Functional neuroimaging biomarkers of anhedonia response to escitalopram plus adjunct aripiprazole treatment for major depressive disorder

BACKGROUND

Identifying neuroimaging biomarkers of antidepressant response may help guide treatment decisions and advance precision medicine.

AIMS

To examine the relationship between anhedonia and functional neurocircuitry in key reward processing brain regions in people with major depressive disorder receiving aripiprazole adjunct therapy with escitalopram.

METHOD

Data were collected as part of the CAN-BIND-1 study. Participants experiencing a current major depressive episode received escitalopram for 8 weeks; escitalopram non-responders received adjunct aripiprazole for an additional 8 weeks. Functional magnetic resonance imaging (on weeks 0 and 8) and clinical assessment of anhedonia (on weeks 0, 8 and 16) were completed. Seed-based correlational analysis was employed to examine the relationship between baseline resting-state functional connectivity (rsFC), using the nucleus accumbens (NAc) and anterior cingulate cortex (ACC) as key regions of interest, and change in anhedonia severity after adjunct aripiprazole.

RESULTS

Anhedonia severity significantly improved after treatment with adjunct aripiprazole.There was a positive correlation between anhedonia improvement and rsFC between the ACC and posterior cingulate cortex, ACC and posterior praecuneus, and NAc and posterior praecuneus. There was a negative correlation between anhedonia improvement and rsFC between the ACC and anterior praecuneus and NAc and anterior praecuneus.

CONCLUSIONS

Eight weeks of aripiprazole, adjunct to escitalopram, was associated with improved anhedonia symptoms. Changes in functional connectivity between key reward regions were associated with anhedonia improvement, suggesting aripiprazole may be an effective treatment for individuals experiencing reward-related deficits. Future studies are required to replicate our findings and explore their generalisability, using other agents with partial dopamine (D2) agonism and/or serotonin (5-HT2A) antagonism.

The Effects of Ketamine on Cognition in Unipolar and Bipolar Depression: A Systematic Review

Objective: To determine the objective neurocognitive effects of (1) single-dose ketamine, (2) repeated-dose ketamine, (3) ketamine adjunct to electroconvulsive therapy (ECT), and (4) ketamine as the anesthetic for ECT in major depressive disorder (MDD) and depression in bipolar disorder (BD). Data Sources: Cochrane, MEDLINE, Embase, and PsycINFO databases were searched on March 19, 2020 (updated July 2, 2020), using the terms terms major depressive disorder bipolar disorder and ketamine and their synonyms. Clinical trial registries (search date May 4, 2020) and reference sections of included articles were also searched. There was no restriction on language or year of publication. Study Selection: Of 4,035 identified articles, 17 met inclusion criteria. Controlled and open-label studies of adults who received at least 1 ketamine treatment for a current major depressive episode, as part of MDD or BD, were included. Only studies measuring cognition using at least 1 validated, objective neurocognitive assessment were eligible. Data Extraction: Results are presented using a narrative review format. Data regarding change in cognitive performance from baseline to end-of-treatment and/or differences in cognition between ketamine and control groups were extracted. Results: There were no negative effects of single- or repeated-dose intravenous ketamine up to 2 weeks post-treatment in MDD. Limited data were available for BD populations, as well as on other routes of ketamine administration. Conclusions: Data to definitively answer the question of whether ketamine has substantive or persistent cognitive effects are insufficient; thus, larger controlled trials measuring cognition as the primary outcome are needed. Future research should focus on different routes of ketamine administration, ketamine enantiomers, and BD populations.

'Distant socializing,' not 'social distancing' as a public health strategy for COVID-19

Social distancing, also referred to as physical distancing, means creating a safe distance of at least two meters (six feet) between yourself and others. This is a term popularized during the COVID-19 pandemic, as it is one of the most important measures to prevent the spread of this virus. However, the term 'social distancing' can be misleading, as it may imply that individuals should stop socializing. However, socializing in a safe context (i.e. over the phone, video-chat, etc.) is especially important during this time of crisis. Therefore, in this narrative review, we suggest the term 'distant socializing' as more apt expression, to promote physical distancing measures while also highlighting the importance of maintaining social bonds. Further, articles discussing the practice, implementation, measurement, and mental health effects of physical distancing are reviewed. Physical distancing is associated with psychiatric symptoms (such as anxiety and depression), suicidal ideation, and domestic violence. Further, unemployment and job insecurity have significantly increased during COVID-19, which may exacerbate these negative mental health effects. Governments, medical institutions, and public health bodies should therefore consider increasing mental health resources both during and after the pandemic, with a specific focus on frontline workers, COVID-19 survivors, and marginalized communities.

Procognitive Effects of Antidepressants and Other Therapeutic Agents in Major Depressive Disorder: A Systematic Review

OBJECTIVE

To review the efficacy of antidepressants and other therapeutic agents for the treatment of cognitive impairment in adults with major depressive disorder (MDD).

DATA SOURCES

We conducted a database search of MEDLINE, PsycINFO, and Embase through Ovid on May 7, 2019. The year of publication was not restricted. The search terms "Major Depressive Disorder," "depress*," "cognit*," and "therapeutics" were used.

STUDY SELECTION

The studies included in this review were clinical trials of antidepressants and other therapeutic agents in MDD populations. Participants were aged between 18 and 65 years and had a DSM-III, -IV, or -5 diagnosis of MDD. In total, 2,045 research papers were screened, 53 full-text articles were assessed, and 26 articles were eligible to be included in this systematic review.

DATA EXTRACTION

The data and quality of research papers were assessed and screened by 2 independent reviewers. Discrepancies were resolved through a third reviewer.

RESULTS

Overall, studies demonstrated that tricyclic antidepressants do not have procognitive effects, while vortioxetine and bupropion have demonstrated procognitive effects in MDD populations relative to selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors. Several non-antidepressant agents, such as modafinil, amphetamines, and erythropoietin, have also demonstrated significant positive effects on cognition in depression.

CONCLUSIONS

Present-day antidepressants and other agents have demonstrated procognitive effects in MDD, but the findings between various agents are mixed. Further research looking at objective measures of cognitive performance would be helpful to obtain more definitive results regarding the efficacy of therapeutics for cognitive impairment in MDD.

The Potential Procognitive Effects of Modafinil in Major Depressive Disorder: A Systematic Review

OBJECTIVE

To assess the efficacy of modafinil, a wakefulness-promoting drug, in major depressive disorder (MDD), with a specific focus on the putative procognitive effects of modafinil.

DATA SOURCES

A database search of MEDLINE, PsycINFO, and Embase was conducted. No date limits were applied (the end date of the search was October 26, 2018), and only articles in English were included. The following search terms were used: modafinil, depression, depress*, major depressive disorder, cognition, cognitive dysfunction, and cogniti*.

STUDY SELECTION

Studies included were placebo-controlled or open-label trials of modafinil in MDD populations. Participants had to be diagnosed with MDD via DSM-IV or DSM-5 criteria, and no other interventions other than standard antidepressant treatment could be used in the trial. Overall, 540 articles were screened, 22 full-text research articles for inclusion criteria were assessed, and 12 studies were included in this review.

DATA EXTRACTION

Two independent reviewers extracted data and assessed the quality of publications.

RESULTS

Modafinil was associated with improvements in executive functioning after 4 weeks of open-label adjunctive treatment in currently depressed participants. Furthermore, in a placebo-controlled study of remitted MDD participants, modafinil led to rapid improvements in episodic and working memory after a single dose. There were contradictory findings on the subjective effects of modafinil on concentration.

CONCLUSIONS

Modafinil shows preliminary evidence of alleviating specific cognitive symptoms in MDD patients, especially in the short term. However, more research using placebo-controlled longitudinal designs is needed to assess the benefits of modafinil, as there are very few studies addressing modafinil and cognition in MDD.

Using a modified version of the "STOP-BANG" questionnaire and nocturnal oxygen desaturation to predict obstructive sleep apnea after stroke or TIA

PURPOSE

Obstructive sleep apnea (OSA) is a risk factor and common morbidity for stroke and transient ischemic attack (TIA). However, screening for OSA in patients with stroke or TIA is uncommonly performed, due in part to difficulties associated with conducting polysomnography (PSG) and Home Sleep Apnea Tests (HSATs). The 8-point "STOP-BANG" questionnaire has been shown to have high methodological quality in screening for OSA. This study examined the clinical utility of a modified version of the "STOP-BANG" questionnaire, which removed neck circumference and included nocturnal oxygen desaturation in diagnosing OSA (ie, the "STOP-BAG-O" tool), with the goal of improving uptake and accuracy in diagnosing OSA.

METHODS

In total, 231 participants completed both the STOP-BAG questionnaire and PSG or HSAT within 12 months of stroke/TIA. Using receiver-operating curves, scores on the "STOP-BAG-O" and "STOP-BAG" questionnaires were assessed for their ability to predict a diagnosis of OSA and classify at least 50% of the study population.

RESULTS

Compared to an OSA diagnosis of AHI≥10, the STOP-BAG (using cut-offs of ≤3 and ≥4) had a sensitivity and specificity of 83.5% and 67.2%, respectively. The STOP-BAG-O (using cut-offs of ≤3 and ≥5) had a sensitivity and specificity of 95.9% and 78.4%, respectively. For all AHI cut-offs used, the area under the curve for the STOP-BAG-O was greater and statistically different (p < 0.001) than that for the STOP-BAG.

CONCLUSIONS

The STOP-BAG-O is a valid tool for identifying risk of OSA post-stroke/TIA. The simplicity of this tool and ease of assessing nocturnal oxygen desaturation makes it a feasible option for widespread use.

Allostatic load but not medical burden predicts memory performance in late-life bipolar disorder

OBJECTIVE

Older patients with bipolar disorder (BD) present with variable degrees of cognitive impairment. Over time, stress, mood episodes, and comorbidities increase the body's allostatic load. We assessed the extent to which allostatic load vs more traditional measures of medical burden account for the heterogeneity in cognition in this population.

METHODS

Thirty-five older euthymic patients with BD and 30 age-equated, gender-equated, and education-equated comparison participants were administered a comprehensive assessment including a neuropsychological battery, and 9 physiological measures to determine allostatic load. The relationship among allostatic load, medical burden, and cognition was assessed.

RESULTS

Compared with the mentally healthy comparators, patients were impaired globally, and in 4 cognitive domains-information-processing speed / executive functioning, delayed memory, language, and visuomotor ability, and presented with greater medical burden but not a different allostatic load. Allostatic load, but not medical burden, was associated with delayed memory performance both in a correlational analysis and in a multivariate regression analysis.

CONCLUSION

Euthymic older patients with BD are impaired on several cognitive domains and have high medical burden. Their memory performance is more strongly associated with allostatic load than with traditional measures of medical burden. These findings need to be replicated and extended longitudinally.