Comparison of the effects of escitalopram and nortriptyline on painful symptoms in patients with major depression

Blocking coprophagy increases the levels of inflammation and depression in healthy mice as well as mice receiving fecal microbiota transplantation from disease model mice donors

Rodents have been extensively used as animal models in microbiome studies. However, all rodents have a habitual nature called coprophagy, a phenomenon that they self-reinoculate feces into their gastrointestinal tract. Recent studies have shown that blocking coprophagy can alter rodents' diversity of gut microbiota, metabolism, neurochemistry, and cognitive behavior. However, whether rodents' coprophagy behavior affects the levels of inflammation and depression is unclear. In order to address this problem, we first blocked coprophagy in healthy mice. It displayed an increase in the levels of depression, verified by depressive-like behaviors and mood-related indicators, and inflammation, verified by the increased levels of the pro-inflammatory cytokine, in coprophagy-blocked mice. Furthermore, we transplanted fecal microbiota from chronic restraint stress (CRS) depression model mice and lipopolysaccharide (LPS) inflammation model mice to healthy recipient mice, respectively. It showed that the disease-like phenotypes in the coprophagy-blocked group were worse than those in the coprophagy-unblocked group, including severer depressive symptoms and higher levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and IFN-γ) in serum, prefrontal cortex (PFC), and hippocampus (HIP). These findings showed that blocking coprophagy in mice not only increased the levels of inflammation and depression in healthy mice but also aggravated inflammation and depression induced by fecal microbiota from disease donors. The discovery may provide a vital reference for future research involving FMT in rodents.

Involvement of the microbiota-gut-brain axis in chronic restraint stress: disturbances of the kynurenine metabolic pathway in both the gut and brain

Emerging evidence suggests that the gut microbiota may interact with the host brain and play pivotal roles in the pathogenesis of neuropsychiatric disorders. However, the mechanism underlying reciprocal interactions along the microbiota-gut-brain axis in depression remains unclear. In this study, a murine model of chronic restraint stress (CRS) was established to investigate the metabolic signaling of tryptophan (Trp) neurotransmission at the intestinal and central levels in depression. The results showed that CRS mice displayed depression- and anxiety-like behaviors. Additionally, kynurenine (Kyn) and its metabolites, an important Trp metabolic pathway, were strongly activated in the brain. Intriguingly, the Kyn toxic signaling was exacerbated in the gut, especially in the colon. Indoleamine 2,3-dioxygenase (IDO), a rate-limiting enzyme responsible for Kyn metabolic pathway initiation, was significantly upregulated in the brain and gut in CRS mice compared with control mice, promoting transfer of Trp metabolic pathway to Kyn signaling. Additionally, administration of IDO inhibitor, 1-methyl-tryptophan (1-MT), partially rescued CRS-induced depression- and anxiety-like changes. Moreover, the enhanced intestinal permeability mediated by CRS allowed toxic metabolites to "leak" into the bloodstream. The microbiome profiles of CRS mice displayed obviously altered taxonomic composition and negative correlations were observed between Enterorhabdus, Parabacteroides and Kyn levels in the brain. Reciprocal crosstalk between the brain and gut was further validated by citalopram treatment, IDO inhibitor and microbiota intervention, which counteracted depression-like behavior, Kyn metabolic signaling and microbiota composition in CRS mice. Meanwhile, Parabacteroides treatment affected Trp metabolism in mouse hippocampus, manifesting as elevated concentration of 5-HT as well as ratio of 5-HT to Trp. These results suggest that long-term stress disrupts Kyn metabolism and endocrine function along the gut-brain axis, accompanied by the disrupted homeostasis of certain microbiota, which collectively contribute to the development of depression-like behavior.

Remote Digital Measurement of Facial and Vocal Markers of Major Depressive Disorder Severity and Treatment Response: A Pilot Study

Objectives: Multiple machine learning-based visual and auditory digital markers have demonstrated associations between major depressive disorder (MDD) status and severity. The current study examines if such measurements can quantify response to antidepressant treatment (ADT) with selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine uptake inhibitors (SNRIs). Methods: Visual and auditory markers were acquired through an automated smartphone task that measures facial, vocal, and head movement characteristics across 4 weeks of treatment (with time points at baseline, 2 weeks, and 4 weeks) on ADT (n = 18). MDD diagnosis was confirmed using the Mini-International Neuropsychiatric Interview (MINI), and the Montgomery-Åsberg Depression Rating Scale (MADRS) was collected concordantly to assess changes in MDD severity. Results: Patient responses to ADT demonstrated clinically and statistically significant changes in the MADRS [F (2, 34) = 51.62, p < 0.0001]. Additionally, patients demonstrated significant increases in multiple digital markers including facial expressivity, head movement, and amount of speech. Finally, patients demonstrated significantly decreased frequency of fear and anger facial expressions. Conclusion: Digital markers associated with MDD demonstrate validity as measures of treatment response.

Comparative Efficacy and Safety of Clonazepam versus Nortriptyline in Restless Leg Syndrome among Forty Plus Women: A Prospective, Open-Label Randomized Study

Aims and Objectives:

The aim of this study is to compare the effect of clonazepam and nortriptyline on rate, frequency, and severity of restless leg syndrome (RLS) in above 40 years women suffering from RLS.

Materials and Methods:

A prospective, randomized, open-label comparative study was conducted at a tertiary care teaching hospital for 1 year. Restless legs syndrome (RLS) diagnosis was based on four essential clinical criteria established by the International RLS Study Group in 2003. Patients were randomized into two groups. Group 1 received tablet clonazepam 0.5 mg bedtime orally daily. Group 2 received tablet nortriptyline 25 mg bedtime orally daily. The primary efficacy endpoints by the International Restless leg Syndrome Scale (IRLS) were evaluated at 0, 4, and 8 weeks. Adverse drug events and safety assessment for vital signs such as blood pressure, pulse, heart rate, waist circumference, and body mass index were compared between two groups.

Results:

Effect on mean IRLSS was statistically more in clonazepam group in comparison to nortriptyline group with comparable results at 8 weeks (P < 0.001), but at 4 weeks, nortriptyline showed less improvement (P < 0.01) versus P < 0.001 in nortriptyline group. Thus, nortriptyline reported relatively more improvement on IRLSS numerically in comparison to clonazepam. Nortriptyline proved to be statistically better in improving the frequency of RLS with comparison to clonazepam, whereas the results were comparable with regard to rate and the severity of RLS. Both the groups were relatively safe and did not produce any change in biochemical parameters and were free from any serious or severe adverse events and overall, both the treatments were well tolerated.

Conclusion:

Both the drugs provided clinically and statistical significant effect on RLS when compared with their respective baselines. However, nortriptyline proved to be statistically better in improving the frequency of RLS in comparison to clonazepam, whereas the results were comparable with regard to rate and the severity of RLS on intergroup comparison. Both the drugs were well tolerated.

Tricyclic Antidepressants Modulate Stressed Mitochondria in Glioblastoma Multiforme Cells

A common feature of solid tumors, including glioblastoma multiforme (GBM), is mitochondrial dysfunction. However, it is reported that the current standard of anti-GBM therapies may potentiate mitochondrial damage and, in effect, support the aggressive character of cancer. As mitochondria are implicated in the modulation of cellular drug sensitivity and chemoresistance mechanisms, activation-stressed mitochondria in GBM cells may represent a new target for anti-GBM therapy that is nontoxic for normal cells.

METHODS

As mitochondria are possible targets for antidepressant drugs used as adjuvant therapy in patients with GBM, we examined their influence on mitochondrial volume and activity, reactive oxygen species level, extracellular lactate concentration, and p65 NF-κB gene expression in GBM cells.

RESULTS

Our investigation showed, for the first time, that tricyclic antidepressants, imipramine and amitriptyline, partially reverse GBM abnormalities.

CONCLUSION

In the light of reported studies, the mitochondrial disturbance observed in glioma cells is a dynamic process that can be reversed or silenced. Moreover, imipramine and amitriptyline are attractive cellular metabolic modulators and can potentially be used to restoring a proper function of mitochondria in GBM cells.

Pain Relief in Depressive Disorders: A Meta-Analysis of the Effects of Antidepressants

BACKGROUND

Pain is a common symptom in patients with depressive disorders, which, if present, worsens the prognosis. However, there is little empirical knowledge of the therapeutic effects of antidepressants on painful physical symptoms of patients with depressive disorders. Furthermore, tricyclic/tetracyclic antidepressants (TCAs) have not yet been included in existing meta-analyses.

METHODS

A broad, systematic search of PubMed literature on antidepressant drug treatment of patients with depressive disorders with comorbid pain symptoms was carried out. A random-effects meta-analysis has been performed among 3 different groups of drugs for the 2 end points: pain and depression.

RESULTS

Fourteen placebo-controlled studies with selective serotonin-noradrenaline reuptake inhibitors (SSNRIs) could be included, with 3 of them also investigating selective serotonin reuptake inhibitors (SSRIs). Three further placebo-controlled SSRI studies were identified, but only 2 placebo-controlled TCA studies.Both SSNRIs and SSRIs, but not TCAs, were significantly superior to placebo as regards their analgesic effects. However, all effects were small. For SSNRIs, there was a strong positive correlation between their effectiveness for pain relief and their positive effect on the mood of the patients.

DISCUSSION

The analgesic effects of SSNRIs and SSRIs in patients with primary depressive disorders can be interpreted as largely equivalent. Because of a lack of placebo-controlled TCA studies, the results for TCAs would be comparable only to those of SSRIs and SSNRIs, if non-placebo-controlled TCA studies were included. The positive correlation found indicates a close relationship of pain relief and antidepressant treatment effects. These results refer merely to patients with primary depressive disorders, not to patients with primary pain disorders. Further studies comparing the effects of different types of antidepressant drugs on pain in depressive patients are warranted.

Unexplained Painful Physical Symptoms in Patients with Major Depressive Disorder: Prevalence, Pathophysiology and Management

Patients with major depression often report pain. In this article, we review the current literature regarding the prevalence and consequences, as well as the pathophysiology, of unexplained painful physical symptoms (UPPS) in patients with major depressive disorder (MDD). UPPS are experienced by approximately two-thirds of depressed patients. The presence of UPPS makes a correct diagnosis of depression more difficult. Moreover, UPPS are a predictor of a poor response to treatment and a more chronic course of depression. Pain, in the course of depression, also has a negative impact on functioning and quality of life. Frequent comorbidity of depression and UPPS has inspired the formulation of an hypothesis regarding a shared neurobiological mechanism of both conditions. Evidence from neuroimaging studies has shown that frontal-limbic dysfunction in depression may explain abnormal pain processing, leading to the presence of UPPS. Increased levels of proinflamatory cytokines and substance P in patients with MDD may also clarify the pathophysiology of UPPS. Finally, dysfunction of the descending serotonergic and noradrenergic pathways that normally suppress ascending sensations has been proposed as a core mechanism of UPPS. Psychological factors such as catastrophizing also play a role in both depression and chronic pain. Therefore, pharmacological treatment and/or cognitive therapy are recommended in the treatment of depression with UPPS. Some data suggest that serotonin and noradrenaline reuptake inhibitors (SNRIs) are more effective than selective serotonin reuptake inhibitors (SSRIs) in the alleviation of depression and UPPS. However, the pooled analysis of eight randomised clinical trials showed similar efficacy of duloxetine (an SNRI) and paroxetine (an SSRI) in reducing UPPS in depression. Further integrative studies examining genetic factors (e.g. polymorphisms of genes for interleukins, serotonin transporter and receptors), molecular factors (e.g. cytokines, substance P) and neuroimaging findings (e.g. functional studies during painful stimulation) might provide further explanation of the pathophysiology of UPPS in MDD and therefore facilitate the development of more effective methods of treatment.

Therapeutic Basis of Clinical Pain Modulation

Pain is a hallmark of almost all bodily ailments and can be modulated by agents, including analgesics and anesthetics that suppress pain signals in the central nervous system. Defects in the modulatory systems, including the endogenous pain-inhibitory pathways, are a major factor in the initiation and chronicity of pain. Thus, pain modulation is particularly applicable to the practice of medicine. This review summarizes the existing literature on pain modulation. Here, we critically reviewed the literature from PubMed on pain modulation published primarily within the past 5 years in high impact journals. Specifically, we have discussed important anatomical landmarks of pain modulation and outlined the endogenous networks and underlying mechanisms of clinically relevant pain modulatory methods. The Gate Control Theory is briefly presented with discussion on the capacity of pain modulation to cause both hyper- and hypoalgesia. An emphasis has been given to highlight key areas in pain research that, because of unanswered questions or therapeutic potential, merit additional scientific scrutiny. The information presented in this paper would be helpful in developing novel therapies, metrics, and interventions for improved patient management.