Treatment Of Major Depressive Disorder Research Articles

Efficacy and Safety of Antidiabetic Agents for Major Depressive Disorder and Bipolar Depression: A Meta-Analysis of Randomized, Double-Blind, Placebo-Controlled Trials.

This meta-analysis aimed to determine the efficacy and safety of antidiabetic agents in the treatment of major depressive disorder and bipolar depression. Randomized controlled trials (RCTs) of antidiabetic agents in major depressive disorder or bipolar depression were searched in three electronic databases and three clinical trial registry websites from their inception up to October 2023. The differences in changes in the depression rating scale scores from baseline to endpoint or pre-defined sessions, response rate, remission rate, rate of side effects and dropout rate between antidiabetic agents and placebo were meta-analyzed. Six RCTs involving 399 participants were included in the final meta-analysis, which did not find that antidiabetics outperformed the placebo in reducing depressive symptoms. The standardized mean difference (SMD) in the depression scores from baseline to endpoint was 0.25 (95% CI -0.1, 0.61). However, a subgroup analysis found a significant difference between antidiabetics and placebos in reducing depressive symptoms in Middle Eastern populations, with an SMD of 0.89 (95% CI 0.44, 1.34). The current meta-analysis does not support the efficacy of antidiabetics being superior to the placebo in the treatment of unipolar and bipolar depression. However, a subgroup analysis indicates that patients from the Middle East may benefit from adding an antidiabetic medication to their ongoing medication(s) for their depression. Larger studies with good-quality study designs are warranted.

Pharmacogenomic overlap between antidepressant treatment response in major depression & antidepressant associated treatment emergent mania in bipolar disorder

There is increasing interest in individualizing treatment selection for more than 25 regulatory approved treatments for major depressive disorder (MDD). Despite an inconclusive efficacy evidence base, antidepressants (ADs) are prescribed for the depressive phase of bipolar disorder (BD) with oftentimes, an inadequate treatment response and or clinical concern for mood destabilization. This study explored the relationship between antidepressant response in MDD and antidepressant-associated treatment emergent mania (TEM) in BD. We conducted a genome-wide association study (GWAS) and polygenic score analysis of TEM and tested its association in a subset of BD-type I patients treated with SSRIs or SNRIs. Our results did not identify any genome-wide significant variants although, we found that a higher polygenic score (PGS) for antidepressant response in MDD was associated with higher odds of TEM in BD. Future studies with larger transdiagnostic depressed cohorts treated with antidepressants are encouraged to identify a neurobiological mechanism associated with a spectrum of depression improvement from response to emergent mania.

Antidepressants available in Japan for older people with major depressive disorder: A systematic review and meta-analysis.

To update the major depressive disorder (MDD) treatment guidelines of the Japanese Society of Mood Disorders, we conducted a systematic review and pairwise meta-analysis of double-blind, randomized, placebo-controlled trials of available antidepressants in Japan for older adults with MDD. Outcome measures included response rate (primary), improvement in depressive symptom scale score, remission rate, all-cause discontinuation, discontinuation due to adverse events, and at least one adverse event. A random-effects model was used to calculate the risk ratio (RR) and standardized mean difference (SMD) with a 95% confidence interval (95% CI). Nine double-blind, randomized, placebo-controlled trials (n = 2145) were identified. No study has been conducted in Japan. Our meta-analysis included the following antidepressants: duloxetine, escitalopram, imipramine, sertraline, venlafaxine, and vortioxetine. Antidepressants have significantly higher response rates than placebo (RR [95% CI] = 1.38 [1.04, 1.83], p = 0.02). Antidepressants outperformed placebo in terms of improving depressive symptom scale score (SMD [95% CI] = -0.62 [-0.92, -0.33], p < 0.0001). However, antidepressants were associated with a higher discontinuation rate due to adverse events (RR [95% CI] = 1.94 [1.30, 2.88], p = 0.001) and a higher incidence of at least one adverse event (RR [95% CI] = 1.11 [1.02, 1.21], p = 0.02) compared to placebo. The groups did not differ significantly in terms of remission rate or all-cause discontinuation. Our meta-analysis concluded that treatment with antidepressants available in Japan is only weakly recommended for moderate to severe MDD in older adults.

Elevated body temperature is associated with depressive symptoms: results from the TemPredict Study

Correlations between altered body temperature and depression have been reported in small samples; greater confidence in these associations would provide a rationale for further examining potential mechanisms of depression related to body temperature regulation. We sought to test the hypotheses that greater depression symptom severity is associated with (1) higher body temperature, (2) smaller differences between body temperature when awake versus asleep, and (3) lower diurnal body temperature amplitude. Data collected included both self-reported body temperature (using standard thermometers), wearable sensor-assessed distal body temperature (using an off-the-shelf wearable sensor that collected minute-level physiological data), and self-reported depressive symptoms from > 20,000 participants over the course of ~ 7 months as part of the TemPredict Study. Higher self-reported and wearable sensor-assessed body temperatures when awake were associated with greater depression symptom severity. Lower diurnal body temperature amplitude, computed using wearable sensor-assessed distal body temperature data, tended to be associated with greater depression symptom severity, though this association did not achieve statistical significance. These findings, drawn from a large sample, replicate and expand upon prior data pointing to body temperature alterations as potentially relevant factors in depression etiology and may hold implications for development of novel approaches to the treatment of major depressive disorder.

Change in Cognitive Function over the Course of Major Depressive Disorder: A Systematic Review and Meta-analysis.

Major depressive disorder (MDD) is associated with significant cognitive deficits during the acute and remitted stages. The aim of this systematic review and meta-analysis was to examine the course of cognitive function whilst considering demographic, treatment, or clinical features of MDD that could moderate the extent of cognitive change. Databases were searched to identify studies that reported on cognitive function in MDD with a ≥12-week test-retest interval. Relevant studies were pooled using random effects modelling to generate an inverse-variance, weighted, mean effect size estimate (Hedges' g) of cognitive change for each cognitive variable and for an overall composite cognitive domain. Of 6898 records, 99 eligible studies were identified from which 69 were meta-analysed, consisting of 4639 MDD patients (agemean = 40.25years, female% = 64.62%) across 44 cognitive variables. In over 95% of cognitive variables, improvements were either of non-significant, negligible, or of a small magnitude, and when compared to matched healthy controls, the possibility of practice effects could not be precluded. Depressive symptom improvement and the number of previous depressive episodes moderated the extent of cognitive change, demonstrating state- and scar-like features for one-quarter of the cognitive domains. Further longitudinal studies are required to elucidate the MDD cognitive trajectory from initial onset. Findings nonetheless suggest that following pharmacological and non-pharmacological treatment, cognitive change in MDD is typically small, but the capacity for change may be less with episode recurrence. Targeting cognition early in the course of illness may facilitate better prognosis and support a more complete functional recovery.

The Potential Role of Aripiprazole Augmentation for Major Depressive Disorder with Anxious Distress in Naturalistic Treatment Setting.

: This study tried to observe clinical benefit of aripiprazole augmentation (ARPA) treatment for major depressive disorder with anxious distress (MDDA) in routine practice. : Retrospective chart review (n = 41) was conducted for clinical benefit of ARPA in patients with MDDA in routine practice. The primary endpoint was the mean change of Hamilton Anxiety Rating scale (HAMA) total scores from baseline to the endpoint. Additional secondary endpoints were also retrieved. : The changes of primary endpoint HAMA (t = 5.731, -4.6, p = 0.001), and secondary endpoints including Hamilton Depression Rating scale (HAMD, t = 4.284, -3.4, p ＜ 0.001), Clinical Global Impression-Clinical Benefit (CGI-CB, -0.9, t = 1.821, p = 0.026), and Clinical Global Impression Score-Severity (CGI-S, t = 3.556, -0.4, p ＜ 0.001) scores were also significantly improved during the study. No significant adverse events were observed. : This study has shown additional benefit of ARPA treatment for MDDA patients in routine practice. However, adequately-powered and well-controlled studies are necessary for generalization of the present findings.

Antipsychotics in child and adolescent patients with major depressive disorder: A retrospective analysis of prescribing patterns.

Depression rates in children/adolescents in the United States have increased in the last 10 years. Fluoxetine and escitalopram are the only 2 antidepressants approved for the treatment of major depression disorder (MDD) in children/adolescents. In adults, some antipsychotics are approved for augmented treatment of MDD. However, there is limited research on antipsychotic augmentation in child/adolescent MDD. This retrospective chart review evaluated antipsychotic prescribing for MDD in hospitalized patients aged 4 to 17 years to determine the frequency of prescribing antipsychotics for MDD and what factors influence the addition of an antipsychotic. For inclusion, patients were diagnosed with MDD and not on an antidepressant or antipsychotic before admission. Binomial logistic regression was used to analyze variables with prescribed antipsychotics as the dependent variable. There were 6.8% of patients prescribed an antipsychotic. Binomial logistic regression analysis found that increased age (odds ratio [OR] 1.28; 95% CI = 1.045, 1.568; P = .017) and multiple admissions within 1 year (OR 3.277; 95% CI = 2.283, 4.705; P < .001) were associated with the use of antipsychotics in patients with MDD. Posttraumatic stress disorder and disruptive mood dysregulation disorder were also associated with the use of antipsychotics. Careful consideration should be taken when using off-label antipsychotics in children due to limited studies on efficacy. Future research is warranted to assess the efficacy and safety of these agents in children and adolescents.

Role of Allicin in Combination with Fluoxetine for the Treatment of Major Depressive Disorder in Rodents: Pharmacokinetic and Pharmacodynamic Study

Background: Depression is one of the most common neurological disorders for which only symptomatic treatment is available with synthetic drugs with serious side effects. Allicin [S-(2-propenyl)-2-propene-1-sulfinothioate] is a bioactive component derived from Allium sativum L. (Garlic). It has the property to penetrate the blood-brain barrier, which reveals its neuroprotective property. A synthetic drug named fluoxetine (selective serotonin re-uptake inhibitor) was introduced for the clinical treatment of depression. It is a selective serotonin re-uptake inhibitor that is well absorbed after oral administration. Aims and Objectives: This study aimed to evaluate the anti-depressant effect of fluoxetine alone and in combination with allicin. Methods: A pharmacokinetic study of allicin alone as well as in combination with fluoxetine was conducted to evaluate peak concentration, peak concentration time, and area under the curve in blood plasma. Furthermore, the biochemical analysis of neurotrophin levels of brain-derived neurotrophic factor (BDNF), serotonin, and dopamine was also performed to determine the anti-depressant activity with synergism effect of allicin and fluoxetine. Results: The results of a pharmacokinetic study for co-administration of fluoxetine with allicin and enhanced neurotrophins and monoamines levels confirmed their effectiveness against depression. They may also be effective in suicidal risk associated with anti-depressant drugs. Conclusion: A combination of synthetic drugs with herbal compounds may be an alternate and effective therapy to overcome harmful effects.

White matter integrity and medication response to antidepressants in major depressive disorder: a review of the literature.

Major Depressive Disorder (MDD) is a severe psychiatric disorder characterized by selective impairments in mood regulation, cognition and behavior. Although it is well-known that antidepressants can effectively treat moderate to severe depression, the biochemical effects of these medications on white matter (WM) integrity are still unclear. Therefore, the aim of the study is to review the main scientific evidence on the differences in WM integrity in responders and non-responders to antidepressant medications. A record search was performed on three datasets (PubMed, Scopus and Web of Science) and ten records matched our inclusion criteria. Overall, the reviewed studies highlighted a good efficacy of antidepressants in MDD treatment. Furthermore, there were differences in WM integrity between responders and non-responders, mainly localized in cingulate cortices, hippocampus and corpus callosum, where the former group showed higher fractional anisotropy and lower axial diffusivity values. Modifications in WM integrity might be partially explained by branching and proliferation as well as neurogenesis of axonal fibers mediated by antidepressants, which in turn may have positively affected brain metabolism and increase the quantity of the serotonergic neurotransmitter within synaptic clefts. However, the reviewed studies suffer from some limitations, including the heterogeneity in treatment duration, antidepressant administration, medical posology, and psychiatric comorbidities. Therefore, future studies are needed to reduce confounding effects of antidepressant medications and to adopt longitudinal and multimodal approaches in order to better characterize the differences in WM integrity between responders and non-responders.

Individual deviations from normative electroencephalographic connectivity predict antidepressant response

BackgroundAntidepressant medications yield unsatisfactory treatment outcomes in patients with major depressive disorder (MDD) with modest advantages over the placebo, partly due to the elusive mechanisms of antidepressant responses and unexplained heterogeneity in patient's response to treatment. Here we develop a novel normative modeling framework to quantify individual deviations in psychopathological dimensions that offers a promising avenue for the personalized treatment for psychiatric disorders. MethodsWe built a normative model with resting-state electroencephalography (EEG) connectivity data from healthy controls of three independent cohorts. We characterized the individual deviation of MDD patients from the healthy norms, based on which we trained sparse predictive models for treatment responses of MDD patients (102 sertraline-medicated and 119 placebo-medicated). Hamilton depression rating scale (HAMD-17) was assessed at both baseline and after the eight-week antidepressant treatment. ResultsWe successfully predicted treatment outcomes for patients receiving sertraline (r = 0.43, p < 0.001) and placebo (r = 0.33, p < 0.001). We also showed that the normative modeling framework successfully distinguished subclinical and diagnostic variabilities among subjects. From the predictive models, we identified key connectivity signatures in resting-state EEG for antidepressant treatment, suggesting differences in neural circuit involvement between sertraline and placebo responses. ConclusionsOur findings and highly generalizable framework advance the neurobiological understanding in the potential pathways of antidepressant responses, enabling more targeted and effective personalized MDD treatment. Trial registrationEstablishing Moderators and Biosignatures of Antidepressant Response for Clinical Care for Depression (EMBARC), NCT#01407094.

Safety and tolerability of cariprazine for the adjunctive treatment of major depressive disorder: a pooled analysis of phase 2b/phase 3 clinical trials.

To characterize the safety and tolerability of adjunctive cariprazine in patients with major depressive disorder (MDD) and inadequate response to monotherapy antidepressant treatment (ADT). Post hoc analyses evaluated pooled data from 2 fixed-dose phase 3 cariprazine studies (1.5 and 3 mg/d [approved doses for MDD]). In a separate safety analysis, cariprazine 0.1-4.5 mg/d was evaluated using data from the 2 fixed-dose trials plus 3 flexible-dose studies grouped by modal-daily dose. In the pooled phase 3 studies (placebo = 503, 1.5 mg/d = 502, 3 mg/d = 503), overall cariprazine-treated patients had high rates of study completion (90%). Patients had mostly mild/moderate treatment-emergent adverse events that caused premature discontinuation of 4.3%. Only akathisia, nausea, and insomnia occurred in ≥5% of cariprazine patients (any group) and at twice the rate of placebo; potential dose-dependent responses were observed for akathisia and insomnia. Cariprazine had a neutral metabolic profile, with mean weight increase of <1 kg. Modal-dose results were similar, and both analyses were consistent with the known safety profile of cariprazine across its approved indications. Adjunctive cariprazine therapy was safe and generally well tolerated in patients with MDD who had not obtained an adequate response to ADT monotherapy; no new safety signals were identified.

Comparison of methods that combine multiple randomized trials to estimate heterogeneous treatment effects.

Individualized treatment decisions can improve health outcomes, but using data to make these decisions in a reliable, precise, and generalizable way is challenging with a single dataset. Leveraging multiple randomized controlled trials allows for the combination of datasets with unconfounded treatment assignment to better estimate heterogeneous treatment effects. This article discusses several nonparametric approaches for estimating heterogeneous treatment effects using data from multiple trials. We extend single-study methods to a scenario with multiple trials and explore their performance through a simulation study, with data generation scenarios that have differing levels of cross-trial heterogeneity. The simulations demonstrate that methods that directly allow for heterogeneity of the treatment effect across trials perform better than methods that do not, and that the choice of single-study method matters based on the functional form of the treatment effect. Finally, we discuss which methods perform well in each setting and then apply them to four randomized controlled trials to examine effect heterogeneity of treatments for major depressive disorder.

Acceptability of home-based transcranial direct current stimulation (tDCS) in major depression: a qualitative analysis of individual experiences

PurposeThe purpose of this paper was to gain a qualitative view of the participant experience of using home-based transcranial direct current stimulation (tDCS). Acceptability impacts patient preference, treatment adherence and outcomes. However, acceptability is usually assessed by rates of attrition, while multifaceted constructs are not reflected or given meaningful interpretations. tDCS is a novel non-invasive brain stimulation that is a potential treatment for major depressive disorder (MDD). Most studies have provided tDCS in a research centre. As tDCS is portable, the authors developed a home-based treatment protocol that was associated with clinical improvements that were maintained in the long term.Design/methodology/approachThe authors examined the acceptability of home-based tDCS treatment in MDD through questionnaires and individual interviews at three timepoints: baseline, at a six-week course of treatment, and at six-month follow-up. Twenty-six participants (19 women) with MDD in a current depressive episode of at least moderate severity were enrolled. tDCS was provided in a bifrontal montage with real-time remote supervision by video conference at each session. A thematic analysis was conducted of the individual interviews.FindingsThematic analysis revealed four main themes: effectiveness, side effects, time commitment and support, feeling held and contained. The themes reflected the high acceptability of tDCS treatment, whereas the theme of feeling contained might be specific to this protocol.Originality/valueQualitative analysis methods and individual interviews generated novel insights into the acceptability of tDCS as a potential treatment for MDD. Feelings of containment might be specific to the present protocol, which consisted of real-time supervision at each session. Meaningful interpretation can provide context to a complex construct, which will aid in understanding and clinical applications.

Assessing expectancy and suggestibility in a trial of escitalopram v. psilocybin for depression.

To investigate the association between pre-trial expectancy, suggestibility, and response to treatment in a trial of escitalopram and investigational drug, COMP360, psilocybin, in the treatment of major depressive disorder (ClinicalTrials.gov registration: NCT03429075). We used data (n = 55) from our recent double-blind, parallel-group, randomized head-to-head comparison trial of escitalopram and investigational drug, COMP360, psilocybin. Mixed linear models were used to investigate the association between pre-treatment efficacy-related expectations, as well as baseline trait suggestibility and absorption, and therapeutic response to both escitalopram and COMP360 psilocybin. Patients had significantly higher expectancy for psilocybin relative to escitalopram; however, expectancy for escitalopram was associated with improved therapeutic outcomes to escitalopram, expectancy for psilocybin was not predictive of response to psilocybin. Separately, we found that pre-treatment trait suggestibility was associated with therapeutic response in the psilocybin arm, but not in the escitalopram arm. Overall, our results suggest that psychedelic therapy may be less vulnerable to expectancy biases than previously suspected. The relationship between baseline trait suggestibility and response to psilocybin therapy implies that highly suggestible individuals may be primed for response to this treatment.

Combining Glial Fibrillary Acidic Protein and Neurofilament Light Chain for the Diagnosis of Major Depressive Disorder.

Major depressive disorder (MDD) is a prevalent brain disorder affecting more than 2% of the world's population. Due to the lack of well-specific biomarkers, it is difficult to distinguish MDD from other diseases with similar clinical symptoms (such as Alzheimer's disease and cerebral thrombosis). In this work, we provided a strategy to address this issue by constructing a combinatorial biomarker of serum glial fibrillary acidic protein (GFAP) and neurofilament light chain (NFL). To achieve the convenient and sensitive detection of two proteins, we developed an electrochemical immunosandwich sensor using two metal-ion-doped carbon dots (Pb-CDs and Cu-CDs) as probes for signal output. Each probe contains approximately 300 Pb2+ or 200 Cu2+, providing excellent signal amplification. This method achieved detection limits of 0.3 pg mL-1 for GFAP and 0.2 pg mL-1 for NFL, lower than most of the reported detection limits. Analysis of real serum samples showed that the concentration ratio of GFAP to NFL, which is associated with the relative degree of brain inflammation and neurodegeneration, is suitable for not only distinguishing MDD from healthy individuals but also specifically distinguishing MDD from Alzheimer's disease and cerebral thrombosis. The good specificity gives the combinatorial GFAP/NFL biomarker broad application prospects in the screening, diagnosis, and treatment of MDD.

Comparative efficacy and tolerability of different anesthetics in electroconvulsive therapy for major depressive disorder: A systematic review and network meta-analysis

Electroconvulsive therapy (ECT) is one of the most effective treatments for major depressive disorder. Modern ECT is conducted with anesthesia, however, the optimal anesthetic agent for ECT is yet to be understood. This study is aimed to compare the effects of different anesthetic agents on antidepressant efficacy and tolerability in depressed individuals undergoing ECT. We searched MEDLINE, EMBASE, the CENTRAL and PsycINFO for randomized controlled trials from database inception until Nov 13, 2022 (PROSPERO: CRD42022375407). Global and local inconsistencies, heterogeneity and publication bias were assessed. Rankings were calculated with the surface under the cumulative ranking curve. A total of 33 studies involving 1898 patients were enrolled. Remission rates were higher for ketamine anesthesia as compared to adjunctive ketamine and propofol. In terms of ranking, ketamine was found to be first in terms of response/remission rates and depressive scores after the 1st, 3rd and 6th ECT and at the end of ECT session, while a higher incidence of adverse events was also observed. No significant advantage of any anesthetic was revealed for the cognitive function after ECT. In summary, based on current evidence, no specific anesthetic is recommended for ECT anesthesia. However, despite more side effects, ketamine monoanesthesia seems to reveal a potential benefit in improving antidepressant efficacy of ECT, and further studies are needed to investigate the relationship between anesthetic agents and the therapeutic effect of ECT.

An integrated precision medicine approach in major depressive disorder: a study protocol to create a new algorithm for the prediction of treatment response.

Major depressive disorder (MDD) is the most common psychiatric disease worldwide with a huge socio-economic impact. Pharmacotherapy represents the most common option among the first-line treatment choice; however, only about one third of patients respond to the first trial and about 30% are classified as treatment-resistant depression (TRD). TRD is associated with specific clinical features and genetic/gene expression signatures. To date, single sets of markers have shown limited power in response prediction. Here we describe the methodology of the PROMPT project that aims at the development of a precision medicine algorithm that would help early detection of non-responder patients, who might be more prone to later develop TRD. To address this, the project will be organized in 2 phases. Phase 1 will involve 300 patients with MDD already recruited, comprising 150 TRD and 150 responders, considered as extremes phenotypes of response. A deep clinical stratification will be performed for all patients; moreover, a genomic, transcriptomic and miRNomic profiling will be conducted. The data generated will be exploited to develop an innovative algorithm integrating clinical, omics and sex-related data, in order to predict treatment response and TRD development. In phase 2, a new naturalistic cohort of 300 MDD patients will be recruited to assess, under real-world conditions, the capability of the algorithm to correctly predict the treatment outcomes. Moreover, in this phase we will investigate shared decision making (SDM) in the context of pharmacogenetic testing and evaluate various needs and perspectives of different stakeholders toward the use of predictive tools for MDD treatment to foster active participation and patients' empowerment. This project represents a proof-of-concept study. The obtained results will provide information about the feasibility and usefulness of the proposed approach, with the perspective of designing future clinical trials in which algorithms could be tested as a predictive tool to drive decision making by clinicians, enabling a better prevention and management of MDD resistance.

Applying artificial intelligence to clinical decision support in mental health: What have we learned?

Clinical decision support systems (CDSS) augmented with artificial intelligence (AI) models are emerging as potentially valuable tools in healthcare. Despite their promise, the development and implementation of these systems typically encounter several barriers, hindering the potential for widespread adoption. Here we present a case study of a recently developed AI-CDSS, Aifred Health, aimed at supporting the selection and management of treatment in major depressive disorder. We consider both the principles espoused during development and testing of this AI-CDSS, as well as the practical solutions developed to facilitate implementation. We also propose recommendations to consider throughout the building, validation, training, and implementation process of an AI-CDSS. These recommendations include: identifying the key problem, selecting the type of machine learning approach based on this problem, determining the type of data required, determining the format required for a CDSS to provide clinical utility, gathering physician and patient feedback, and validating the tool across multiple settings. Finally, we explore the potential benefits of widespread adoption of these systems, while balancing these against implementation challenges such as ensuring systems do not disrupt the clinical workflow, and designing systems in a manner that engenders trust on the part of end users.

Effectiveness of Medical Cannabis for the Treatment of Depression: A Naturalistic Outpatient Study.

There is a lack of studies on the course and effectiveness of medical cannabis in the treatment of major depressive disorder (MDD). Retrospective longitudinal (18 weeks) study of n=59 outpatients with MDD, treated with medical cannabis via a telemedical platform. Previous treatment with antidepressant medication was required for inclusion into the study. Standardized data collection was carried out at entry and during monthly consultations. Severity of depression was measured on a 0-10 point rating scale. Side-effects were assessed by a checklist. Patients were 20-54 years old; 72.9% were male; one third reported times of regular cannabis consumption within the previous five years. Drop-out rate was 22% after 18 weeks. Mean severity of depression decreased from 6.9 points (SD 1.5) at entry to 3.8 points (2.7) at week 18 (baseline observation carried forward; 95% CI for the mean difference: 2.4 to 3.8; p<0.001). A treatment response (>50% reduction of the initial score) was seen in 50.8% at week 18. One third of patients complained about side effects, none was considered as severe. Concomitant antidepressant medication (31% of patients) was not associated with outcome. Medical cannabis was well tolerated and dropout rate was comparable to those in clinical trials of antidepressant medication. Patients reported a clinically significant reduction of depression severity. Further research on the effectiveness of medical cannabis for MDD seems warranted. Risks of this medication, such as sustaining or inducing a cannabis use disorder, or side effects such as poor concentration, must be taken into consideration.

Safety, tolerability, pharmacodynamic and wellbeing effects of SPL026 (dimethyltryptamine fumarate) in healthy participants: a randomized, placebo-controlled phase 1 trial.

Due to their potential impact on mood and wellbeing there has been increasing interest in the potential of serotonergic psychedelics such as N,N-dimethyltryptamine (DMT) in the treatment of major depressive disorder (MDD). The aim of Part A of this study was to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamic (PD) profile of escalating doses of SPL026 (DMT fumarate) in psychedelic-naïve healthy participants to determine a dose for administration to patients with MDD in the subsequent Phase 2a part of the trial (Part B: not presented in this manuscript). In the Phase 1, randomized, double-blind, placebo-controlled, parallel-group, single dose-escalation trial, psychedelic-naïve participants were randomized to placebo (n = 8) or four different escalating doses [9, 12, 17 and 21.5 mg intravenously (IV)] of SPL026 (n = 6 for each dose) together with psychological support from 2 therapy team members. PK and acute (immediately following dosing experience) psychometric measures [including mystical experience questionnaire (MEQ), ego dissolution inventory (EDI), and intensity rating visual analogue scale (IRVAS)] were determined. Additional endpoints were measured as longer-term change from baseline to days 8, 15, 30 and 90. These measures included the Warwick and Edinburgh mental wellbeing scale and Spielberger's state-trait anxiety inventory. SPL026 was well tolerated, with an acceptable safety profile, with no serious adverse events. There was some evidence of a correlation between maximum plasma concentration and increased IRVAS, MEQ, and EDI scores. These trends are likely to require confirmation in a larger sample size. Using the analysis of the safety, tolerability, PD, PK results, doses of 21.5 mg SPL026 were the most likely to provide an intense, tolerated experience. Based on the data obtained from this part of the trial, a dose of 21.5 mg SPL026 given as a 2-phase IV infusion over 10 min (6 mg/5 min and 15.5 mg/5 min) was selected as the dose to be taken into patients in Part B (to be presented in a future manuscript).Clinical trial registration:www.clinicaltrials.gov, identifier NCT04673383; https://www.clinicaltrialsregister.eu, identifier 2020-000251-13; https://www.isrctn.com/, identifier ISRCTN63465876.