Therapeutic options for treatment-resistant depression

Involvement of PI3K/AKT Pathway in the Rapid Antidepressant Effects of Crocetin in Mice with Depression-Like Phenotypes

The current first-line antidepressants have the drawback of slow onset, which greatly affects the treatment of depression. Crocetin, one of the main active ingredients in saffron (Crocus sativus L.), has been demonstrated to have antidepressant activities, but whether it has a rapid antidepressant effect remains unclear. This study aimed to investigate the onset, duration, and mechanisms of the rapid antidepressant activity of crocetin (20, 40 and 80 mg/kg, intraperitoneal injection) in male mice subjected to chronic restraint stress (CRS). The results of behavioral tests showed that crocetin exerted rapid antidepressant-like effect in mice with depression-like phenotypes, including rapid normalization of depressive-like behaviors within 3 h, and the effects could be maintained for 2 days. Hematoxylin-eosin (HE) and Nissl staining showed that crocetin ameliorated hippocampal neuroinflammation and nerve injuries in mice with depression-like phenotypes. The levels of inflammatory factors, corticosterone and pro brain-derived neurotrophic factor in crocetin-administrated mice serum were significantly reduced compared with those in the CRS group, as well as the levels of inflammatory factors in hippocampus. What's more, Western blot analyses showed that, compared to CRS-induced mice, the relative levels of mitogen-activated kinase phosphatase 1 and toll-like receptor 4 were significantly reduced after the administration of crocetin, and the relative expressions of extracellular signal-regulated kinase 1/2 (ERK1/2), cAMP-response element binding protein, phosphorylated phosphoinositide 3 kinase (p-PI3K)/PI3K, phosphorylated protein kinase B (p-AKT)/AKT, phosphorylated glycogen synthase kinase 3β (p-GSK3β)/GSK3β, phosphorylated mammalian target of rapamycin (p-mTOR)/mTOR were markedly upregulated. In conclusion, crocetin exerted rapid antidepressant effects via suppressing the expression of inflammatory cytokines and the apoptosis of neuronal cells through PI3K/AKT signaling pathways. The rapid antidepressant effect of crocetin (40 mg/kg) could be maintained for at least 2 days after single treatment.

A Meta-Analysis of the Antidepressant Responses in Pivotal Trials on Esketamine Nasal Spray and Atypical Antipsychotics

Purpose

This meta-analysis assessed whether atypical antipsychotics (AAPs) and esketamine nasal spray (ESK-NS), which are mechanistically distinct, differ in antidepressant outcomes.

Patients and Methods

Data were extracted from 12 trials of ESK-NS or AAPs in depressed patients (4276) with inadequate response or resistance to conventional antidepressants. Montgomery-Åsberg Depression Rating Scale (MADRS) score reductions from baseline and response rates (≥50% reduction) were analyzed.

Results

At endpoint, the estimated MADRS score reduction of pooled ESK-NS arms was greater than pooled AAP arms (+9.16 points, p < 0.0001). The reduction also was greater in the pooled control arms of the ESK-NS trials than the pooled control arms of the AAP trials (+7.57 points, p < 0.0001). The mean difference in the reductions between pooled ESK-NS and control arms was 1.87 points greater than that between pooled AAP and control arms, but this difference was not significant (95% CI: -4.49, 0.74, p = 0.16). Relative to their respective control arms, the mean difference in response rates was 25% for the pooled ESK-NS and 9% for the pooled AAP arms; the mean response rate was 16% greater in the pooled ESK-NS studies than the pooled AAP studies (p = 0.0004). Comparisons against specific AAPs showed mean differences in the MADRS score reductions at 1 week between the experimental and control arms that were numerically larger in the ESK-NS trials than in the aripiprazole trials (mean difference of 1.71 points, p = 0.06) and the brexpiprazole trials (mean difference of 2.05 points, p = 0.02).

Conclusion

The ESK-NS arms showed numerically larger MADRS score reductions at week-1 and endpoint, and a significantly larger response rate compared with AAP arms. Prospective studies involving direct comparisons are warranted to compare the relative efficacy between these treatment regimens.

Psychoactive substances 25H-NBOMe and 25H-NBOH induce antidepressant-like behavior in male rats

Ring-substituted phenethylamines are believed to induce psychedelic effects primarily by interacting with 5-hydroxytryptamine 2 (5-HT2A) receptors in the brain. We assessed the effect of the psychedelic substances 25H-NBOMe and 25H-NBOH on the depressive-like behavior of male adult rats. Naive Wistar rats were divided into groups to assess the effects of different doses (0.1 mg/kg, 1 mg/kg, and 3 mg/kg) of 25H-NBOMe and 25H-NBOH. The substances were administered intraperitoneally and the hallucinogenic properties were evaluated using the head twitch response test (HTR). Additionally, we assessed their locomotor activity in the open field test (OFT) and depressive-like behavior in the forced swimming test (FST). Our data demonstrated that all doses of synthetic psychedelic substances evaluated exhibited hallucinogenic effects. Interestingly, we observed that both 25H-NBOMe and 25H-NBOH produced a significantly greater motivation to escape in the FST, compared to the control group. Furthermore, we found no significant differences in locomotor activity during the OFT, except for the dose of 3 mg/kg, which induced a reduction in locomotion. This study provides new insights into a potential psychedelic substance, specifically by demonstrating the previously unknown antidepressant properties of a single dose of both 25H-NBOMe and 25H-NBOH. These findings contribute to the ongoing progress of experimental psychiatry toward developing safe and effective clinical practices in the field of psychedelics research.

Instantaneous antidepressant effect of lateral habenula deep brain stimulation in rats studied with functional MRI

The available treatments for depression have substantial limitations, including low response rates and substantial lag time before a response is achieved. We applied deep brain stimulation (DBS) to the lateral habenula (LHb) of two rat models of depression (Wistar Kyoto rats and lipopolysaccharide-treated rats) and observed an immediate (within seconds to minutes) alleviation of depressive-like symptoms with a high-response rate. Simultaneous functional MRI (fMRI) conducted on the same sets of depressive rats used in behavioral tests revealed DBS-induced activation of multiple regions in afferent and efferent circuitry of the LHb. The activation levels of brain regions connected to the medial LHb (M-LHb) were correlated with the extent of behavioral improvements. Rats with more medial stimulation sites in the LHb exhibited greater antidepressant effects than those with more lateral stimulation sites. These results indicated that the antidromic activation of the limbic system and orthodromic activation of the monoaminergic systems connected to the M-LHb played a critical role in the rapid antidepressant effects of LHb-DBS. This study indicates that M-LHb-DBS might act as a valuable, rapid-acting antidepressant therapeutic strategy for treatment-resistant depression and demonstrates the potential of using fMRI activation of specific brain regions as biomarkers to predict and evaluate antidepressant efficacy.

Approach to Diagnosis and Management of Treatment-Resistant Depression

Major depressive disorder is a chronic and recurrent illness that affects 20% of adults during their lifetime and is one of the leading causes of suicide in the United States. A systematic measurement-based care approach is the essential first step in the diagnosis and management of treatment-resistant depression (TRD) by promptly identifying individuals with depression and avoiding delays in treatment initiation. As comorbidities may be associated with poorer outcomes to commonly used antidepressants and increase risk of drug-drug interactions, their recognition and treatment is an essential component of management of TRD.

Electroconvulsive therapy for treatment-resistant depression

Electroconvulsive therapy (ECT), the oldest brain stimulation procedure in psychiatry, is associated with rapid response and remission in majority of patients with resistant, severe, and sometimes life-threatening depression. ECT has been included as an essential component in the definition of treatment-resistant depression (TRD) to display the course and diversification of TRD. On the other hand, ECT remains the treatment of choice for the most severe incapacitating forms of TRD and is a cost-effective treatment. In this chapter, we reviewed some essential studies, meta-analysis, and expert guidelines regarding ECT in TRD. ECT should not be considered as a treatment of last resort, and its administration should be considered on the basis of individual patient and illness factors. The clinical role of ECT vs other neurostimulation treatments for TRD, that is, repetitive transcranial magnetic stimulation, were also explored. Much effort has been directed toward the clinical and basic research about mechanisms of action of ECT in depression. A thorough understanding of the neurobiological effects of ECT may increase our understanding of its therapeutic effects, ultimately leading to improved patient care. We also showed that the distinct mechanisms of ECT in biological treatments of major depressive disorder (MDD) and some recent approaches to understand this most common psychiatric disorder. ECT should remain a standard part of modern psychiatric medicine. We recommend a more careful and thoughtful application of this traditional but effective technology.

Apparent Lack of Benefit of Combining Repetitive Transcranial Magnetic Stimulation with Internet-Delivered Cognitive Behavior Therapy for the Treatment of Resistant Depression: Patient-Centered Randomized Controlled Pilot Trial

Background: Treatment-resistant depression (TRD) is considered one of the major clinical challenges in the field of psychiatry. An estimated 44% of patients with major depressive disorder (MDD) do not respond to two consecutive antidepressant therapies, and 33% do not respond to up to four antidepressants. Over 15% of all patients with MDD remain refractory to any treatment intervention. rTMS is considered a treatment option for patients with TRD. Likewise, iCBT is evidence-based, symptom-focused psychotherapy recommended for the treatment of TRD. Objective: This study aimed to evaluate the initial comparative clinical effectiveness of rTMS treatment with and without iCBT as an innovative intervention for the treatment of participants diagnosed with TRD. Methods: This study is a prospective two-arm randomized controlled trial. Overall, 78 participants diagnosed with TRD were randomized to one of two treatment interventions: rTMS sessions alone and rTMS sessions plus iCBT. Participants in each group were made to complete evaluation measures at baseline, and 6 weeks (discharge) from treatment. The primary outcome measure was baseline to six weeks change in mean score for the 17-item Hamilton depression rating scale (HAMD-17). Secondary outcomes included mean baseline to six-week changes in the Columbia suicide severity rating scale (CSSRS) for the rate of suicidal ideations, the QIDS-SR16 for subjective depression, and the EQ-5D-5L to assess the quality of health in participants. Results: A majority of the participants were females 50 (64.1%), aged ≥ 40 39 (50.0%), and had college/university education 54 (73.0%). After adjusting for the baseline scores, the study failed to find a significant difference in the changes in mean scores for participants from baseline to six weeks between the two interventions under study on the HAMD-17 scale: F (1, 53) = 0.15, p = 0.70, partial eta squared = 0.003, CSSRS; F (1, 56) = 0.04 p = 0.85, partial eta squared = 0.001, QIDS-SR16 scale; F (1, 53) = 0.04 p = 0.61, partial eta squared = 0.005, and EQ-5D-VAS; F (1, 51) = 0.46 p = 0.50, and partial eta squared = 0.009. However, there was a significant reduction in means scores at week six compared to baseline scores for the combined study population on the HAMD-17 scale (42%), CSSRS (41%), QIDS-SR16 scale (35%), and EQ-VAS scale (62%). Conclusion: This study did not find that combined treatment of TRD with rTMS + iCBT (unguided) was superior to treatment with rTMS alone. Our findings do not support the use of combined treatment of rTMS + iCBT for the management of TRD disorders.

Efficacy and safety of nitrous oxide for patients with treatment-resistant depression, a randomized controlled trial

Nitrous oxide (N₂O), an N-methyl-D-aspartate glutamate receptor antagonist, has demonstrated a rapid-onset antidepressant effect for treatment-resistant depression (TRD) preliminarily in the United States. This study aimed to test the efficacy and safety of N₂O for TRD patients in China. In this double-blinded, placebo-controlled trial, 44 patients with TRD were randomized to receive a one-hour inhalation of a mixture of either 50% N₂O/50% oxygen (N₂O group) or 50% air/50% oxygen (placebo group). The primary outcome was the change on the 17-item Hamilton Depression Rating Scale (HDRS-17) over a course of two weeks. Using modified intention-to-treat analysis, the between group difference was found in the HDRS-17 score at two hours and 24 h after inhalation treatment, while no significant difference was found in week one and week two. Patients receiving N₂O reported a significantly higher number of adverse events. All the adverse events lasted for no more than 24 h. No serious adverse events were reported. A single inhalation of 50% N₂O effectively alleviates depression in patients with TRD in China. The efficacy lasts for no more than one week. N₂O is safe for patients with TRD.

Pathological fear, anxiety and negative affect exhibit distinct neurostructural signatures: evidence from psychiatric neuroimaging meta-analysis

Internalizing disorders encompass anxiety, fear and depressive disorders, which exhibit overlap at both conceptual and symptom levels. Given that a neurobiological evaluation is lacking, we conducted a Seed-based D-Mapping comparative meta-analysis including coordinates as well as original statistical maps to determine common and disorder-specific gray matter volume alterations in generalized anxiety disorder (GAD), fear-related anxiety disorders (FAD, i.e., social anxiety disorder, specific phobias, panic disorder) and major depressive disorder (MDD). Results showed that GAD exhibited disorder-specific altered volumes relative to FAD including decreased volumes in left insula and lateral/medial prefrontal cortex as well as increased right putamen volume. Both GAD and MDD showed decreased prefrontal volumes compared to controls and FAD. While FAD showed less robust alterations in lingual gyrus compared to controls, this group presented intact frontal integrity. No shared structural abnormalities were found. Our study is the first to provide meta-analytic evidence for distinct neuroanatomical abnormalities underlying the pathophysiology of anxiety-, fear-related and depressive disorders. These findings may have implications for determining promising target regions for disorder-specific neuromodulation interventions (e.g. transcranial magnetic stimulation or neurofeedback).

rTMS/iTBS and Cognitive Rehabilitation for Deficits Associated With TBI and PTSD: A Theoretical Framework and Review

Rehabilitation of cognitive and psychosocial deficits resulting from traumatic brain injury (TBI) continues to be an area of concern in health care. Commonly co-occurring psychiatric disorders, such as major depressive disorder and posttraumatic stress disorder, create additional hurdles when attempting to remediate cognitive sequelae. There is increased need for procedures that will yield consistent gains indicative of recovery of function. Intermittent theta-burst stimulation (iTBS), a form of repetitive transcranial magnetic stimulation, has potential as an instrument that can be tailored to aid cognitive processes and support functional gains. The use of iTBS enables direct stimulation of desired neural systems. iTBS, performed in conjunction with behavioral interventions (e.g., cognitive rehabilitation, psychotherapy), may result in additive success in facilitating cognitive restoration and adaptation. The purpose of this theoretical review is to illustrate how the technical and physiological aspects of iTBS may enhance other forms of neurorehabilitation for individuals with TBI. Future research on combinatorial iTBS interventions has the potential to translate to other complex neuropsychiatric conditions.

Transcutaneous Electrical Cranial-Auricular Acupoint Stimulation vs. Escitalopram for Patients With Mild-to-Moderate Depression (TECAS): Study Design for a Randomized Controlled, Non-inferiority Trial

Background

Previous studies in animals and humans indicated that transcutaneous vagus nerve stimulation (tVNS) and transcutaneous electrical acupoint stimulation (TEAS) on trigeminal nerve-innervated forehead acupoints can relief the symptoms of depression. However, due to the limited investigations on these two interventions, more research are needed to confirm their efficacy in depression. To improve the efficacy of the single treatment, we combined two treatments and created a novel non-invasive stimulation, transcutaneous electrical cranial-auricular acupoint stimulation (TECAS). To assess the efficacy and safety of TECAS, we compare it with a selective serotonin reuptake inhibitor (SSRI), escitalopram, for the treatment of depression.

Methods/Design

This is a multi-center, non-inferiority, randomized controlled trial that will involve 470 patients with mild to moderate depression. Patients will be randomly assigned to either the TECAS group or the escitalopram group in a 1:1 ratio. The TEAS group will receive two sessions of treatments per day for 8 consecutive weeks, and the escitalopram group will receive 8 weeks of oral escitalopram tablets prescribed by clinical psychiatrists as appropriate for their condition. The primary outcome is the clinical response as determined by Montgomery-Åsberg Depression Rating Scale (MADRS) scores at week 8, with -10% as the non-inferior margin. The secondary outcomes include the response rate determined by 17-item Hamilton Depression Rating Scale (HAMD-17), remission rate, changes from baseline in the scores on the MADRS, the HAMD-17, the Hamilton Anxiety Rating Scale (HAMA), the Pittsburgh Sleep Quality Index (PSQI), and the Short Form 36 Health Survey (SF-36).

Discussion

This will be the first randomized controlled trial to compare the efficacy of TECAS with escitalopram for depression. If effective, this novel intervention could have significant clinical and research implications for patients with depression.

Clinical Trial Registration

[ClinicalTrials.gov], identifier [NCT03909217].

Augmentation strategies for treatment resistant major depression: A systematic review and network meta-analysis

OBJECTIVE

To compare the efficacy and discontinuation of augmentation agents in adult patients with treatment-resistant depression (TRD). We conducted a systematic review and network meta-analyses (NMA) to combine direct and indirect comparisons of augmentation agents.

METHODS

We included randomized controlled trials comparing one active drug with another or with placebo following a treatment course up to 24 weeks. Nineteen agents were included: stimulants, atypical antipsychotics, thyroid hormones, antidepressants, and mood stabilizers. Data for response/remission and all-cause discontinuation rates were analyzed. We estimated effect-size by relative risk using pairwise and NMA with random-effects model.

RESULTS

A total of 65 studies (N = 12,415) with 19 augmentation agents were included in the NMA. Our findings from the NMA for response rates, compared to placebo, were significant for: liothyronine, nortriptyline, aripiprazole, brexpiprazole, quetiapine, lithium, modafinil, olanzapine (fluoxetine), cariprazine, and lisdexamfetamine. For remission rates, compared to placebo, were significant for: thyroid hormone(T4), aripiprazole, brexpiprazole, risperidone, quetiapine, and olanzapine (fluoxetine). Compared to placebo, ziprasidone, mirtazapine, and cariprazine had statistically significant higher discontinuation rates. Overall, 24% studies were rated as having low risk of bias (RoB), 63% had moderate RoB and 13% had high RoB.

LIMITATIONS

Heterogeneity in TRD definitions, variable trial duration and methodological clinical design of older studies and small number of trials per comparisons.

CONCLUSIONS

This NMA suggests a superiority of the regulatory approved adjunctive atypical antipsychotics, thyroid hormones, dopamine compounds (modafinil and lisdexamfetamine) and lithium. Acceptability was lower with ziprasidone, mirtazapine, and cariprazine. Further research and head-to-head studies should be considered to strengthen the best available options for TRD.

Lipid Biomarkers in Depression: Does Antidepressant Therapy Have an Impact?

Studies have revealed mixed results on how antidepressant drugs affect lipid profiles of patients with major depression disorder (MDD). Even less is known about how patients respond to a switch of antidepressant medication with respect to their metabolic profile. For this, effects of a switch in antidepressants medication on lipid markers were studied in MDD patients. 15 participants (females = 86.67%; males = 13.33%; age: 49.45 ± 7.45 years) with MDD and a prescribed switch in their antidepressant medication were recruited at a psychosomatic rehabilitation clinic. Participants were characterized (with questionnaires and blood samples) at admission to the rehabilitation clinic (baseline, T0) and followed up with a blood sample two weeks (T1) later. HDL, LDL, total cholesterol, and triglycerides were determined (T0), and their change analyzed (Wilcoxon test) at follow up (T1). Decrements in HDL (p = 0.041), LDL (p < 0.001), and total cholesterol (p < 0.001) were observed two weeks after a switch in antidepressant medication. Triglycerides showed no difference (p = 0.699). Overall, LDL, HDL, and total cholesterol are affected by a change in antidepressant drugs in patients with MDD. These observations are of clinical relevance for medical practitioners in the planning and management of treatment strategies for MDD patients.

A Network Meta-Analysis of the Clinical Efficacy and Safety of Commonly Used Chinese Patent Medicines in the Auxiliary Treatment of Poststroke Depression

Background

Poststroke depression (PSD) is a serious complication of clinical cerebrovascular disease. Patients not only have depression-related emotional symptoms but also have physical symptoms, such as autonomic dysfunction. At the same time, patients with varying degrees of depression will delay the neurological function of stroke patients. The recovery time of cognitive function and limb function will increase the risk of accidental death and even aggravate the mortality of cerebrovascular disease. Through combining data analysis and related literature, seven types of Chinese patent medicines (CPMs) widely used in the clinical treatment of PSD have been screened out. These herbs exhibit some clinical comparability under the conditions that the syndrome type and dosage form are relatively uniform. Therefore, in this study, the network meta-analysis method was used to evaluate the safety and efficacy of the seven CPMs screened out, and the probability ranking was performed to screen the best clinical auxiliary treatment plan of CPM.

Methods

We searched the Chinese databases, including CNKI, WANFANG, and VIP, as well as the English databases, including the Cochrane Library, EMBASE, and PubMed, from inception to May 31, 2020, to identify randomized controlled trials (RCTs) on seven kinds of CPMs that were the subjects of the clinical research. The bias risk and quality of the included studies were analyzed with the Cochrane Handbook (version 5.1), ADDIS, and R software, and the results were compared in a network meta-analysis (NMA).

Results

In terms of clinical effectiveness, the seven kinds of CPMs all improved clinical curative effects, with Jieyu Anshen capsule adjuvant treatment having the most significant effect [odds ratio (OR) = 5.00, 95% CI (1.72–9.48)]. Wuling capsule AT can effectively reduce the score index of scale factors for the HAMD score, NIHSS score, and TESS score [mean difference (MD) = −3.95, 95% CI (−4.88–3.00); OR = −3.25, 95% CI (−5.46)–1.05); OR = 0.22, 95% CI (0.05–0.79), resp.].

Conclusion

The mechanisms of seven CPMs in the adjuvant treatment of PSD have advantages. In terms of safety and efficacy, the CPMs had better clinical adjuvant treatment performance. Although this study concluded that the Jieyu Anshen capsule is the preferred drug for clinical treatment, a clear conclusion still needs to be verified in a high-quality randomized controlled study. In clinical practice, accurate selection and application can be carried out according to the specific characteristics of patients.

Effectiveness and safety of Wendan decoction for post-stroke depression: A protocol for systematic review and meta-analysis

BACKGROUND

Post-stroke depression (PSD) refers to a series of affective disorder syndromes that occur after stroke and are often accompanied by physical symptoms. PSD presents with low mood and lack of interest as the main characteristics along with the symptoms of stroke. The physical symptoms of PSD include sleep disorder, loss of appetite, and reluctance to communicate. Although Wendan decoction has been suggested to be effective in the treatment of PSD, there is no meta-analysis providing evidence for the usefulness of Wendan decoction for treating PSD.

METHODS

The following electronic databases will be searched: the Cochrane Library, PubMed, EMBASE, China National Knowledge Infrastructure, Wan Fang databases, Chinese Biomedical Literature Database, and China Science and Technology Journal Database. Each database will be searched from its inception to November 2021. Two independent researchers will conduct study selection, data extraction, and risk bias assessment. Any discrepancies will be resolved through consultation with a third researcher. If the included data are suitable, we will conduct a meta-analysis using RevMan v5.4 software.

RESULTS

In this systematic review, the effectiveness and safety of Wendan decoction in the treatment of PSD will be evaluated.

CONCLUSION

The findings of this meta-analysis will provide evidence-based data for the application of Wendan decoction in the treatment of PSD.

ETHICS AND DISSEMINATION

Individual patient data and privacy will not be involved in this research,so ethics approval is not required.

INPLASY REGISTRATION NUMBER

INPLASY2021110018.

Lithium augmentation of ketamine increases insulin signaling and antidepressant-like active stress coping in a rodent model of treatment-resistant depression

Lithium, a mood stabilizer and common adjunctive treatment for refractory depression, shares overlapping mechanisms of action with ketamine and enhances the duration of ketamine's antidepressant actions in rodent models at sub-therapeutic doses. Yet, in a recent clinical trial, lithium co-treatment with ketamine failed to improve antidepressant outcomes in subjects previously shown to respond to ketamine alone. The potential for lithium augmentation to improve antidepressant outcomes in ketamine nonresponders, however, has not been explored. The current study examined the behavioral, molecular and metabolic actions of lithium and ketamine co-treatment in a rodent model of antidepressant resistance. Male Wistar rats were administered adrenocorticotropic hormone (ACTH; 100 µg/day, i.p. over 14 days) and subsequently treated with ketamine (10 mg/kg; 2 days; n = 12), lithium (37 mg/kg; 2 days; n = 12), ketamine + lithium (10 mg/kg + 37 mg/kg; 2 days; n = 12), or vehicle saline (0.9%; n = 12). Rats were subjected to open field (6 min) and forced swim tests (6 min). Peripheral blood and brain prefrontal cortical (PFC) tissue was collected one hour following stress exposure. Western blotting was used to determine the effects of treatment on extracellular signal-regulated kinase (ERK); mammalian target of rapamycin (mTOR), phospho kinase B (Akt), and glycogen synthase kinase-3ß (GSK3ß) protein levels in the infralimbic (IL) and prelimbic (PL) subregions of the PFC. Prefrontal oxygen consumption rate (OCR) and extracellular acidification rates (ECAR) were also determined in anterior PFC tissue at rest and following stimulation with brain-derived neurotrophic factor (BDNF) and tumor necrosis factor α (TNFα). Blood plasma levels of mTOR and insulin were determined using enzyme-linked immunosorbent assays (ELISAs). Overall, rats receiving ketamine+lithium displayed a robust antidepressant response to the combined treatment as demonstrated through significant reductions in immobility time (p < 0.05) and latency to immobility (p < 0.01). These animals also had higher expression of plasma mTOR (p < 0.01) and insulin (p < 0.001). Tissue bioenergetics analyses revealed that combined ketamine+lithium treatment did not significantly alter the respiratory response to BDNF or TNFα. Animals receiving both ketamine and lithium had significantly higher phosphorylation (p)-to-total expression ratios of mTOR (p < 0.001) and Akt (p < 0.01), and lower ERK in the IL compared to control animals. In contrast, pmTOR/mTOR levels were reduced in the PL of ketamine+lithium treated animals, while pERK/ERK expression levels were elevated. Taken together, these data demonstrate that lithium augmentation of ketamine in antidepressant nonresponsive animals improves antidepressant-like behavioral responses under stress, together with peripheral insulin efflux and region-specific PFC insulin signaling.

Novel drug developmental strategies for treatment-resistant depression

Major depressive disorder is a leading cause of disability worldwide. Because conventional therapies are ineffective in many patients, novel strategies are needed to overcome treatment‐resistant depression (TRD). Limiting factors of successful drug development in the last decades were the lack of (1) knowledge of pathophysiology, (2) translational animal models and (3) objective diagnostic biomarkers. Here, we review novel drug targets and drug candidates currently investigated in Phase I–III clinical trials. The most promising approaches are inhibition of glutamatergic neurotransmission by NMDA and mGlu₅ receptor antagonists, modulation of the opioidergic system by κ receptor antagonists, and hallucinogenic tryptamine derivates. The only registered drug for TRD is the NMDA receptor antagonist, S‐ketamine, but add‐on therapies with second‐generation antipsychotics, certain nutritive, anti‐inflammatory and neuroprotective agents seem to be effective. Currently, there is an intense research focus on large‐scale, high‐throughput omics and neuroimaging studies. These results might provide new insights into molecular mechanisms and potential novel therapeutic strategies.

DNA methylation in stress and depression: from biomarker to therapeutics

Epigenetic mechanisms such as DNA methylation (DNAm) have been associated with stress responses and increased vulnerability to depression. Abnormal DNAm is observed in stressed animals and depressed individuals. Antidepressant treatment modulates DNAm levels and regulates gene expression in diverse tissues, including the brain and the blood. Therefore, DNAm could be a potential therapeutic target in depression. Here, we reviewed the current knowledge about the involvement of DNAm in the behavioural and molecular changes associated with stress exposure and depression. We also evaluated the possible use of DNAm changes as biomarkers of depression. Finally, we discussed current knowledge limitations and future perspectives.

Emodin Prevented Depression in Chronic Unpredicted Mild Stress-Exposed Rats by Targeting miR-139-5p/5-Lipoxygenase

Background

The use of medicinal plant ingredients is one of the goals of developing potential drugs for treating depression. Compelling evidence suggests that anti-inflammatory medicines may block the occurrence of depression. We studied the effect of a natural compound, emodin, on the development of psychosocial stress-induced depression and the underlying mechanisms.

Methods

Chronic unpredicted mild stress (CUMS) for 7 weeks was performed to replicate psychosocial stress in rats. The sucrose preference test, force swimming test, and open field test were used to evaluate their behaviors. The differentially expressed proteins in the hippocampus were analyzed using proteomics. Nissl staining and Golgi staining were used to detect the loss of neurons and synapses, immunohistochemical staining was used to detect the activation of microglia, and the enzyme-linked immunosorbent assay was used to detect the levels of pro-inflammatory cytokines. Western blotting, immunofluorescence, and quantitative polymerase chain reaction were also performed.

Results

Hippocampal inflammation with up-regulated 5-lipoxygenase (5-LO) was observed in the depressed rats after CUMS exposure. The upregulation of 5-LO was caused by decreased miR-139-5p. To observe the effect of emodin, we screened out depression-susceptible (DeS) rats during CUMS and treated them with emodin (80 mg/kg/day). Two weeks later, emodin prevented the depression behaviors in DeS rats along with a series of pathological changes in their hippocampi, such as loss of neurons and spines, microglial activation, increased interleukin-1β and tumor necrosis factor-α, and the activation of 5-LO. Furthermore, we demonstrated that emodin inhibited its excess inflammatory response, possibly by targeting miR-139-5p/5-LO and modulating glycogen synthase kinase 3β and nuclear factor erythroid 2-related factor 2.

Conclusion

These results provide important evidence that emodin may be a candidate agent for the treatment of depression and established a key role of miR-139-5p/5-LO in the inflammation of depression.

Inflammation-Induced Histamine Impairs the Capacity of Escitalopram to Increase Hippocampal Extracellular Serotonin

Commonly prescribed selective serotonin reuptake inhibitors (SSRIs) inhibit the serotonin transporter to correct a presumed deficit in extracellular serotonin signaling during depression. These agents bring clinical relief to many who take them; however, a significant and growing number of individuals are resistant to SSRIs. There is emerging evidence that inflammation plays a significant role in the clinical variability of SSRIs, though how SSRIs and inflammation intersect with synaptic serotonin modulation remains unknown. In this work, we use fast in vivo serotonin measurement tools to investigate the nexus between serotonin, inflammation, and SSRIs. Upon acute systemic lipopolysaccharide (LPS) administration in male and female mice, we find robust decreases in extracellular serotonin in the mouse hippocampus. We show that these decreased serotonin levels are supported by increased histamine activity (because of inflammation), acting on inhibitory histamine H3 heteroreceptors on serotonin terminals. Importantly, under LPS-induced histamine increase, the ability of escitalopram to augment extracellular serotonin is impaired because of an off-target action of escitalopram to inhibit histamine reuptake. Finally, we show that a functional decrease in histamine synthesis boosts the ability of escitalopram to increase extracellular serotonin levels following LPS. This work reveals a profound effect of inflammation on brain chemistry, specifically the rapidity of inflammation-induced decreased extracellular serotonin, and points the spotlight at a potentially critical player in the pathology of depression, histamine. The serotonin/histamine homeostasis thus, may be a crucial new avenue in improving serotonin-based treatments for depression.SIGNIFICANCE STATEMENT Acute LPS-induced inflammation (1) increases CNS histamine, (2) decreases CNS serotonin (via inhibitory histamine receptors), and (3) prevents a selective serotonin reuptake inhibitor (SSRI) from effectively increasing extracellular serotonin. A targeted depletion of histamine recovers SSRI-induced increases in extracellular hippocampal serotonin.

Antidepressant Use and Suicide Rates in Adults Aged 75 and Above: A Swedish Nationwide Cohort Study

Background: The treatment of depression is a main strategy for suicide prevention in older adults. We aimed to calculate suicide rates by antidepressant prescription patterns in persons aged ≥ 75 years. A further aim was to estimate the contribution of antidepressants to the change in suicide rates over time.

Methods: Swedish residents aged ≥ 75 years (N = 1,401,349) were followed between 2007 and 2014 in a national register-based retrospective cohort study. Biannual suicide rates were calculated for those with selective serotonin reuptake inhibitor (SSRI) single use, mirtazapine single use, single use of other antidepressants and use of ≥ 2 antidepressants. The contribution of antidepressants to the change in biannual suicide rates was analyzed by decomposition analysis.

Results: There were 1,277 suicides. About one third of these were on an antidepressant during their last 3 months of life. In the total cohort, the average biannual suicide rate in non-users of antidepressants was 13 per 100,000 person-years. The corresponding figure in users of antidepressants was 34 per 100,000 person-years. These rates were 25, 42 and 65 per 100,000 person-years in users of SSRI, mirtazapine and ≥ 2 antidepressants, respectively. In the total cohort, antidepressant users contributed by 26% to the estimated increase of 7 per 100,000 in biannual suicide rates. In men, biannual suicide rates increased by 11 suicides per 100,000 over the study period; antidepressant users contributed by 25% of the change. In women, those on antidepressant therapy accounted for 29% of the estimated increase of 4.4 per 100,000.

Conclusion: Only one third of the oldest Swedish population who died by suicide filled an antidepressant prescription in their last 3 months of life. Higher suicide rates were observed in mirtazapine users compared to those on SSRIs. Users of antidepressants accounted for only one quarter of the increase in the suicide rate. The identification and treatment of suicidal older adults remains an area for prevention efforts.

Network meta-analysis of Chinese patent medicine adjuvant treatment of poststroke depression

BACKGROUND

Poststroke depression is one of the common complications of clinical cerebrovascular diseases. It is commonly seen in 3 to 6 months after the onset of stroke. The incidence rate is 22% to 75%. The patient not only has depression-related emotional symptoms, but also are accompanied by autonomic nervous disorders and other physical symptoms. It will also delay the recovery time of patients' neurological function, cognitive function, and limb function due to different degrees of depression, and even further aggravate the mortality and risk of accidental death of cerebrovascular disease. In recent years, Chinese patent medicine combined with western medicine has been widely used in the treatment of this disease. Many clinical practices have proved that the adjuvant treatment of pure Chinese herbal medicine can effectively alleviate the poststroke depression state and reduce the neurological deficits. The author has sorted out the relevant literature and data analysis to screen out the seven most representative and commonly used Chinese patent medicine preparations in clinical treatment of poststroke depression, which have certain clinical comparability when the dosage form and syndrome type are relatively unified. The network meta-analysis method is used to select the best clinical treatment plan, so as to provide reference value and evidence-based medicine evidence for the clinical optimization of drug selection.

METHODS

Using computer retrieval technology, comprehensive retrieval of CNKI, VIP, CBM, and WANFANG Chinese electronic database and the Cochrane Library, PubMed, Web of Science and EMBASE foreign electronic database. Search the clinical randomized controlled trials of these 7 kinds of Chinese patent medicines for adjuvant treatment of poststroke depression, and set a period of time is from the establishment of the database to May 31, 2020. The 3 authors will screen the literatures that meets the inclusion criteria, extract the data independently according to the predesigned rules, and evaluate the literature quality and bias risk of the included research according to the Cochrane 5.1 manual standard. R and the Aggregate Data Drug Information System software were used for data consolidation and network meta-analysis to evaluate the ranking probability of all interventions.

RESULTS

This network meta-analysis and probability ranking will identify the best Chinese patent medicine adjuvant treatment for poststroke depression.

CONCLUSION

This study will provide systematic evidence-based medicine evidence for Chinese patent medicine adjuvant treatment for poststroke depression, and help clinicians, patients with poststroke depression and decision-makers to make more effective, safer, and economic optimal treatment plan in the decision-making process.

PROSPERO REGISTRATION NUMBER

CRD42020164543.

Psychiatric Prescribing Patterns for Depression Treatment in an Outpatient Depression Clinic

OBJECTIVE

To elucidate psychiatric prescribing patterns for depression treatment in patients being seen by an outpatient depression clinic as of 2018.

EXPERIMENTAL DESIGN

Single-center, observational analysis.

PRINCIPLE OBSERVATION

Selective serotonin receptor inhibitors are most commonly used by patients, and the majority of trials have adequate duration (2 months or longer).

CONCLUSION

Healthcare providers observed in this study follow depression treatment guidelines and ensure medications are given an adequate trial.

Comparative effectiveness of different forms of traditional Chinese medicine for treatment of post-stroke depression: Protocol for network meta-analysis of randomized controlled trials

BACKGROUND

Traditional Chinese medicine (TCM) therapy is effective for post-stroke depression (PSD). TCM therapy encompasses various forms of practices. However, the comparative effectiveness of these therapies is still not clear. Here, we provide a network meta-analysis protocol to compare the effects of different types of TCM therapy on PSD, using both direct and indirect evidence.

METHODS

Twelve databases investigation will be conducted through the keywords from their inception to June 1, 2019. At least 2 independent reviewers will identify eligible articles. EndNote X7 software is utilized to manage the literatures and RevMan V.5.3 (The Cochrane Collaboration) software is for data processing throughout the review. The package "netmeta" (version 0.5-0) in R (version 3.0.2, The R Foundation for Statistical Computing) will be used to perform network meta-analysis (NMA). In addition, the overall quality of evidence is evaluated by GRADEPro software, and Cochrane Collaboration Risk of Bias Tool is employed for the methodological quality. Generally speaking, this review protocol is reported according to the preferred reporting items for systematic review and meta-analysis protocols 2015 guidelines.

RESULTS

According to this protocol, it will provide evidence in support of, or against, the hypothesis that TCM therapy for PSD is more effective than pharmacotherapy. The results of this study will also provide evidence on relative efficacy of different forms of TCM. Furthermore, this analysis will show which form(s) of TCM therapy is (are) the most effective.

CONCLUSION

The results will help PSD doctors and patients choose the treatment regimen which is effective, time-saving and economical.

PROSPERO REGISTRATION NUMBER

CRD42016041594.

Treating Depression With Tai Chi: State of the Art and Future Perspectives

Major depressive disorder (MDD) is one of the most prevalent mental illnesses in America. Current treatments for MDD are unsatisfactory given high non-response rates, high relapse rates, and undesirable side effects. Accumulating evidence suggests that Tai Chi, a popular mind-body intervention that originated as a martial art, can significantly regulate emotion and relieve the symptoms of mood disorders. In addition, the availability of instructional videos and the development of more simplified and less structured Tai Chi has made it a promising low-intensity mind-body exercise. In this article, we first examine a number of clinical trials that implemented Tai Chi as a treatment for depression. Then, we explore several mechanisms by which Tai Chi may alleviate depressive symptoms, hypothesizing that the intervention may modulate the activity and connectivity of key brain regions involved in mood regulation, reduce neuro-inflammatory sensitization, modulate the autonomic nervous system, and regulate hippocampal neurogenesis. Finally, we discuss common challenges of the intervention and possible ways to address them. Specifically, we pose developing a simplified and tailored Tai Chi protocol for patients with depression, comparatively investigating Tai Chi with other mind-body interventions such as yoga and Baduanjin, and developing new mind-body interventions that merge the advantages of multiple mind-body exercises.

Medicaid spending burden among beneficiaries with treatment-resistant depression

Aim: To evaluate Medicaid spending and healthcare resource utilization (HRU) in treatment-resistant depression (TRD). Materials & methods: TRD beneficiaries were identified from Medicaid claims databases (January 2010–March 2017) and matched 1:1 with major depressive disorder (MDD) beneficiaries without TRD (non-TRD-MDD) and randomly selected patients without MDD (non-MDD). Differences in HRU and per-patient-per-year costs were reported in incidence rate ratios (IRRs) and cost differences (CDs), respectively. Results: TRD beneficiaries had higher HRU than 1:1 matched non-TRD-MDD (e.g., inpatient visits: IRR = 1.41) and non-MDD beneficiaries (N = 14,710 per cohort; e.g., inpatient visits: IRR = 3.42, p < 0.01). TRD beneficiaries incurred greater costs versus non-TRD-MDD (CD = US$4382) and non-MDD beneficiaries (CD = US$8294; p < 0.05). Conclusion: TRD is associated with higher HRU and costs versus non-TRD-MDD and non-MDD. TRD poses a significant burden to Medicaid.

Insulin-stimulated mTOR activation in peripheral blood mononuclear cells associated with early treatment response to lithium augmentation in rodent model of antidepressant-resistance

Lithium has been shown to have some therapeutic efficacy as an adjunctive treatment for intractable forms of major depression. Activation of mammalian target of rapamycin (mTOR) and inhibition of glycogen synthase kinase-3β (GSK3β) have been implicated in its putative mechanisms of action. These proteins are integral components of the insulin signaling pathway, which may serve as a critical co-regulator of drug action. Utilizing an animal model of tricyclic antidepressant resistance, we investigated the relationship between insulin signaling and antidepressant response to lithium augmentation. Pre-treatment with adrenocorticotropic hormone (ACTH 100 µg/day i.p.) for 14 days effectively blocked the immobility-reducing effects of an acute dose of imipramine (10 mg/kg i.p.) in the forced swim test (FST). Lithium augmentation (100 mg/kg i.p.) rescued the antidepressant-like effects of imipramine in this model. Total and phosphorylated (p) levels of protein kinase B (Akt), mTOR, and GSK3β protein were quantified in the infralimbic cortex (ILPFC) following FST stress via Western blot. Levels of mTOR and pmTOR were further quantified in isolated peripheral blood mononuclear cells (PBMCs) following insulin stimulation (10 mg/mL for 5 min) via ELISA. Elevated levels of phosphorylated insulin signaling proteins were present in the ILPFC of ACTH-pretreated animals that received both imipramine and lithium, together with a concurrent increase in mTOR activation in PBMCs. Large correlations were observed between immobility time and insulin-stimulated mTOR levels in PBMCs. We propose that PBMC insulin challenge may be a useful probe for predicting antidepressant response to lithium administration, and potentially other therapies acting via similar mechanisms of action.

Medication Adherence, Health Care Utilization, and Costs in Patients With Major Depressive Disorder Initiating Adjunctive Atypical Antipsychotic Treatment

PURPOSE

The purpose of this study was to compare medication adherence, health care utilization, and cost among patients receiving adjunctive treatment for major depressive disorder (MDD) with brexpiprazole, quetiapine, or lurasidone.

METHODS

Using Truven Health MarketScan® Commercial, Medicaid, and Medicare Supplemental Databases, we identified adults with MDD initiating adjunctive treatment with brexpiprazole, quetiapine, or lurasidone (index atypical antipsychotic [AAP]). We compared medication adherence and persistence measured by proportion of days covered (PDC) and treatment duration of index AAP, all-cause and psychiatric hospital care (hospitalization or emergency department visit), and medical costs during 6-month follow-up. Models performed included logistic regression for hospital care, linear regression for PDC and cost, and Cox proportional hazards regression for time to discontinuation, adjusting for demographic, clinical, and utilization differences during the 6 months before index AAP.

FINDINGS

The total sample included 778 brexpiprazole, 626 lurasidone, and 3458 quetiapine therapy initiators. Adjusting for baseline differences, the risk of discontinuation of index AAP was statistically significantly higher for quetiapine than for brexpiprazole (hazard ratio [HR] = 1.13; 95% CI, 1.02-1.25; P = 0.023) and did not differ between lurasidone and brexipiprazole (HR = 1.14; 95% CI, 1.00-1.29; P = 0.054). The adjusted rate of all-cause hospitalization or emergency department visit in the postindex period was lowest for brexpiprazole at 27.4% (95% CI, 24.0%-31.0%), compared with 31.1% (95% CI, 27.3%-35.2%) for lurasidone and 35.3% (95% CI, 33.5%-37.1%) for quetiapine (P< 0.001 for all comparisons). Quetiapine users had increased all-cause costs compared with brexpiprazole users (estimate = $2309; 95% CI, $31-$4587; P = 0.047); all-cause medical costs did not differ between lurasidone and brexpiprazole (estimate = $913; 95% CI, $-2033 -$3859; P = 0.543). Adjusted psychiatric hospital care, psychiatric costs, and PDC did not differ significantly among the groups.

IMPLICATIONS

In patients with MDD and a variety of insurance types, brexpiprazole use was associated with statistically significantly lower risks of discontinuation, risk of hospital care (hospitalization and ED visits), and all-cause medical costs compared with adjunctive quetiapine. Differences between brexpiprazole and lurasidone were not statistically significant. These findings suggest that drug choice is associated with subsequent health care utilization and costs.

Diminished responses to monoaminergic antidepressants but not ketamine in a mouse model for neuropsychiatric lupus

BACKGROUND

A significant proportion of patients suffering from major depression fail to remit following treatment and develop treatment-resistant depression. Developing novel treatments requires animal models with good predictive validity. MRL/lpr mice, an established model of systemic lupus erythematosus, show depression-like behavior.

AIMS

We evaluated responses to classical antidepressants, and associated immunological and biochemical changes in MRL/lpr mice.

METHODS AND RESULTS

MRL/lpr mice showed increased immobility in the forced swim test, decreased wheel running and sucrose preference when compared with the controls, MRL/MpJ mice. In MRL/lpr mice, acute fluoxetine (30 mg/kg, intraperitoneally (i.p.)), imipramine (10 mg/kg, i.p.) or duloxetine (10 mg/kg, i.p.) did not decrease the immobility time in the Forced Swim Test. Interestingly, acute administration of combinations of olanzapine (0.03 mg/kg, subcutaneously)+fluoxetine (30 mg/kg, i.p.) or bupropion (10 mg/kg, i.p.)+fluoxetine (30 mg/kg, i.p.) retained efficacy. A single dose of ketamine but not three weeks of imipramine (10 mg/kg, i.p.) or escitalopram (5 mg/kg, i.p.) treatment in MRL/lpr mice restored sucrose preference. Further, we evaluated inflammatory, immune-mediated and neuronal mechanisms. In MRL/lpr mice, there was an increase in autoantibodies' titers, [3H]PK11195 binding and immune complex deposition. There was a significant infiltration of the brain by macrophages, neutrophils and T-lymphocytes. p11 mRNA expression was decreased in the prefrontal cortex. Further, there was an increase in the 5-HT_2aR expression, plasma corticosterone and indoleamine 2,3-dioxygenase activity.

CONCLUSION

In summary, the MRL/lpr mice could be a useful model for Treatment Resistant Depression associated with immune dysfunction with potential to expedite antidepressant drug discovery.

Earlier Versus Later Augmentation with an Antipsychotic Medication in Patients with Major Depressive Disorder Demonstrating Inadequate Efficacy in Response to Antidepressants: A Retrospective Analysis of US Claims Data

Introduction

There is little evidence regarding the most effective timing of augmentation of antidepressants (AD) with antipsychotics (AP) in patients with major depressive disorder (MDD) who inadequately respond to first-line AD (inadequate responders). The study’s objective was to understand the association between timing of augmentation of AD with AP and overall healthcare costs in inadequate responders.

Methods

Using the Truven Health MarketScan^® Medicaid, Commercial, and Medicare Supplemental databases (7/1/09–12/31/16), we identified adult inadequate responders if they had one of the following indicating incomplete response to initial AD: psychiatric hospitalization or emergency department (ED) visit, initiating psychotherapy, or switching to or adding on a different AD. Two mutually exclusive cohorts were identified on the basis of time from first qualifying event date to first date of augmentation with an AP (index date): 0–6 months (early add-on) and 7–12 months (late add-on). Patients were further required to be continuously enrolled 1 year before (baseline) and 1 year after (follow-up) index date. Patients with schizophrenia or bipolar disorder diagnoses were excluded. General linear regression was used to estimate adjusted healthcare costs in the early versus late add-on cohort, controlling for baseline demographic and clinical characteristics, insurance type, medications, and ED visits or hospitalizations.

Results

Of the 6935 identified inadequate responders, 68.7% started an AP early and 31.3% late. At baseline, before AP augmentation, patients in the early add-on cohort had higher psychiatric comorbid disease burden (47.3% vs. 42.5%; p < 0.001) and higher inpatient utilization [mean (SD) 0.41 (0.72) vs. 0.27 (0.67); p < 0.001] than in late add-on cohort. During follow-up, the adjusted total all-cause healthcare cost was significantly lower in the early vs. late add-on cohort ($18,864 vs. $20,452; p = 0.046).

Conclusion

Findings of this real-world study suggest that, in patients with MDD who inadequately responded to first-line AD treatment, adding an AP earlier reduces overall healthcare costs.

Funding

Otsuka Pharmaceutical Development and Commercialization, Inc. and Lundbeck.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0838-2) contains supplementary material, which is available to authorized users.

Treating depression with adjunctive antipsychotics

OBJECTIVES

To evaluate the efficacy and safety of using adjunctive antipsychotics in patients with major depressive disorder.

METHOD

Studies published since the last Cochrane review conducted in 2010 were identified via a literature search of recognised databases, using the keywords "adjunct*", "augment*", "antipsychotic" and "depression", and systematically evaluated. A targeted review of relevant guidelines was undertaken.

RESULTS

Adjunctive antipsychotics produce a small but significant improvement in depressive symptoms in most studies. Most of the studies focussed on patients with an inadequate response to antidepressants rather than patients with treatment resistant depression. Treatment guidelines were variable but generally supported the use of adjunctive antipsychotics while cautioning about the risk of side effects. Most were non-specific about the length of time adjunctive antipsychotics should be prescribed.

CONCLUSIONS

The studies do not support the routine use of adjunctive antipsychotics in patients with an inadequate response to antidepressants. They may be beneficial when used short-term in patients with treatment resistant depression who have specific symptoms (severe ruminations, melancholia, major sleep disturbance) that appear to respond well to adjunctive antipsychotics. There is no support for long-term use. Research should focus on specifying which symptom profiles are responsive and how adjunctive antipsychotics compare to other strategies in treatment resistant depression.

Food for Mood: Relevance of Nutritional Omega-3 Fatty Acids for Depression and Anxiety

The central nervous system (CNS) has the highest concentration of lipids in the organism after adipose tissue. Among these lipids, the brain is particularly enriched with polyunsaturated fatty acids (PUFAs) represented by the omega-6 (ω6) and omega-3 (ω3) series. These PUFAs include arachidonic acid (AA) and docosahexaenoic acid (DHA), respectively. PUFAs have received substantial attention as being relevant to many brain diseases, including anxiety and depression. This review addresses an important question in the area of nutritional neuroscience regarding the importance of ω3 PUFAs in the prevention and/or treatment of neuropsychiatric diseases, mainly depression and anxiety. In particular, it focuses on clinical and experimental data linking dietary intake of ω3 PUFAs and depression or anxiety. In particular, we will discuss recent experimental data highlighting how ω3 PUFAs can modulate neurobiological processes involved in the pathophysiology of anxiety and depression. Potential mechanisms involved in the neuroprotective and corrective activity of ω3 PUFAs in the brain are discussed, in particular the sensing activity of free fatty acid receptors and the activity of the PUFAs-derived endocannabinoid system and the hypothalamic-pituitary-adrenal axis.

Cannabidiol Induces Rapid and Sustained Antidepressant-Like Effects Through Increased BDNF Signaling and Synaptogenesis in the Prefrontal Cortex

Currently available antidepressants have a substantial time lag to induce therapeutic response and a relatively low efficacy. The development of drugs that addresses these limitations is critical to improving public health. Cannabidiol (CBD), a non-psychotomimetic component of Cannabis sativa, is a promising compound since it shows large-spectrum therapeutic potential in preclinical models and humans. However, its antidepressant properties have not been completely investigated. Therefore, the aims of this study were to investigate in male rodents (i) whether CBD could induce rapid and sustained antidepressant-like effects after a single administration and (ii) whether such effects could be related to changes in synaptic proteins/function. Results showed that a single dose of CBD dose-dependently induced antidepressant-like effect (7-30 mg/kg) in Swiss mice submitted to the forced swim test (FST), 30 min (acute) or 7 days (sustained) following treatment. Similar effects were observed in the Flinders Sensitive and Flinders Resistant Line (FSL/FRL) rats and the learned helplessness (LH) paradigm using Wistar rats. The acute antidepressant effects (30 min) were associated with increased expression of synaptophysin and PSD95 in the medial prefrontal cortex (mPFC) and elevated BDNF levels in both mPFC and hippocampus (HPC). CBD also increased spine density in the mPFC after 30 min, but not 7 days later. Intracerebroventricular injection of the TrkB antagonist, K252a (0.05 nmol/μL), or the mTOR inhibitor, rapamycin (1 nmol/μL), abolished the behavioral effects of CBD. These results indicate that CBD induces fast and sustained antidepressant-like effect in distinct animal models relevant for depression. These effects may be related to rapid changes in synaptic plasticity in the mPFC through activation of the BDNF-TrkB signaling pathway. The data support a promising therapeutic profile for CBD as a new fast-acting antidepressant drug.

How Does Repetitive Transcranial Magnetic Stimulation Influence the Brain in Depressive Disorders?: A Review of Neuroimaging Magnetic Resonance Imaging Studies

OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is a nonpharmacological technique used to stimulate the brain. It is a safe and proven alternative tool to treat resistant major depressive disorders (MDDs). Neuroimaging studies suggest a wide corticolimbic network is involved in MDDs. We researched observable changes in magnetic resonance imaging induced by rTMS to clarify the operational mechanism.

METHODS

A systematic search of the international literature was performed using PubMed and Embase, using papers published up to January 1, 2017. The following MESH terms were used: (depression or major depressive disorder) and (neuroimaging or MRI) and (rTMS or repetitive transcranial magnetic stimulation). We searched the databases using a previously defined strategy to identify potentially eligible studies.

RESULTS

Both structural and functional changes were observed on magnetic resonance imagings performed before and after rTMS. Various areas of the brain were impacted when rTMS was used. Although the results were very heterogeneous, a pattern that involved the anterior cingulate cortex and the prefrontal cortex emerged. These are known to be regions of interest in MDDs. However, the various parameters used in rTMS make any generalization difficult.

CONCLUSIONS

Repetitive transcranial magnetic stimulation helps to treat MDDs with good efficacy. Its effect on the brain, as observed in several neuroimaging studies, seems to impact on the structural and functional features of several networks and structures involved in major depressive disorders.

Ketamine-based anesthesia improves electroconvulsive therapy outcomes: a randomized-controlled study

BACKGROUND

Major depressive disorder (MDD) is a common and debilitating condition that can be challenging to treat. Electroconvulsive therapy (ECT) is currently the therapeutic gold standard for treatment-resistant MDD. We tested our hypothesis that ketamine-based anesthesia for ECT results in superior improvement in treatment-resistant MDD outcomes compared with propofol-based anesthesia.

METHODS

Patients with treatment-resistant MDD were enrolled in a randomized clinical trial with assignment to ketamine- or propofol-based anesthesia arms. Using a modified intention-to-treat analysis, we compared the median number of ECT treatments required to achieve a 50% reduction (primary outcome) and a score ≤ 10 (secondary outcome) on the Montgomery-Asberg depression rating scale (MADRS) between anesthesia groups.

RESULTS

The study was terminated as significant results were found after the first planned interim analysis with 12 patients in each of the ketamine (intervention) and propofol (control) groups. All ketamine patients achieved at least a 50% MADRS reduction after a median of two ECT treatments whereas ten propofol patients (83%) achieved the same outcome after a median of four ECT treatments. All ketamine patients and seven propofol patients (58%) achieved MDD remission (MADRS ≤ 10). Log rank tests showed that both time-to-50% reduction and remission differed significantly between groups. Adverse events and recovery time were similar between groups.

CONCLUSIONS

In this early-terminated small-sized study, ketamine-based anesthesia compared with propofol-based anesthesia provided response and remission after fewer ECT sessions.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT01935115). Registered 4 September 2013.

Subgenual Anterior Cingulate-Medial Orbitofrontal Functional Connectivity in Medication-Resistant Major Depression: A Neurobiological Marker for Accelerated Intermittent Theta Burst Stimulation Treatment?

BACKGROUND

Accelerated repetitive transcranial magnetic stimulation paradigms have been shown to result in fast decreases in depressive symptoms and suicidal ideation. Although the subgenual anterior cingulate cortex (sgACC) region has been put forward as a possible biological marker, so far, no studies evaluated the clinical effects of accelerated intermittent theta burst stimulation (aiTBS) on sgACC functional connectivity (FC).

METHODS

Fifty patients with treatment-resistant depression were enrolled in this registered randomized double-blind sham-controlled crossover aiTBS treatment study. All received 20 iTBS sessions applied to the left dorsolateral prefrontal cortex (5 daily sessions spread over 4 days). Forty-four complete resting-state functional magnetic resonance imaging scans were collected. Baseline resting-state functional magnetic resonance imaging scans were compared with a matched healthy control group. Besides depression severity, all patients were also assessed with the Scale for Suicide Ideation and the Beck Hopelessness Scale.

RESULTS

Our main resting-state functional magnetic resonance imaging findings indicate that a positive sgACC FC correlation with the medial orbitofrontal cortex could distinguish aiTBS responders from nonresponders at baseline. Beneficial aiTBS treatment strengthened sgACC-medial orbitofrontal cortex FC patterns. Moreover, this increased FC pattern was associated with a decrease in feelings of hopelessness.

CONCLUSIONS

Clinical response to aiTBS treatment is not only characterized by stronger FC patterns between the sgACC and the medial orbitofrontal cortex, but it is also associated with decreases in hopelessness. Our observations provide a possible neurobiological explanation why accelerated repetitive transcranial magnetic stimulation paradigms may result in prompt attenuation of negative thinking in depressed patients.

Dextromethorphan/quinidine pharmacotherapy in patients with treatment resistant depression: A proof of concept clinical trial

BACKGROUND

At least one-third of patients with major depressive disorder (MDD) have treatment-resistant depression (TRD), defined as lack of response to two or more adequate antidepressant trials. For these patients, novel antidepressant treatments are urgently needed.

METHODS

The current study is a phase IIa open label clinical trial examining the efficacy and tolerability of a combination of dextromethorphan (DM) and the CYP2D6 enzyme inhibitor quinidine (Q) in patients with TRD. Dextromethorphan acts as an antagonist at the glutamate N-methyl-d-aspartate (NMDA) receptor, in addition to other pharmacodynamics properties that include activity at sigma-1 receptors. Twenty patients with unipolar TRD who completed informed consent and met all eligibility criteria we enrolled in an open-label study of DM/Q up to 45/10mg by mouth administered every 12h over the course of a 10-week period, and constitute the intention to treat (ITT) sample. Six patients discontinued prior to study completion.

RESULTS

There was no treatment-emergent suicidal ideation, psychotomimetic or dissociative symptoms. Montgomery-Asberg Depression Rating Scale (MADRS) score was reduced from baseline to the 10-week primary outcome (mean change: -13.0±11.5, t₁₉=5.0, p<0.001), as was QIDS-SR score (mean change: -5.9±6.6, t₁₉=4.0, p<0.001). The response and remission rates in the ITT sample were 45% and 35%, respectively.

LIMITATIONS

Open-label, proof-of-concept design.

CONCLUSIONS

Herein we report acceptable tolerability and preliminary efficacy of DM/Q up to 45/10mg administered every 12h in patients with TRD. Future larger placebo controlled randomized trials in this population are warranted.

Efficacy of off-label augmentation in unipolar depression: A systematic review of the evidence

Treatment of unipolar depression with currently available antidepressants is still unsatisfactory. Augmentation with lithium or second generation antipsychotics is an established practice in non-responders to antidepressant monotherapy, but is also associated with a substantial non-response rate and with non-tolerance. Based on a systematic review of the literature, including meta-analyses, randomized controlled trials (RCTs), non-randomized comparative studies and case studies, off-label augmentation agents (administered in addition to an antidepressant, without FDA approval for treatment of MDD) were identified and evaluated regarding their efficacy using levels of evidence. The agents had to be added to an existing antidepressant regime with the aim of achieving an improved clinical response to an ongoing antidepressant treatment (augmentation) or an earlier onset of effect when starting antidepressant and augmentation agent simultaneously (acceleration). Five substances, modafinil, ketamine, pindolol, testosterone and estrogen (the latter two in hormone-deficient patients) were shown to be clinically effective in high evidence studies. For the six drugs dexamethasone, mecamylamine, riluzole, amantadine, pramipexole and yohimbine clear proof of efficacy was not possible due to low levels of evidence, small sample sizes or discordant results. For the two agents methylphenidate and memantine only studies with negative outcomes could be found. Overall, the quality of study designs was low and results were often contradictory. However, the use of pindolol, ketamine, modafinil, estrogen and testosterone might be an option for depressed patients who are not responding to antidepressant monotherapy or established augmentation strategies. Further high quality studies are necessary and warranted.

Comparative efficacy and tolerability of pharmacological and somatic interventions in adult patients with treatment-resistant depression: a systematic review and network meta-analysis

OBJECTIVE

Major depressive disorder (MDD) affects about 10-15% of the general population in a lifetime. A considerable number of patients fail to achieve full symptom remission despite adequate treatment and are considered treatment resistant (TRD). The current study compared the relative efficacy and tolerability of pharmacological and somatic TRD interventions by means of a Bayesian network meta-analysis.

RESEARCH DESIGN AND METHODS

An electronic literature search of MEDLINE, MEDLINE In-Process, EMBASE, PsycInfo, EconLit and Cochrane Library databases for trials published between September 2003 and September 2014 was conducted. Key outcomes extracted were disease severity change from baseline, response and remission rates at various timepoints and discontinuation due to adverse events.

RESULTS

Of the 3876 abstracts identified, 31 publications/randomised controlled trials (RCTs) were included in the analysis; 19 RCTs investigating 13 pharmacological interventions and 12 RCTs investigating electroconvulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS). The evidence synthesis investigating efficacy outcomes of TRD treatments demonstrated superior efficacy for ketamine compared to pharmacological and somatic interventions at 2 weeks after treatment initiation. At 4, 6 and 8 weeks, quetiapine augmentation (800 mg/day) and risperidone augmentation were found to be the first and second best treatments, respectively. Networks were small for response rate and remission rate outcomes at most timepoints. The most tolerable treatment was lamotrigine augmentation showing a comparable profile to placebo/sham.

CONCLUSIONS

This analysis revealed scarcity of long-term data on sustained remission that would allow a comparative long-term efficacy assessment. Key limitations of the analysis can be considered the search timeframe and the use of mapping formula for the depression scores.

Hippocampal CysLT1R knockdown or blockade represses LPS-induced depressive behaviors and neuroinflammatory response in mice

Evidence suggests that neuroinflammation is involved in depression and that the cysteinyl leukotriene receptor 1 (CysLT₁R) plays a potential pathophysiological role in several types of CNS disorders. Our previous study has shown that knockdown of hippocampal CysLT₁R in mice prevents the depressive-like phenotype and neuroinflammation induced by chronic mild stress (CMS). Here, we examined the effects of hippocampal CysLT₁R knockdown and CysLT₁R blockade on LPS-induced depressive-like behavior in mice. We found that injection of LPS (0.5 mg/kg, ip) caused marked increase in hippocampal CysLT₁R expression, which was reversed by pretreatment with fluoxetine (20 mg·kg^-1·d^-1 for 7 d, ig). Knockdown of hippocampal CysLT₁R or blockade of CysLT₁R by pretreatment with pranlukast (0.5 mg/kg, ip) significantly suppressed LPS-induced depressive behaviors, as evidenced by decreases in mouse immobility time in the forced swimming test (FST) and tail suspension test (TST) and latency to feed in the novelty-suppressed feeding (NSF) test. Moreover, both CysLT₁R knockdown and CysLT₁R blockade markedly prevented LPS-induced neuroinflammation, as shown by the suppressed activation of microglia and NF-κB signaling as well as the hippocampal levels of TNF-α and IL-1β in mice. Our results suggest that CysLT₁R may be involved in LPS-induced depressive-like behaviors and neuroinflammation, and that downregulation of CysLT₁R could be a novel and potential therapeutic strategy for the treatment of depression, at least partially due to its role in neuroinflammation.

Characteristics of U.S. Veteran Patients with Major Depressive Disorder who require "next-step" treatments: A VAST-D report

OBJECTIVE

Finding effective and lasting treatments for patients with Major Depressive Disorder (MDD) that fail to respond optimally to initial standard treatment is a critical public health imperative. Understanding the nature and characteristics of patients prior to initiating "next-step" treatment is an important component of identifying which specific treatments are best suited for individual patients. We describe clinical features and demographic characteristics of a sample of Veterans who enrolled in a "next-step" clinical trial after failing to achieve an optimal outcome from at least one well-delivered antidepressant trial.

METHODS

1522 Veteran outpatients with nonpsychotic MDD completed assessments prior to being randomized to study treatment. Data is summarized and presented in terms of demographic, social, historical and clinical features and compared to a similar, non-Veteran sample.

RESULTS

Participants were largely male and white, with about half unmarried and half unemployed. They were moderately severely depressed, with about one-third reporting recent suicidal ideation. More than half had chronic and/or recurrent depression. General medical and psychiatric comorbidities were highly prevalent, particularly PTSD. Many had histories of childhood adversity and bereavement. Participants were impaired in multiple domains of their lives and had negative self-worth.

LIMITATIONS

These results may not be generalizable to females, and some characteristics may be specific to Veterans of US military service. There was insufficient data on age of clinical onset and depression subtypes, and three novel measures were not psychometrically validated.

CONCLUSIONS

Characterizing VAST-D participants provides important information to help clinicians understand features that may optimize "next-step" MDD treatments.

Reliability of In Vitro and In Vivo Methods for Predicting the Effect of P-Glycoprotein on the Delivery of Antidepressants to the Brain

As the effect of P-glycoprotein (P-gp) transport on antidepressant delivery has been extensively evaluated using in vitro cellular and in vivo rodent models, an increasing number of publications have addressed the effect of P-gp in limiting brain penetration of antidepressants and causing treatment-resistant depression in current clinical therapies. However, contradictory results have been observed in different systems. It is of vital importance to understand the potential for drug interactions related to P-gp at the blood-brain barrier (BBB), and whether coadministration of a P-gp inhibitor together with an antidepressant is a good clinical strategy for dosing of patients with treatment-resistant depression. In this review, the complicated construction of the BBB, the transport mechanisms for compounds that cross the BBB, and the basic characteristics of antidepressants are illustrated. Further, the reliability of different systems related to antidepressant brain delivery, including in vitro bidirectional transport cell lines, in vivo Mdr1 knockout mice, and chemical inhibition studies in rodents are analyzed, supporting a low possibility that P-gp affects currently marketed antidepressants when these results are extrapolated to the human BBB. These findings can also be applied to other central nervous system drugs.

Developing the language of futility in psychiatry with care

In psychiatric practice, treatment success is, in many instances, not an achievable goal. Psychiatrists may often not acknowledge treatment failure in their patients and seldom consider that patients may be in situations that share similarities with end-of-life dilemmas in general somatic medicine. In such instances, futile treatment may be continued and patient suffering may be prolonged. Doctors should play a leading role in patient education, diagnosis, promoting best treatment options, motivation and support, but patients should be given the opportunity to take ownership of their illness and their future. In the discipline of psychiatry, physician-assisted suicide may be an option but warrants careful consideration. Contemporary psychiatrists may act paternalistically, refusing to accept the limitations of their scientific skills and/or struggle with the moral good of 'letting go' when required. It is arguably the seeming complexity of gauging patients' understanding (competency, capacity) to make informed decisions that perpetuates futile treatment. Most patients, even in the presence of ongoing serious psychiatric illness, are able to give consent. Psychiatrists should be aware of the difference between being alive and living. Ongoing suffering cannot be condoned. The personhood of every patient and his/her bio-psycho-social and spiritual needs should, as far as possible, be respected. Psychiatrists should embrace the realisation of treatment futility and, in some cases, end-of-life decisions and take on the challenge as well as the responsibility of serving patients with mental illness in the best way possible.

Brain stimulation treatments in bipolar disorder: A review of the current literature

OBJECTIVES

Brain stimulation techniques are non-pharmacologic strategies which offer additional therapeutic options for treatment-resistant depression (TRD). The purpose of this paper is to review the current literature regarding the use of brain stimulation in resistant bipolar disorder (BD), with particular reference to hypomanic/manic symptoms.

METHODS

Keywords pertaining to the brain simulation techniques used in the treatment of depression (either unipolar or bipolar) along with their role in regard to hypomanic/manic symptoms were used to conduct an electronic search of the literature. Pertinent findings were identified by the authors and reviewed.

RESULTS

Brain stimulation techniques represent a valid therapeutic option in TRD. They have been extensively studied in unipolar depression and, to a minor extent, in the depressive phase of BD, showing encouraging but often limited results. With exception of electroconvulsive therapy, the efficacy of brain stimulation in the treatment of manic symptoms of bipolar patients is still uncertain and needs to be fully evaluated.

CONCLUSIONS

Brain stimulation in BD is derived from its use in unipolar depression. However, there are many important differences between these two disorders and more studies with a systematic approach need to be conducted on larger samples of bipolar patients with treatment-resistant characteristics.

Mood and neuropsychological effects of different doses of ketamine in electroconvulsive therapy for treatment-resistant depression

BACKGROUND

Treatment-resistant depression (TRD) is a growing clinical challenge. Electroconvulsive therapy (ECT) is an effective tool for TRD treatment. However, there remains a subset of patients who do not respond to this treatment with common anesthetic agent. Ketamine, a noteworthy anesthetic agent, has emerged as an augmentation to enhance the antidepressant efficacy of ECT. Trials of i.v. ketamine in TRD indicated dose-related mood enhancing efficacy. We aimed to explore anesthetic and subanesthetic concentrations of ketamine in ECT for TRD with respect to their impact on mood and neuropsychological effects.

METHODS

Ninety TRD patients (36 males, 54 females; average age, 30.6 years old) were randomly assigned to receive either ketamine (0.8mg/kg) (n=30), subanesthetic ketamine (0.5mg/kg) plus propofol (0.5mg/kg) (n=30) or propofol (0.8mg/kg) (n=30) as an anesthetic and underwent 8 ECT sessions. The primary outcome measures were the 17-item Hamilton Depression Rating Scale (HDRS-17), cognitive assessments and seizure parameters.

RESULTS

The ketamine group had an earlier improvement in HDRS-17, longer seizure duration, lower electric quantity, a higher remission rate, and a lower degree of executive cognitive impairment compared to the ketamine+propofol and propofol groups. The ketamine+propofol group showed earlier improvement in the HDRS-17, a longer seizure duration and a different seizure energy index when compared to the propofol group.

LIMITATIONS

The postoperative dissociative side effect was not assessed.

CONCLUSIONS

Both anesthetic and subanesthetic concentrations of ketamine have rapid mood enhancing actions in ECT for TRD, while anesthetic concentrations results in larger magnitudes of antidepression and cognitive protection. ECT with ketamine anesthesia might be an optimized therapy for patients with TRD.

Knockdown of hippocampal cysteinyl leukotriene receptor 1 prevents depressive behavior and neuroinflammation induced by chronic mild stress in mice

RATIONALE

Numerous studies have demonstrated that neuroinflammation is associated with depression-like symptoms and neuropsychological disturbances, and cysteinyl leukotriene receptor 1 (CysLT1R) was reported to be involved in neuroinflammation. The pathophysiological role of CysLT1R has been reported in several types of brain damage. However, the role of CysLT1R in depression remains to be elucidated.

OBJECTIVES

We aimed to investigate the effect of hippocampal CysLT1R downregulation on depressive behaviors and neuroinflammatory responses in mice exposed to chronic mild stress (CMS).

RESULTS

We firstly found that expression of hippocampal CysLT1R was gradually increased over CMS exposure, while 3 weeks treatment with fluoxetine reversed the increment of hippocampal CysLT1R expression. Hippocampal CysLT1R knockdown suppressed CMS-induced depressive-like behaviors as evidenced by decreases in immobility time in tail suspension test (TST), decreased latency to feed in novelty-suppressed feeding (NSF) test, and by increase in the number of entries and decrease in time spent in the open arm in elevated plus maze (EPM) test. Increments of hippocampal NF-κB p65, IL-1β, and TNF-α induced by CMS were also prevented by hippocampal CysLT1R knockdown beforehand.

CONCLUSIONS

Hippocampal CysLT1R participates in depression, and knockdown of hippocampal CysLT1R prevents CMS-induced depressive-like behaviors and neuroinflammation, suggesting that suppression of CysLT1R could prevent the development of depression.