Treatment-resistant depression in primary care across Canada

Cognitive Profiles in Treatment-Resistant Late-Life Depression and their Impact on Treatment Outcomes

BACKGROUND

Late-life depression (LLD) is associated with cognitive impairment, yet substantial heterogeneity exists among patients. Data on the extent of cognitive impairments is inconclusive, particularly in patients with treatment-resistant depression (TRD). We investigated the cognitive profiles of patients with treatment-resistant vs. nonresistant LLD and aimed to identify distinct cognitive subgroups. Additionally, we examined whether cognitive subgroups differentially responded to treatment with bilateral repetitive transcranial magnetic stimulation (rTMS).

METHODS

165 patients with LLD were divided into treatment-resistant and nonresistant groups and compared to healthy controls (HC) on measures of executive function, information processing speed, verbal learning, and memory. Cluster analysis identified subgroups based on cognitive scores. Demographic and clinical variables, as well as outcomes with bilateral rTMS, were compared between cognitive subgroups.

RESULTS

Patients with LLD, particularly TRD, exhibited significantly worse cognitive performance than HC. A three-cluster solution was found, including "Cognitively Intact" (n = 89), "Cognitively Diminished" (n = 29), and "Impaired Memory" (n = 47) subgroups. Both the "Cognitively Diminished" and "Impaired Memory" subgroups had more anxiety symptoms and a higher proportion of patients with TRD than the "Cognitively Intact" group, though the latter did not survive multiple comparison correction. No significant differences were observed in outcomes to rTMS treatment.

CONCLUSIONS

Patients with LLD exhibited impairments across cognitive domains, which were more pronounced in TRD. Three identified cognitive subgroups responded similarly to rTMS treatment, indicating its effectiveness across cognitive profiles, especially when medications are not tolerated. Future research should examine the relationship among cognitive subgroups, cognitive decline, and neurodegeneration.

Psychedelic therapy in depression and substance use disorders

Psychoactive substances obtained from botanicals have been applied for a wide variety of purposes in the rituals of different cultures for thousands of years. Classical psychedelics from N,N'-dimethyltryptamine, psilocybin, mescaline and various lysergamides cause specific alterations in perception, emotion and cognition by acting through serotonin 5-HT2A receptor activation. Lysergic acid diethylamide, the first famous breakthrough in the field, was discovered by chance by Albert Hoffman in the Zurich Sandoz laboratory in 1943, and studies on its psychoactive effects began to take place in the literature. Studies in this area were blocked after the legislation controlling the use and research of psychedelic drugs came into force in 1967, but since the 1990s, it has started to be a matter of scientific curiosity again by various research groups. In particular, with the crucial reports of psychotherapy-assisted psilocybin applications for life-threatening cancer-related anxiety and depression, a new avenues have been opened in the treatment of psychiatric diseases such as treatment-resistant depression and substance addictions. An increasing number of studies show that psychedelics have a very promising potential in the treatment of neuropsychiatric diseases where the desired efficiency cannot be achieved with conventional treatment methods. In this context, we discuss psychedelic therapy, encompassing its historical development, therapeutic applications and potential treatment effects-especially in depression, trauma disorders and substance use disorders-within the framework of ethical considerations.

Treatment resistant depression: A comparative study of access, pathways, and outcomes between Caucasian and ethnic minority individuals

BACKGROUND

Treatment resistant depression (TRD) is considered when an individual fails to respond to two or more different antidepressants in adequate doses, duration and with adequate adherence within the same major depressive episode.

AIM

To examine the clinical profiles of TRD patients through data from electronic healthcare records and compare characteristics and treatment pathways of ethnic minority and non-minority patients in UK.

METHODS

A retrospective, longitudinal, observational cohort study of patients with TRD was carried out in 10 Mental Health NHS Foundation Trusts in the Akrivia Health/UK Clinical Record Interactive Search (CRIS) system network. The CRIS system was used as a means of analysing de-identified data across 3.2 million anonymised patients' records.

RESULTS

10,048 patient records were deemed eligible for this study, of which 20.2 % of patients identified as BAME, and 79.8 % patients identified as White. Overall, around half of the patients were likely to be prescribed an antidepressant within 2 months of the MDD diagnosis. White patients were prescribed more antidepressants than the BAME group (p < 0.001), with a significant effect size for comorbidities.

LIMITATIONS

The nature of the data source limited the ability to filter for short treatment durations as clinicians did not often record concrete medication end-dates in clinical note fields.

CONCLUSION

There are significant differences in care pathways between ethnic groups in relation to TRD patients. It is vital to understand factors causing these potential clinical biases and increase awareness and education to deliver the most effective treatments for TRD in ethnic minority patients.

Roles of the medial and lateral orbitofrontal cortex in major depression and its treatment

We describe evidence for dissociable roles of the medial and lateral orbitofrontal cortex (OFC) in major depressive disorder (MDD) from structure, functional activation, functional connectivity, metabolism, and neurochemical systems. The reward-related medial orbitofrontal cortex has lower connectivity and less reward sensitivity in MDD associated with anhedonia symptoms; and the non-reward related lateral OFC has higher functional connectivity and more sensitivity to non-reward/aversive stimuli in MDD associated with negative bias symptoms. Importantly, we propose that conventional antidepressants act to normalize the hyperactive lateral (but not medial) OFC to reduce negative bias in MDD; while other treatments are needed to operate on the medial OFC to reduce anhedonia, with emerging evidence suggesting that ketamine may act in this way. The orbitofrontal cortex is the key cortical region in emotion and reward, and the current review presents much new evidence about the different ways that the medial and lateral OFC are involved in MDD.

Connectivity-guided intermittent theta burst versus repetitive transcranial magnetic stimulation for treatment-resistant depression: a randomized controlled trial

Disruption in reciprocal connectivity between the right anterior insula and the left dorsolateral prefrontal cortex is associated with depression and may be a target for neuromodulation. In a five-center, parallel, double-blind, randomized controlled trial we personalized resting-state functional magnetic resonance imaging neuronavigated connectivity-guided intermittent theta burst stimulation (cgiTBS) at a site based on effective connectivity from the right anterior insula to the left dorsolateral prefrontal cortex. We tested its efficacy in reducing the primary outcome depression symptoms measured by the GRID Hamilton Depression Rating Scale 17-item over 8, 16 and 26 weeks, compared with structural magnetic resonance imaging (MRI) neuronavigated repetitive transcranial magnetic stimulation (rTMS) delivered at the standard stimulation site (F3) in patients with 'treatment-resistant depression'. Participants were randomly assigned to 20 sessions over 4-6 weeks of either cgiTBS (n = 128) or rTMS (n = 127) with resting-state functional MRI at baseline and 16 weeks. Persistent decreases in depressive symptoms were seen over 26 weeks, with no differences between arms on the primary outcome GRID Hamilton Depression Rating Scale 17-item score (intention-to-treat adjusted mean, -0.31, 95% confidence interval (CI) -1.87, 1.24, P = 0.689). Two serious adverse events were possibly related to TMS (mania and psychosis). MRI-neuronavigated cgiTBS and rTMS were equally effective in patients with treatment-resistant depression over 26 weeks (trial registration no. ISRCTN19674644).

Sustained Mood Improvement with Laughing Gas Exposure (SMILE): Study protocol for a randomized placebo-controlled pilot trial of nitrous oxide for treatment-resistant depression

BACKGROUND

Nitrous oxide has shown potentially as an efficacious intervention for treatment-resistant depression, yet there remains insufficient evidence pertaining to repeated administration of nitrous oxide over time and active placebo-controlled studies with optimal blinding. Thus, we aim to examine the feasibility and preliminary efficacy of a six-week follow up study examining the effects of a 4 week course of weekly administered nitrous oxide as compared to the active placebo, midazolam.

METHODS

In this randomized, active placebo-controlled, pilot trial, 40 participants with treatment-resistant depression will receive either inhaled nitrous oxide (1 hour at 50% concentration) plus intravenous saline (100mL) or inhaled oxygen (1 hour at 50% concentration) plus intravenous midazolam (0.02 mg/kg in 100mL, up to 2mg) once per week, for 4 consecutive weeks. Participants will be followed up for 6 weeks starting from the first treatment visit. Primary feasibility outcomes include recruitment rate, withdrawal rate, adherence, missing data, and adverse events. The primary exploratory clinical outcome is change in Montgomery-Åsberg Depression Rating Scale (MADRS) score at day 42 of the study. Other exploratory clinical outcomes include remission (defined as MADRS score <10), response (defined as ≥ 50% reduction in MADRS score), and adverse side effects.

DISCUSSION

This pilot study will provide valuable information regarding the feasibility and preliminary efficacy of repeated nitrous oxide administration over time for treatment-resistant depression. If feasible, this study will inform the design of a future definitive trial of nitrous oxide as an efficacious and fast-acting treatment for treatment-resistant depression.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04957368. Registered on July 12, 2021.

Repetitive Transcranial Magnetic Stimulation With and Without Text4Support for the Treatment of Resistant Depression: Protocol for a Patient-Centered Multicenter Randomized Controlled Pilot Trial

BACKGROUND

Treatment-resistant depression (TRD) is the inability of a patient with major depressive disorder (MDD) to accomplish or achieve remission after an adequate trial of antidepressant treatments. Several combinations and augmentation treatment strategies for TRD exist, including the use of repetitive transcranial magnetic stimulation (rTMS), and new therapeutic options are being introduced. Text4Support, a text message-based form of cognitive behavioral therapy that allows patients with MDD to receive daily supportive text messages for correcting or altering negative thought patterns through positive reinforcement, may be a useful augmentation treatment strategy for patients with TRD. It is however currently unknown if adding the Text4Support intervention will enhance the response of patients with TRD to rTMS treatment.

OBJECTIVE

This study aims to assess the initial comparative clinical effectiveness of rTMS with and without the Text4Support program as an innovative patient-centered intervention for the management of patients diagnosed with TRD.

METHODS

This study is a multicenter, prospective, parallel-design, 2-arm, rater-blinded randomized controlled pilot trial. The recruitment process is scheduled to last 12 months. It will involve active treatment for 6 weeks, observation, and a follow-up period of 6 months for participants in the study arms. In total, 200 participants diagnosed with TRD at rTMS care clinics in Edmonton, Alberta, and rTMS clinics in Halifax, Nova Scotia will be randomized to 1 of 2 treatment arms (rTMS sessions alone or rTMS sessions plus Text4Support intervention). Participants in each group will be made to complete evaluation measures at baseline, and 1, 3, and 6 months. The primary outcome measure will be the mean change in the scores of the Patient Health Questionnaire-9 (PHQ-9). The secondary outcome measures will involve the scores of the 7-item Generalized Anxiety Disorders Scale (GAD-7), Columbia-Suicide Severity Rating Scale (CSSRS), and World Health Organization-Five Well-Being Index (WHO-5). Patient data will be analyzed with descriptive statistics, repeated measures, and correlational analyses. Qualitative data will be analyzed using the thematic analysis framework.

RESULTS

The results of the study are expected to be available 18 months from the start of recruitment. We hypothesize that participants enrolled in the rTMS plus Text4Support intervention treatment arm of the study will achieve superior outcomes compared with the outcomes of participants enrolled in the rTMS alone arm.

CONCLUSIONS

The application of the combination of rTMS and Text4Support has not been investigated previously. Therefore, we hope that this study will provide a concrete base of data to evaluate the practical application and efficacy of using the novel combination of these 2 treatment modalities.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/46830.

Pro-inflammatory markers are associated with response to sequential pharmacotherapy in major depressive disorder: a CAN-BIND-1 report

OBJECTIVE

There is limited literature on associations between inflammatory tone and response to sequential pharmacotherapies in major depressive disorder (MDD).

METHODS

In a 16-week open-label clinical trial, 211 participants with MDD were treated with escitalopram 10-20 mg daily for 8 weeks. Responders continued escitalopram while non-responders received adjunctive aripiprazole 2-10 mg daily for 8 weeks. Plasma levels of pro-inflammatory markers-C-reactive protein, interleukin (IL)-1β, IL-6, IL-17, interferon-gamma (IFN)-Γ, tumor necrosis factor (TNF)-α, and Chemokine C-C motif ligand-2 (CCL-2)-measured at baseline, and after 2, 8 and 16 weeks were included in logistic regression analyzes to assess associations between inflammatory markers and treatment response.

RESULTS

Pre-treatment IFN-Γ and CCL-2 levels were significantly associated with a lower of odds of response to escitalopram at 8 weeks. Increases in CCL-2 levels from weeks 8 to 16 in escitalopram non-responders were significantly associated with higher odds of non-response to adjunctive aripiprazole at week 16.

CONCLUSION

Higher pre-treatment levels of IFN-Γ and CCL-2 were associated with non-response to escitalopram. Increasing levels of these pro-inflammatory markers may be associated with non-response to adjunctive aripiprazole. These findings require validation in independent clinical populations.

Sleep Quality After Quetiapine Augmentation in Patients With Treatment-Resistant Depression and Personality Disorders

PURPOSE/BACKGROUND

Quetiapine is a first-line augmenting agent for treatment-resistant depression (TRD) and is used off-label in insomnia. Quetiapine and its active metabolite norquetiapine act mostly on 5-HT2A, 5-HT2C, H1, and D2 as antagonists and on 5-HT1A as partial agonists. Patients with TRD often have comorbid personality disorder (PD), and evidence suggests an association between sleep disturbance and recovery among patients with PD. Here, we aimed to evaluate the effects of quetiapine on sleep in TRD patients with and without PD (PD+/PD-).

METHODS/PROCEDURES

We reviewed health records of 38 patients with TRD (20 TRD/PD+) who had been treated with a pharmacotherapy regimen including quetiapine. Clinical outcomes were determined by comparing changes in sleep items of the Hamilton Depression Rating Scale at the beginning (T0) and after 3 months of an unchanged treatment (T3).

FINDINGS/RESULTS

Patients with TRD/PD+ and TRD/PD- taking quetiapine showed significant improvement in sleep items from T0 to T3 (P < 0.001, ηp2 ≥ 0.19). There was a significant personality × time interaction for sleep-maintenance insomnia (P = 0.006, ηp2 = 0.23), with TRD/PD+ showing a greater improvement at T3 compared with TRD/PD- (P = 0.01). While exploring other sleep items, no personality × time interaction was found. In the TRD/PD- group, improvement in sleep items was associated with an overall improvement in depressive symptoms (r = 0.55, P = 0.02).

IMPLICATIONS/CONCLUSIONS

Quetiapine induced greater improvements in sleep-maintenance insomnia among TRD/PD+ patients than TRD/PD-. These findings suggest quetiapine could have a therapeutic role for insomnia in PD underscoring a distinct underlying neurobiological mechanism of sleep disturbance in people living with PD.

Treatment-Resistant Depression in America Latina study: one-year follow-up of treatment resistant depression patients under standard of care reveals insights on quality of life, disability, work impairment, and depressive symptoms

Introduction

Depressive Disorders are on the rise worldwide. This is also the case in Latin America (LatAm). Treatment-Resistant Depressive Disorder (TRD) poses additional burden to patients with depression. Impacts quality of life (QoL) and other dimensions, and standard of care (SOC) is insufficient to achieve the desired clinical outcomes. Evidence from LatAm is, however, lacking. The present study was devised as a 1-year follow-up of the SOC in TRD patients in LatAm to explore the burden of TRD.

Methods

This was an observational, multinational, longitudinal study. Patients with clinical diagnosis of TRD in LatAm were included in a 1-year follow-up with SOC. Beyond the Sociodemographic characterization, outcome measures were QoL (EQ-5D-5L), disability (Sheehan Disability Scale - SDS), work productivity (Work Productivity and Activity Incapacity Questionnaire: depression - WPAI:D) and depression severity (Patient Health Questionnaire-PHQ9). Patients were assessed every 3-months and comparison was performed based on change from baseline to each visit and end of study (EOS - 12 months).

Results

Patients averaged 48 (± 13.12) years, mostly female (80.9%) and married/consensual union (42.5%) or single patients (34.4%). Despite the SOC treatment, three-quarters of the patients remained symptomatic at EOS, regardless of the significant longitudinal decrease (p ≤ 0.001). Similar trends were found for disability (p ≤ 0.001) -82.2% of the patients reporting work/school disruption at EOS-, percentage of work (34%) and activity impairment (40%) at EOS (p ≤ 0.001) and only 29.2% of patients with depressive severity "none" at EOS (p ≤ 0.001). The results portray the need to improve clinical outcomes in this complex and burdensome disease in LatAm.

Discussion

Here we show that the burden of TRD remains significant in essential dimensions of everyday life at EOS underlining the need for better therapeutic solutions. The improvements in most patients do not provide the desired outcome of return to the state before the condition. Further research should focus on identifying which treatments provide better outcomes in a real-world context.

The clinical & economic burden of treatment-resistant depression in the Gulf-Cooperation Council: The Kingdom of Saudi Arabia, Kuwait and the United Arab Emirates

OBJECTIVE

The current analysis assessed the economic and clinical burden of treatment-Resistant Depression (TRD) imposed on the Kingdom of Saudi Arabia (KSA), Kuwait and United Arab Emirates (UAE) from the societal perspective.

METHODS

A Microsoft Excel® based Markov model was developed to estimate the overall burden of disease imposed by TRD across KSA, Kuwait and UAE. Data for the models' adaptation were retrieved from literature and validated by country-specific key opinion leaders. The cycle length and time horizon used in the model were 4 weeks and 1 year, respectively.

RESULTS

The study results estimated that at the end of 1-year time horizon, overall burden imposed by TRD was 3994, 982 and 670 million USD in KSA, Kuwait, and UAE, respectively. This can be attributed to the high cost incurred due to non-responsive health state (ranging from 44% to 47%). The productivity loss was either the greatest or second greatest component of TRD's burden in the countries of interest (ranging from 32% to 43%).

CONCLUSIONS

TRD represents a large clinical and economic burden on both individual patients and society. Hence, noval and innovative treatments are especially required for the management of TRD patients.

Evaluation, Treatment, and Referral of Treatment-Resistant Depression in Primary Care

The Psychiatric Consultation Service at Massachusetts General Hospital sees medical and surgical inpatients with comorbid psychiatric symptoms and conditions. During their twice-weekly rounds, Dr Stern and other members of the Consultation Service discuss diagnosis and management of hospitalized patients with complex medical or surgical problems who also demonstrate psychiatric symptoms or conditions. These discussions have given rise to rounds reports that will prove useful for clinicians practicing at the interface of medicine and psychiatry.

Prim Care Companion CNS Disord. 2023;25(4):22f03438.

Author affiliations are listed at the end of this article.

Overview of treatment-resistant depression

Patients with major depressive disorder (MDD) often exhibit an inadequate treatment response or failure to achieve remission following treatment with antidepressant drugs. Treatment-resistant depression (TRD) is proposed to identify this clinical scenario. Compared to those without TRD, patients with TRD have significantly lower health-related quality of life in mental and physical dimensions, more functional impairment and productivity loss, and higher healthcare costs. TRD imposes a massive burden on the individual, family, and society. However, a lack of consensus on the TRD definition limits the comparison and interpretation of TRD treatment efficacy across trials. Furthermore, because of the various TRD definitions, there is scarce treatment guideline specifically for TRD, in contrast to the rich treatment guidelines for MDD. In this chapter, common issues related to TRD, such as proper definitions of an adequate antidepressant trial and TRD, were carefully reviewed. Prevalence of and clinical outcomes related to TRD were summarized. We also summarized the staging models ever proposed for the diagnosis of TRD. Furthermore, we highlighted variations in the definition regarding the lack of or an inadequate response in treatment guidelines for depression. Up-to-date treatment options for TRD, including pharmacological strategies, psychotherapeutic interventions, neurostimulation techniques, glutamatergic compounds, and even experimental agents were reviewed.

Impact of insulin and insulin resistance on brain dopamine signalling and reward processing- an underexplored mechanism in the pathophysiology of depression?

Type 2 diabetes and major depressive disorder (MDD) are the leading causes of disability worldwide and have a high comorbidity rate with fatal outcomes. Despite the long-established association between these conditions, the underlying molecular mechanisms remain unknown. Since the discovery of insulin receptors in the brain and the brain's reward system, evidence has accumulated indicating that insulin modulates dopaminergic (DA) signalling and reward behaviour. Here, we review the evidence from rodent and human studies, that insulin resistance directly alters central DA pathways, which may result in motivational deficits and depressive symptoms. Specifically, we first elaborate on the differential effects of insulin on DA signalling in the ventral tegmental area (VTA) - the primary DA source region in the midbrain - and the striatum as well as its effects on behaviour. We then focus on the alterations induced by insulin deficiency and resistance. Finally, we review the impact of insulin resistance in DA pathways in promoting depressive symptoms and anhedonia on a molecular and epidemiological level and discuss its relevance for stratified treatment strategies.

Incidence of treatment-resistant depression during the first mood depressive episode

INTRODUCTION

In spite of several approaches and therapeutic measures, treatment-resistant depression (TRD) continues to inflict serious, individual and collective consequences. Therefore, there is a persistent need to scrutinize the concept of TRD in order to adapt the therapeutic strategies.

AIM

To estimate the incidence of TRD in patients with a first major depressive episode (MDD), and study factors associated with resistance.

METHODS

A descriptive prospective longitudinal study of outpatients with a first MDD, was conducted. Patients with a history of subthreshold hypomania were excluded. Eligible patients were put on a selective serotonin reuptake inhibitor (SSRI), either fluoxetine or sertraline. Participants were followed regularly until they had a therapeutic response or they met the criteria for TRD.

RESULTS

The study involved 82 adults. The incidence of treatment-resistant depression was 19.4% CI95%=[5.5-33.3]. Among the sociodemographic and clinical factors, family history of psychosis (p=0.038) and chronic respiratory comorbidities (p=0.016) were associated with TRD. The small size of the sample is a potential limitation of this study. Besides, the use of only two SSRIs could influence the results.

CONCLUSION

In this study, the incidence of TRD was at the lower limit of the rates reported in clinical studies. Clinical factors associated with TRD suggest the relevance of genotype analysis to identify patients with TRD. Furthermore, our results highlight the importance of heeding comorbidities to optimize care. Larger multicenter studies are needed to generalize.

Cognitive-affective processes and suicidality in response to repetitive transcranial magnetic stimulation for treatment resistant depression

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) can elicit 45-55 % response rates and may alleviate suicidality symptoms in treatment resistant depression (TRD). Blunted anticipatory reward sensitivity and negatively biased self-referential processing may predict trajectories of depressive and suicidality symptoms in rTMS for TRD and be modulated during treatment.

METHODS

Fifty-five individuals with TRD received four weeks of low-frequency rTMS applied to the right dorsolateral prefrontal cortex (LFR-rTMS) and were followed until 17 weeks post-baseline. Participants completed behavioral measures of anticipatory reward sensitivity and self-referential processing at baseline and five weeks post-baseline (approximately one-week post-treatment). We examined whether baseline anticipatory reward sensitivity and self-referential processing predicted trajectories of depressive and suicidality symptoms from baseline to follow-up and whether these cognitive-affective variables showed change from baseline to week five.

RESULTS

Anticipatory reward sensitivity and negative self-referential encoding at baseline were associated with higher overall depressive symptoms and suicidality from baseline to 17 weeks post-baseline. At week five, participants self-attributed a higher number of positive traits and a lower number of negative traits and had a lesser tendency to remember negative relative to positive traits they had self-attributed, compared to baseline.

LIMITATIONS

The specificity of these results to LFR-rTMS is unknown in the absence of a comparison group, and our relatively small sample size precluded the interpretation of null results.

CONCLUSIONS

Baseline blunted anticipatory reward sensitivity and negative biases in self-referential processing may be risk factors for higher depressive symptoms and suicidality during and after LFR-rTMS, and LFR-rTMS may modulate self-referential processing.

Local Injection for Treating Mood Disorders (LIFT-MOOD): A Pilot Feasibility RCT of Stellate Ganglion Block for Treatment-Resistant Depression

Background

With nearly one-third of patients with major depressive disorder being resistant to available antidepressants, there is a need to develop new treatments for this population. Stellate ganglion block (SGB) is a procedure used to block sympathetic input to the central autonomic system; it has been administered to treat several conditions, including pain. Recently, indications for SGB have extended and the potential benefits for psychiatric disorders are under investigation.

Methods

The Local Injection For Treating Mood Disorders (LIFT-MOOD) study investigated the feasibility of a trial of 2 right-sided injections of bupivacaine 0.5% (7 mL) at the stellate ganglion in participants with treatment-resistant depression (TRD) using a randomized, placebo-controlled, pilot trial. Ten participants were randomized in a 1:1 allocation to receive active treatment or placebo (saline). Primary feasibility outcomes included recruitment rate, withdrawal, adherence, missing data, and adverse events. As a secondary, exploratory objective, we explored the efficacy of SGB in improving symptoms of depression by calculating the change in scores from baseline to follow-up on day 42 for each treatment group.

Results

The recruitment rate was reasonable and sufficient, retention and adherence were high, missing data were low, and adverse events were mild and temporary. Both treatment groups demonstrated decreases in Montgomery-Åsberg Depression Rating Scale scores, compared to baseline, by the end of the study.

Conclusion

This study supports the feasibility of a confirmatory trial of SGB in participants with TRD. Conclusions regarding efficacy cannot be made based on this preliminary study due to the small number of participants who completed active treatment. Larger-scale randomized controlled trials with long-term follow-ups and alternate sham procedures are needed to assess the efficacy and duration of symptom improvement with the use of SGB in TRD.

Vagally Mediated Heart Rate Variability Is Associated With Executive Function Changes in Patients With Treatment-Resistant Depression Following Magnetic Seizure Therapy

OBJECTIVES

Magnetic seizure therapy (MST) is a novel investigational brain stimulation modality for patients with treatment-resistant depression (TRD). MST is a potential alternative seizure-based treatment to electroconvulsive therapy (ECT), given that it may offer equivalent antidepressant efficacy, yet with a relative sparing of cognitive functioning. Heart rate variability (HRV) is a marker of central autonomic functioning. We aimed to explore the relationships among baseline HRV, age, clinical outcome, and executive function following MST, in patients with TRD.

MATERIALS AND METHODS

Eighty-eight TRD patients (55 females; 18-70 years) were enrolled and 48 patients completed a course of MST in an open-label study. Patients received MST treatments two to three times per week, using one of three stimulation frequencies (ie, 100 Hz, 50 Hz, or 25 Hz) at 100% stimulator output. Root mean square of the successive R-R differences (RMSSD), an index of HRV, was computed from a baseline electrocardiogram (ECG) recording. Clinical symptoms were assessed using the Hamilton Depression Rating Scale (HAM-D₂₄) and the Quick Inventory of Depressive Symptomatology (QIDS₁₆). Executive function was assessed using the Trail Making Test and the Mazes Test from the MATRICS battery.

RESULTS

Baseline RMSSD was correlated with baseline HAM-D₂₄ (r = -0.340, p = 0.001) and baseline Mazes Test (r = 0.417, p = 0.0007) but not with baseline Trail Making Test. Furthermore, baseline RMSSD was not correlated with changes on the HAM-D₂₄, QIDS₁₆, or total scores on the Trail Making Test. However, there was a significant correlation between baseline RMSSD and improvement on the Mazes Test following MST (r = 0.502, p = 0.0004).

CONCLUSIONS

Since this is an open-label trial, the influence of the placebo effect cannot be excluded. However, our results suggest that baseline RMSSD may be a state-biomarker of depression and executive function impairment. Additionally, while baseline vagally mediated resting cardiac activity did not predict the outcome of depression, it may mediate executive function improvements following MST.

Overweight, obesity, and individual symptoms of depression: A multicohort study with replication in UK Biobank

OBJECTIVES

Obesity is associated with increased risk of depression, but the extent to which this association is symptom-specific is unknown. We examined the associations of overweight and obesity with individual depressive symptoms.

METHODS

We pooled data from 15 population-based cohorts comprising 57,532 individuals aged 18 to 100 years at study entry. Primary analyses were replicated in an independent cohort, the UK Biobank study (n = 122,341, age range 38 to 72). Height and weight were assessed at baseline and body mass index (BMI) was computed. Using validated self-report measures, 24 depressive symptoms were ascertained once in 16 cross-sectional, and twice in 7 prospective cohort studies (mean follow-up 3.2 years).

RESULTS

In the pooled analysis of the primary cohorts, 22,045 (38.3 %) participants were overweight (BMI between 25 and 29.9 kg/m2), 12,025 (20.9 %) class I obese (BMI between 30 and 34.9 kg/m2), 7,467 (13.0 %) class II-III obese (BMI ≥ 35 kg/m2); and 7,046 (12.3 %) were classified as depressed. After multivariable adjustment, obesity class I was cross-sectionally associated with 1.11-fold (95 % confidence interval 1.01-1.22), and obesity class II-III with 1.31-fold (1.16-1.49) higher odds of overall depression. In symptom-specific analyses, robust associations were apparent for 4 of the 24 depressive symptoms ('could not get going/lack of energy', 'little interest in doing things', 'feeling bad about yourself, and 'feeling depressed'), with confounder-adjusted odds ratios of having 3 or 4 of these symptoms being 1.32 (1.10-1.57) for individuals with obesity class I, and 1.70 (1.34-2.14) for those with obesity class II-III. Elevated C-reactive protein and 21 obesity-related diseases explained 23 %-31 % of these associations. Symptom-specific associations were confirmed in longitudinal analyses where obesity preceded symptom onset, were stronger in women compared with men, and were replicated in UK Biobank.

CONCLUSIONS

Obesity is associated with a distinct set of depressive symptoms. These associations are partially explained by systemic inflammation and obesity-related morbidity. Awareness of this obesity-related symptom profile and its underlying biological correlates may inform better targeted treatments for comorbid obesity and depression.

Epidemiology of treatment resistant depression among major depressive disorder patients in Israel

INTRODUCTION

Major depressive disorder (MDD) is one of the most common mental disorders worldwide, estimated to affect 10-15% of the population per year. Treatment resistant depression (TRD) is estimated to affect a third of these patients who show difficulties in social and occupational function, decline of physical health, suicidal thoughts and increased health care utilization. We describe the prevalence of MDD, TRD and associated healthcare resource utilization in Maccabi Healthcare Services (MHS), a 2.5 million-member state-mandated health service in Israel.

METHODS

All MHS members with an MDD diagnosis were identified within the years 2017-2018 and prevalence assessed by age, sex and TRD. To assess the incidence of MDD, members aged 18-65 years at the start of any MDD episode were identified between 1^st January 2016 and 31^st May 2018 with at least one systemic first-line antidepressant treatment within three months before or after the initial episode. Treatment patterns, time on first-line treatment, and healthcare resource utilization were compared by TRD.

RESULTS

A total of 4960 eligible MDD patients were identified (median age = 51 years, 65% female), representing a period prevalence of 0.218%, and of those, a high proportion of patients received drug treatment (92%). Among incident MDD cases (n = 2553), 24.4% had TRD. Factors associated with TRD included increasing age and personality disorder. Median time on treatment was 3.7 months (longer for those without TRD than those with) and 81.9% of patients purchased more than one month's supply of therapy. In the year after index, patients with TRD had a significant increased number of visits to primary care physicians, psychiatrists, emergency room visits, general hospitalizations, and psychiatric hospitalizations.

CONCLUSION

Our study shows that prevalence of MDD in Israel is low compared to other countries, however once diagnosed, patients' are likely to receive drug treatment. Among patients diagnosed with MDD, the proportion of TRD is similar to other countries, increases with age and is associated with increased healthcare utilization, therefore should be a focus of continued research for finding effective long term treatment options.

Understanding the neurobiological basis of anhedonia in major depressive disorder - evidence for reduced neural activation during reward and loss processing

BACKGROUND

Anhedonia is a key symptom of major depressive disorder (MDD). Anhedonia is associated with aberrant reward processing, but whether it might interfere similarly with the neural processing of aversive stimuli, such as monetary loss, remains unknown. We aimed to investigate potential associations between anhedonia and neural response during reward and loss processing in patients with MDD.

METHODS

We investigated blood-oxygen-level-dependent response in the orbitofrontal cortex, cingulate cortex, insula and basal ganglia during monetary reward and loss processing in 182 patients with MDD, using a card-guessing paradigm. We measured anhedonia with the Social and Physical Anhedonia Scale (SASPAS), and we tested for the main and interaction effects of SASPAS scores and the experimental condition (reward or loss) in a full factorial model.

RESULTS

We detected a negative main effect of anhedonia, as well as a significant interaction effect of anhedonia and the experimental condition, on orbitofrontal and insular neural response. Post hoc analyses revealed that the interaction was driven by a significant association between higher anhedonia scores and hypoactivation during loss processing. We observed no significant association between anhedonia and neural response during reward processing.

LIMITATIONS

This study had a cross-sectional design.

CONCLUSION

Our findings confirmed that altered neural processing in the orbitofrontal cortex and insula is a neurobiological feature of anhedonic symptomatology in people with MDD. The pronounced association between anhedonia and blunted neural response during loss processing supports a broader concept for the neurobiological basis of anhedonia. Hence, MDD with anhedonic features might be characterized by reduced neural response to external stimuli, potentially because of amotivation.

Nitrous oxide for the treatment of psychiatric disorders: A systematic review of the clinical trial landscape

OBJECTIVE

To systematically review published research studies and ongoing clinical trials investigating nitrous oxide (N₂ O) in psychiatric disorders, providing an up-to-date snapshot of the clinical research landscape.

METHODS

A comprehensive literature search was conducted for studies published until June 2021 using the OVID databases (MEDLINE, Embase, APA PsycInfo) and the clinical trial registries (ClinicalTrials.gov, ICTRP).

RESULTS

In total, five relevant published articles were identified, among which four investigated N₂ O for depression. One single-dose randomized controlled trial (RCT) for treatment-resistant depression (TRD), one triple crossover RCT comparing 50% vs. 25% N₂ O for TRD, and one repeated-dose RCT for major depressive disorder (MDD) suggest that N₂ O has preliminary feasibility with rapid-acting effects on symptoms of depression. From the public registries, 10 relevant ongoing clinical trials were identified. They aim to explore the use of N₂ O for MDD, post-traumatic stress disorder, bipolar disorder, obsessive-compulsive disorder, and suicidal ideation. To date, the typical treatment protocol parameters were a single session of 50% N₂ O delivered for 60 min, although the concentration of 25% is also being explored. Projected enrolment numbers for ongoing trials (M = 55.0) were much higher than sample sizes for published studies (M = 13.0), suggesting that there potentially will be more large-scale RCTs published in the next few years.

CONCLUSION

Preliminary studies support the feasibility of administering N₂ O for depression; however, appropriate blinding is a critical challenge. Larger-scale RCTs with repeated doses of N₂ O and follow-up times beyond 1 month are needed to confirm the feasibility, therapeutic efficacy, and sustainability of response.

Neutrophil/lymphocyte, platelet/lymphocyte and monocyte/lymphocyte ratios in patients with affective disorders

OBJECTIVE

There is substantial evidence to support that the alterations in the immune-inflammation system play a crucial role in the pathogenic mechanism of affective disorders. The neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and monocyte/lymphocyte ratio (MLR) have been recently investigated as simple, rapid, and inexpensive inflammation markers. The purpose of the research is to use large-scale clinical data to study the difference of the inflammation ratios in first-episode MDD, recurrent MDD, BD depressive episodes and manic episode.

METHODS

A cross-sectional design was applied to retrospectively analyse the data that were extracted from electronic health records. A total of 16,174 Chinese affective disorder patients were enrolled in this study, and 6681 healthy subjects served as controls. The differences in the NLR, MLR, PLR and whole blood count data among different groups were compared, and the contributing factors for the occurrence of MDD and BD were analysed.

RESULTS

First-episode and recurrent MDD patients exhibited significantly elevated NLRs and MLRs compared to healthy controls. Compared with the MDD patients, the BD patients showed higher NLRs and MLRs and lower PLRs. Further analysis showed that the BD manic episode patients had significantly elevated NLRs and MLRs compared to patients with BD depressive episodes or MDD. MLR was a risk factor for the occurrence of MDD and that the NLR and MLR were risk factors for the occurrence of BD.

CONCLUSIONS

Our study highlights the role of systemic inflammation in the pathophysiology of MDD and BD, particularly during manic BD episodes.

Translational control by ketamine and its implications for comorbid cognitive deficits in depressive disorders

Ketamine has shown antidepressant effects in patients with major depressive disorder (MDD) resistant to first-line treatments and approved for use in this patient population. Ketamine induces several forms of synaptic plasticity, which are proposed to underlie its antidepressant effects. However, the molecular mechanism of action directly responsible for ketamine's antidepressant effects remains under active investigation. It was recently demonstrated that the effectors of the mammalian target of rapamycin complex 1 (mTORC1) signalling pathway, namely, eukaryotic initiation factor 4E (eIF4E) binding proteins 1 and 2 (4E-BP1 and 4E-BP2), are central in mediating ketamine-induced synaptic plasticity and behavioural antidepressant-like effect. 4E-BPs are a family of messenger ribonucleic acid (mRNA) translation repressors inactivated by mTORC1. We observed that their expression in inhibitory interneurons mediates ketamine's effects in the forced swim and novelty suppressed feeding tests and the long-lasting inhibition of GABAergic neurotransmission in the hippocampus. In addition, another effector pathway that regulates translation elongation downstream of mTORC1, the eukaryotic elongation factor 2 kinase (eEF2K), has been implicated in ketamine's behavioural effects. We will discuss how ketamine's rapid antidepressant effect depends on the activation of neuronal mRNA translation through 4E-BP1/2 and eEF2K. Furthermore, given that these pathways also regulate cognitive functions, we will discuss the evidence of ketamine's effect on cognitive function in MDD. Overall, the data accrued from pre-clinical research have implicated the mRNA translation pathways in treating mood symptoms of MDD. However, it is yet unclear whether the pro-cognitive potential of subanesthetic ketamine in rodents also engages these pathways and whether such an effect is consistently observed in the treatment-resistant MDD population.

Does Neuroinflammation Underlie the Cognitive Changes Observed With Dietary Interventions?

Dietary interventions, such as calorie restriction and ketogenic diet, have been extensively studied in ageing research, including in cognitive decline. Epidemiological studies indicate beneficial effects of certain dietary regimes on mental health, including mood disorders and dementia. However, randomised-controlled trials (the gold-standard of evidence-based medicine) on calorie restriction diets and the ketogenic diet have yet to show clinically convincing effects in neuropsychiatric disorders. This review will examine the quality of studies and evidence base for the ketogenic and calorie restriction diets in common neuropsychiatric conditions, collating findings from preclinical experiments, case reports or small clinical studies, and randomised controlled clinical trials. The major cellular mechanisms that mediate the effects of these dietary interventions on brain health include neuroinflammation, neuroprotection, and neuromodulation. We will discuss the studies that have investigated the roles of these pathways and their interactions. Popularity of the ketogenic and calorie restriction diets has grown both in the public domain and in psychiatry research, allowing for informed review of the efficacy, the limitations, and the side effects of these diets in specific patient populations. In this review we will summarise the clinical evidence for these diets in neuropsychiatry and make suggestions to improve clinical translation of future research studies.

Connectivity-Guided Theta Burst Transcranial Magnetic Stimulation Versus Repetitive Transcranial Magnetic Stimulation for Treatment-Resistant Moderate to Severe Depression: Magnetic Resonance Imaging Protocol and SARS-CoV-2-Induced Changes for a Randomized Double-blind Controlled Trial

Background

Depression is a substantial health and economic burden. In approximately one-third of patients, depression is resistant to first-line treatment; therefore, it is essential to find alternative treatments. Transcranial magnetic stimulation (TMS) is a neuromodulatory treatment involving the application of magnetic pulses to the brain that is approved in the United Kingdom and the United States in treatment-resistant depression. This trial aims to compare the clinical effectiveness, cost-effectiveness, and mechanism of action of standard treatment repetitive TMS (rTMS) targeted at the F3 electroencephalogram site with a newer treatment—a type of TMS called theta burst stimulation (TBS) targeted based on measures of functional brain connectivity. This protocol outlines brain imaging acquisition and analysis for the Brain Imaging Guided Transcranial Magnetic Stimulation in Depression (BRIGhTMIND) study trial that is used to create personalized TMS targets and answer the proposed mechanistic hypotheses.

Objective

The aims of the imaging arm of the BRIGhTMIND study are to identify functional and neurochemical brain signatures indexing the treatment mechanisms of rTMS and connectivity-guided intermittent theta burst TMS and to identify imaging-based markers predicting response to treatment.

Methods

The study is a randomized double-blind controlled trial with 1:1 allocation to either 20 sessions of TBS or standard rTMS. Multimodal magnetic resonance imaging (MRI) is acquired for each participant at baseline (before TMS treatment) with T1-weighted and task-free functional MRI during rest used to estimate TMS targets. For participants enrolled in the mechanistic substudy, additional diffusion-weighted sequences are acquired at baseline and at posttreatment follow-up 16 weeks after treatment randomization. Core data sets of T1-weighted and task-free functional MRI during rest are acquired for all participants and are used to estimate TMS targets. Additional sequences of arterial spin labeling, magnetic resonance spectroscopy, and diffusion-weighted images are acquired depending on the recruitment site for mechanistic evaluation. Standard rTMS treatment is targeted at the F3 electrode site over the left dorsolateral prefrontal cortex, whereas TBS treatment is guided using the coordinate of peak effective connectivity from the right anterior insula to the left dorsolateral prefrontal cortex. Both treatment targets benefit from the level of MRI guidance, but only TBS is provided with precision targeting based on functional brain connectivity.

Results

Recruitment began in January 2019 and is ongoing. Data collection is expected to continue until January 2023.

Conclusions

This trial will determine the impact of precision MRI guidance on rTMS treatment and assess the neural mechanisms underlying this treatment in treatment-resistant depressed patients.

Trial Registration

ISRCTN Registry ISRCTN19674644; https://www.isrctn.com/ISRCTN19674644

International Registered Report Identifier (IRRID)

DERR1-10.2196/31925

Treatment-Resistant Depression in Poland—Epidemiology and Treatment

(1) Background: Major depressive disorder (MDD) is one of the most prevalent psychiatric disorders worldwide. Although several antidepressant drugs have been developed, up to 30% of patients fail to achieve remission, and acute remission rates decrease with the number of treatment steps required. The aim of the current project was to estimate and describe the population of treatment-resistant depression (TRD) patients in outpatient clinics in Poland. (2) Methods: The project involved a representative sample of psychiatrists working in outpatient clinics, chosen through a process of quota random sampling. The doctors completed two questionnaires on a consecutive series of patients with MDD, which captured the patients’ demographics, comorbidities, and medical histories. TRD was defined as no improvement seen after a minimum of two different antidepressant drug therapies applied in sufficient doses for a minimum of 4 weeks each. The data were weighted and extrapolated to the population of TRD outpatients in Poland. (3) Results: A total of 76 psychiatrists described 1781 MDD patients, out of which 396 fulfilled the criteria of TRD. The TRD patients constituted 25.2% of all MDD patients, which led to the number of TRD outpatients in Poland being estimated at 34,800. The demographics, comorbidities, medical histories, and histories of treatment of Polish TRD patients were described. In our sample of the TRD population (mean age: 45.6 ± 13.1 years; female: 64%), the patients had experienced 2.1 ± 1.6 depressive episodes (including the current one), and the mean duration of the current episode was 4.8 ± 4.4 months. In terms of treatment strategies, most patients (around 70%) received monotherapy during the first three therapies, while combination antidepressant drugs (ADs) were applied more often from the fourth line of treatment. The use of additional medications and augmentation was reported in only up to one third of the TRD patients. During all of the treatment steps, patients most often received a selective serotonin reuptake inhibitor (SSRI) and a serotonin norepinephrine reuptake inhibitor (SNRI). (4) Conclusions: TRD is a serious problem, affecting approximately one fourth of all depressive patients and nearly 35,000 Poles.

Molecular Mechanisms of Psilocybin and Implications for the Treatment of Depression

Therapeutic deficiencies with monoaminergic antidepressants invites the need to identify and develop novel rapid-acting antidepressants. Hitherto, ketamine and esketamine are identified as safe, well-tolerated rapid-acting antidepressants in adults with treatment-resistant depression, and also mitigate measures of suicidality. Psilocybin is a naturally occurring psychoactive alkaloid and non-selective agonist at many serotonin receptors, especially at serotonin 5-HT_2A receptors, and is found in the Psilocybe genus of mushrooms. Preliminary studies with psilocybin have shown therapeutic promise across diverse populations including major depressive disorder. The pharmacodynamic mechanisms mediating the antidepressant and psychedelic effects of psilocybin are currently unknown but are thought to involve the modulation of the serotonergic system, primarily through agonism at the 5-HT_2A receptors and downstream changes in gene expression. It is also established that indirect effects on dopaminergic and glutamatergic systems are contributory, as well as effects at other lower affinity targets. Along with the direct effects on neurochemical systems, psilocybin alters neural circuitry and key brain regions previously implicated in depression, including the default mode network and amygdala. The aim of this review is to synthesize the current understanding of the receptor pharmacology and neuronal mechanisms underlying the psychedelic and putative antidepressant properties of psilocybin.

Treatment resistance in psychiatry: state of the art and new directions

Treatment resistance affects 20-60% of patients with psychiatric disorders; and is associated with increased healthcare burden and costs up to ten-fold higher relative to patients in general. Whilst there has been a recent increase in the proportion of psychiatric research focussing on treatment resistance (R² = 0.71, p < 0.0001), in absolute terms this is less than 1% of the total output and grossly out of proportion to its prevalence and impact. Here, we provide an overview of treatment resistance, considering its conceptualisation, assessment, epidemiology, impact, and common neurobiological models. We also review new treatments in development and future directions. We identify 23 consensus guidelines on its definition, covering schizophrenia, major depressive disorder, bipolar affective disorder, and obsessive compulsive disorder (OCD). This shows three core components to its definition, but also identifies heterogeneity and lack of criteria for a number of disorders, including panic disorder, post-traumatic stress disorder, and substance dependence. We provide a reporting check-list to aid comparisons across studies. We consider the concept of pseudo-resistance, linked to poor adherence or other factors, and provide an algorithm for the clinical assessment of treatment resistance. We identify nine drugs and a number of non-pharmacological approaches being developed for treatment resistance across schizophrenia, major depressive disorder, bipolar affective disorder, and OCD. Key outstanding issues for treatment resistance include heterogeneity and absence of consensus criteria, poor understanding of neurobiology, under-investment, and lack of treatments. We make recommendations to address these issues, including harmonisation of definitions, and research into the mechanisms and novel interventions to enable targeted and personalised therapeutic approaches.

Prevalence and Impact of Treatment-Resistant Depression in Latin America: a Prospective, Observational Study

Approximately one-third of patients with major depressive disorder (MDD) have treatment-resistant depression (TRD). The TRAL study will evaluate the prevalence and impact of TRD among patients with MDD in four Latin American countries. In this multicenter, prospective, observational study, patients with MDD were recruited from 33 reference sites in Mexico, Colombia, Brazil, and Argentina. Patients were assessed for TRD, defined as failure to respond to ≥ 2 antidepressant medications of adequate dose and duration. Demographics, previous/current treatments, depressive symptoms, functioning, healthcare resource utilization, and work impairment were also collected and evaluated using descriptive statistics, chi-square test, Fisher exact test, t-test for independent samples, or the Mann-Whitney nonparametric test, as appropriate. 1475 patients with MDD were included in the analysis (mean age, 45.6 years; 78% women); 89% were receiving relevant psychiatric treatment. 429 patients met criteria for TRD, and a numerically higher proportion of patients with TRD was present in public versus private sites of care (31% vs 27%). The mean Montgomery-Asberg Depression Rating Scale score was 25.0 among all MDD patients and was significantly higher for patients with TRD versus non-TRD (29.4 vs 23.3; P < 0.0001). Patients with TRD, versus those with non-TRD, were significantly more likely to be older, have a longer disease duration, have more comorbidities, be symptomatic, have a higher median number of psychiatric consultations, and report greater work impairment. Patients with TRD have a disproportionate burden of disease compared to those with non-TRD. Appropriate treatment for TRD is a substantial unmet need in Latin America. https://www.ClinicalTrials.gov identifier NCT03207282, 07/02/2017.

Age effects on treatment patterns in 138,097 patients with unipolar depression followed in general practices in Germany

BACKGROUND

Risk factors and comorbidities associated with depression vary with age and must be considered when selecting appropriate anti-depressant medication for patients. Studies are lacking which focus both on treatments prescribed and include a broad age spectrum. The goal of this study was to investigate whether age of patients at diagnosis impact the type of antidepressant drug class prescribed.

METHODS

This retrospective cohort study based on the Disease Analyzer database (IQVIA) included 138,097 patients with depression followed in 1188 general practices from date of first depression diagnosis given between 2015 and 2018 (index date). Patients aged 18-30, 31-65 and > 65 were compared in homogeneous groups based on gender and insurance type. Odds ratios adjusted by gender, insurance type, treatment site and Charlson-Comorbidity-Index were used to assess the difference in probability of receiving prescription for antidepressant drug classes as well as individual treatment drugs by age group.

RESULTS

The cohort included 13,553 (9.8%), 82,524 (59.8%) and 42,020 (30.4%) patients aged 18-30 years (young), 31-65 years (middle-aged) and >65 years (older). Less than half of patients received anti-depressant medication, with 4717 (34.8%) aged 18-30, 35,014 (42.4%) aged 31-65, and 20,294 (48.3%) aged 65 or older receiving at least one anti-depressant medication. Tri- and tetra-cyclic mediations were prescribed to 65.8% of patients aged >65, and 59.0% of patients aged 31-65. Selective serotonin reuptake inhibitors (SSRIs) and selective norepinephrine reuptake inhibitors (SNRIs) were prescribed to 55.5% of patients. Older patients showed an increased probability (OR: 1.3 [1.26-1.34 95% CI], p < 0.0001) for tri- and tetra-cyclic medication, while younger patients showed an increased probability for SSRIs and SNRIs (OR: 1.23 [1.16-1.30 95% CI], p < 0.0001).

CONCLUSION

Age-related differences in anti-depressant medication prescription were shown, with older patients above 65 years predominantly receiving tri- and tetra-cyclic medication, while younger patients aged 18-30 received SSRIs more frequently. Further studies with homogeneous groups relating to comorbidity profile and disease severity are needed to fully understand age effects on treatment patterns.

Ketamine monotherapy versus adjunctive ketamine in adults with treatment-resistant depression: Results from the Canadian Rapid Treatment Centre of Excellence

A proportion of individuals with major depressive disorder (MDD) do not receive adequate therapeutic benefit from conventional monoaminergic antidepressant drugs, leading to treatment-resistant depression (TRD). Ketamine has been shown to provide rapid and significant efficacy in treating patients with TRD. The majority of published studies have investigated the adjunctive efficacy of ketamine with one or more monoaminergic antidepressants. There remains a clinical need to ascertain the relative effectiveness of ketamine monotherapy versus adjunctive ketamine treatment in adults with TRD. In this retrospective study, we investigate multidimensional, self-reported outcomes (i.e., antidepressant, anti-suicidality, antianxiety, and anti-functional impairment) of 220 patients to compare monotherapy (n = 39) and adjunctive (n = 181) ketamine treatment for TRD at a community-based clinic. Both groups had clinically and statistically significant antidepressant effects (p < 0.05). Individuals receiving ketamine monotherapy exhibited a significantly greater reduction on the suicidal ideation (SI) item of the Quick Inventory for Depressive Symptomatology-Self Report 16-Item (QIDS-SR₁₆) than the adjunctive group, with a small effect size [F (1, 265) = 4.73; p = 0.03*; partial η² = 0.02], and a significantly higher proportion of partial responders at post-infusion 4 (p = 0.034*). No other between-group differences were significant. Limitations include the small sample, single-centred, open-label, non-randomized, uncontrolled, retrospective nature of this study and indication bias. Our real-world evidence suggests that ketamine may be effective as monotherapy or adjunct to monoamine-based treatments. A priority research and clinical vista is to identify subsets of individuals with TRD who are most likely to have a desired therapeutic outcome with monotherapy versus adjunctive ketamine treatment.

Prolonged saturated, but not monounsaturated, high-fat feeding provokes anxiodepressive-like behaviors in female mice despite similar metabolic consequences

Obesity significantly increases the risk for anxiety and depression. Our group has recently demonstrated a role for nucleus accumbens (NAc) pro-inflammatory nuclear factor kappa-B (NFkB) signaling in the development of anxiodepressive-like behaviors by diet-induced obesity in male mice. The NAc is a brain region involved in goal-oriented behavior and mood regulation whose functions are critical to hedonic feeding and motivation. While the incidence of depression and anxiety disorders is significantly higher in women than in men, the use of female animal models in psychiatric research remains limited. We set out to investigate the impact of chronic intake of saturated and monounsaturated high-fat diets (HFD) on energy metabolism and on anxiety- and despair-like behaviors in female mice and to ascertain the contribution of NAc NFkB-mediated inflammation herein.

Adult C57Bl6N female mice were fed either a saturated HFD, an isocaloric monounsaturated HFD or a control low-fat diet for 24 weeks, after which metabolic profiling and behavioral testing for anxiodepressive-like behaviors were conducted. Plasma was collected at time of sacrifice for quantification of leptin, inflammatory markers as well as 17 β-estradiol levels and brains were harvested to analyze NAc expression of pro-inflammatory genes and estrogen-signaling molecules. In another group of female mice placed on the saturated HFD or the control diet for 24 weeks, we performed adenoviral-mediated invalidation of the NFkB signaling pathway in the NAc prior to behavioral testing.

While both HFDs provoked obesity and metabolic impairments, only the saturated HFD triggered anxiodepressive-like behaviors and caused marked elevations in plasma estrogen. This saturated HFD-specific behavioral phenotype could not be explained by NAc inflammation alone and was unaffected by NAc invalidation of the NFkB signaling pathway. Instead, we found changes in the expression of estrogen signaling markers. Such results diverge from the inflammatory mechanisms underlying diet- and obesity-induced metabolic dysfunction and anxiodepressive-like behavior onset in male mice and call attention to the role of estrogen signaling in diet-related anxiodepressive-like phenotypes in female mice.

Rediscovering Psilocybin as an Antidepressive Treatment Strategy

There has recently been a renewal of interest in psychedelic research on the use of psilocybin in psychiatric treatment and, in particular, for the treatment of major depressive disorder (MDD). Several state-of-the-art studies have provided new insight into the mechanisms of action of psilocybin and its therapeutic potential. Nevertheless, many questions remain unanswered. With this review, we provide an overview of the current state of research on the potential mechanisms of psilocybin, its antidepressant potential, and the associated risks and adverse effects, to provide an update on a controversial topic discussed in psychopharmacology. A database search was conducted in Medline including articles on psilocybin over the period of the last 20 years. Despite the promising progress in understanding the mechanisms of psilocybin, the exact antidepressive mechanism and the role of the psychedelic experience remain elusive. The studies included in this review found high treatment effect sizes for psilocybin as an antidepressant. However, the results must be regarded as preliminary due to several limitations. Although the current studies observed no severe adverse events, several questions regarding safety and utility remain and must be subject of future research.

Treatment adequacy and remission of depression and anxiety disorders and quality of life in primary care older adults

BACKGROUND

Studies on the long-term outcomes of receiving adequate treatment for depression and anxiety disorders are scarce. The aims of this study were to assess the association between adequacy of care and remission of common mental disorders (CMD) and change in quality of life among a population of older adults consulting in primary care.

METHODS

The study was conducted among 225 older adults with a CMD who participated in the longitudinal ESA-Services study. Adequacy of care was assessed using administrative and self-reported data and was based on Canadian guidelines and relevant literature. CMD were measured at baseline and follow-up using self-reported measures (DSM-5 criteria) and physician diagnostic codes (International Classification of Diseases, 9^th and 10^th revisions) for depression and anxiety disorders. The remission of CMD was defined by the presence of at least one disorder at baseline and absence at follow-up. Quality of life was measured at baseline and follow-up using a visual analog scale and the Satisfaction With Life Scale. To estimate the probability to receive adequate/inadequate care, a propensity score was calculated, and analyses were weighted by the inverse probability. Weighted multivariable analyses were carried out to assess the remission of CMD and change in quality of life as a function of adequacy of care controlling for individual and health system factors.

RESULTS

Results showed that 40% of older adults received adequate care for CMD and 55% were in remission at follow-up. Adequacy of care was associated with remission of CMD (AOR: 0.66; CI 0.45-0.97; p-value: 0.032). Participants receiving adequate care had an improvement between baseline and follow-up of 0.7 (beta: 0.69, CI 0.18; 1.20, p = 0.008) point on the Satisfaction With Life Scale, while a marginal association was observed with improvement in HRQOL (beta: 2.83, CI 0.12; 5.79, p = 0.060).

CONCLUSION

The findings contribute to the rare observational studies on the association between adequacy of care for CMD and long-term treatment effects. Future studies on population effectiveness should focus on patient indicators of quality of care which may better predict long-term outcomes for patients with depression and anxiety.

Transcriptome-wide association study of treatment-resistant depression and depression subtypes for drug repurposing

Major depressive disorder (MDD) is the single largest contributor to global disability and up to 20-30% of patients do not respond to at least two antidepressants (treatment-resistant depression, TRD). This study leveraged imputed gene expression in TRD to perform a drug repurposing analysis. Among those with MDD, we defined TRD as having at least two antidepressant switches according to primary care records in UK Biobank (UKB). We performed a transcriptome-wide association study (TWAS) of TRD (n = 2165) vs healthy controls (n = 11,188) using FUSION and gene expression levels from 21 tissues. We identified compounds with opposite gene expression signatures (ConnectivityMap data) compared to our TWAS results using the Kolmogorov-Smirnov test, Spearman and Pearson correlation. As symptom patterns are routinely assessed in clinical practice and could be used to provide targeted treatments, we identified MDD subtypes associated with TRD in UKB and analysed them using the same pipeline described for TRD. Anxious MDD (n = 14,954) and MDD with weight gain (n = 4697) were associated with TRD. In the TWAS, two genes were significantly dysregulated (TMEM106B and ATP2A1 for anxious and weight gain MDD, respectively). A muscarinic receptor antagonist was identified as top candidate for repurposing in TRD; inhibition of heat shock protein 90 was the main mechanism of action identified for anxious MDD, while modulators of metabolism such as troglitazone showed promising results for MDD with weight gain. This was the first TWAS of TRD and associated MDD subtypes. Our results shed light on possible pharmacological approaches in individuals with difficult-to-treat depression.

Anhedonia as a central factor in depression: Neural mechanisms revealed from preclinical to clinical evidence

Anhedonia is one of the core symptoms of major depressive disorder (MDD), which is often inadequately treated by traditional antidepressants. The modern framework of anhedonia extends the definition from impaired consummatory pleasure or interest in rewards to a broad spectrum of deficits that impact functions such as reward anticipation, approach motivation, effort expenditure, reward valuation, expectation, and reward-cue association learning. Substantial preclinical and clinical research has explored the neural basis of reward deficits in the context of depression, and has implicated mesocorticolimbic reward circuitry comprising the nucleus accumbens, ventral pallidum, ventral tegmental area, amygdala, hippocampus, anterior cingulate, insula, orbitofrontal cortex, and other prefrontal cortex regions. Dopamine modulates several reward facets including anticipation, motivation, effort, and learning. As well, serotonin, norepinephrine, opioids, glutamate, Gamma aminobutyric acid (GABA), and acetylcholine are also involved in anhedonia, and medications targeting these systems may also potentially normalize reward processing in depression. Unfortunately, whereas reward anticipation and reward outcome are extensively explored by both preclinical and clinical studies, translational gaps remain in reward motivation, effort, valuation, and learning, where clinical neuroimaging studies are in the early stages. This review aims to synthesize the neurobiological mechanisms underlying anhedonia in MDD uncovered by preclinical and clinical research. The translational difficulties in studying the neural basis of reward are also discussed.

Zebrafish as an Animal Model for Testing Agents with Antidepressant Potential

Depression is a serious mental disease that, according to statistics, affects 320 million people worldwide. Additionally, a current situation related to the COVID-19 pandemic has led to a significant deterioration of mental health in people around the world. So far, rodents have been treated as basic animal models used in studies on this disease, but in recent years, Danio rerio has emerged as a new organism that might serve well in preclinical experiments. Zebrafish have a lot of advantages, such as a quick reproductive cycle, transparent body during the early developmental stages, high genetic and physiological homology to humans, and low costs of maintenance. Here, we discuss the potential of the zebrafish model to be used in behavioral studies focused on testing agents with antidepressant potential.

High-fat diet induces neuroinflammation and reduces the serotonergic response to escitalopram in the hippocampus of obese rats

Clinical studies indicate that obese individuals have an increased risk of developing co-morbid depressive illness and that these patients have reduced responses to antidepressant therapy, including selective serotonin reuptake inhibitors (SSRIs). Obesity, a condition of chronic mild inflammation including obesity-induced neuroinflammation, is proposed to contribute to decreases in synaptic concentrations of neurotransmitters like serotonin (5HT) by decreasing 5HT synthesis in the dorsal raphe nucleus (DRN) and/or affecting 5HT reuptake in DRN target regions like the hippocampus. In view of these observations, the goal of the current study was to examine inflammatory markers and serotonergic dynamics in co-morbid obesity and depression. Biochemical and behavioral assays revealed that high-fat diet produced an obesity and depressive-like phenotype in one cohort of rats and that these changes were marked by increases in key pro-inflammatory cytokines in the hippocampus. In real time using fast scan cyclic voltammetry (FSCV), we observed no changes in basal levels of hippocampal 5HT; however responses to escitalopram were significantly impaired in the hippocampus of obese rats compared to diet resistant rats and control rats. Further studies revealed that these neurochemical observations could be explained by increases in serotonin transporter (SERT) expression in the hippocampus driven by elevated neuroinflammation. Collectively, these results demonstrate that obesity-induced increases in neuroinflammation adversely affect SERT expression in the hippocampus of obese rats, thereby providing a potential synaptic mechanism for reduced SSRI responsiveness in obese subjects with co-morbid depressive illness.

From vision to action: Canadian leadership in ethics and neurotechnology

This chapter explores the complex neuroethical aspects of neurosurgery and neuromodulation in the context of Canadian healthcare and innovation, as seen through the lens of the Pan Canadian Neurotechnology Ethics Consortium (PCNEC). Highlighted are key areas of ethical focus, each with its own unique challenges: technical advances, readiness and risk, vulnerable populations, medico-legal issues, training, and research. Through an exploration of Canadian neurotechnological practice from these various clusters, we provide a critical review of progress, describe opportunities to address areas of debate, and seek to foster ethical innovation. Underpinning this comprehensive review are the fundamental principles of solution-oriented, practical neuroethics, with beneficence and justice at the core. In our view, it is a moral imperative that neurotechnological advancements include a delineation of ethical priorities for future guidelines, oversight, and interactions.

Genetic and clinical characteristics of treatment-resistant depression using primary care records in two UK cohorts

Treatment-resistant depression (TRD) is a major contributor to the disability caused by major depressive disorder (MDD). Primary care electronic health records provide an easily accessible approach to investigate TRD clinical and genetic characteristics. MDD defined from primary care records in UK Biobank (UKB) and EXCEED studies was compared with other measures of depression and tested for association with MDD polygenic risk score (PRS). Using prescribing records, TRD was defined from at least two switches between antidepressant drugs, each prescribed for at least 6 weeks. Clinical-demographic characteristics, SNP-based heritability (h²_SNP) and genetic overlap with psychiatric and non-psychiatric traits were compared in TRD and non-TRD MDD cases. In 230,096 and 8926 UKB and EXCEED participants with primary care data, respectively, the prevalence of MDD was 8.7% and 14.2%, of which 13.2% and 13.5% was TRD, respectively. In both cohorts, MDD defined from primary care records was strongly associated with MDD PRS, and in UKB it showed overlap of 71-88% with other MDD definitions. In UKB, TRD vs healthy controls and non-TRD vs healthy controls h²_SNP was comparable (0.25 [SE = 0.04] and 0.19 [SE = 0.02], respectively). TRD vs non-TRD was positively associated with the PRS of attention deficit hyperactivity disorder, with lower socio-economic status, obesity, higher neuroticism and other unfavourable clinical characteristics. This study demonstrated that MDD and TRD can be reliably defined using primary care records and provides the first large scale population assessment of the genetic, clinical and demographic characteristics of TRD.

Role of the Pharmacist in Managing Treatment-Resistant Depression: A Focus on Ketamine

The impact of depression is well described in the literature, and it is most prominent in patients who have trialed multiple treatments. Treatment-resistant depression (TRD) is particularly debilitating, and it is associated with significant morbidity and mortality. Despite this, there seems to be therapeutic inertia in adopting novel therapies in current practice. Ketamine is an N-methyl-D-aspartate receptor antagonist and anesthetic agent which has recently been shown to be effective in the management of TRD when administered intravenously or intranasally. The treatments, however, are not easily accessible due to restrictions in prescribing and dispensing, high costs, and the slow uptake of evidence-based practice involving ketamine within the Canadian healthcare system. Given the limited treatment options for TRD, novel approaches should be considered and adopted into practice, and facilitated by a multi-disciplinary approach. Pharmacists play a critical role in ensuring access to quality care. This includes dissemination of evidence supporting pharmacological treatments and facilitating translation into current practice. Pharmacists are uniquely positioned to collaborate with prescribers and assess novel treatment options, such as ketamine, address modifiable barriers to treatment, and triage access to medications during transitions of care. Extending the reach of these novel psychiatric treatments in both tertiary and primary care settings creates an emerging role for pharmacists in the collaborative effort to better manage treatment-resistant depression.

Electroconvulsive Therapy and Age: Effectiveness, Safety and Tolerability in the Treatment of Major Depression among Patients under and over 65 Years of Age

Electroconvulsive therapy (ECT) remains the most effective therapy in treatment-resistant depression. However, the safety of ECT has been consistently questioned, particularly among elderly patients. We assessed the efficacy and safety of ECT in patients before and after 65 years old. The study was conducted between 2015 and 2018 and included 91 patients (61 under and 29 over 65 years old) with major depression undergoing ECT. The Hamilton Depression Rating Scale was used to evaluate efficacy. Cognitive functions were assessed using: MMSE, RAVLT, Trail Making Test, Stroop Test and Autobiographical Memory Interview-Short Form. ECT was more effective in older patients as compared to younger (p < 0.001). No serious adverse events were observed in either group. Increased blood pressure and arrhythmias were more common in the older compared to the younger group (p = 0.044 and p = 0.047, respectively), while disturbances of consciousness did not differ between groups (p = 0.820). Most of the cognitive functions remained unchanged compared to baseline, whereas the outcomes of MMSE, RAVLT and Stroop tests showed greater improvements in the older compared to the younger group (all p < 0.05). The decline in the retrieval consistency of autobiographical memory was more pronounced in the younger group (p = 0.024). ECT is a highly effective, safe and well-tolerated method of treating depression regardless of age.

Magnetic seizure therapy for treatment-resistant depression

BACKGROUND

Magnetic seizure therapy (MST) is a potential alternative to electroconvulsive therapy (ECT). Reports to date on use of MST for patients with treatment-resistant depression (TRD) are limited.

OBJECTIVES

To evaluate the effects of MST in comparison with sham-MST, antidepressant, and other forms of electric or magnetic treatment for adults with TRD.

SEARCH METHODS

In March 2020, we searched a wide range of international electronic sources for published, unpublished, and ongoing studies. We handsearched the reference lists of all included studies and relevant systematic reviews and conference proceedings of the Annual Meeting of the American College of Neuropsychopharmacology (ACNP), the Annual Scientific Convention and Meeting, and the Annual Meeting of the European College of Neuropsychopharmacology (ECNP) to identify additional studies.

SELECTION CRITERIA

All randomised clinical trials (RCTs) focused on MST for adults with TRD.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently. For binary outcomes, we calculated risk ratios (RRs) and 95% confidence intervals (CIs). For continuous data, we estimated mean differences (MDs) between groups and 95% CIs. We employed a random-effects model for analyses. We assessed risk of bias for included studies and created a 'Summary of findings' table using the GRADE approach. Our main outcomes of interest were symptom severity, cognitive function, suicide, quality of life, social functioning, dropout for any reason, serious adverse events, and adverse events that led to discontinuation of treatment.

MAIN RESULTS

We included three studies (65 participants) comparing MST with ECT. Two studies reported depressive symptoms with the Hamilton Rating Scale for Depression (HAMD). However, in one study, the data were skewed and there was an imbalance in baseline characteristics. Analysis of these two studies showed no clear differences in depressive symptoms between treatment groups (MD 0.71, 95% CI -2.23 to 3.65; 2 studies, 40 participants; very low-certainty evidence). Two studies investigated multiple domains of cognitive function. However most of the outcomes were not measured by validated neuropsychological tests, and many of the data suffered from unbalanced baseline and skewed distribution. Analysis of immediate memory performance measured by the Wechsler Memory Scale showed no clear differences between treatment groups (MD 0.40, 95% CI -4.16 to 4.96; 1 study, 20 participants; very low-certainty evidence). Analysis of delayed memory performance measured by the Wechsler Memory Scale also showed no clear differences between treatment groups (MD 2.57, 95% CI -2.39 to 7.53; 1 study, 20 participants; very low-certainty evidence). Only one study reported quality of life, but the data were skewed and baseline data were unbalanced across groups. Analysis of quality of life showed no clear differences between treatment groups (MD 14.86, 95% CI -42.26 to 71.98; 1 study, 20 participants; very low-certainty evidence). Only one study reported dropout and adverse events that led to discontinuation of treatment. Analysis of reported data showed no clear differences between treatment groups for this outcome (RR 1.38, 95% CI 0.28 to 6.91; 1 study, 25 participants; very low-certainty evidence). Adverse events occurred in only two participants who received ECT (worsening of preexisting coronary heart disease and a cognitive adverse effect). None of the included studies reported outcomes on suicide and social functioning. No RCTs comparing MST with other treatments were identified.

AUTHORS' CONCLUSIONS

Evidence regarding effects of MST on patients with TRD is currently insufficient. Our analyses of available data did not reveal clearly different effects between MST and ECT. We are uncertain about these findings because of risk of bias and imprecision of estimates. Large, long, well-designed, and well-reported trials are needed to further examine the effects of MST.

Economic Burden of Treatment-Resistant Depression among Adults with Chronic Non-Cancer Pain Conditions and Major Depressive Disorder in the US

OBJECTIVE

Major depressive disorder (MDD) and chronic non-cancer pain conditions (CNPC) often co-occur and exacerbate one another. Treatment-resistant depression (TRD) in adults with CNPC can amplify the economic burden. This study examined the impact of TRD on direct total and MDD-related healthcare resource utilization (HRU) and costs among commercially insured patients with CNPC and MDD in the US.

METHODS

The retrospective longitudinal cohort study employed a claims-based algorithm to identify adults with TRD from a US claims database (January 2007 to June 2017). Costs (2018 US$) and HRU were compared between patients with and without TRD over a 12-month period after TRD/non-TRD index date. Counterfactual recycled predictions from generalized linear models were used to examine associations between TRD and annual HRU and costs. Post-regression linear decomposition identified differences in patient-level factors between TRD and non-TRD groups that contributed to the excess economic burden of TRD.

RESULTS

Of the 21,180 adults with CNPC and MDD, 10.1% were identified as having TRD. TRD patients had significantly higher HRU, translating into higher average total costs (US$21,015_TRD vs US$14,712_{No TRD}) and MDD-related costs (US$1201_TRD vs US$471_{No TRD}) compared with non-TRD patients (all p < 0.001). Prescription drug costs accounted for 37.6% and inpatient services for 30.7% of the excess total healthcare costs among TRD patients. TRD patients had a significantly higher number of inpatient (incidence rate ratio [IRR] 1.30, 95% CI 1.14-1.47) and emergency room visits (IRR 1.21, 95% CI 1.10-1.34) than non-TRD patients. Overall, 46% of the excess total costs were explained by differences in patient-level characteristics such as polypharmacy, number of CNPC, anxiety, sleep, and substance use disorders between the TRD and non-TRD groups.

CONCLUSION

TRD poses a substantial direct economic burden for adults with CNPC and MDD. Excess healthcare costs may potentially be reduced by providing timely interventions for several modifiable risk factors.

Repetitive Transcranial Magnetic Stimulation for People With Treatment-Resistant Depression: A Health Technology Assessment

BACKGROUND

Major depression is one of the most diagnosed mental illnesses in Canada. Generally, people are treated successfully with antidepressants or psychotherapy, but some people do not respond to these treatments (called treatment-resistant depression [TRD]). Repetitive transcranial magnetic stimulation (rTMS) delivers magnetic pulses to stimulate the areas of the brain associated with mood regulation. Several modalities of rTMS exist (e.g., high frequency rTMS, intermittent theta burst stimulation [iTBS], deep transcranial magnetic stimulation). We conducted a health technology assessment of rTMS for people with TRD, which included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding rTMS, and patient preferences and values.

METHODS

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Risk of Bias in Systematic Reviews (ROBIS) tool and Cochrane Risk of Bias for Randomized Controlled Trials and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-utility analysis with a 3-year horizon from a public payer perspective. We also analyzed the 5-year budget impact of publicly funding rTMS for people with TRD in Ontario. To assess the potential value of rTMS, we spoke with people who have TRD. Seven rTMS modalities were considered: low-frequency (1 Hz) stimulation, high-frequency (10-20 Hz) stimulation, unilateral stimulation, bilateral stimulation, iTBS, continuous theta burst stimulation, and deep transcranial magnetic stimulation.

RESULTS

We included 58 primary studies, 9 systematic reviews, and 1 network meta-analysis in the clinical evidence review. Most rTMS modalities were more effective than sham treatment for all outcomes (GRADE: Moderate to High). All rTMS modalities were similar to one another in response and remission rates (GRADE: not reported) and were similar to electroconvulsive therapy (ECT) in response and remission rates (GRADE: Moderate). Moreover, in both the reference case and scenario analyses, two rTMS modalities (rTMS or iTBS), followed by ECT when patients did not respond to initial treatment, were less expensive and more effective than ECT alone. They were cost-effective compared with pharmacotherapy alone at a willingness-to-pay amount of $50,000 per quality-adjusted life-year (QALY). The annual budget impact of publicly funding rTMS would range from $9.3 million in year 1 to $15.76 million in year 5, for a total of $63.2 million over the next 5 years. People with TRD we spoke with reported that their experiences were generally favourable, and their attitudes toward rTMS were positive. Similarly, psychiatrists had positive attitudes toward and acceptance of rTMS. Our quantitative literature review on preferences revealed some gaps in psychiatrists' knowledge of rTMS, which could have been influenced by their level of training on rTMS.

CONCLUSIONS

Most rTMS modalities are likely more effective than sham rTMS on all outcomes. All rTMS modalities are similar to ECT and to one another in response and remission rates. Compared with ECT alone, two rTMS modalities (high-frequency rTMS and iTBS), followed by ECT when necessary in a stepped care pathway, were less costly and more effective for managing adults with TRD. These types of rTMS (high-frequency rTMS and iTBS) were cost-effective compared with pharmacotherapy alone at a willingness-to-pay amount of $50,000 per QALY. Publicly funding rTMS (high-frequency rTMS and iTBS) for the treatment of adults with TRD in Ontario over the next 5 years would add $63.2 million in total costs. People with TRD had positive experiences and attitudes toward rTMS.

Using a machine learning approach to investigate factors associated with treatment-resistant depression among adults with chronic non-cancer pain conditions and major depressive disorder

OBJECTIVE

Presence of chronic non-cancer pain conditions (CNPC) among adults with major depressive disorder (MDD) may reduce benefits of antidepressant therapy, thereby increasing the possibility of treatment resistance. This study sought to investigate factors associated with treatment-resistant depression (TRD) among adults with MDD and CNPC using machine learning approaches.

METHODS

This retrospective cohort study was conducted using a US claims database which included adults with newly diagnosed MDD and CNPC (January 2007-June 2017). TRD was identified using a clinical staging algorithm for claims data. Random forest (RF), a machine learning method, and logistic regression was used to identify factors associated with TRD. Initial model development included 42 known and/or probable factors that may be associated with TRD. The final refined model included 20 factors.

RESULTS

Included in the sample were 23,645 patients (73% female mean age: 55 years; 78% with ≥2 CNPC, and 91% with joint pain/arthritis). Overall, 11.4% adults (N = 2684) met selected criteria for TRD. The five leading factors associated with TRD were the following: mental health specialist visits, polypharmacy (≥5 medications), psychotherapy use, anxiety, and age. Cross-validated logistic regression model indicated that those with TRD were younger, more likely to have anxiety, mental health specialist visits, polypharmacy, and psychotherapy use with adjusted odds ratios (AORs) ranging from 1.93 to 1.27 (all ps < .001).

CONCLUSION

Machine learning identified several factors that warrant further investigation and may serve as potential targets for clinical intervention to improve treatment outcomes in patients with TRD and CNPC.

The Neurostimulation of the Brain in Depression Trial: Protocol for a Randomized Controlled Trial of Transcranial Direct Current Stimulation in Treatment-Resistant Depression

Background

Major depressive disorder (MDD) is the second highest cause of disability worldwide. Standard treatments for MDD include medicine and talk therapy; however, approximately 1 in 5 Canadians fail to respond to these approaches and must consider alternatives. Transcranial direct current stimulation (tDCS) is a safe, noninvasive method that uses electrical stimulation to change the activation pattern of different brain regions. By targeting those regions known to be affected in MDD, tDCS may be useful in ameliorating treatment-resistant depression.

Objective

The objective of the Neurostimulation of the Brain in Depression trial is to compare the effectiveness of active versus sham tDCS in treating patients with ultraresistant MDD. The primary outcome will be the improvement in depressive symptoms, as measured by the change on the Mongtomery-Asberg Depression Rating Scale. Secondary outcomes will include changes in the Quick Inventory of Depressive Symptomatology Scale (subjective assessment), the World Health Organization Disability Assessment Schedule 2.0 (functional assessment), and the Screen for Cognitive Impairment in Psychiatry (cognitive assessment). Adverse events will be captured using the Young Mania Rating Scale; tDCS Adverse Events Questionnaire; Frequency, Intensity, and Burden of Side Effects Rating Scale; and Patient-Rated Inventory of Side Effects Scale. A parallel component of the study will involve assaying for baseline language function and the effect of treatment on language using an exploratory acoustic and semantic corpus analysis on recorded interviews. Participant accuracy and response latency on an auditory lexical decision task will also be evaluated.

Methods

We will recruit inpatients and outpatients in the city of Edmonton, Alberta, and will deliver the study interventions at the Grey Nuns and University of Alberta Hospitals. Written informed consent will be obtained from all participants before enrollment. Eligible participants will be randomly assigned, in a double-blinded fashion, to receive active or sham tDCS, and they will continue receiving their usual pharmacotherapy and psychotherapy throughout the trial. In both groups, participants will receive 30 weekday stimulation sessions, each session being 30 minutes in length, with the anode over the left dorsolateral prefrontal cortex and the cathode over the right. Participants in the active group will be stimulated at 2 mA throughout, whereas the sham group will receive only a brief period of stimulation to mimic skin sensations felt in the active group. Measurements will be conducted at regular points throughout the trial and 30 days after trial completion.

Results

The trial has been approved by the University of Alberta Research Ethics Board and is scheduled to commence in June 2021. The target sample size is 60 participants.

Conclusions

This is a protocol for a multicenter, double-blinded, randomized controlled superiority trial comparing active versus sham tDCS in patients with treatment-resistant MDD.

Trial Registration

ClinicalTrials.gov NCT04159012; http://clinicaltrials.gov/ct2/show/NCT04159012.

International Registered Report Identifier (IRRID)

PRR1-10.2196/22805

Depression: Biological markers and treatment

Nowadays depression is considered as a systemic illness with different biological mechanisms involved in its etiology, including inflammatory response, hypothalamic-pituitary-adrenal (HPA) axis dysregulation and neurotransmitter and neurotrophic systems imbalance. Novel "omics" approaches, such as metabolomics and glycomics provide information about altered metabolic pathways and metabolites, as well as disturbances in glycosylation processes affected by or causing the development of depression. The clinical diagnosis of depression continues to be established based on the presence of the specific symptoms, but due to its heterogeneous underlying biological background, that differs according to the disease stage, there is an unmet need for treatment response biomarkers which would facilitate the process of appropriate treatment selection. This paper provides an overview of the role of major stress response system, the HPA axis, and its dysregulation in depression, possible involvement of neurotrophins, especially brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor and insulin-like growth factor-1, in the development of depression. Article discusses how activated inflammation processes and increased cytokine levels, as well as disturbed neurotransmitter systems can contribute to different stages of depression and could specific metabolomic and glycomic species be considered as potential biomarkers of depression. The second part of the paper includes the most recent findings about available medical treatment of depression. The described biological factors impose an optimistic conclusion that they could represent easy obtainable biomarkers potentially predicting more personalized treatment and diagnostic options.

Cause-specific life years lost in individuals with treatment-resistant depression: A Danish nationwide register-based cohort study

BACKGROUND

Depression is associated with excess mortality, but it is not known how treatment-resistance influences life expectancy. We estimated cause-specific excess mortality and Life Years Lost (LYL) in patients with treatment-resistant depression (TRD).

METHODS

The population included all individuals born and living in Denmark who redeemed their first prescription for an antidepressant at age 18-69 years between 2005 and 2012, identified in the Danish National Prescription Registry. TRD was defined as at least two additional and different antidepressant trials within two years. Mortality rate ratios (MRRs) were estimated with Cox regression adjusted for age at first prescription, calendar year and comorbidity. Differences in life expectancy were estimated by the Life Years Lost (LYL) method.

RESULTS

The cohort included 154,513 first-time pharmacologically treated patients with depression, of whom 8,294 (5.4%) were identified as having TRD. Patients were followed for 1,032,245 person-years during which 9,795 deaths occurred. Men and women with TRD had significantly higher mortality than non-TRD (aMRR: 1.34, 95% CI 1.18-1.52 and aMRR: 1.39, 95% CI 1.19-1.63, respectively). Life expectancy for men and women with TRD was 1.21 (95% CI 0.36-2.44) and 1.24 (95% CI 0.35-2.34) years shorter than in all patients with depression. Suicide accounted for the majority of excess LYL, with 1.10 (95% CI 0.46-1.61) years in men and 0.82 (95% CI 0.44-1.27) years in women with TRD.

LIMITATIONS

Using redeemed prescriptions to define TRD may increase the risk of misclassification.

CONCLUSIONS

Patients not responding adequately to several treatment trials are at increased risk for premature death, particularly suicide.