Non response at week 4 as clinically useful indicator for antidepressant combination in major depressive disorder. A sequential RCT

SSRIs in the Treatment of Depression: A Pharmacological CUL-DE-SAC?

The widespread adoption of selective serotonin reuptake inhibitors (SSRIs) as first-line pharmacological treatments in the management of clinical depression transformed the landscape of drug therapy for this condition. SSRIs are safer and better tolerated than the tricyclic antidepressants (TCAs) that they replaced. However, they have limitations that may have placed a ceiling on the expectations of first-line pharmacological treatment. Notable problems with SSRIs include induction of anxiety on treatment initiation, delayed onset of significant therapeutic effect, sexual dysfunction, sleep disturbance and overall modest efficacy. The latter is linked with an inability of SSRIs to effectively treat syndromes of anhedonia and cognitive impairment. Combined serotonin and noradrenaline reuptake inhibitors (SNRIs), such as venlafaxine, have produced some limited improvements over SSRIs in efficacy, at the cost of a greater side-effect burden. Attempts to supplement serotonin reuptake activity with actions at serotonin receptor sub-types have not yet yielded substantial benefits; however, vortioxetine may provide more utility in the management of cognitive impairment. Future advances might come from the development of SNRIs, which more closely mimic the actions of effective TCAs. There may also be possible benefits to be derived from combining SSRIs with 5-HT4 receptor agonists and 5-HT7 receptor antagonists.

Relationship between circulating mitochondrial DNA and microRNA in patients with major depression

BACKGROUND

MicroRNAs (miRNAs) and circulating cell-free mitochondrial DNA (ccf-mtDNA) have attracted interest as biological markers of affective disorders. In response to stress, it is known that miRNAs in mitochondria diffuse out of the cytoplasm alongside mtDNA; however, this process has not yet been identified. We hypothesized that miRNAs derived from specific cell nuclei cause mitochondrial damage and mtDNA fragmentation under MDD-associated stress conditions.

METHODS

A comprehensive analysis of the plasma miRNA levels and quantification of the plasma ccf-mtDNA copy number were performed in 69 patients with depression to determine correlations and identify genes and pathways interacting with miRNAs. The patients were randomly assigned to receive either selective serotonin reuptake inhibitors (SSRI) or mirtazapine. Their therapeutic efficacy over four weeks was evaluated in relation to miRNAs correlated with ccf-mtDNA copy number.

RESULTS

The expression levels of the five miRNAs showed a significant positive correlation with the ccf-mtDNA copy number after correcting for multiple testing. These miRNAs are involved in gene expression related to thyroid hormone synthesis, the Hippo signaling pathway, vasopressin-regulated water reabsorption, and lysine degradation. Of these five miRNAs, miR-6068 and miR-4708-3p were significantly associated with the SSRI and mirtazapine treatment outcomes, respectively.

LIMITATIONS

This study did not show comparison with a healthy group.

CONCLUSIONS

The expression levels of specific miRNAs were associated with ccf-mtDNA copy number in untreated depressed patients; moreover, these miRNAs were linked to antidepressant treatment outcomes. These findings are expected to lead to the elucidation of new pathological mechanism of depression.

Changes in Multiple microRNA Levels with Antidepressant Treatment Are Associated with Remission and Interact with Key Pathways: A Comprehensive microRNA Analysis

Individual treatment outcomes to antidepressants varies widely, yet the determinants to this difference remain elusive. MicroRNA (miRNA) gene expression regulation in major depressive disorder (MDD) has attracted interest as a biomarker. This 4-week randomized controlled trial examined changes in the plasma miRNAs that correlated with the treatment outcomes of mirtazapine (MIR) and selective serotonin reuptake inhibitor (SSRI) monotherapy. Pre- and post- treatment, we comprehensively analyzed the miRNA levels in MDD patients, and identified the gene pathways linked to these miRNAs in 46 patients. Overall, 141 miRNA levels significantly demonstrated correlations with treatment remission after 4 weeks of MIR, with miR-1237-5p showing the most robust and significant correlation after Bonferroni correction. These 141 miRNAs displayed a negative correlation with remission, indicating a decreasing trend. These miRNAs were associated with 15 pathways, including TGF-β and MAPK. Through database searches, the genes targeted by these miRNAs with the identified pathways were compared, and it was found that MAPK1, IGF1, IGF1R, and BRAF matched. Alterations in specific miRNAs levels before and after MIR treatment correlated with remission. The miRNAs mentioned in this study have not been previously reported. No other studies have investigated treatment with MIR. The identified miRNAs also correlated with depression-related genes and pathways.

Pre-treatment plasma cytokine levels as potential predictors of short-term remission of depression

OBJECTIVES

The response to antidepressants varies significantly among individuals and is difficult to predict before treatment. In this randomised control trial, we explored cytokines that correlate with the therapeutic effect of mirtazapine (MIR) and selective serotonin reuptake inhibitors (SSRIs) and whether they could be predictors of remission for each antidepressant.

METHODS

Plasma cytokines, such as tumour necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were assayed in 95 participants before medication and assayed by the enzyme-linked immunosorbent assay. The Hamilton Rating Scale for Depression assessed depressive symptoms over 4 weeks.

RESULTS

In the SSRI group, the baseline GM-CSF level was significantly higher in the remission group than in the non-remission group (p = .022). In the MIR group, the baseline level of TNF-α was significantly higher (p = .039) and IL-2 was lower (p = .032) in the remission group than in the non-remission group. In patients prescribed with MIR, the cut-off values of TNF-α (10.035 pg/mL) and IL-2 (1.170 pg/mL) calculated from the receiver operating characteristic curve suggested that the remission rate, which corresponds to a positive predictive value, could be increased from 31.3% to 60.0% and 50.0%, respectively. For those prescribed with SSRIs, the remission rate was 37.0% and using the cut-off value of GM-CSF (0.205 pg/mL), the remission rate could be almost doubled to 70%.

CONCLUSIONS

Our study shows that pre-treatment plasma concentrations of TNF-α, IL-2, and GM-CSF may suggest the predictability of remission by SSRIs or MIR.

Personality as a basis for antidepressant selection for patients with depression: A two-point outcome study at 4 and 8 weeks

BACKGROUND

The treatment course for depression is multifactorial, and the gold standard method for antidepressant selection remains unclear. Therefore, we focused on patients' personality as a possible indicator of the treatment response to mirtazapine and selective serotonin reuptake inhibitors (SSRIs) and whether it can contribute to antidepressant selection.

METHODS

One hundred one patients with major depressive disorder were randomized at baseline to receive either mirtazapine or SSRI treatment. Their personality was measured using the NEO Five-Factor Inventory at baseline, and depressive symptoms were evaluated using the Hamilton Rating Scale for Depression at baseline and 4 and 8 weeks. Stepwise multivariable logistic regression and receiver operating characteristic analyses were performed to determine the association of personality traits with remission and better antidepressant selection.

RESULTS

Neuroticism had the substantial influence on remission at 4 and 8 weeks among the entire sample. The cutoff T-score of neuroticism for predicting remission at 4 weeks was 62.5. The patients with moderate neuroticism (scores below the cutoff) were more likely to experience remission after 4-week mirtazapine treatment (remission rate: 73.7 %) than after SSRI treatment (40.0 %); those with high neuroticism (scores above the cutoff) were more likely to experience remission after 8-week SSRI treatment (74.1 %) than after mirtazapine treatment (35.7 %).

LIMITATIONS

The small sample size increased the confidence intervals.

CONCLUSIONS

The treatment response of the patients with depression differed according to the type of antidepressants and degree of neuroticism. Measuring personality traits at treatment initiation may help in selecting better antidepressants and predicting the time to remission.

Combining Antidepressants vs Antidepressant Monotherapy for Treatment of Patients With Acute Depression: A Systematic Review and Meta-analysis

IMPORTANCE

Combining antidepressants is frequently done in the treatment of acute depression, but studies have yielded conflicting results.

OBJECTIVE

To conduct a systematic review and meta-analysis assessing efficacy and tolerability of combination therapy. Combinations using presynaptic α2-autoreceptor antagonists or bupropion were investigated separately.

DATA SOURCES

MEDLINE, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were systematically searched from each database inception through January 2020.

STUDY SELECTION

Randomized clinical trials (RCTs) comparing combinations of antidepressants with antidepressant monotherapy in adult patients with acute depression were included.

DATA EXTRACTION AND SYNTHESIS

Following guidelines from Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and recommendations from the Cochrane Handbook, 2 reviewers independently performed a literature search, study selection, data extraction, and evaluation of risk of bias. Data were pooled in random-effects analyses.

MAIN OUTCOMES AND MEASURES

Primary outcome was efficacy measured as standardized mean difference (SMD); secondary outcomes were response, remission, change from baseline in rating scale scores, number of dropouts, and number of dropouts due to adverse events.

RESULTS

Thirty-nine RCTs including 6751 patients were eligible. Combination treatment was statistically significantly associated with superior treatment outcomes relative to monotherapy (SMD = 0.31; 95% CI, 0.19-0.44). Combining a reuptake inhibitor with an antagonist of presynaptic α2-autoreceptors was superior to other combinations (SMD = 0.37; 95% CI, 0.19-0.55). Bupropion combinations were not superior to monotherapy (SMD = 0.10; 95% CI, -0.07 to 0.27). Numbers of dropouts and dropouts due to adverse events did not differ between treatments. Studies were heterogeneous, and there was indication of publication bias (Egger test result was positive; P = .007, df = 36), but results remained robust across prespecified secondary outcomes and sensitivity and subgroup analyses, including analyses restricted to studies with low risk of bias.

CONCLUSIONS AND RELEVANCE

In this meta-analysis of RCTs comparing combinations of antidepressants with antidepressant monotherapy, combining antidepressants was associated with superior treatment outcomes but not with more patients dropping out of treatment. Combinations using an antagonist of presynaptic α2-autoreceptors may be preferable and may be applied as a first-line treatment in severe cases of depression and for patients considered nonresponders.

Multiple Pre-Treatment miRNAs Levels in Untreated Major Depressive Disorder Patients Predict Early Response to Antidepressants and Interact with Key Pathways

Major depressive disorder (MDD) is a life-impairing disorder, and early successful treatment is important for a favorable prognosis. However, early response to antidepressants differs widely among individuals, and is difficult to predict pre-treatment. As miRNAs have been reported to play important roles in depression, identification of miRNAs associated with antidepressant treatment responses and their interacting genes and pathways will be beneficial in understanding the predictors and molecular mechanisms of depression treatment. This randomized control trial examined miRNAs correlated with the early therapeutic effect of selective serotonin reuptake inhibitors (SSRIs; paroxetine or sertraline) and mirtazapine monotherapy. Before medication, we comprehensively analyzed the miRNA expression of 92 depressed participants and identified genes and pathways interacting with miRNAs. A total of 228 miRNAs were significantly correlated with depressive symptoms improvements after 2 weeks of SSRIs treatment, with miR-483.5p showing the most robust correlation. These miRNAs are involved in 21 pathways, including TGF-β, glutamatergic synapse, long-term depression, and the mitogen-activated protein kinase (MAPK) signaling pathways. Using these miRNAs enabled us to predict SSRI response at week 2 with a 57% difference. This study shows that pre-treatment levels of miRNAs could be used to predict early responses to antidepressant administration, a knowledge of genes, and an identification of genes and pathways associated with the antidepressant response.

Efficacy and safety of tipepidine as adjunctive therapy in major depressive disorder: A randomized, double-blind, placebo-controlled clinical trial

AIM

Tipepidine, a synthetic, non-opioid expectorant, has been shown to improve depressive-like behavior in animal models of depression. In this study, we assessed the efficacy and tolerability of tipepidine combination therapy with citalopram in treatment of major depressive disorder (MDD).

METHODS

In a randomized, double-blinded, placebo-controlled clinical trial, 62 patients with MDD were assigned into two parallel groups to receive citalopram (up to 40 mg/day) plus placebo or citalopram plus tipepidine (30 mg twice daily) for 6 weeks. Participants were assessed with the Hamilton Rating Scale for Depression (HAM-D) at baseline and Weeks 2, 4, and 6.

RESULTS

Fifty-six patients completed the trial. The tipepidine group showed greater improvement in HAM-D scores from baseline to all three study time points (P = 0.048 for all). The remission and response-to-treatment rates were significantly higher in the tipepidine group (53.6% and 100%) compared to the placebo group (25.0% and 75%) at the study end-point (P = 0.029 and 0.005, respectively). The remission and response times in patients in the tipepidine group were also shorter compared with the placebo group (log-rank P = 0.020 and 0.004). There was no significant difference between the two groups in baseline parameters or frequency of side-effects.

CONCLUSION

Tipepidine combination therapy with citalopram can effectively improve symptoms of patients with MDD in a shorter period of treatment. However, further studies with larger sample sizes and longer follow-up treatment are needed to confirm our findings.

A pilot, open-label, 8-week study evaluating desvenlafaxine for treatment of major depression in methadone-maintained individuals with opioid use disorder

Depression is one of the most prevalent psychiatric disorders among opioid-dependent individuals. Clinical trials testing selective serotonin reuptake inhibitors among depressed patients on methadone maintenance therapy (MMT) failed to show efficacy, whereas those on tricyclic antidepressants produced mixed results with potential for cardiotoxicity. Desvenlafaxine (DESV) is a SNRI with minimal cardiotoxicity and drug interactions. This study sought to assess feasibility and tolerability of using DESV in depressed patients on MMT. A total of 18 depressed individuals on MMT received DESV (50-100 mg/day) for 8 weeks. Participants were assessed for the following: (a) Safety of DESV using Systematic Assessment for Treatment Emergent Events-GI, ECG [corrected Q-T (QTc) interval measurement] and methadone serum levels; (b) depressive symptoms using Montgomery-Äsberg Depression Rating Scale (MADRS); and (c) other outcomes including anxiety, suicidality, craving, substance use, quality of life, and other depression scales. Registration number on ClinicalTrials.gov is NCT02200406. Among participants who completed the study, MADRS scores significantly decreased at week 8 compared with baseline. Responders and remitters on MADRS at week 8 were 61 and 50%, respectively. There was no significant change in [corrected Q-T (QTc) interval measurement] between baseline and week 4. DESV was well tolerated and associated with improvement of depressive symptoms. DESV may be a promising contender to treat depression in individuals on MMT and deserves further exploration in a randomized double-blinded clinical trial.

Early improvement and response to antidepressant medications in adults with major depressive disorder. Meta-analysis and study of a sample with treatment-resistant depression

BACKGROUND

Initial improvement in the first weeks of antidepressant (AD) treatment is a useful early predictor of complete AD response. We performed a meta-analysis of AD studies to investigate whether a partial decrease in depressive symptoms by week 4 was associated with response and remission by weeks 6-14 in major depressive disorder (MDD). Finally, we focused on treatment-resistant depression (TRD: lack of response to prior AD) to test the impact of early improvement on a second AD treatment outcome and to compare different switching strategies.

METHODS

Meta-analysis was conducted on AD naturalistic studies published between 01.01.2000 and 06.30.2017. TRD was an exclusion criterion. TRD was analyzed in 407 MDD patients treated with venlafaxine for 6 weeks. The MADRS was used to define very early improvement (VEI: > 20% decrease at week 2), early improvement (EI: > 30% decrease at week 4) and remission (week 6 MADRS < 10). A theoretical model was used to simulate AD switch in TRD patients who failed to achieve remission (Algorithm A), VEI (Algorithm B) or EI (Algorithm C).

RESULTS

Our meta-analysis (9 studies; N = 6185) showed significant associations between early improvement, response (OR: 3.28 95% C.I: 2.06-5.20) and remission (OR: 2.10 95% C.I: 1.53-2.87). 24.6% of TRD sample remitted. VEI was a poor outcome predictor: sensitivity = 0.52 (0.40-0.63); specificity = 0.82 (0.76-0.86); AUC = 0.67 (0.62-0.71). EI had a moderate predictive power: sensitivity = 0.87 (0.77-0.93); specificity = 0.71 (0.66-0.77); AUC = 0.76 (0.71-0.80). The best treatment scenario was Algorithm C (switch after 4 weeks) in which remission rate was marginally increased (35.1% vs 33.7% of Algorithm A). Algorithm B (switch after 2 weeks) led to a 4.3% decrease in remission compared to Algorithm A.

LIMITATIONS

Inclusion of a naturalistic sample without a control arm; simulation of treatments.

CONCLUSION

Although literature data suggest a correlation between an initial improvement of depressive symptoms and later response and remission during AD treatment, our analysis shows that such an early improvement is not a reliable outcome predictor in TRD. The nature of TRD is complex and different biological mechanisms and treatments might be necessary for TRD patients.