Clinical Implications of the STAR*D Trial

Gut Hormones as Potential Therapeutic Targets or Biomarkers of Response in Depression: The Case of Motilin

Recent research has identified the gut–brain axis as a key mechanistic pathway and potential therapeutic target in depression. In this paper, the potential role of gut hormones as potential treatments or predictors of response in depression is examined, with specific reference to the peptide hormone motilin. This possibility is explored through two methods: (1) a conceptual review of the possible links between motilin and depression, including evidence from animal and human research as well as clinical trials, based on a literature search of three scientific databases, and (2) an analysis of the relationship between a functional polymorphism (rs2281820) of the motilin (MLN) gene and cross-national variations in the prevalence of depression based on allele frequency data after correction for potential confounders. It was observed that (1) there are several plausible mechanisms, including interactions with diet, monoamine, and neuroendocrine pathways, to suggest that motilin may be relevant to the pathophysiology and treatment of depression, and (2) there was a significant correlation between rs2281820 allele frequencies and the prevalence of depression after correcting for multiple confounding factors. These results suggest that further evaluation of the utility of motilin and related gut peptides as markers of antidepressant response is required and that these molecular pathways represent potential future mechanisms for antidepressant drug development.

Clinically Significant Changes in the 17- and 6-Item Hamilton Rating Scales for Depression: A STAR*D Report

OBJECTIVE

To develop clinically meaningful improvement thresholds in both the 17-item and the 6-item Hamilton Rating Scale for Depression (HRSD) total scores in depressed outpatients.

METHODS

The post-hoc analysis included all adult outpatients with non-psychotic major depressive disorder in the STAR*D trial who entered and exited the first treatment step (up to 14 weeks of citalopram) with a complete set of study measures at baseline and exit and at least one post-baseline measure. Within-patient change and linear regression anchor-based analyses were conducted to define meaningful and substantial changes in the HRSD17 and HRSD6 using three patient-reported outcomes [Work and Social Adjustment Scale (WSAS), Quality of Life Enjoyment and Satisfaction-Short Form (Q-LES-Q-SF); Mini-Q-LES-Q] obtained at baseline and exit from the first treatment step in STAR*D.

RESULTS

Linear regression analyses identified a meaningful change threshold for the HRSD17 as 3.9 [3.7-4.1] [lower, upper 95% CI] and a substantial change as 7.8 [7.4-8.3] with the WSAS. Analogous thresholds based on the Q-LES-Q-SF were 5.8 [5.5-6.1] and 11.6 [11.0-12.2], respectively, and 4.9 [4.7-5.2] and 9.9 [9.3-10.4] for the Mini-QLES-Q, respectively. For the HRSD6, linear regression analyses with the WSAS identified a meaningful change as 2.2 [2.1-2.4], while a substantial change was 4.5 [4.2-4.7]. Analogous figures based on the Q-LES-Q-SF were 3.2 [3.0-3.4] and 6.4 [6.1-6.8]. Similarly, based on the Mini-QLESQ, results were 2.8 [2.6-2.9] and 5.6 [5.3-5.9]. For both the HRSD17 and the HRSD6, within-patient analyses produced less precise estimates of the same change thresholds with substantial overlap between groups. Based on the WSAS, a clinically meaningful change in the HRSD17 total score was 9.6 (SD = 6.5), while a substantial change was 15.0 (SD = 6.7). Analogous change thresholds based on the Q-LESQ-SF were 12.9 (SD = 6.2) and 16.8 (SD = 6.4), respectively. For the Mini-Q-LES-Q, thresholds were 10.9 (SD = 6.5) and 16.1 (SD = 6.2).

CONCLUSION

A 4-6 point change in the HRSD17 is clinically meaningful; a 7-12 point change is clinically substantial. For the HRSD6, analogous estimates were 2-3 and 4-7 point changes, respectively.

Accelerated transcranial magnetic stimulation (aTMS) to treat depression with treatment switching: study protocol of a pilot, randomized, delayed-start trial

Background

Repetitive transcranial magnetic stimulation (rTMS) is a technique for stimulating brain activity using a transient magnetic field to induce an electrical current in the brain producing depolarization of focal groups of brain cells. TMS is a protocol approved by the U.S. Food and Drug Administration in routine clinical practice as a treatment for depression. A major limitation of rTMS is the large amount of time taken for a standard protocol (38 min a day for 20–30 working days). The optimal type and duration of TMS are still uncertain, as is the optimal strategy for continuing or changing the type of rTMS if there is a poor initial response.

Objectives

The trial aims to assess whether a 1-week compressed course of left dorsolateral prefrontal (L DLPFC) 5 Hz accelerated rTMS (aTMS) treatment is as effective as an established 4-week course of non-accelerated rTMS and if additional 5 Hz L DLPFC aTMS treatments will be efficacious in non-responders as compared to 1 Hz right DLPFC aTMS treatment.

Methods

A randomized, single-blind, delayed-start trial was planned to commence in Jan 2020. A total of 60 patients will be enrolled from the Institute of Mental Health Singapore within a 2-year period and randomized into the early or delayed-start phase of the trial. The primary outcome of the trial is the improvement of Montgomery-Asberg Depression Rating scale at the end of the active treatment phase.

Discussion

If this study protocol proves to be effective, the findings of this trial will be updated to the College of Psychiatrists, Academy of Medicine Singapore, as well as published in a peer-reviewed journal to enhance local and international TMS treatment guidelines.

Trial registration

ClinicalTrials.gov ID: NCT03941106

The effect of intravenous, intranasal, and oral ketamine in mood disorders: A meta-analysis

BACKGROUND

Ketamine is established as a rapid and effective treatment in adults with treatment-resistant depression (TRD). The availability of different formulations and routes of delivery invites the need for evaluating relative effect sizes.

METHODS

Effect size with respect to depression symptom reduction for each formulation and route of delivery was compared at discrete time-points (i.e., 24 h, 2-6 days, 7-20 days, 21-28 days) in adults with TRD. A random-effects meta-analysis was conducted to evaluate the effect size across intravenous, intranasal and oral routes of administration. Analysis was also conducted evaluating the effect size of racemic ketamine to esketamine.

RESULTS

The pooled effect size for intranasal ketamine/esketamine at 24 h was g = 1.247 (n = 5, 95% CI: 0.591-1.903, p < 0.01). At 2-6 days, the pooled effect size for intravenous ketamine/esketamine was g = 0.949 (n = 14, 95% CI: -0.308-2.206, p = 0.139). At 7-20 days, intranasal ketamine had a pooled effect size of g = 1.018 (n = 4, 95% CI: 0.499-1.538, p < 0.01). At 21-28 days, oral ketamine had a pooled effect size of g = 0.633 (n = 2, 95% CI: 0.368-0.898, p < 0.01).

LIMITATIONS

Additional comparative studies are needed with regards to the efficacy of different formulations and routes of delivery.

CONCLUSIONS

The short-term efficacy of intravenous and intranasal ketamine/esketamine for adults with TRD was established. Interpreting the efficacy of oral ketamine was limited by the need for studies with larger samples across independent sites. No conclusions regarding comparative efficacy of the disparate formulations and routes of delivery can be derived from this analysis. Direct comparative studies are needed to further inform treatment options for TRD.

The effects of childhood trauma on the onset, severity and improvement of depression: The role of dysfunctional attitudes and cortisol levels

BACKGROUND

Childhood trauma is an important early social risk factor for the development of the major depressive disorder (MDD). Both childhood trauma and depression are associated with dysfunctional attitudes and dysregulation in stress hormones. We aimed to clarify the path from childhood trauma to depression and identify potential predictors of antidepressant treatment outcomes.

OBJECTIVES

One hundred and thirty-nine MDD patients and 112 healthy controls were included at baseline. Depressive symptoms were assessed with both self-reported and expert-rated scales. Childhood trauma and dysfunctional attitudes were evaluated and blood cortisol levels were assayed. Patients received an open-label antidepressant trial with paroxetine and their depressive symptoms were monitored by the Hamilton Depression Rating Scale (HAMD) during 6 months of treatment. After 6 months, 94 patients received the same assessments as the baseline.

RESULTS

At baseline, the influence of childhood trauma on depression diagnosis was mediated by dysfunctional attitudes. In patients with MDD, the influence of childhood trauma on depression severity was mediated by both dysfunctional attitudes and cortisol levels. Baseline childhood trauma predicted the antidepressant treatment outcome during early treatment phase and baseline cortisol levels predicted the antidepressant treatment outcome at later treatment phase. After 6-month antidepressant treatment, a significant remission by time effect was found on dysfunctional attitudes and depression severity but not on cortisol levels.

CONCLUSION

Effect of childhood trauma on depression onset was mediated by dysfunctional attitudes. The relationship between childhood trauma and depressive symptoms was mediated by dysfunctional attitudes and cortisol levels in MDD patients. Baseline childhood trauma and cortisol levels may be moderators for antidepressant treatment response at different treatment phase.