of altered states, paired with separate individualized psychotherapy-only sessions timed 24–48 h post ketamine induction, takes advantage of peak ketamine-induced dendritic spine growth in the prefrontal cortex and limbic system, and normalized network connectivity across brain structures. This strategically timed paired-session approach also exploits the therapeutic potential created by precision-calibrated ketamine-linked high-entropy brain states and associated psychedelic experiences that are posited to disrupt overly rigid maladaptive thoughts, behaviors, and disturbing memories associated with treatment-resistant depression; paired sessions also support integration of the felt sense of happiness and connectivity associated with psychedelic experiences.

Perioperative Breast Analgesia: a Systematic Review of the Evidence for Perioperative Analgesic Medications

PURPOSE OF REVIEW

Breast surgery is common and may result in significant acute as well as chronic pain. A wide range of pharmacologic interventions is available including opioids, non-steroidal anti-inflammatory drugs (NSAIDs), N-methyl-D-aspartate (NMDA) receptor antagonists, anticonvulsants, and other non-opioids with analgesic properties. We present a review of the evidence for these pharmacologic interventions. A literature search of the MEDLINE database was performed via PubMed with combined terms related to breast surgery, anesthesia, and analgesia. Articles were limited to randomized controlled trial (RCT) design, adult patients undergoing elective surgery on the breast (not including biopsy), and pharmacologic interventions only. Article titles and abstracts were screened, and risk of bias assessments were performed.

RECENT FINDINGS

The search strategy initially captured 7254 articles of which 60 articles met the full inclusion criteria. Articles were organized according to intervention: 6 opioid agonists, 14 NSAIDs and acetaminophen, 4 alpha-2 agonists, 7 NMDA receptor antagonists, 6 local anesthetics, 7 steroids, 15 anticonvulsants (one of which also discussed an NMDA antagonist), 1 antiarrhythmic, and 2 serotonin reuptake inhibitors (one of which also studied an anticonvulsant). A wide variety of medications is effective for perioperative breast analgesia, but results vary by agent and dose. The most efficacious are likely NSAIDs and anticonvulsants. Some agents may also decrease the incidence of chronic postoperative pain, including flurbiprofen, gabapentin, venlafaxine, and memantine. While many individual agents are well studied, optimal combinations of analgesic medications remain unclear.

Ascorbic acid intake is inversely associated with prevalence of depressive symptoms in US midlife women: A cross-sectional study

BACKGROUND

With the endocrine changes in menopausal transition period, associations between dietary ascorbic acid intake and depressive symptoms may be different. This investigation examined cross-sectional relations between dietary ascorbic acid intake of women and prevalence of depressive symptoms.

METHODS

This is a secondary analysis performed on a subsample of the Study of Women's Health Across the Nation (SWAN). Women enrolled had measures of CES-D depression scores and ascorbic acid intake. Regression models were used to study cross-sectional associations between ascorbic acid intake and depressive symptoms.

RESULTS

A total of 3088 women aged 42-52 years at baseline were included in the present study. Dietary ascorbic acid intake was inversely associated with depressive symptoms. The adjusted OR and 95% CI of depressive symptoms was 0.699 (0.524 - 0.934) in quartile 4 (the highest) versus quartile 1 (the lowest) of the ascorbic acid intake. Restricted cubic spline analyze showed a suggestion of L-shaped associations between ascorbic acid intake and depressive symptoms.

CONCLUSIONS

Ascorbic acid intake is inversely associated with prevalence of depressive symptoms in midlife women. Future prospective cohort studies are needed to confirm these findings.

Integrative multi-omics landscape of fluoxetine action across 27 brain regions reveals global increase in energy metabolism and region-specific chromatin remodelling

Depression and anxiety are major global health burdens. Although SSRIs targeting the serotonergic system are prescribed over 200 million times annually, they have variable therapeutic efficacy and side effects, and mechanisms of action remain incompletely understood. Here, we comprehensively characterise the molecular landscape of gene regulatory changes associated with fluoxetine, a widely-used SSRI. We performed multimodal analysis of SSRI response in 27 mammalian brain regions using 310 bulk RNA-seq and H3K27ac ChIP-seq datasets, followed by in-depth characterisation of two hippocampal regions using single-cell RNA-seq (20 datasets). Remarkably, fluoxetine induced profound region-specific shifts in gene expression and chromatin state, including in the nucleus accumbens shell, locus coeruleus and septal areas, as well as in more well-studied regions such as the raphe and hippocampal dentate gyrus. Expression changes were strongly enriched at GWAS loci for depression and antidepressant drug response, stressing the relevance to human phenotypes. We observed differential expression at dozens of signalling receptors and pathways, many of which are previously unknown. Single-cell analysis revealed stark differences in fluoxetine response between the dorsal and ventral hippocampal dentate gyri, particularly in oligodendrocytes, mossy cells and inhibitory neurons. Across diverse brain regions, integrative omics analysis consistently suggested increased energy metabolism via oxidative phosphorylation and mitochondrial changes, which we corroborated in vitro; this may thus constitute a shared mechanism of action of fluoxetine. Similarly, we observed pervasive chromatin remodelling signatures across the brain. Our study reveals unexpected regional and cell type-specific heterogeneity in SSRI action, highlights under-studied brain regions that may play a major role in antidepressant response, and provides a rich resource of candidate cell types, genes, gene regulatory elements and pathways for mechanistic analysis and identifying new therapeutic targets for depression and anxiety.

Effects of flavonols on emotional behavior and compounds of the serotonergic system: A preclinical systematic review

Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter that regulates multiple psychophysiological functions. An imbalance of 5-HT in the brain can modulate emotional behavior such as depression and anxiety. Substances, such as flavonols, naturally found in some plants and foods have beneficial effects on psychiatric disorders, have been studied. The aim of this systematic review was to investigate the effects of flavonols on morphological, physiological, and cellular aspects of the serotonergic system as well as on some behaviors modulated by this system. Literature searches were performed in the LILACS, Web of Science, Scopus, PubMed and Sigle via Open Grey databases, from which 1725 studies were found. Using a predefined protocol registered on the CAMARADES website, 18 studies were chosen for qualitative synthesis. Internal validity was assessed using the SYRCLE's risk of bias tool. The Kappa index was also measured to analyze agreement among the reviewers. The results of this systematic review showed that flavonols have been reported to modify physiological aspects of the serotonergic system, increasing levels of serotonin and decreasing levels of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA) and promoting antioxidant effects in encephalic regions. Moreover, the results showed that flavonols can also modulate of the serotonergic system, being associated with antidepressant and anxiolytic activities. Additionally, flavonols were found to not have psychostimulant effect; they can, however, reverse damage to locomotor activity.

Hippocampal BMP signaling as a common pathway for antidepressant action

The benefits of current treatments for depression are limited by low response rates, delayed therapeutic effects, and multiple side effects. Antidepressants affect a variety of neurotransmitter systems in different areas of the brain, and the mechanisms underlying their convergent effects on behavior have been unclear. Here we identify hippocampal bone morphogenetic protein (BMP) signaling as a common downstream pathway that mediates the behavioral effects of five different antidepressant classes (fluoxetine, bupropion, duloxetine, vilazodone, trazodone) and of electroconvulsive therapy. All of these therapies decrease BMP signaling and enhance neurogenesis in the hippocampus. Preventing the decrease in BMP signaling blocks the effect of antidepressant treatment on behavioral phenotypes. Further, inhibition of BMP signaling in hippocampal newborn neurons is sufficient to produce an antidepressant effect, while chemogenetic silencing of newborn neurons prevents the antidepressant effect. Thus, inhibition of hippocampal BMP signaling is both necessary and sufficient to mediate the effects of multiple classes of antidepressants.

Novel insights into antidepressant mechanism of Kai Xin San formula: Inhibiting NLRP3 inflammasome activation by promoting autophagy

BACKGROUND

Kai Xin San (KXS) was widely applied for the treatment of depression for thousands of years. However, the underlying antidepressant mechanism of KXS remains not clear.

PURPOSE

This study aimed to investigate whether NLRP3 inflammasome and autophagy are involved in inflammation-induced depression and antidepressant mechanism of KXS.

METHODS

Wistar rats were exposed to chronic unpredictable mild stress (CUMS) for 6 weeks, and KXS (3, 5, and 10 g/kg/d) was administrated during the last 2 weeks of CUMS procedure. The effects of KXS on depressive-like behaviors, neuroinflammation, NLRP3 inflammasome activation, and autophagy were investigated in CUMS rats. Rat astrocytes were employed to further explore the potential mechanism of KXS in regulating NLRP3 inflammasome and autophagy. Autophagy inhibitor 3-methyladenine (3-MA, 5 mM) was used in vitro to elucidate the role of autophagy in the antidepressant mechanism of KXS.

RESULTS

In vivo, KXS improved depressive-like behaviors of CUMS rats in sucrose preference test, open field test and forced swimming test. Moreover, KXS inhibited the neuroinflammation induced by CUMS and promoted autophagy in prefrontal cortex of rats. The results in vitro further validated the anti-inflammatory and proautohapgic effects of KXS. More importantly, autophagy inhibitor 3-MA diminished the inhibitory effect of KXS on NLRP3 inflammasome activation in rat astrocytes.

CONCLUSION

KXS ameliorated CUMS-induced depressive behaviors in rats and inhibited the NLRP3 inflammasome-mediated inflammation in vivo and in vitro. These effects might be regulated by KXS-induced autophagy.

Neuropharmacological Activity of the New Piperazine Derivative 2-(4-((1- Phenyl-1H-Pyrazol-4-yl)Methyl)Piperazin-1-yl)Ethyl Acetate is Modulated by Serotonergic and GABAergic Pathways

BACKGROUND

Pharmacological treatments for mental disorders, such as anxiety and depression, present several limitations and adverse effects. Therefore, new pharmacotherapy with anxiolytic and antidepressant potential is necessary, and the study of compounds capable of interacting with more than one pharmacological target may provide new therapeutic options.

OBJECTIVES

In this study, we proposed the design, synthesis of a new compound, 2-(4-((1-phenyl-1H-pyrazol-4-yl)methyl)piperazin-1-yl)ethyl acetate (LQFM192), pharmacological evaluation of its anxiolytic-like and antidepressant-like activities, as well as the possible mechanisms of action involved.

METHODS

Administration of LQFM192 was carried out prior to the exposure of male Swiss mice to behavioral tests, such as the elevated plus-maze and forced swimming test. The involvement of the serotonergic system was studied by pretreatment with WAY-100635 or p-chlorophenylalanine (PCPA) and the involvement of the benzodiazepine site of the GABAA receptor by pretreatment with flumazenil.

RESULTS

The treatment with LQFM192 at doses of 54 and 162 µmol/kg demonstrated anxiolyticlike activity that was blocked by WAY-100635, PCPA, and flumazenil pretreatments. The potential antidepressant-like activity was visualized at the same doses and blocked by WAY-100635 and PCPA.

CONCLUSION

In summary, the anxiolytic-like activity of LQFM192 is mediated by the serotonergic system and the benzodiazepine site of the GABAA receptor, and the antidepressant-like activity through the serotonergic system.

Molecular Consequences of Depression Treatment: A Potential In Vitro Mechanism for Antidepressants-Induced Reprotoxic Side Effects

The incidence of depression among humans is growing worldwide, and so is the use of antidepressants. However, our fundamental understanding regarding the mechanisms by which these drugs function and their off-target effects against human sexuality remains poorly defined. The present study aimed to determine their differential toxicity on mouse spermatogenic cells and provide mechanistic data of cell-specific response to antidepressant and neuroleptic drug treatment. To directly test reprotoxicity, the spermatogenic cells (GC-1 spg and GC-2 spd cells) were incubated for 48 and 96 h with amitriptyline (hydrochloride) (AMI), escitalopram (ESC), fluoxetine (hydrochloride) (FLU), imipramine (hydrochloride) (IMI), mirtazapine (MIR), olanzapine (OLZ), reboxetine (mesylate) (REB), and venlafaxine (hydrochloride) (VEN), and several cellular and biochemical features were assessed. Obtained results reveal that all investigated substances showed considerable reprotoxic potency leading to micronuclei formation, which, in turn, resulted in upregulation of telomeric binding factor (TRF1/TRF2) protein expression. The TRF-based response was strictly dependent on p53/p21 signaling and was followed by irreversible G2/M cell cycle arrest and finally initiation of apoptotic cell death. In conclusion, our findings suggest that antidepressants promote a telomere-focused DNA damage response in germ cell lines, which broadens the established view of antidepressants' and neuroleptic drugs' toxicity and points to the need for further research in this topic with the use of in vivo models and human samples.

Assessment of psychiatric comorbidities and serotonergic or noradrenergic medication use on blood pressure using 24-hour ambulatory blood pressure monitoring

In this study, the authors aimed to assess both nighttime and daytime blood pressure (BP) variability using 24-hour ambulatory BP monitoring (ABPM) in persons with and without psychiatric conditions and with or without selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs) treatment. In this retrospective study, patients who underwent psychiatric evaluation and ABPM within 6 months of each other between January 1, 2012 and December 31, 2017 were identified using billing data. Participants were divided into three groups-participants with no psychiatric diagnosis and no psychiatric medicine (-Diagnosis/-Medication), those with psychiatric diagnosis and on SSRIs/SNRIs (+Diagnosis/+Medication), and psychiatric diagnosis but no psychiatric medications (+Diagnosis/-Medication). Day and nighttime systolic and diastolic BPs were compared between groups controlling for relevant variables using multivariable linear regression models. A total of 475 participants met inclusion criteria including 135 in the -Diagnosis/-Medication group, 232 in the +Diagnosis/+Medication group, and 108 in the +Diagnosis/-Medication group. In adjusted multivariable analysis, the +Diagnosis/+Medication group had higher nighttime systolic BP (median 120 vs 110 mm (Hg); p = .01) and nighttime diastolic BP (median 68 vs 63 mm (Hg); p = .006) as compared to -Diagnosis/-Medication. No statistically significant differences in BPs between the -Diagnosis/-Medication and +Diagnosis/-Medication groups were observed, after adjustment. Use of SSRIs/SNRIs was associated with significantly higher nocturnal systolic and diastolic BP among patients with psychiatric diagnosis using SSRIs/SNRIs but not associated with psychiatric diagnosis without SSRI/SNRI use. SSRIs/SNRIs use may be associated with higher BP levels and this merits future prospective studies using ABPM to assess day and nighttime BP changes with SSRIs/SNRIs use.

Drug Repurposing for the Management of Depression: Where Do We Stand Currently?

A slow rate of new drug discovery and higher costs of new drug development attracted the attention of scientists and physicians for the repurposing and repositioning of old medications. Experimental studies and off-label use of drugs have helped drive data for further studies of approving these medications. A deeper understanding of the pathogenesis of depression encourages novel discoveries through drug repurposing and drug repositioning to treat depression. In addition to reducing neurotransmitters like epinephrine and serotonin, other mechanisms such as inflammation, insufficient blood supply, and neurotoxicants are now considered as the possible involved mechanisms. Considering the mentioned mechanisms has resulted in repurposed medications to treat treatment-resistant depression (TRD) as alternative approaches. This review aims to discuss the available treatments and their progress way during repositioning. Neurotransmitters’ antagonists, atypical antipsychotics, and CNS stimulants have been studied for the repurposing aims. However, they need proper studies in terms of formulation, matching with regulatory standards, and efficacy.

L. Cucurbita pepo Alleviates Chronic Unpredictable Mild Stress via Modulation of Apoptosis, Neurogenesis, and Gliosis in Rat Hippocampus

Pumpkin has received significant attention due to its nutritional compounds that have antioxidant, antifatigue, and anti-inflammatory effects. This study is aimed at assessing the antidepressant-like effect of L. Cucurbita pepo, sweet pumpkin, in an animal model of chronic unpredictable mild stress (CUMS) and investigating its effect on the histological structure of hippocampus compared to fluoxetine. Forty male albino rats assigned into the negative control, positive control (CUMS), and Flu-treated and pumpkin-treated groups (n = 10) were utilized in this study. Exposing rats to CUMS continued for 28 days, and treatments used were applied during the last 14 days of exposure. Behavioral, biochemical, and histopathological changes were assessed after 28 days. In this study, pumpkin significantly reduced the immobility time (p = 0.02), corticosterone (p < 0.001), TNF-α, IL-6 (p < 0.001), and malondialdehyde (p = 0.003), whereas it significantly increased the level of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) in the serum of rats exposed to CUMS. Pumpkin markedly relieved the degenerative and atrophic changes observed in the CA3 region and the dentate gyrus of the hippocampus. It significantly reduced caspase-3 and increased glial fibrillary acidic protein (GFAP) immunoexpression in the CA3 and DG. In conclusion, administration of pumpkin extract improved the behavioral, biochemical, and hippocampal pathological alternations induced in rats after exposure to CUMS in a comparable pattern to fluoxetine. This study highlighted the potential efficacy of pumpkin in alleviating depression disorder either alone or in conjugation with conventional antidepressant therapy.

Depression and Pain: use of antidepressant

Background:

Emotional disorders are common comorbid affectations that exacerbate the severity and persistence of chronic pain. Specifically, depressive symptoms can lead to an excessive duration and intensity of pain. Clinical and preclinical studies have been focused on the underlying mechanisms of chronic pain and depression comorbidity and the use of antidepressants to reduce pain.

Aim:

This review provides an overview of the comorbid relationship of chronic pain and depression, the clinical and pre-clinical studies performed on the neurobiological aspects of pain and depression, and the use of antidepressants as analgesics.

Methods:

A systematic search of literature databases was conducted according to pre-defined criteria. The authors independently conducted a focused analysis of the full-text articles.

Results:

Studies suggest that pain and depression are highly intertwined and may co-exacerbate physical and psychological symptoms. One important biochemical basis for pain and depression focuses on the serotonergic and norepinephrine system, which have been shown to play an important role in this comorbidity. Brain structures that codify pain are also involved in mood. It is evident that using serotonergic and norepinephrine antidepressants are strategies commonly employed to mitigate pain

Conclusion:

Literature indicates that pain and depression impact each other and play a prominent role in the development and maintenance of other chronic symptoms. Antidepressants continue to be a major therapeutic tool for managing chronic pain. Tricyclic antidepressants (TCAs) are more effective in reducing pain than Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Noradrenaline Reuptake Inhibitors (SNRIs).

Protective effects of antidepressant citalopram against abnormal APP processing and amyloid beta-induced mitochondrial dynamics, biogenesis, mitophagy and synaptic toxicities in Alzheimer's disease

The purpose of this study is to study the neuroprotective role of selective serotonin reuptake inhibitor (SSRI), citalopram, against Alzheimer's disease (AD). Multiple SSRIs, including citalopram, are reported to treat patients with depression, anxiety and AD. However, their protective cellular mechanisms have not been studied completely. In the current study, we investigated the protective role of citalopram against impaired mitochondrial dynamics, defective mitochondrial biogenesis, defective mitophagy and synaptic dysfunction in immortalized mouse primary hippocampal cells (HT22) expressing mutant APP (SWI/IND) mutations. Using quantitative RT-PCR, immunoblotting, biochemical methods and transmission electron microscopy methods, we assessed mutant full-length APP/C-terminal fragments and Aβ levels and mRNA and protein levels of mitochondrial dynamics, biogenesis, mitophagy and synaptic genes in mAPP-HT22 cells and mAPP-HT22 cells treated with citalopram. Increased levels of mRNA levels of mitochondrial fission genes, decreased levels of fusion biogenesis, autophagy, mitophagy and synaptic genes were found in mAPP-HT22 cells relative to WT-HT22 cells. However, mAPP-HT22 cells treated with citalopram compared to mAPP-HT22 cells revealed reduced levels of the mitochondrial fission genes, increased fusion, biogenesis, autophagy, mitophagy and synaptic genes. Our protein data agree with mRNA levels. Transmission electron microscopy revealed significantly increased mitochondrial numbers and reduced mitochondrial length in mAPP-HT22 cells; these were reversed in citalopram-treated mAPP-HT22 cells. Cell survival rates were increased in citalopram-treated mAPP-HT22 relative to citalopram-untreated mAPP-HT22. Further, mAPP and C-terminal fragments werealso reduced in citalopram-treated cells. These findings suggest that citalopram reduces mutant APP and Aβ and mitochondrial toxicities and may have a protective role of mutant APP and Aβ-induced injuries in patients with depression, anxiety and AD.

Opioid and/or Psychotropic Use Increases Intraprocedural Sedation Drug Requirements

Objectives Acute pain management in opioid users can be challenging in the perioperative period. This study focuses on whether use of opioids increases sedation medication requirements in patients undergoing port placement under moderate sedation.

Materials and Methods A retrospective review was performed on all patients undergoing port placement between June 1, 2017, and June 30, 2019. Exclusion criteria included receiving general anesthesia, no sedation, and errors in data entry. Data collection included demographics, use of opioids, benzodiazepines, antidepressants, tobacco, alcohol, and sedation data.

Results Opioid, benzodiazepine, and selective serotonin reuptake inhibitors (SSRIs)/serotonin-norepinephrine reuptake inhibitors (SNRIs) use was significantly associated with higher sedation drug dose requirements. Patients using opioids required 10.5% higher doses of midazolam compared with nonusers. Benzodiazepine users required 16.3% additional dosage of midazolam than nonusers. Finally, patients on SSRIs/SNRIs medications required 11.8% higher midazolam dosing when compared with nonusers.

Conclusion Anticipating higher needs of sedation medications during procedures in patients with history of psychotropic agents use can allow for more effective sedation and patient satisfaction. More patient and provider awareness is needed on this topic, as health care policy is moving toward value-based healthcare, with patient satisfaction surveys being one of its indicators.