New Serotonin-Norepinephrine Reuptake Inhibitors and Their Anesthetic and Analgesic Considerations

Neuropathic pain management: a focused review of current treatments and novel data from main ongoing clinical trials

INTRODUCTION

Neuropathic pain (NP) remains a significant challenge in clinical practice, requiring a sophisticated pharmacotherapeutic strategy for effective symptom management. This review provides a comprehensive analysis of the current pharmacological treatments for NP, focusing on their efficacy, mechanism of action, and therapeutic potential. Additionally, it evaluates ongoing clinical trials investigating novel drugs and therapeutic approaches, highlighting emerging trends and future directions in NP management.

AREAS COVERED

This review examines first- to third-line therapeutic modalities for NP, critically analyzing their efficacy, safety profiles, and clinical applications. It also includes an overview of ongoing clinical trials exploring innovative pharmacological therapies. A thorough literature review was conducted using the MEDLINE database without temporal limitations, offering a detailed assessment of established and emerging treatments.

EXPERT OPINION

While current pharmacological options offer significant symptom relief, their overall effectiveness in managing NP remains limited, highlighting the need for further therapeutic advancements. Staying informed about emerging therapies and clinical trials is vital to enhancing patient care and quality of life. The future of NP management lies in optimizing individualized treatment strategies, refining therapeutic approaches, and fostering interdisciplinary collaboration. Close monitoring of outcomes and continued research are essential for advancing understanding and improving the precision of NP therapies.

Pharmaco-Multiomics: A New Frontier in Precision Psychiatry

The landscape of psychiatric care is poised for transformation through the integration of pharmaco-multiomics, encompassing genomics, proteomics, metabolomics, transcriptomics, epigenomics, and microbiomics. This review discusses how these approaches can revolutionize personalized treatment strategies in psychiatry by providing a nuanced understanding of the molecular bases of psychiatric disorders and individual pharmacotherapy responses. With nearly one billion affected individuals globally, the shortcomings of traditional treatments, characterized by inconsistent efficacy and frequent adverse effects, are increasingly evident. Advanced computational technologies such as artificial intelligence (AI) and machine learning (ML) play crucial roles in processing and integrating complex omics data, enhancing predictive accuracy, and creating tailored therapeutic strategies. To effectively harness the potential of pharmaco-multiomics approaches in psychiatry, it is crucial to address challenges such as high costs, technological demands, and disparate healthcare systems. Additionally, navigating stringent ethical considerations, including data security, potential discrimination, and ensuring equitable access, is essential for the full realization of this approach. This process requires ongoing validation and comprehensive integration efforts. By analyzing recent advances and elucidating how different omic dimensions contribute to therapeutic customization, this review aims to highlight the promising role of pharmaco-multiomics in enhancing patient outcomes and shifting psychiatric treatments from a one-size-fits-all approach towards a more precise and patient-centered model of care.

Examining depression, antidepressants use, and class and their potential associations with osteoporosis and fractures in adult women: Results from ten NHANES cohorts

INTRODUCTION

Osteoporosis, a significant public health concern, affects millions of adult women globally, leading to increased morbidity and fracture risk. Antidepressant use, prevalent in this demographic, is suggested to influence bone mineral density (BMD), yet evidence remains limited across antidepressant classes.

OBJECTIVE/AIM

We investigated the association between antidepressant use and osteoporosis in a representative sample of adult women in the United States, focusing on different classes of antidepressants and their potential associations with BMD and fracture risk.

METHODS

We conducted a cross-sectional analysis using data from ten cohorts of the National Health and Nutrition Examination Survey (NHANES) spanning 1999-2000 to 2017-2020. The sample included adult women, with data collected on antidepressant use, BMD scores, and reported fractures. Statistical models adjusted for potential confounders such as Major Depressive Disorder (MDD), age, physical activity, and comorbidities.

RESULTS

Antidepressant use was associated with a 44 % increase in the odds of osteoporosis. Phenylpiperazines showed the highest association, followed by miscellaneous antidepressants and tricyclic antidepressants (TCAs). Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) also demonstrated significant, though comparatively lower associations. The odds of fractures were elevated by 62 % among antidepressant users, particularly with phenylpiperazines and miscellaneous antidepressants. A dose-response analysis indicated that both the number and duration of antidepressants were associated with increased odds of osteoporosis.

CONCLUSION

Our findings underscore the need for heightened awareness of the adverse effects of antidepressants on bone health, particularly in adult women. Careful consideration is necessary when prescribing these medications, especially in populations at risk for osteoporosis and MDD.

An Exploration of the Interplay Between Caffeine and Antidepressants Through the Lens of Pharmacokinetics and Pharmacodynamics

Caffeine consumption is regarded as a widespread phenomenon, and its usage has continued to increase. In addition, the growing usage of antidepressants worldwide and increase in mental health disorders were shown in recent statistical analyses conducted by the World Health Organisation. The coadministration of caffeine and antidepressants remains a concern due to potential interactions that can alter a patient's response to therapy. This review investigates the pharmacokinetic and pharmacodynamic interactions between caffeine and the five main classes of antidepressants: selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), serotonin and norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), and other antidepressants not categorised by class, which we have categorised as 'miscellaneous'. The interaction between fluvoxamine and caffeine resulted in increased concentrations of caffeine in the body and lowered the renal clearance of fluvoxamine. Other SSRIs such as fluoxetine and escitalopram had augmented antidepressant effects by decreasing their renal clearance and prolonging their effects in the body when coadministered with caffeine. Caffeine may also increase the concentration of paroxetine, potentially affecting its pharmacodynamic effects. TCAs such as clomipramine, imipramine, desipramine, and sertraline, were found to reduce the metabolism of caffeine. However, studies suggest caffeine had no significant effect on the concentration of these medications in blood or brain tissue. The inhibition of caffeine at high doses when used with MAOIs such as tranylcypromine and phenelzine was found to lead to a higher likelihood of experiencing hypertension. Coadministration of caffeine with venlafaxine (SNRIs) suggests minimal interactions between the two substances and the pharmacodynamic effects of venlafaxine were unlikely to be impacted by caffeine consumption. Miscellaneous antidepressants (reboxetine, mianserin, agomelatine, maprotiline, and mirtazapine) displayed varying pharmacodynamic interactions with caffeine, resulting in increased antidepressant effects where vortioxetine, maprotiline, and mirtazapine failed to demonstrate any interactions. In conclusion, caffeine demonstrated varying effects on the pharmacokinetic and pharmacodynamic properties of each class of antidepressants, with several classes of antidepressants demonstrating a similar effect on caffeine.

An overview of the non-procedural treatment options for peripheral neuropathic pain

Peripheral neuropathic pain is common in patients with peripheral nerve injury and can significantly impact both their function and quality of life. There is a wide variety of non-interventional treatment approaches, including pharmacologic therapy, physical/occupational therapy, modalities (therapeutic, mechanical, thermal, etc.), psychology, and lifestyle modification. First line pharmacologic therapy for peripheral neuropathic pain includes gabapentinoids, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors. Other classes of medications, such as topical treatments, opioids, and cannabinoids, have more limited usefulness in treatment but remain part of a treatment regimen. Physical and occupational therapy, psychological interventions, and lifestyle medicine are important adjuncts in the treatment and prevention of future peripheral neuropathic pain. The strength of the evidence supporting each intervention varies, with that for pharmacologic intervention being the strongest. A combination of these options tailored to the individual needs of the patient likely will result in the best treatment outcome for peripheral neuropathic pain.

The effect of serotonin reuptake and serotonin-noradrenaline reuptake inhibitors on motor symptoms in Parkinson's disease: A PPMI-based matched-subject study

Background: Depression often co-occurs with Parkinson's disease (PD) and is effectively treated with selective serotonin reuptake inhibitors (SSRI) and serotonin and noradrenaline reuptake inhibitors (SNRI), but their effect on motor symptoms has not yet been conclusively demonstrated. Objective: To assess the impact of the SSRI/SNRI on the motor symptoms of PD. Methods: We used data from the Parkinson's Progression Markers Initiative database, in a matched subject design with a target group (N = 47) which had been taking SSRI/SNRI medication and a control group (N = 90) which had not. Matching criteria included Movement Disorders Society Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS-III) total score and its subscales' scores, and levodopa equivalent daily dose (LEDD) at the time of the first examination (initial LEDD). For the target group, we compared the MDS-UPDRS-III score before and after taking the SSRI/SNRI medication, while for the control group we compared two equally spaced examinations. Results: In the target group, we found a greater worsening of motor scores, which was associated with lower values of initial LEDD. In addition, apathy was an independent predictor of motor worsening. Conclusions: SSRI/SNRI-use seems to be characterized by a steeper worsening of motor symptoms, which can be predicted by a lower initial LEDD. Further research should continue to investigate the effect of SSRI/SNRI-use on motor symptoms in PD.

Evaluating the safety and efficacy of zuranolone in the management of major depressive disorder and postpartum depression, with or without concurrent insomnia: a rigorous systematic review and meta-analysis

Introduction

Major depressive disorder (MDD), postpartum depression (PPD), and insomnia are neuropsychological conditions in which zuranolone is used to improve symptoms and prognosis of the disorder. This meta-analysis aimed to determine the efficacy of zuranolone in comparison to other drugs used for treating these conditions.

Methods

This meta-analysis included patients aged between 18 and 75 years who were diagnosed with major depressive disorder and postpartum depression with or without insomnia and were administered zuranolone for treatment. Only randomized controlled trials (RCTs) were included, and animal studies were excluded. The databases used were PubMed, Scopus, Cochrane, and Clinicaltrials.gov, with MeSH terms and relevant keywords for (Zuranolone) and (Depression). The Cochrane risk of bias tool was used for quality assessment.

Results

The meta-analysis included eight RCTs that analyzed data from 2031 patients. The meta-analysis revealed statistically significant changes in the Hamilton Depression Rating Scale (HAM-D), Montgomery-Åsberg Depression Rating Scale (MADRS), Hamilton Anxiety Rating Scale (HAM-A), and treatment-emergent adverse effects (TEAE) scores in the PPD subgroup. HAM-D and TEAEs scores were also significant in the MDD subgroup, but the changes in the MADRS, HAM-A, and Bech-6 scores were insignificant. Serious adverse events were insignificant in all subgroups.

Conclusion

Meta-analysis found a significant improvement in depressive symptoms with zuranolone treatment, especially on day 15. This suggests that zuranolone is a promising therapeutic option for patients with MDD and PPD with or without insomnia.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=459554, identifier CRD42023459554.

Sialic Acid-Functionalized Gold Nanoparticles for Sensitive and Selective Colorimetric Determination of Serotonin

We present a novel colorimetric method inspired by nature's complex mechanisms, capable of selectively determining serotonin with high sensitivity. This method exploits the inherent binding affinity of serotonin with sialic acid (SA) molecules anchored to gold nanoparticles (SA-AuNPs). Upon serotonin binding, SA-AuNPs aggregate, and a characteristic red shift in the absorbance of SA-AuNPs accompanied by a dramatic color change (red to blue) occurs, readily observable even without instrumentation. The proposed method effectively eliminates interventions from potential interfering species such as dopamine, epinephrine, l-tyrosine, glucosamine, galactose, mannose, and oxalic acid. The absence of a color change with l-tryptophan, a structurally related precursor of serotonin, further confirms the high selectivity of this approach for serotonin detection. The colorimetric method has a wide linear dynamic range (0.05-1.0 μM), low limit of detection (0.02 μM), and fast response time (5 min). The limit of detection of the method is lower than other colorimetric serotonin sensors reported so far. The possible use of the proposed method in biological sample analysis was evaluated by employing a serotonin recovery assay in processed human plasma. The recoveries ranged from 90.5 to 104.2%, showing promising potential for clinical applications.

Risk of abnormal uterine bleeding associated with high-affinity compared with low-affinity serotonin and norepinephrine reuptake inhibitors

BACKGROUND

Concerns have been raised about the potential association between selective serotonin reuptake inhibitors (SSRIs)/serotonin-norepinephrine reuptake inhibitors (SNRIs) and the risk of abnormal uterine bleeding (AUB), which may be influenced by the affinity of SSRIs/SNRIs for serotonin transporter. Thus, we assessed whether SSRIs/SNRIs with high-affinity for serotonin transporter are associated with AUB compared to SSRIs/SNRIs with low-affinity in non-pregnant women.

METHODS

Using the UK Clinical Practice Research Datalink, we identified a cohort of women aged 15-24 years, newly prescribed a high- or low-affinity SSRI/SNRI between 1990 and 2019. Confounding was addressed using standardized morbidity ratio weighting. We used weighted Cox proportional hazards models to estimate the hazard ratio (HR) and 95 % confidence interval (CI) of AUB associated with high-affinity compared with low-affinity SSRIs/SNRIs. We assessed the risk of anemia as a secondary outcome.

RESULTS

The cohort included 156,307 users of high-affinity SSRIs/SNRIs and 102,631 users of low-affinity SSRIs/SNRIs. High-affinity SSRIs/SNRIs were not associated with an increased risk of AUB compared with low-affinity SSRIs/SNRIs (incidence rates: 46.3 versus 42.4 per 1000 person-years, respectively; HR 1.01, 95 % CI 0.93-1.09). Duration of use, age, and comorbidities did not modify the risk. However, high-affinity SSRIs/SNRIs were associated with an increased risk of anemia (HR 1.29, 95 % CI 1.04-1.61) compared with low-affinity SSRIs/SNRIs.

LIMITATIONS

Residual confounding may still be present.

CONCLUSIONS

The risk of AUB did not differ between high- and low-affinity SSRIs/SNRIs. However, the potential risk of anemia suggests the need for monitoring and further investigation of the risk of AUB with these medications.

Serotonin norepinephrine reuptake inhibitors in managing neuropathic pain following spinal and non-spinal surgery: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

While serotonin norepinephrine reuptake inhibitors (SNRIs) offer promise in managing Post-surgical neuropathic pain (PSNP), uncertainties remain. This study aims to evaluate the effectiveness and adverse events of SNRIs in managing PSNP.

METHODS

Systematic searches of PubMed, Embase, and Cochrane databases up to January 1st 2023 identified randomized controlled trials (RCTs) comparing SNRIs to placebo for PSNP. The primary outcome measures were pain at rest and adverse events post-surgery. Subgroup analyses were conducted based on surgical type and specific SNRIs.

RESULTS

A total of 19 RCTs, encompassing 1440 participants (719 in the SNRI group vs 721 in the placebo group), met the inclusion criteria and were included. The pooled results demonstrated that pain scores were significantly lower in patients treated with SNRIs at 2 hours (MD:-0.26; 95%CI: -0.47 to -0.04; p=0.02), 6 hours (MD:-0.68; 95%CI: -1.01 to -0.34; p<0.0001), 24 hours (MD:-0.54; 95%CI: -0.99 to -0.09; p=0.02), and 48 hours (MD:-0.66; 95%CI: -1.23 to -0.10; p=0.02) post-surgery. In terms of adverse events, dizziness (OR:2.53; 95%CI: 1.34-4.78; p=0.004) and dry mouth (OR:2.21; 95%CI: 1.25-3.92; p=0.007) were significantly higher in the SNRIs group. Subgroup analysis showed that SNRI was found to significantly lower the 24-hour pain score after spinal surgery (MD:-0.45; 95%CI: -0.84 to -0.05; p=0.03). Duloxetine (MD:-0.63; 95%CI: -1.15 to -0.11; p=0.02) had a significant effect in lowering the 24-hour pain score at rest compared to placebo, whereas venlafaxine did not.

CONCLUSIONS

SNRIs yielded considerable pain score reductions across multiple post-surgical intervals, although accompanied by an increased incidence of dizziness and dry mouth.

Pain management considerations in patients living with both pain syndromes and cardiovascular diseases and disorders

Concomitant pain syndromes and cardiovascular disease (CVD) and disorders are associated with significant morbidity, impaired quality of life, and neuropsychiatric disorders. There is an interplay between the mechanisms of pathophysiology of both CVD and pain syndromes. Patients with CVD (and/or disorders) as well as pain syndromes have an increased propensity for drug-drug/disease interactions. Therefore, an understanding of how to use pharmacotherapy to treat pain syndromes, in the context of patients who have diagnoses of CVD and/or disorders, is paramount to patients' success in achieving adequate pain control and appropriately managing CVD and/or disorders, all while decreasing the risk of adverse events (AEs) both from pharmacotherapy to treat pain and CVD (and/or disorders). Based on the appraisal of literature and authors' clinical expertise, it was determined that gabapentinoids, opioids, skeletal muscle relaxants, tricyclic antidepressants, clonidine, serotonin norepinephrine-reuptake inhibitors, dronabinol, carbamazepine, second-generation antipsychotics, non-steroidal anti-inflammatory drugs, aspirin, corticosteroids, and topical anesthetics have the most evidence for use in patients with CVD and/or disorders. However, the literature surrounding the use of pharmacotherapy for pain management is limited to retrospective studies and there is a lack of well-designed, prospective, randomized trials; this also includes head-to-head comparator studies. Unlike many CVD-related pharmacotherapy studies, data studying pain management in patients with CVD lacks standardized outcomes that are consistent among the pool of data. Overall, the decision to prescribe specific pain management therapies in patients with CVD and/or disorders should include assessment of pain severity, type of pain, drug-drug/disease interactions, adjuvant therapies required, and the risk or presence of AEs.

Pharmacological strategies for appetite modulation in eating disorders: a narrative review

BACKGROUND

A substantial increase in the prevalence of eating disorders has been noticed over the past decades. Priority in the treatment of eating disorders is justifiably given to psychosocial interventions. However, it is also well known that centrally acting drugs can significantly affect appetite and food consumption.

AIM

To narratively review the available neurobiological data on the mechanisms of central regulation of eating behavior as a rationale to summarize pharmacological strategies for appetite modulation in eating disorders.

METHODS

The authors have carried out a narrative review of scientific papers published from January 2013 to March 2023 in the PubMed and Web of Science electronic databases. Studies were considered eligible if they included data on the neurobiological mechanisms of appetite regulation or the results of clinical trials of centrally acting drugs in eating disorders. Relevant studies were included regardless of their design. Descriptive analysis was used to summarize the obtained data.

RESULTS

The review included 51 studies. The available neurobiological and clinical data allowed us to identify the following pharmacological strategies for appetite modulation in eating disorders: serotonergic, catecholaminergic, amino acidergic and peptidergic. However, implementation of these data into clinical practice difficult due to an insufficient number of good-quality studies, which is particularly relevant for adolescents as there is a research gap in this population.

CONCLUSION

The progress in neurobiological understanding of the mechanisms of central regulation of appetite opens opportunities for new pharmacotherapeutic approaches aimed at changing the patterns of eating behavior. Obviously, treatment of eating disorders is a much broader problem and cannot be reduced to the correction of eating patterns. Nevertheless, at certain stages of treatment, drug-induced modulation of appetite can play an important role among multi-targeted biological and psychosocial interventions. Translation of neurobiological data into clinical practice requires a large number of clinical studies to confirm the long-term efficacy and safety of pharmacotherapeutic approaches and to develop personalized algorithms for the treatment of various forms of eating disorders in different age groups.

Antidepressant Use and Lung Cancer Risk and Survival: A Meta-analysis of Observational Studies

Recent preclinical studies have linked antidepressants (AD) to their potential anticancer effects in multiple cancers, but the impact on lung cancer remains unclear. This meta-analysis examined the associations between ADs and lung cancer incidence and survival. The Web of Science, Medline, CINAHL, and PsycINFO databases were searched to identify eligible studies published by June 2022. We conducted a meta-analysis using a random-effects model to compare the pooled risk ratio (RR) and 95% confidence interval (CI) in those treated with or without ADs. Heterogeneity was examined using Cochran Q test and inconsistency I² statistics. The methodologic quality of the selected studies was assessed using the Newcastle-Ottawa Scale for observational studies. Our analysis, including 11 publications involving 1,200,885 participants, showed that AD use increased lung cancer risk by 11% (RR = 1.11; 95% CI = 1.02-1.20; I² = 65.03%; n = 6) but was not associated with overall survival (RR = 1.04; 95% CI = 0.75-1.45; I² = 83.40%; n = 4). One study examined cancer-specific survival. Subgroup analysis showed that serotonin and norepinephrine reuptake inhibitors (SNRIs) were associated with an increased lung cancer risk by 38% (RR = 1.38; 95% CI = 1.07-1.78; n = 2). The quality of selected studies was good (n = 5) to fair (n = 6). Our data analysis suggests that SNRIs were associated with an elevated risk of lung cancer, raising concerns regarding the use of AD treatment in patients vulnerable to lung cancer. The effects of ADs-particularly SNRIs-and their interplay with cigarette use and lung cancer risk in vulnerable patients merits further study.

Significance

In this meta-analysis of 11 observational studies, we found evidence of a statistically significant association between the use of certain ADs and lung cancer risk. This effect merits further study, particularly as it relates to known environmental and behavioral drivers of lung cancer risk, such as air pollution and cigarette smoke.

Antidepressant pharmaceuticals in aquatic systems, individual-level ecotoxicological effects: growth, survival and behavior

The growing consumption of antidepressant pharmaceuticals has resulted in their widespread occurrence in the environment, particularly in waterways with a typical concentration range from ng L^-1 to μg L^-1. An increasing number of studies have confirmed the ecotoxic potency of antidepressants, not only at high concentrations but also at environmentally relevant levels. The present review covers literature from the last decade on the individual-level ecotoxicological effects of the most commonly used antidepressants, including their impact on behavior, growth, and survival. We focus on the relationship between antidepressants physico-chemical properties and dynamics in the environment. Furthermore, we discuss the advantages of considering behavioral changes as sensitive endpoints in ecotoxicology, as well as some current methodological shortcomings in the field, including low standardization, reproducibility and context-dependency.

Could the fibromyalgia syndrome be triggered or enhanced by COVID-19?

Fibromyalgia (FM) is a complex disease with an uncertain aetiology and intricate pathophysiology. Although its genesis is not fully explained, potential environmental factors, such as viral infections might trigger FM or worsen patients' clinical outcomes. The SARS-CoV-2 virus may affect central and peripheral nervous systems, leading to musculoskeletal, neurological, and psychological disturbances. These symptoms might persist at least 12 months beyond the recovery, often referred to as post-COVID syndrome, which resembles FM syndrome. In this sense, we argued the potential consequences of COVID-19 exclusively on FM syndrome. First, we have described post-COVID syndrome and its painful symptoms. Afterwards, we argued whether FM syndrome could be triggered or enhanced by COVID-19 infection or by numerous and persistent stressors imposed daily by the pandemic setting (isolation, uncertainty, depression, mental stress, generalized anxiety, and fear of the virus). In addition, we have demonstrated similarities between pathophysiological mechanisms and cardinal symptoms of FM and COVID-19, speculating that SARS-CoV-2 might represent a critical mediator of FM or an exacerbator of its symptoms once both syndromes share similar mechanisms and complaints. Therefore, pharmacologic and non-pharmacological approaches commonly used to treat FM could serve as strategic therapies to attenuate painful and neurological manifestations of post-COVID syndrome. Although it is still theoretical, clinicians and researchers should be alert of patients who develop symptoms similar to FM or those who had their FM symptoms increased post-COVID to manage them better.

Monoamine control of descending pain modulation after mild traumatic brain injury

Traumatic brain injury (TBI) is a significant public health concern, with the majority of injuries being mild. Many TBI victims experience chronic pain. Unfortunately, the mechanisms underlying pain after TBI are poorly understood. Here we examined the contribution of spinal monoamine signaling to dysfunctional descending pain modulation after TBI. For these studies we used a well-characterized concussive model of mild TBI. Measurements included mechanical allodynia, the efficacy of diffuse noxious inhibitory control (DNIC) endogenous pain control pathways and lumber norepinephrine and serotonin levels. We observed that DNIC is strongly reduced in both male and female mice after mild TBI for at least 12 weeks. In naïve mice, DNIC was mediated through α2 adrenoceptors, but sensitivity to α2 adrenoceptor agonists was reduced after TBI, and reboxetine failed to restore DNIC in these mice. The intrathecal injection of ondansetron showed that loss of DNIC was not due to excess serotonergic signaling through 5-HT₃ receptors. On the other hand, the serotonin-norepinephrine reuptake inhibitor, duloxetine and the serotonin selective reuptake inhibitor escitalopram both effectively restored DNIC after TBI in both male and female mice. Therefore, enhancing serotonergic signaling as opposed to noradrenergic signaling alone may be an effective pain treatment strategy after TBI.