Ketamine for Treatment-Resistant Depression: A Gateway to Novel Treatment Approaches

Treatment-resistant depression (TRD) is a disabling and demoralizing phenomenon for patients and clinicians. For many years, treatment for depression has relied on the monoamine theory, with medications limited in efficacy and requiring prolonged use before any therapeutic effects are evident. The current article reviews novel approaches to pharmacological treatment of TRD, including N-methyl-D-aspartate glutamate receptor antagonists and other receptor agonists and antagonists beyond serotonin and norepinephrine. [Journal of Psychosocial Nursing and Mental Health Services, 56(10), 11-14.].

[Lithium augmentation to monoamine oxidase-inhibitors in treatment-resistant depressive disorders: case report and overview of literature]

Three patients suffering from a treatment-resistant depression were being treated with a monoamine oxidase (mao-)inhibitor and received lithium augmentation to achieve better recovery. One patient showed significant improvement of depressive symptoms within 24 hours, one patient showed very little respons and one patient did not respond at all. Literature research led to other casereports, where adding lithium to mao-inhibitors had also been effective. The growing amount of arguments of a positive effect of lithium augmentation to mao-inhibitors asks for more research to collect more evidence and a better understanding of this new, potentially effective treatment.

[How we see the development of clinical trials from the investigators' side?]

This is a discussion paper on research in clinical pharmacology in the field of psychiatry. In addition to other factors the decline in discovery and development of new drugs in the field of psychiatry and the developments and growing complexity in the field of clinical trial technology, including outsourcing and risk based monitoring, reduced the number of young clinical researchers interested in this important field. The challenges posed by the restructuring within the pharmacological industry - including digitalization - should induce changes in the structure and in the processes of clinical pharmacology research and in the training of clinical research staff members. The approval of esketamine nasal spray for treatment resistant depression by the FDA and the results of research with psychedelics call for more education and training in this specific field.

Treatment-resistant and multi-therapy-resistant criteria for bipolar depression: consensus definition

BACKGROUND

Most people with bipolar disorder spend a significant percentage of their lifetime experiencing either subsyndromal depressive symptoms or major depressive episodes, which contribute greatly to the high levels of disability and mortality associated with the disorder. Despite the importance of bipolar depression, there are only a small number of recognised treatment options available. Consecutive treatment failures can quickly exhaust these options leading to treatment-resistant bipolar depression (TRBD). Remarkably few studies have evaluated TRBD and those available lack a comprehensive definition of multi-therapy-resistant bipolar depression (MTRBD).AimsTo reach consensus regarding threshold definitions criteria for TRBD and MTRBD.

METHOD

Based on the evidence of standard treatments available in the latest bipolar disorder treatment guidelines, TRBD and MTRBD criteria were agreed by a representative panel of bipolar disorder experts using a modified Delphi method.

RESULTS

TRBD criteria in bipolar depression was defined as failure to reach sustained symptomatic remission for 8 consecutive weeks after two different treatment trials, at adequate therapeutic doses, with at least two recommended monotherapy treatments or at least one monotherapy treatment and another combination treatment. MTRBD included the same initial definition as TRBD, with the addition of failure of at least one trial with an antidepressant, a psychological treatment and a course of electroconvulsive therapy.

CONCLUSIONS

The proposed TRBD and MTRBD criteria may provide an important signpost to help clinicians, researchers and stakeholders in judging how and when to consider new non-standard treatments. However, some challenging diagnostic and therapeutic issues were identified in the consensus process that need further evaluation and research.Declaration of interestIn the past 3 years, M.B. has received grant/research support from the NIH, Cooperative Research Centre, Simons Autism Foundation, Cancer Council of Victoria, Stanley Medical Research Foundation, MBF, NHMRC, Beyond Blue, Rotary Health, Geelong Medical Research Foundation, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Meat and Livestock Board, Organon, Novartis, Mayne Pharma, Servier, Woolworths, Avant and the Harry Windsor Foundation, has been a speaker for Astra Zeneca, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Janssen Cilag, Lundbeck, Merck, Pfizer, Sanofi Synthelabo, Servier, Solvay and Wyeth and served as a consultant to Allergan, Astra Zeneca, Bioadvantex, Bionomics, Collaborative Medicinal Development, Eli Lilly, Grunbiotics, Glaxo SmithKline, Janssen Cilag, LivaNova, Lundbeck, Merck, Mylan, Otsuka, Pfizer and Servier. A.C. has received fees for lecturing from pharmaceutical companies namely Lundbeck and Sunovion. A.J.C. has in the past 3 years received honoraria for speaking from Astra Zeneca and Lundbeck, honoraria for consulting from Allergan, Janssen, Lundbeck and LivaNova and research grant support from Lundbeck. G.M.G. holds shares in P1Vital and has served as consultant, advisor or CME speaker for Allergan, Angelini, Compass pathways, MSD, Lundbeck, Otsuka, Takeda, Medscape, Minervra, P1Vital, Pfizer, Servier, Shire and Sun Pharma. J.G. has received research funding from National Institute for Health Research, Medical Research Council, Stanley Medical Research Institute and Wellcome. H.G. received grants/research support, consulting fees or honoraria from Gedeon Richter, Genericon, Janssen Cilag, Lundbeck, Otsuka, Pfizer and Servier. R.H.M.-W. has received support for research, expenses to attend conferences and fees for lecturing and consultancy work (including attending advisory boards) from various pharmaceutical companies including Astra Zeneca, Cyberonics, Eli Lilly, Janssen, Liva Nova, Lundbeck, MyTomorrows, Otsuka, Pfizer, Roche, Servier, SPIMACO and Sunovion. R.M. has received research support from Big White Wall, Electromedical Products, Johnson and Johnson, Magstim and P1Vital. S.N. received honoraria from Lundbeck, Jensen and Otsuka. J.C.S. has received funds for research from Alkermes, Pfizer, Allergan, J&J, BMS and been a speaker or consultant for Astellas, Abbott, Sunovion, Sanofi. S.W has, within the past 3 years, attended advisory boards for Sunovion and LivaNova and has undertaken paid lectures for Lundbeck. D.J.S. has received honoraria from Lundbeck. T.S. has reported grants from Pathway Genomics, Stanley Medical Research Institute and Palo Alto Health Sciences; consulting fees from Sunovion Pharamaceuticals Inc.; honoraria from Medscape Education, Global Medical Education and CMEology; and royalties from Jones and Bartlett, UpToDate and Hogrefe Publishing. S.P. has served as a consultant or speaker for Janssen, and Sunovion. P.T. has received consultancy fees as an advisory board member from the following companies: Galen Limited, Sunovion Pharmaceuticals Europe Ltd, myTomorrows and LivaNova. E.V. received grants/ research support, consulting fees or honoraria from Abbott, AB-Biotics, Allergan, Angelini, Dainippon Sumitomo, Ferrer, Gedeon Richter, Janssen, Lundbeck, Otsuka and Sunovion. L.N.Y. has received grants/research support, consulting fees or honoraria from Allergan, Alkermes, Dainippon Sumitomo, Janssen, Lundbeck, Otsuka, Sanofi, Servier, Sunovion, Teva and Valeant. A.H.Y. has undertaken paid lectures and advisory boards for all major pharmaceutical companies with drugs used in affective and related disorders and LivaNova. He has also previously received funding for investigator-initiated studies from AstraZeneca, Eli Lilly, Lundbeck and Wyeth. P.R.A.S. has received research funding support from Corcept Therapeutics Inc. Corcept Therapeutics Inc fully funded attendance at their internal conference in California USA and all related expenses. He has received grant funding from the Medical Research Council UK for a collaborative study with Janssen Research and Development LLC. Janssen Research and Development LLC are providing non-financial contributions to support this study. P.R.A.S. has received a presentation fee from Indivior and an advisory board fee from LivaNova.

Ethical Reasoning in Prescribing and Monitoring Psychotropic Medications

Traditionally, schools of nursing teach legal and ethical responsibilities at the pre-licensure and advanced practice levels, with emphasis on legal duties and ethical principles. However, involving clinicians in the process of ethical reasoning, a process similar to the scientific method and nursing process, is much less common. The current article describes and demonstrates the steps in ethical reasoning in common situations faced by prescribing advanced practice RNs and psychiatric-mental health nurses. [Journal of Psychosocial Nursing and Mental Health Services, 57(1), 7-10.].

Glucose and lipid-related biomarkers and the antidepressant response to infliximab in patients with treatment-resistant depression

The tumor necrosis factor (TNF) antagonist infliximab was previously found to reduce depressive symptoms in patients with treatment-resistant major depression (TRD) who exhibited high baseline inflammation, as reflected by plasma C-reactive protein (CRP) >5 mg/L. Further predictors of antidepressant response to infliximab included differential expression of peripheral blood gene transcripts that were related not only to inflammation but also to glucose and lipid metabolism. To determine whether plasma biomarkers of glucose and lipid metabolism were similarly associated with antidepressant response to infliximab and with relevant gene transcripts, we measured concentrations of glucose, insulin, and protein hormones that regulate glucose homeostasis and metabolism (leptin, resistin, and adiponectin), as well as cholesterols, triglycerides, and non-esterified fatty acids (NEFA), in medically-stable TRD outpatients at baseline and 2 weeks after the first infusion of infliximab (n = 26) or placebo (n = 26). Treatment response was defined as 50% reduction in depressive symptoms at any point during the 12-week trial. We found that baseline cholesterol (total, low-density lipoprotein [LDL], and non-high-density lipoprotein [non-HDL]), triglycerides and NEFA were elevated in patients who exhibited an antidepressant response to infliximab (all p < 0.05) but not placebo (all p > 0.299). HDL and non-HDL cholesterol concentrations also correlated with two lipid-related gene transcripts that were predictive of antidepressant response (r = 0.33 to 0.39, p < 0.05). Although not associated with response to infliximab, resistin correlated with numerous glucose-related transcripts (r = -0.32 to 0.37, p < 0.05) and was higher at 2 weeks post-infusion in patients treated with infliximab compared to placebo (p = 0.028). Concentrations of cholesterol (total, LDL, HDL, non-HDL) were also lower at 2 weeks in patients treated with infliximab compared to placebo, but only in those patients with CRP >5 mg/L at baseline (all p < 0.05). These results are consistent with previous work showing that high inflammation in patients with depression is associated with metabolic alterations, which together predict response to both traditional and experimental antidepressant therapies. Additionally, our findings suggest a causal relationship between increased inflammation and high cholesterol in depression, as a single infusion of infliximab reduced cholesterol in TRD patients with high CRP compared to placebo.

Early life adversity blunts responses to pioglitazone in depressed, overweight adults

PURPOSE

Early life adversity is associated with both metabolic impairment and depression in adulthood, as well as with poorer responses to antidepressant medications. It is not yet known whether individual differences in sensitivity to antidiabetic medications could also be related to early life adversity. We examined whether a history of early life adversity affected the observed changes in metabolic function and depressive symptoms in a randomized trial of pioglitazone for augmentation of standard treatments for depression.

PURPOSE

Early life adversity is associated with both metabolic impairment and depression in adulthood, as well as with poorer responses to antidepressant medications. It is not yet known whether individual differences in sensitivity to antidiabetic medications could also be related to early life adversity. We examined whether a history of early life adversity affected the observed changes in metabolic function and depressive symptoms in a randomized trial of pioglitazone for augmentation of standard treatments for depression.

FINDINGS

We found that early life adversity significantly impaired the metabolic response to pioglitazone. Effects on depressive symptoms did not reach significance, but nonetheless suggested that pioglitazone could mitigate the depressant effects of childhood adversity, only among those insulin resistant at baseline.

CONCLUSIONS

We conclude that a history of early life adversity may impair the body's ability to respond to insulin sensitizing pharmacotherapy, and furthermore that its contribution to resistant depression may function in part via the generation of an insulin resistant phenotype.

Effects of psilocybin therapy on personality structure

OBJECTIVE

To explore whether psilocybin with psychological support modulates personality parameters in patients suffering from treatment-resistant depression (TRD).

METHOD

Twenty patients with moderate or severe, unipolar, TRD received oral psilocybin (10 and 25 mg, one week apart) in a supportive setting. Personality was assessed at baseline and at 3-month follow-up using the Revised NEO Personality Inventory (NEO-PI-R), the subjective psilocybin experience with Altered State of Consciousness (ASC) scale, and depressive symptoms with QIDS-SR16.

RESULTS

Neuroticism scores significantly decreased while Extraversion increased following psilocybin therapy. These changes were in the direction of the normative NEO-PI-R data and were both predicted, in an exploratory analysis, by the degree of insightfulness experienced during the psilocybin session. Openness scores also significantly increased following psilocybin, whereas Conscientiousness showed trend-level increases, and Agreeableness did not change.

CONCLUSION

Our observation of changes in personality measures after psilocybin therapy was mostly consistent with reports of personality change in relation to conventional antidepressant treatment, although the pronounced increases in Extraversion and Openness might constitute an effect more specific to psychedelic therapy. This needs further exploration in future controlled studies, as do the brain mechanisms of postpsychedelic personality change.

Efficacy of adjunctive low-dose cariprazine in major depressive disorder: a randomized, double-blind, placebo-controlled trial

This 19-week, double-blind, placebo-controlled, randomized phase 2 study evaluated the efficacy, safety, and tolerability of adjunctive cariprazine (0.1-0.3 and 1.0-2.0 mg/day) as an antidepressant treatment for adults with treatment-resistant major depressive disorder (MDD) (NCT00854100). The primary endpoint was change in the Montgomery-Åsberg Depression Rating Scale (MADRS) total score and the secondary was change in the Clinical Global Impression-Intensity score. Additional efficacy parameters were also assessed. A total of 231 patients were randomized. None of the predefined parameters reached significance for either cariprazine doses, but higher doses yielded numerically greater mean changes in MADRS and Clinical Global Impression-Intensity scores, and MADRS response and remission rates, compared with placebo. No differences were seen on any measures between cariprazine 0.1-0.3 mg/day and placebo. Cariprazine was relatively well tolerated, and common treatment-emergent adverse events (incidence ≥5% and twice the placebo group rate) in both dosage groups included headache, arthralgia, restlessness, fatigue, increased appetite, insomnia, dry mouth, and constipation. In conclusion, both cariprazine doses were relatively well tolerated; although differences were not statistically significant, patients treated with cariprazine 1.0-2.0 mg/day had greater mean decreases in measures of depression symptoms compared with placebo, which is consistent with another adjunctive cariprazine MDD study, and thus warrants further investigation.

Mirtazapine added to SSRIs or SNRIs for treatment resistant depression in primary care: phase III randomised placebo controlled trial (MIR)

OBJECTIVE

To investigate the effectiveness of combining mirtazapine with serotonin-noradrenaline reuptake inhibitor (SNRI) or selective serotonin reuptake inhibitor (SSRI) antidepressants for treatment resistant depression in primary care.

DESIGN

Two parallel group multicentre phase III randomised placebo controlled trial.

SETTING

106 general practices in four UK sites; Bristol, Exeter, Hull, and Keele/North Staffs, August 2013 to October 2015.

PARTICIPANTS

480 adults aged 18 or more years who scored 14 or more on the Beck depression inventory, second revision, fulfilled ICD-10 (international classification of diseases, 10th revision) criteria for depression, and had used an SSRI or SNRI for at least six weeks but were still depressed. 241 were randomised to mirtazapine and 239 to placebo, both given in addition to usual SSRI or SNRI treatment. Participants were stratified by centre and minimised by baseline Beck depression inventory score, sex, and current psychological therapy. They were followed up at 12, 24, and 52 weeks. 431 (89.8%) were included in the (primary) 12 week follow-up.

MAIN OUTCOME MEASURES

Depressive symptoms at 12 weeks after randomisation, measured using the Beck depression inventory II score as a continuous variable. Secondary outcomes included measures of anxiety, quality of life, and adverse effects at 12, 24, and 52 weeks.

RESULTS

Beck depression inventory II scores at 12 weeks were lower in the mirtazapine group after adjustment for baseline scores and minimisation or stratification variables, although the confidence interval included the null (mean (SD) scores at 12 weeks: 18.0 (12.3) in the mirtazapine group, 19.7 (12.4) in the placebo group; adjusted difference between means -1.83 (95% confidence interval -3.92 to 0.27); P=0.09). Adverse effects were more common in the mirtazapine group and were associated with the participants stopping the trial drug.

CONCLUSION

This study did not find evidence of a clinically important benefit for mirtazapine in addition to an SSRI or SNRI over placebo in a treatment resistant group of primary care patients with depression. This remains an area of important unmet need where evidence of effective treatment options is limited.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN06653773.

Mortality in treatment-resistant unipolar depression: A register-based cohort study in Sweden

BACKGROUND

The impact of treatment resistant depression (TRD) on mortality is not established.

METHODS

Using Swedish national registers, 118,774 patients between 18-69 years of age who had been prescribed an antidepressant and been diagnosed with depression in specialized care were identified. Patients with at least two additional treatment trials during the same depressive episode were classified as having TRD. Data on the covariates of sex, age, history of depression, self-harm, substance use disorders, and other psychiatric and somatic comorbidities was also used. Relative risks comparing TRD patients with other depressed patients were calculated as hazard ratios (HR) for all-cause mortality and for external and non-external causes of death, as well as excess mortality rate ratios (EMRR), with 95% confidence intervals (CI).

RESULTS

In total 15,013 patients (13%) were classified with TRD. Adjusted HR for all-cause mortality was 1.35 (95% CI 1.21-1.50). Mortality from external causes (including suicides and accidents) was markedly higher in TRD patients than in other depressed patients (HR 1.97; 1.69-2.29), while mortality from non-external causes was similar. The adjusted EMRR was 1.52 (1.31-1.76), highest among patients 18-29 years old (EMRR 2.03; 1.31-1.76) and patients without somatic comorbidity (EMRR 1.99; 1.63-2.43).

LIMITATIONS

Severity of depression and adherence to treatment were not available in the data.

CONCLUSIONS

Patients with TRD may have an increased all-cause mortality compared to other depressed patients, mainly for external causes of death. The relative mortality is highest among young and physically healthy patients.

Rapid effectiveness of intravenous ketamine for ultraresistant depression in a clinical setting and evidence for baseline anhedonia and bipolarity as clinical predictors of effectiveness

BACKGROUND

Intravenous ketamine has been established as an efficacious and safe treatment, with transient effect, for treatment-resistant depression. However, the effectiveness of intravenous ketamine in non-research settings and with ultraresistant depression patients remains understudied.

AIMS

This study aims to measure the response and remission rates in ultraresistant depression patients in a clinical setting by means of a retrospective, open label, database study. Secondarily, the study will attempt to support previous findings of clinical predictors of effectiveness with intravenous ketamine treatment.

METHODS

Fifty patients with ultraresistant depression were treated between May 2015-December 2016, inclusive, in two community hospitals in Edmonton using six ketamine infusions of 0.5 mg/kg over 40 min over 2-3 weeks. Data were collected retrospectively from inpatient and outpatient charts. Statistical analysis to investigate clinical predictors of effectiveness included logistic regression analysis using a dependent variable of a 50% reduction in rating scale score at any point during treatment.

RESULTS

At baseline, the average treatment resistance was severe, with a Maudsley Staging Method score of 12.1 out of 15, 90.0% were resistant to electroconvulsive therapy, and the average Beck Depression Inventory score was 34.2. The response rate was 44% and remission rate was 16%. As a single predictor, moderate or severe anhedonia at baseline predicted a 55% increased likelihood of response. As a combined predictor, this level of anhedonia at baseline with a diagnosis of bipolar depression predicted a 73% increase in likelihood of response.

CONCLUSION

In a clinical setting, intravenous ketamine showed effectiveness in a complex, severely treatment-resistant, depressed population on multiple medication profiles concurrently. This study gave support to anhedonia and bipolar depression as clinical predictors of effectiveness.

Propofol for Treatment-Resistant Depression: A Pilot Study

BACKGROUND

We hypothesized that propofol, a unique general anesthetic that engages N-methyl-D-aspartate and gamma-aminobutyric acid receptors, has antidepressant properties. This open-label trial was designed to collect preliminary data regarding the feasibility, tolerability, and efficacy of deep propofol anesthesia for treatment-resistant depression.

METHODS

Ten participants with moderate-to-severe medication-resistant depression (age 18-45 years and otherwise healthy) each received a series of 10 propofol infusions. Propofol was dosed to strongly suppress electroencephalographic activity for 15 minutes. The primary depression outcome was the 24-item Hamilton Depression Rating Scale. Self-rated depression scores were compared with a group of 20 patients who received electroconvulsive therapy.

RESULTS

Propofol treatments were well tolerated by all subjects. No serious adverse events occurred. Montreal Cognitive Assessment scores remained stable. Hamilton scores decreased by a mean of 20 points (range 0-45 points), corresponding to a mean 58% improvement from baseline (range 0-100%). Six of the 10 subjects met the criteria for response (>50% improvement). Self-rated depression improved similarly in the propofol group and electroconvulsive therapy group. Five of the 6 propofol responders remained well for at least 3 months. In posthoc analyses, electroencephalographic measures predicted clinical response to propofol.

CONCLUSIONS

These findings demonstrate that high-dose propofol treatment is feasible and well tolerated by individuals with treatment-resistant depression who are otherwise healthy. Propofol may trigger rapid, durable antidepressant effects similar to electroconvulsive therapy but with fewer side effects. Controlled studies are warranted to further evaluate propofol's antidepressant efficacy and mechanisms of action. ClinicalTrials.gov: NCT02935647.

Comparative study of esketamine and racemic ketamine in treatment-resistant depression: Protocol for a non-inferiority clinical trial

INTRODUCTION

The use of ketamine as an option in the treatment of depressive disorder is growing rapidly, supported by numerous clinical trials attesting its efficacy and safety. Esketamine, the S (+) enantiomer of ketamine, is the most widely used form in the anesthetic environment in some countries, and new studies have shown that it may also be effective in depression and with better tolerability. However, no study so far has directly compared esketamine with racemic ketamine. Here we propose a protocol of a clinical trial to evaluate esketamine as a noninferior medication when compared to ketamine in the treatment of patients with treatment-resistant depression.

METHODS/DESIGN

This study protocol is for a randomized, controlled, double-blind noninferiority clinical trial. Subjects will be 18 years or older, with major depression characterized as treatment-resistant. Participants will receive a single infusion of either esketamine (0.25 mg/kg) or ketamine (0.5 mg/kg) over 40 minutes. The primary outcome will be the difference in remission rates between the 2 treatment arms at 24 and 72 hours after drug infusion. Secondary outcomes will include other timepoints, measurements of cognition, dissociation, and blood biomarkers.

DISCUSSION

A head-to-head study is the best way to evaluate whether the esketamine is in fact comparable to the racemic ketamine in terms of both efficacy and safety, and, if positive, it would be an initial step to increase the access to that type of treatment worldwide.

ETHICS AND DISSEMINATION

The study was approved by the local Institutional Review Board (University Hospital Professor Edgard Santos-Federal University of Bahia-Number: 46657415.0.0000.0049). Subjects will only participate after voluntarily agreeing and signing the Informed Consent Form. The study findings will be published in peer-reviewed journals and presented at national and international conferences.

TRIAL REGISTRATION

This trial has been registered in the Japan Primary Registries Network (JPRN): UMIN000032355, which is affiliated with the World Health Organization.

The Efficacy of Buprenorphine in Major Depression, Treatment-Resistant Depression and Suicidal Behavior: A Systematic Review

Although several pharmacological options to treat depression are currently available, approximately one third of patients who receive antidepressant medications do not respond adequately or achieve a complete remission. Thus, novel strategies are needed to successfully address those who did not respond, or partially respond, to available antidepressant pharmacotherapy. Research findings revealed that the opioid system is significantly involved in the regulation of mood and incentives salience and may be an appropriate target for novel therapeutic agents. The present study aimed to systematically review the current literature about the use of buprenorphine (BUP) for major depression, treatment-resistant depression (TRD), non-suicidal self-injury (NSSI) behavior, and suicidal behavior. We investigated Pubmed and Scopus databases using the following keywords: "buprenorphine AND depression", "buprenorphine AND treatment resistant depression", "buprenorphine AND suicid*", "buprenorphine AND refractory depression". Several evidence demonstrate that, at low doses, BUP is an efficacious, well-tolerated, and safe option in reducing depressive symptoms, serious suicidal ideation, and NSSI, even in patients with TRD. However, more studies are needed to evaluate the long-term effects, and relative efficacy of specific combinations (e.g., BUP + samidorphan (BUP/SAM), BUP + naloxone (BUP/NAL), BUP + naltrexone) over BUP monotherapy or adjunctive BUP treatment with standard antidepressants, as well as to obtain more uniform guidance about the optimal BUP dosing interval.

Finding factors that predict treatment-resistant depression: Results of a cohort study

BACKGROUND

Treatment for depressive disorders often requires subsequent interventions. Patients who do not respond to antidepressants have treatment-resistant depression (TRD). Predicting who will develop TRD may help healthcare providers make more effective treatment decisions. We sought to identify factors that predict TRD in a real-world setting using claims databases.

METHODS

A retrospective cohort study was conducted in a US claims database of adult subjects with newly diagnosed and treated depression with no mania, dementia, and psychosis. The index date was the date of antidepressant dispensing. The outcome was TRD, defined as having at least three distinct antidepressants or one antidepressant and one antipsychotic within 1 year after the index date. Predictors were age, gender, medical conditions, medications, and procedures 1 year before the index date.

RESULTS

Of 230,801 included patients, 10.4% developed TRD within 1 year. TRD patients at baseline were younger; 10.87% were between 18 and 19 years old versus 7.64% in the no-TRD group, risk ratio (RR) = 1.42 (95% confidence interval [CI] 1.37-1.48). TRD patients were more likely to have an anxiety disorder at baseline than non-TRD patients, RR = 1.38 (95% CI 1.35-1.14). At 3.68, fatigue had the highest RR (95% CI 3.18-4.25). TRD patients had substance use disorders, psychiatric conditions, insomnia, and pain more often at baseline than non-TRD patients.

CONCLUSION

Ten percent of subjects newly diagnosed and treated for depression developed TRD within a year. They were younger and suffered more frequently from fatigue, substance use disorders, anxiety, psychiatric conditions, insomnia, and pain than non-TRD patients.

Kynurenine pathway metabolism and the neurobiology of treatment-resistant depression: Comparison of multiple ketamine infusions and electroconvulsive therapy

Current first-line antidepressants can take weeks or months to decrease depressive symptoms. Low dose ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, shows potential for a more rapid antidepressant effect, with efficacy also evident in previously treatment-resistant populations. However, a greater understanding of the physiological mechanisms underlying such effects is required. We assessed the potential impact of ketamine infusion on neurobiological drivers of kynurenine pathway metabolism in major depression (HPA axis hyperactivity, inflammation) in patients with treatment-resistant depression compared to gender-matched healthy controls. Furthermore, we assessed these biomarkers before and after electroconvulsive therapy (ECT), which is currently the gold standard for management of treatment-resistant depression. As previously demonstrated, treatment with ketamine and ECT was associated with improved depressive symptoms in patients. At baseline, waking cortisol output was greater in the ECT cohort, kynurenine was greater in the ketamine cohort, and kynurenic acid was lower in patients compared to healthy controls, although inflammatory markers (IL-6, IL-8, IL-10 or IFN-γ) were similar in patients and controls. Furthermore, in patients who responded to ECT, the cortisol awakening response was decreased following treatment. Despite a trend towards reduced kynurenine concentrations in those who responded to ketamine, ketamine was not associated with significant alterations in any of the biomarkers assessed.

Effectiveness of theta burst versus high-frequency repetitive transcranial magnetic stimulation in patients with depression (THREE-D): a randomised non-inferiority trial

BACKGROUND

Treatment-resistant major depressive disorder is common; repetitive transcranial magnetic stimulation (rTMS) by use of high-frequency (10 Hz) left-side dorsolateral prefrontal cortex stimulation is an evidence-based treatment for this disorder. Intermittent theta burst stimulation (iTBS) is a newer form of rTMS that can be delivered in 3 min, versus 37·5 min for a standard 10 Hz treatment session. We aimed to establish the clinical effectiveness, safety, and tolerability of iTBS compared with standard 10 Hz rTMS in adults with treatment-resistant depression.

METHODS

In this randomised, multicentre, non-inferiority clinical trial, we recruited patients who were referred to specialty neurostimulation centres based at three Canadian university hospitals (Centre for Addiction and Mental Health and Toronto Western Hospital, Toronto, ON, and University of British Columbia Hospital, Vancouver, BC). Participants were aged 18-65 years, were diagnosed with a current treatment-resistant major depressive episode or could not tolerate at least two antidepressants in the current episode, were receiving stable antidepressant medication doses for at least 4 weeks before baseline, and had an HRSD-17 score of at least 18. Participants were randomly allocated (1:1) to treatment groups (10 Hz rTMS or iTBS) by use of a random permuted block method, with stratification by site and number of adequate trials in which the antidepressants were unsuccessful. Treatment was delivered open-label but investigators and outcome assessors were masked to treatment groups. Participants were treated with 10 Hz rTMS or iTBS to the left dorsolateral prefrontal cortex, administered on 5 days a week for 4-6 weeks. The primary outcome measure was change in 17-item Hamilton Rating Scale for Depression (HRSD-17) score, with a non-inferiority margin of 2·25 points. For the primary outcome measure, we did a per-protocol analysis of all participants who were randomly allocated to groups and who attained the primary completion point of 4 weeks. This trial is registered with ClinicalTrials.gov, number NCT01887782.

FINDINGS

Between Sept 3, 2013, and Oct 3, 2016, we randomly allocated 205 participants to receive 10 Hz rTMS and 209 participants to receive iTBS. 192 (94%) participants in the 10 Hz rTMS group and 193 (92%) in the iTBS group were assessed for the primary outcome after 4-6 weeks of treatment. HRSD-17 scores improved from 23·5 (SD 4·4) to 13·4 (7·8) in the 10 Hz rTMS group and from 23·6 (4·3) to 13·4 (7·9) in the iTBS group (adjusted difference 0·103 [corrected], lower 95% CI -1·16; p=0·0011), which indicated non-inferiority of iTBS. Self-rated intensity of pain associated with treatment was greater in the iTBS group than in the 10 Hz rTMS group (mean score on verbal analogue scale 3·8 [SD 2·0] vs 3·4 [2·0] out of 10; p=0·011). Dropout rates did not differ between groups (10 Hz rTMS: 13 [6%] of 205 participants; iTBS: 16 [8%] of 209 participants); p=0·6004). The most common treatment-related adverse event was headache in both groups (10 Hz rTMS: 131 [64%] of 204; iTBS: 136 [65%] of 208).

INTERPRETATION

In patients with treatment-resistant depression, iTBS was non-inferior to 10 Hz rTMS for the treatment of depression. Both treatments had low numbers of dropouts and similar side-effects, safety, and tolerability profiles. By use of iTBS, the number of patients treated per day with current rTMS devices can be increased several times without compromising clinical effectiveness.

FUNDING

Canadian Institutes of Health Research.

Predictors of Response to Ketamine in Treatment Resistant Major Depressive Disorder and Bipolar Disorder

Objectives: Extant evidence indicates that ketamine exerts rapid antidepressant effects in treatment-resistant depressive (TRD) symptoms as a part of major depressive disorder (MDD) and bipolar disorder (BD). The identification of depressed sub-populations that are more likely to benefit from ketamine treatment remains a priority. In keeping with this view, the present narrative review aims to identify the pretreatment predictors of response to ketamine in TRD as part of MDD and BD. Method: Electronic search engines PubMed/MEDLINE, ClinicalTrials.gov, and Scopus were searched for relevant articles from inception to January 2018. The search term ketamine was cross-referenced with the terms depression, major depressive disorder, bipolar disorder, predictors, and response and/or remission. Results: Multiple baseline pretreatment predictors of response were identified, including clinical (i.e., Body Mass Index (BMI), history of suicide, family history of alcohol use disorder), peripheral biochemistry (i.e., adiponectin levels, vitamin B12 levels), polysomnography (abnormalities in delta sleep ratio), neurochemistry (i.e., glutamine/glutamate ratio), neuroimaging (i.e., anterior cingulate cortex activity), genetic variation (i.e., Val66Met BDNF allele), and cognitive functioning (i.e., processing speed). High BMI and a positive family history of alcohol use disorder were the most replicated predictors. Conclusions: A pheno-biotype of depression more, or less likely, to benefit with ketamine treatment is far from complete. Notwithstanding, metabolic-inflammatory alterations are emerging as possible pretreatment response predictors of depressive symptom improvement, most notably being cognitive impairment. Sophisticated data-driven computational methods that are iterative and agnostic are more likely to provide actionable baseline pretreatment predictive information.

Finding treatment-resistant depression in real-world data: How a data-driven approach compares with expert-based heuristics

BACKGROUND

Depression that does not respond to antidepressants is treatment-resistant depression (TRD). TRD definitions include assessments of treatment response, dose and duration, and implementing these definitions in claims databases can be challenging. We built a data-driven TRD definition and evaluated its performance.

METHODS

We included adults with depression, ≥1 antidepressant, and no diagnosis of mania, dementia, or psychosis. Subjects were stratified into those with and without proxy for TRD. Proxies for TRD were electroconvulsive therapy, deep brain, or vagus nerve stimulation. The index date for subjects with proxy for TRD was the procedure date, and for subjects without, the date of a randomly selected visit. We used three databases. We fit decision tree predictive models. We included number of distinct antidepressants, with and without adequate doses and duration, number of antipsychotics and psychotherapies, and expert-based definitions, 3, 6, and 12 months before index date. To assess performance, we calculated area under the curve (AUC) and transportability.

RESULTS

We analyzed 33,336 subjects with no proxy for TRD, and 3,566 with the proxy. Number of antidepressants and antipsychotics were selected in all periods. The best model was at 12 months with an AUC = 0.81. The rule transported well and states that a subject with ≥1 antipsychotic or ≥3 antidepressants in the last year has TRD. Applying this rule, 15.8% of subjects treated for depression had TRD.

CONCLUSION

The definition that best discriminates between subjects with and without TRD considers number of distinct antidepressants (≥3) or antipsychotics (≥1) in the last year.

Efficacy and Safety of Intranasal Esketamine Adjunctive to Oral Antidepressant Therapy in Treatment-Resistant Depression: A Randomized Clinical Trial

Importance

Approximately one-third of patients with major depressive disorder (MDD) do not respond to available antidepressants.

Objective

To assess the efficacy, safety, and dose-response of intranasal esketamine hydrochloride in patients with treatment-resistant depression (TRD).

Design, Setting, and Participants

This phase 2, double-blind, doubly randomized, delayed-start, placebo-controlled study was conducted in multiple outpatient referral centers from January 28, 2014, to September 25, 2015. The study consisted of 4 phases: (1) screening, (2) double-blind treatment (days 1-15), composed of two 1-week periods, (3) optional open-label treatment (days 15-74), and (4) posttreatment follow-up (8 weeks). One hundred twenty-six adults with a DSM-IV-TR diagnosis of MDD and history of inadequate response to 2 or more antidepressants (ie, TRD) were screened, 67 were randomized, and 60 completed both double-blind periods. Intent-to-treat analysis was used in evaluation of the findings.

Interventions

In period 1, participants were randomized (3:1:1:1) to placebo (n = 33), esketamine 28 mg (n = 11), 56 mg (n = 11), or 84 mg (n = 12) twice weekly. In period 2, 28 placebo-treated participants with moderate-to-severe symptoms were rerandomized (1:1:1:1) to 1 of the 4 treatment arms; those with mild symptoms continued receiving placebo. Participants continued their existing antidepressant treatment during the study. During the open-label phase, dosing frequency was reduced from twice weekly to weekly, and then to every 2 weeks.

Main Outcomes and Measures

The primary efficacy end point was change from baseline to day 8 (each period) in the Montgomery-Åsberg Depression Rating Scale (MADRS) total score.

Results

Sixty-seven participants (38 women, mean [SD] age, 44.7 [10.0] years) were included in the efficacy and safety analyses. Change (least squares mean [SE] difference vs placebo) in MADRS total score (both periods combined) in all 3 esketamine groups was superior to placebo (esketamine 28 mg: -4.2 [2.09], P = .02; 56 mg: -6.3 [2.07], P = .001; 84 mg: -9.0 [2.13], P < .001), with a significant ascending dose-response relationship (P < .001). Improvement in depressive symptoms appeared to be sustained (-7.2 [1.84]) despite reduced dosing frequency in the open-label phase. Three of 56 (5%) esketamine-treated participants during the double-blind phase vs none receiving placebo and 1 of 57 participants (2%) during the open-label phase had adverse events that led to study discontinuation (1 event each of syncope, headache, dissociative syndrome, and ectopic pregnancy).

Conclusions and Relevance

In this first clinical study to date of intranasal esketamine for TRD, antidepressant effect was rapid in onset and dose related. Response appeared to persist for more than 2 months with a lower dosing frequency. Results support further investigation in larger trials.

Trial Registration

clinicaltrials.gov identifier: NCT01998958.

Psilocybin with psychological support improves emotional face recognition in treatment-resistant depression

RATIONALE

Depressed patients robustly exhibit affective biases in emotional processing which are altered by SSRIs and predict clinical outcome.

OBJECTIVES

The objective of this study is to investigate whether psilocybin, recently shown to rapidly improve mood in treatment-resistant depression (TRD), alters patients' emotional processing biases.

METHODS

Seventeen patients with treatment-resistant depression completed a dynamic emotional face recognition task at baseline and 1 month later after two doses of psilocybin with psychological support. Sixteen controls completed the emotional recognition task over the same time frame but did not receive psilocybin.

RESULTS

We found evidence for a group × time interaction on speed of emotion recognition (p = .035). At baseline, patients were slower at recognising facial emotions compared with controls (p < .001). After psilocybin, this difference was remediated (p = .208). Emotion recognition was faster at follow-up compared with baseline in patients (p = .004, d = .876) but not controls (p = .263, d = .302). In patients, this change was significantly correlated with a reduction in anhedonia over the same time period (r = .640, p = .010).

CONCLUSIONS

Psilocybin with psychological support appears to improve processing of emotional faces in treatment-resistant depression, and this correlates with reduced anhedonia. Placebo-controlled studies are warranted to follow up these preliminary findings.

Treatment resistant depression: A multi-scale, systems biology approach

An estimated 50% of depressed patients are inadequately treated by available interventions. Even with an eventual recovery, many patients require a trial and error approach, as there are no reliable guidelines to match patients to optimal treatments and many patients develop treatment resistance over time. This situation derives from the heterogeneity of depression and the lack of biomarkers for stratification by distinct depression subtypes. There is thus a dire need for novel therapies. To address these known challenges, we propose a multi-scale framework for fundamental research on depression, aimed at identifying the brain circuits that are dysfunctional in several animal models of depression as well the changes in gene expression that are associated with these models. When combined with human genetic and imaging studies, our preclinical studies are starting to identify candidate circuits and molecules that are altered both in models of disease and in patient populations. Targeting these circuits and mechanisms can lead to novel generations of antidepressants tailored to specific patient populations with distinctive types of molecular and circuit dysfunction.

Psilocybin with psychological support for treatment-resistant depression: six-month follow-up

RATIONALE

Recent clinical trials are reporting marked improvements in mental health outcomes with psychedelic drug-assisted psychotherapy.

OBJECTIVES

Here, we report on safety and efficacy outcomes for up to 6 months in an open-label trial of psilocybin for treatment-resistant depression.

METHODS

Twenty patients (six females) with (mostly) severe, unipolar, treatment-resistant major depression received two oral doses of psilocybin (10 and 25 mg, 7 days apart) in a supportive setting. Depressive symptoms were assessed from 1 week to 6 months post-treatment, with the self-rated QIDS-SR16 as the primary outcome measure.

RESULTS

Treatment was generally well tolerated. Relative to baseline, marked reductions in depressive symptoms were observed for the first 5 weeks post-treatment (Cohen's d = 2.2 at week 1 and 2.3 at week 5, both p < 0.001); nine and four patients met the criteria for response and remission at week 5. Results remained positive at 3 and 6 months (Cohen's d = 1.5 and 1.4, respectively, both p < 0.001). No patients sought conventional antidepressant treatment within 5 weeks of psilocybin. Reductions in depressive symptoms at 5 weeks were predicted by the quality of the acute psychedelic experience.

CONCLUSIONS

Although limited conclusions can be drawn about treatment efficacy from open-label trials, tolerability was good, effect sizes large and symptom improvements appeared rapidly after just two psilocybin treatment sessions and remained significant 6 months post-treatment in a treatment-resistant cohort. Psilocybin represents a promising paradigm for unresponsive depression that warrants further research in double-blind randomised control trials.

Use of Ketamine in Elderly Patients with Treatment-Resistant Depression

PURPOSE OF REVIEW

The purpose of this paper is to provide a review of the use of ketamine as an antidepressant for treatment-resistant depression (TRD) in the geriatric population. Available treatment options for late-life treatment-resistant depression are limited and include electroconvulsive therapy and transcranial magnetic stimulation as well as possible pharmacologic augmentation. Ketamine has been shown to be a promising treatment in TRD; however, data regarding the use of ketamine in the elderly includes only five case reports.

RECENT FINDINGS

We discuss the use of ketamine for late-life TRD and present two cases where ketamine led to a significant and sustained improvement in depressive symptoms. Ketamine is a promising treatment for geriatric patients with TRD. Further studies in the elderly will provide valuable insights into the use of ketamine for a population much in need of safe and effective treatments for TRD.

Backing into the future: pharmacological approaches to the management of resistant depression

Pragmatic studies indicate that a substantial number of depressed patients do not remit with current first-line antidepressant treatments and after two failed treatment steps the chance of remission with subsequent therapies is around 15%. This paper focuses on current evidence for pharmacological treatments in resistant depression as well as possible future developments. For patients who have failed to respond to two antidepressant trials, augmentation with atypical antipsychotic drugs, specifically quetiapine and aripiprazole, has the best evidence for efficacy, though older treatments such as lithium and triiodothyronine still have utility. The striking antidepressant effect of ketamine in resistant depression has stimulated research into glutamatergic compounds; however, capturing the efficacy of ketamine with drugs suitable for continuous use has proved challenging. Growing knowledge of the pathophysiological role of inflammation in depression offers great opportunities for future treatment in terms of repurposing anti-inflammatory agents from general medicine and pre-treatment stratification of those depressed patients in whom such interventions are likely to be beneficial. Finally an older drug, the dopamine receptor agonist pramipexole, if used carefully may well improve the prospects of depressed patients who are refractory to current approaches.

Increase in PAS-induced neuroplasticity after a treatment course of intranasal ketamine for depression. Report of three cases from a placebo-controlled trial

BACKGROUND

Animal studies suggest that neural plasticity may play a role in the antidepressant effects of a single ketamine dose. However, the potential effects of repeated ketamine treatments on human neuroplasticity are unknown.

METHODS

This pilot RCT study measured plasticity-induced changes before and after a ketamine course, in three treatment-resistant depressed subjects, who were randomized to receive 8 intranasal treatments of 100mg ketamine or 4.5mg midazolam. Mood ratings were performed by a trained blinded rater at baseline and 24h-48h after the ketamine course, using the Montgomery Asberg Depression Rating Scale (MADRS). Neuroplasticity was assessed in the motor cortex using a paired associative stimulation (PAS) paradigm at baseline and 24h-48h after the treatment course. No changes in current psychotropic medication or dosage were permitted for 4weeks prior to trial entry and throughout the trial.

RESULTS

The subject receiving ketamine, but not those receiving midazolam, presented a marked increase in neural plasticity after the treatment course. However, mood changes were not associated with changes in neural plasticity.

LIMITATIONS

Pilot study with small sample size. Concomitant antidepressant medications taken. Plasticity was tested in the motor cortex only, thus the generalizability of these findings to other brain areas cannot be assumed.

CONCLUSIONS

These results suggest that a course of intranasal ketamine may enhance synaptic plasticity in subjects with depression, but this was not associated with antidepressant effects. Further research on this topic is warranted.

Systematic Review of Clinical Practice Guidelines for Failed Antidepressant Treatment Response in Major Depressive Disorder, Dysthymia, and Subthreshold Depression in Adults

OBJECTIVE

This systematic review critically evaluated clinical practice guidelines (CPGs) for treating adults with major depressive disorder, dysthymia, or subthreshold or minor depression for recommendations following inadequate response to first-line treatment with selective serotonin reuptake inhibitors (SSRIs).

METHOD

Searches for CPGs (January 2004 to November 2014) in English included 7 bibliographic databases and grey literature sources using CPG and depression as the keywords. Two raters selected CPGs on depression with a national scope. Data extraction included definitions of adequate response and recommended treatment options. Two raters assessed quality using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument.

RESULTS

From 46,908 citations, 3167 were screened at full text. From these 21 CPG were applicable to adults in primary care and outpatient settings. Five CPGs consider patients with dysthymia or subthreshold or minor depression. None provides recommendations for those who do not respond to first-line SSRI treatment. For adults with MDD, most CPGs do not define an "inadequate response" or provide specific suggestions regarding how to choose alternative medications when switching to an alternative antidepressant. There is variability between CPGs in recommending combination strategies. AGREE II ratings for stakeholder involvement in CPG development, editorial independence, and rigor of development are domains in which depression guidelines are often less robust.

CONCLUSIONS

About half of patients with depression require second-line treatment to achieve remission. Consistency and clarity in guidelines for second-line treatment of depression are therefore important for clinicians but lacking in most current guidelines. This may reflect a paucity of primary studies upon which to base conclusions.

Psychedelics in the treatment of unipolar mood disorders: a systematic review

Unipolar mood disorders, including major depressive disorder and persistent depressive disorder (dysthymia), confer high rates of disability and mortality and a very high socioeconomic burden. Current treatment is suboptimal in most cases and there is little of note in the pharmaceutical development pipeline. The psychedelic drugs, including lysergic acid diethylamide and psilocybin, were used extensively in the treatment of mood disorders, and other psychiatric conditions, before their prohibition in the late 1960s. They are relatively safe when used in medically controlled environments, with no reported risk of dependence. Here, we present a systematic review of published clinical treatment studies using psychedelics in patients with broadly defined UMD, and consider their place in psychiatry. Whilst all of the included studies have methodological shortcomings, of 423 individuals in 19 studies, 335 (79.2%) showed clinician-judged improvement after treatment with psychedelics. A recently completed pilot study in the UK favours the use of psilocybin with psychological support in treatment resistant depressive disorder. The evidence overall strongly suggests that psychedelics should be re-examined in modern clinical trials for their use in unipolar mood disorders and other non-psychotic mental health conditions.

Metabolomic signatures of drug response phenotypes for ketamine and esketamine in subjects with refractory major depressive disorder: new mechanistic insights for rapid acting antidepressants

Ketamine, at sub-anesthetic doses, is reported to rapidly decrease depression symptoms in patients with treatment-resistant major depressive disorder (MDD). Many patients do not respond to currently available antidepressants, (for example, serotonin reuptake inhibitors), making ketamine and its enantiomer, esketamine, potentially attractive options for treatment-resistant MDD. Although mechanisms by which ketamine/esketamine may produce antidepressant effects have been hypothesized on the basis of preclinical data, the neurobiological correlates of the rapid therapeutic response observed in patients receiving treatment have not been established. Here we use a pharmacometabolomics approach to map global metabolic effects of these compounds in treatment-refractory MDD patients upon 2 h from infusion with ketamine (n=33) or its S-enantiomer, esketamine (n=20). The effects of esketamine on metabolism were retested in the same subjects following a second exposure administered 4 days later. Two complementary metabolomics platforms were used to provide broad biochemical coverage. In addition, we investigated whether changes in particular metabolites correlated with treatment outcome. Both drugs altered metabolites related to tryptophan metabolism (for example, indole-3-acetate and methionine) and/or the urea cycle (for example, citrulline, arginine and ornithine) at 2 h post infusion (q<0.25). In addition, we observed changes in glutamate and circulating phospholipids that were significantly associated with decreases in depression severity. These data provide new insights into the mechanism underlying the rapid antidepressant effects of ketamine and esketamine, and constitute some of the first detailed metabolomics mapping for these promising therapies.

Ketamine: Future Treatment For Unresponsive Depression?

Major Depressive Disorder (MDD) is a debilitating mental health condition which accounts for a significant portion of worldwide disability. Historically, the suggested pharmacotherapy to treat MDD have been monoaminergic-acting antidepressants, such as SSRIs or SNRIs. These drugs can provide relief, but often take weeks to noticeably improve depressive symptoms and are not always effective, leading to a condition known as Treatment-Resistant Depression (TRD). It is believed that 50% MDD sufferers in Ireland suffer from TRD, and thus the development of improved pharmacotherapies is necessary. One emerging therapy is low dose, intravenous (R-S)-Ketamine (ketamine). While the molecular basis of ketamine's therapeutic effect has not been fully determined, it has shown to effectively and swiftly mitigate the symptoms of TRD. Barriers do exist preventing the legal prescription of ketamine, including its questionable safety profile and risk of inducing dependence. Despite this, ketamine remains a promising pharmacotherapy for TRD and further investigation is required.

Increased Serum Levels of Oxytocin in 'Treatment Resistant Depression in Adolescents (TRDIA)' Group

Objective

‘Treatment-resistant depression’ is depression that does not respond to an adequate regimen of evidence-based treatment. Treatment-resistant depression frequently becomes chronic. Children with treatment-resistant depression might also develop bipolar disorder (BD). The objective of this study was to determine whether serum levels of oxytocin (OXT) in treatment-resistant depression in adolescents (TRDIA) differ from non-treatment-resistant depression in adolescents (non-TRDIA) or controls. We also investigated the relationships between serum OXT levels and the clinical symptoms, severity, and familial histories of adolescent depressive patients.

Methods

We measured serum OXT levels: TRDIA (n = 10), non-TRDIA (n = 27), and age- and sex- matched, neurotypical controls (n = 25). Patients were evaluated using the Children’s Depression Rating Scale-Revised (CDRS-R) and the Depression Self-Rating Scale for Children-Japanese Version (DSRS-C-J). The patients were also assessed retrospectively using the following variables: familial history of major depressive disorder and BD (1st degree or 2nd degree), history of disruptive mood dysregulation disorder, recurrent depressive disorder (RDD), history of antidepressant activation.

Results

Serum levels of OXT among the TRDIA and non-TRDIA patients and controls differed significantly. Interestingly, the rates of a family history of BD (1st or 2nd degree), RDD and a history of antidepressant activation in our TRDIA group were significantly higher than those of the non-TRDIA group.

Conclusions

Serum levels of OXT may play a role in the pathophysiology of TRDIA.

Treatment Resistant Depression with Loss of Antidepressant Response: Rapid-Acting Antidepressant Action of Dextromethorphan, A Possible Treatment Bridging Molecule

Dextromethorphan (DM) may have ketamine-like rapid-acting, treatment-resistant, and conventional antidepressant effects.^1,2 This reports our initial experience with DM in unipolar Major Depressive Disorder (MDD). A patient with treatment-resistant MDD (failing adequate trials of citalopram and vortioxetine) with loss of antidepressant response (to fluoxetine and bupropion) twice experienced a rapid-acting antidepressant effect within 48 hours of DM administration and lasting 7 days, sustained up to 20 days with daily administration, then gradually developing labile loss of antidepressant response over the ensuing 7 days. Upon full relapse in DSM-5 MDD while taking 600 mg/day of the strong CYP2D6 inhibitor bupropion XL, a 300 mg oral loading dose of DM was given, followed by 60 mg po bid after an additional dose-finding period, without side effects. DM exhibited a ketamine-like rapid-acting antidepressant effect, thought to be mediated by mTOR activation (related to NMDA PCP site antagonism, sigma-1 and beta adrenergic receptor stimulation) and 5HTT inhibition, resulting in AMPA receptor trafficking, and dendritogenesis, spinogenesis, synaptogenesis, and increased neuronal survival (related to NMDA antagonism and sigma-1 and mTOR signaling). This report appears to be the first report of a rapid-acting effect in unipolar MDD and adds to antidepressant effects observed in the retrospective chart review of 77 patients with Bipolar II Disorder (Kelly and Lieberman 2014). If replicated, there is some reason to think that the administration of other agents with DM, such as lithium or D-cycloserine, might prolong the duration of the rapid-antidepressant effect.

Neural correlates of improved executive function following erythropoietin treatment in mood disorders

BACKGROUND

Cognitive dysfunction in depression and bipolar disorder (BD) is insufficiently targeted by available treatments. Erythropoietin (EPO) increases neuroplasticity and may improve cognition in mood disorders, but the neuronal mechanisms of these effects are unknown. This functional magnetic resonance imaging (fMRI) study investigated the effects of EPO on neural circuitry activity during working memory (WM) performance.

METHOD

Patients with treatment-resistant major depression, who were moderately depressed, or with BD in partial remission, were randomized to eight weekly infusions of EPO (40 000 IU) (N = 30) or saline (N = 26) in a double-blind, parallel-group design. Patients underwent fMRI, mood ratings and blood tests at baseline and week 14. During fMRI patients performed an n-back WM task.

RESULTS

EPO improved WM accuracy compared with saline (p = 0.045). Whole-brain analyses revealed that EPO increased WM load-related activity in the right superior frontal gyrus (SFG) compared with saline (p = 0.01). There was also enhanced WM load-related deactivation of the left hippocampus in EPO-treated compared to saline-treated patients (p = 0.03). Across the entire sample, baseline to follow-up changes in WM performance correlated positively with changes in WM-related SFG activity and negatively with hippocampal response (r = 0.28-0.30, p < 0.05). The effects of EPO were not associated with changes in mood or red blood cells (p ⩾0.08).

CONCLUSIONS

The present findings associate changes in WM-load related activity in the right SFG and left hippocampus with improved executive function in EPO-treated patients.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov: NCT00916552.

Ketamine for treatment-resistant depression: recent developments and clinical applications

Approximately one-third of patients with major depressive disorder (MDD) do not respond to existing antidepressants, and those who do generally take weeks to months to achieve a significant effect. There is a clear unmet need for rapidly acting and more efficacious treatments. We will review recent developments in the study of ketamine, an old anaesthetic agent which has shown significant promise as a rapidly acting antidepressant in treatment-resistant patients with unipolar MDD, focusing on clinically important aspects such as dose, route of administration and duration of effect. Additional evidence suggests ketamine may be efficacious in patients with bipolar depression, post-traumatic stress disorder and acute suicidal ideation. We then discuss the safety of ketamine, in which most neuropsychiatric, neurocognitive and cardiovascular disturbances are short lasting; however, the long-term effects of ketamine are still unclear. We finally conclude with important information about ketamine for primary and secondary physicians as evidence continues to emerge for its potential use in clinical settings, underscoring the need for further investigation of its effects.

The role of GSK-3 in treatment-resistant depression and links with the pharmacological effects of lithium and ketamine: A review of the literature

BACKGROUND

Since the discovery of antidepressants, new treatments have emerged with fewer side effects but no greater efficacy. Glycogen synthase kinase 3 β (GSK-3β), a kinase known for its activity on glycogen synthesis, has in the last few years raised growing interest in biological psychiatry. Several efficient treatments in major depression have an inhibitory effect on this kinase, which could be targeted in new mood disorder treatments.

METHODS

The aim of this review is to summarize findings concerning the intracellular pharmacologic effects of GSK-3β inhibitors on mood. After a brief description of the intracellular transduction pathways implicated in both GSK-3β and mood disorders, we reviewed the results demonstrating GSK-3β involvement in the effects of lithium and ketamine.

RESULTS

GSK-3β can be inhibited through several mechanisms such as serine phosphorylation or binding in a proteic scaffold and others. Its inhibition is implicated in numerous cellular pathways of interest involved in neuronal growth and architecture, cell survival, neurogenesis or synaptic plasticity. This inhibition appears to be both efficient and sufficient in improving mood in animal models. In human beings, several levels of evidence show GSK-3β inhibition with antidepressant use. Crucially, strong inhibition has been shown with lithium via the proteic scaffold PP2A/β-arrestin/AKT, and with the rapid antidepressant effect of ketamine via p70S6K.

CONCLUSION

Our review focuses on mechanisms whereby the GSK-3β pathway has a part in the antidepressant effect of lithium and ketamine. This article highlights the importance of translational research from cell and animal models to the clinical setting in order to develop innovative therapeutic targets.

Is treatment-resistant depression a useful concept?

The term treatment-resistant depression (TRD) is widely used in the context of managing mood disorders, but defining it, both conceptually and in practice, has proven difficult. Most definitions have focused on pharmacotherapy but even these have struggled to capture the complexity of varying response and duration of treatment. Both clinically and for research studies a meaningful definition of TRD is necessary because it may lead to the development of 'therapy-defined depressive subtypes' and the discovery of novel antidepressants. This brief perspective critically reviews the concept of treatment resistance and how it can be more clearly defined so as to achieve a better understanding of depression and facilitate clinical treatment trials.

Antidepressant augmentation with metyrapone for treatment-resistant depression (the ADD study): a double-blind, randomised, placebo-controlled trial

BACKGROUND

Many patients with major depressive disorder have treatment-resistant depression, defined as no adequate response to two consecutive courses of antidepressants. Some evidence suggests that antiglucocorticoid augmentation of antidepressants might be efficacious in patients with major depressive disorder. We aimed to test the proof of concept of metyrapone for the augmentation of serotonergic antidepressants in the clinically relevant population of patients with treatment-resistant depression.

METHODS

This double-blind, randomised, placebo-controlled trial recruited patients from seven UK National Health Service (NHS) Mental Health Trusts from three areas (northeast England, northwest England, and the Leeds and Bradford area). Eligible patients were aged 18-65 years with treatment-resistant depression (Hamilton Depression Rating Scale 17-item score of ≥18 and a Massachusetts General Hospital Treatment-Resistant Depression staging score of 2-10) and taking a single-agent or combination antidepressant treatment that included a serotonergic drug. Patients were randomly assigned (1:1) through a centralised web-based system to metyrapone (500 mg twice daily) or placebo, in addition to their existing antidepressant regimen, for 21 days. Permuted block randomisation was done with a block size of two or four, stratified by centre and primary or secondary care setting. The primary outcome was improvement in Montgomery-Åsberg Depression Rating Scale (MADRS) score 5 weeks after randomisation, analysed in the modified intention-to-treat population of all randomly assigned patients that completed the MADRS assessment at week 5. The study has an International Standard Randomised Controlled Trial Number (ISRCTN45338259) and is registered with the EU Clinical Trial register, number 2009-015165-31.

FINDINGS

Between Feb 8, 2011, and Dec 10, 2012, 165 patients were recruited and randomly assigned (83 to metyrapone and 82 to placebo), with 143 (87%) completing the primary outcome assessment (69 [83%] in the metyrapone and 74 [90%] in the placebo group). At 5 weeks, MADRS score did not significantly differ between groups (21·7 points [95% CI 19·2-24·4] in the metyrapone group vs 22·6 points [20·1-24·8] in the placebo group; adjusted mean difference of -0·51 points [95% CI -3·48 to 2·46]; p=0·74). 12 serious adverse events were reported in four (5%) of 83 patients in the metyrapone group and six (7%) of 82 patients in the placebo group, none of which were related to study treatment. 134 adverse events occurred in 58 (70%) patients in the metyrapone group compared with 95 events in 45 (55%) patients in the placebo group, of which 11 (8%) events in the metyrapone group and four (4%) in the placebo group were judged by principle investigators at the time of occurrence to be probably related to the study drug.

INTERPRETATION

Metyrapone augmentation of antidepressants is not efficacious in a broadly representative population of patients with treatment-resistant depression within the NHS and therefore is not an option for patients with treatment-resistant depression in routine clinical practice at this time. Further research is needed to clarify if such augmentation might benefit subpopulations with demonstrable hypothalamic-pituitary-adrenal axis abnormalities.

FUNDING

Efficacy and Mechanism Evaluation (EME) programme, a UK Medical Research Council and National Institute for Health Research partnership.

Fewer study participants needed to demonstrate superior antidepressant efficacy when using the Hamilton melancholia subscale (HAM-D₆) as outcome measure

BACKGROUND

In the development of new antidepressant treatments, the failed study has unfortunately become a prevalent problem. The number of failed studies could probably be reduced significantly by applying more informative outcome measures. Previous studies have indicated that the 6-item melancholia subscale (HAM-D6) of the 17-item Hamilton Depression Rating Scale (HAM-D17) may be more informative than other scales, due to its superior psychometric properties. In the present study we investigated whether the HAM-D6 had higher informativeness than the HAM-D17 based on data from a randomized placebo-controlled trial (RCT) testing the effect of erythropoietin (EPO) as augmentation therapy in patients with treatment-resistant depression.

METHODS

We assessed the scalability (Mokken analysis of unidimensionality), responsiveness (item responsiveness analysis) and ability to show drug-placebo separation (estimation of sample size needed to detect statistically significant difference between EPO and placebo) of the HAM-D6 and the HAM-D17.

RESULTS

The HAM-D6 demonstrated higher scalability, higher responsiveness, and better drug-placebo separation compared to the HAM-D17. As a consequence, only 39 participants per group would be required to detect a statistically significant difference between EPO and placebo when using the HAM-D6 as outcome measure, whereas the required group size for HAM-D17 would be 146 participants.

LIMITATIONS

The EPO RCT was not originally designed to investigate the research questions addressed in this study.

CONCLUSIONS

Both for ethical and financial reasons it is of interest to minimize the number of participants in clinical trials. Therefore, we suggest employing the HAM-D6 as outcome measure in clinical trials of depression.

Role of Neuro-Immunological Factors in the Pathophysiology of Mood Disorders: Implications for Novel Therapeutics for Treatment Resistant Depression

Mood disorders are associated with persistently high rates of morbidity and mortality, despite the widespread availability of antidepressant treatments. One limitation to extant therapeutic options has been that nearly all approved antidepressant pharmacotherapies exert a similar primary action of blocking monoamine transporters, and few options exist for transitioning treatment resistant patients to alternatives with distinct mechanisms. An emerging area of science that promises novel pathways to antidepressant and mood-stabilizing therapies has followed from evidence that immunological factors play major roles in the pathophysiology of at least some mood disorder subtypes. Here we review evidence that the compounds that reduce the release or signaling of neuroactive cytokines, particularly IL-1β, IL-6, and TNF-α, can exert antidepressant effects in subgroups of depressed patients who are identified by blood-based biomarkers associated with inflammation. Within this context we discuss the role of microglia in central neuroinflammation, and the interaction between the peripheral immune system and the central synaptic microenvironment during and after neuroinflammation. Finally we review data using preclinical neuroinflammation models that produce depression-like behaviors in experimental animals to guide the discovery of novel neuro-immune drug targets.

[Antidepressant-resistant depression and the bipolar spectrum -- diagnostic and therapeutic considerations]

According to the results of epidemiological studies mood disorders with unipolar (major and minor depressive disorder; dysthymia) or bipolar features are among the most prevalent psychiatric disorders. These disorders with their frequent comorbidities (alcohol and/or drug use disorders, smoking, suicide, cardiovascular disorders) pose great public health challenge and cause substantial individual and familar burdens as well. Since SSRIs and other new antidepressant agents entered the market the possibilities to treat depression improved substantially but 25-35 percent of major depressives do not respond even to the second antidepressant trial but the rate of patients who are resistant after the third and fourth adequate antidepressant trial are around only 15-25 and 10 percent, respectively. Pharmacotherapy-resistant depression is a multicausal phenomenon. Along with its well-known risk-factors investigations of the past decade have revealed that unrecognised or hidden (subsyndromal or subthreshold) bipolarity is one of the most frequent causes of treatment resistance. In the case of bipolar depression (either as a part of syndromal bipolar I or II disorder or a subsyndromal manifestation) antidepressant monotherapy should be avoided and, instead of it, the administration of a mood stabilizer (primarily lithium and lamotrigine) or some atypical antipsychotics (preferably quetiapine) are recommended. If antidepressant is inevitably necessary in bipolar depression, we should use it always in combination with mood stabilizers or atypical antipsychotics.

[Combining a classic monoamine oxidase inhibitor with a tricyclic antidepressant in therapy-resistant depression: a case report and literature review]

Combining a monoamine oxidase inhibitor (MAOI) with a tricyclic antidepressant (TCA) is considered to be contra-indicated because there is a risk that the recipient develops a serotonin syndrome. An accidental clinical observation motivated us to search and study publications relating to the risk and effectivity of combining these two types of antidepressants.<br/> AIM: To search and study articles on the risks and effectivity of combining the use of MAOIs and TCAs in the treatment of therapy-resistant depression.<br/> METHOD: We searched in PubMed and also studied relevant articles that papers referred to in the database.<br/> RESULTS: Because many case-reports have been misinterpreted, the patients' risk of developing a serotonin syndrome and other complications as a result of the combined use of MAOIs and TCAs is overestimated. The literature provides some evidence that the combination therapy may be effective for some patients who have not responded to TCA or MAO-I monotherapy. Combination therapy seems to be safe if monitored carefully and if TCAs with marked serotonergic affinity are avoided. To enhance safety, the MAOI should be added to a TCA or both the TCA and MAOI should be started simultaneously and titrated slowly.<br/> CONCLUSION: The combination of a MAOI and a TCA can be a possible treatment for patients with treatment resistant depression when monotherapy with either a TCA or a MAOI has failed.

[The use of the monoamine oxidase inhibitor isocarboxazide in treatment-resistant depression]

The antidepressant efficacy of isocarboxazide is well established; however, the clinical use early became restricted and today the use of isocarboxazide in Denmark is very limited. Isocarboxazide is safe when keeping a low tyramine-containing diet and avoiding concomitant treatment with certain drugs. The risk of developing oedema can be reduced by vitamin B6 treatment. Normal dosage isocarboxazide may be prescribed for all patients because isocarboxazide is not metabolized through the CYP2D6 enzyme complex like most other antidepressants. It is recommended to include isocarboxazide in the official treatment algorithms for patients who are resistant to conventional antidepressant therapy and electroconvulsive therapy.

Efficacy, safety, and tolerability of augmentation pharmacotherapy with aripiprazole for treatment-resistant depression in late life: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Treatment-resistant major depression is common and potentially life-threatening in elderly people, in whom little is known about the benefits and risks of augmentation pharmacotherapy. We aimed to assess whether aripiprazole is associated with a higher probability of remission than is placebo.

METHODS

We did a randomised, double-blind, placebo-controlled trial at three centres in the USA and Canada to test the efficacy and safety of aripiprazole augmentation for adults aged older than 60 years with treatment-resistant depression (Montgomery Asberg Depression Rating Scale [MADRS] score of ≥15). Patients who did not achieve remission during a pre-trial with venlafaxine extended-release (150-300 mg/day) were randomly assigned (1:1) to the addition of aripiprazole (target dose 10 mg [maximum 15 mg] daily) daily or placebo for 12 weeks. The computer-generated randomisation was done in blocks and stratified by site. Only the database administrator and research pharmacists had knowledge of treatment assignment. The primary endpoint was remission, defined as an MADRS score of 10 or less (and at least 2 points below the score at the start of the randomised phase) at both of the final two consecutive visits, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00892047.

FINDINGS

From July 20, 2009, to Dec 30, 2013, we recruited 468 eligible participants, 181 (39%) of whom did not remit and were randomly assigned to aripiprazole (n=91) or placebo (n=90). A greater proportion of participants in the aripiprazole group achieved remission than did those in the placebo group (40 [44%] vs 26 [29%] participants; odds ratio [OR] 2·0 [95% CI 1·1-3·7], p=0·03; number needed to treat [NNT] 6·6 [95% CI 3·5-81·8]). Akathisia was the most common adverse effect of aripiprazole (reported in 24 [26%] of 91 participants on aripiprazole vs 11 [12%] of 90 on placebo). Compared with placebo, aripiprazole was also associated with more Parkinsonism (15 [17%] of 86 vs two [2%] of 81 participants), but not with treatment-emergent suicidal ideation (13 [21%] of 61 vs 19 [29%] of 65 participants) or other measured safety variables.

INTERPRETATION

In adults aged 60 years or older who do not achieve remission from depression with a first-line antidepressant, the addition of aripiprazole is effective in achieving and sustaining remission. Tolerability concerns include the potential for akathisia and Parkinsonism.

FUNDING

National Institute of Mental Health, UPMC Endowment in Geriatric Psychiatry, Taylor Family Institute for Innovative Psychiatric Research, National Center for Advancing Translational Sciences, and the Campbell Family Mental Health Research Institute.