Predictors of cognitive impairment in treatment-resistant depression

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.

Ketamine vs Electroconvulsive Therapy for Treatment-Resistant Depression: A Secondary Analysis of a Randomized Clinical Trial

Importance

The ELEKT-D: Electroconvulsive Therapy (ECT) vs Ketamine in Patients With Treatment Resistant Depression (TRD) (ELEKT-D) trial demonstrated noninferiority of intravenous ketamine vs ECT for nonpsychotic TRD. Clinical features that can guide selection of ketamine vs ECT may inform shared decision-making for patients with TRD.

Objective

To evaluate whether selected clinical features were associated with differential improvement with ketamine vs ECT.

Design, Setting, and Participants

This secondary analysis of an open-label noninferiority randomized clinical trial was a multicenter study conducted at 5 US academic medical centers from April 7, 2017, to November 11, 2022. Analyses for this study, which were not prespecified in the trial protocol, were conducted from May 10 to Oct 31, 2023. The study cohort included patients with TRD, aged 21 to 75 years, who were in a current nonpsychotic depressive episode of at least moderate severity and were referred for ECT by their clinicians.

Exposures

Eligible participants were randomized 1:1 to receive either 6 infusions of ketamine or 9 treatments with ECT over 3 weeks.

Main Outcomes and Measures

Association between baseline factors (including 16-item Quick Inventory of Depressive Symptomatology Self-Report [QIDS-SR16], Montgomery-Asberg Depression Rating Scale [MADRS], premorbid intelligence, cognitive function, history of attempted suicide, and inpatient vs outpatient status) and treatment response were assessed with repeated measures mixed-effects model analyses.

Results

Among the 365 participants included in this study (mean [SD] age, 46.0 [14.5] years; 191 [52.3%] female), 195 were randomized to the ketamine group and 170 to the ECT group. In repeated measures mixed-effects models using depression levels over 3 weeks and after false discovery rate adjustment, participants with a baseline QIDS-SR16 score of 20 or less (-7.7 vs -5.6 points) and those starting treatment as outpatients (-8.4 vs -6.2 points) reported greater reduction in the QIDS-SR16 with ketamine vs ECT. Conversely, those with a baseline QIDS-SR16 score of more than 20 (ie, very severe depression) and starting treatment as inpatients reported greater reduction in the QIDS-SR16 earlier in course of treatment (-8.4 vs -6.7 points) with ECT, but scores were similar in both groups at the end-of-treatment visit (-9.0 vs -9.9 points). In the ECT group only, participants with higher scores on measures of premorbid intelligence (-14.0 vs -11.2 points) and with a comorbid posttraumatic stress disorder diagnosis (-16.6 vs -12.0 points) reported greater reduction in the MADRS score. Those with impaired memory recall had greater reduction in MADRS during the second week of treatment (-13.4 vs -9.6 points), but the levels of MADRS were similar to those with unimpaired recall at the end-of-treatment visit (-14.3 vs -12.2 points). Other results were not significant after false discovery rate adjustment.

Conclusions and Relevance

In this secondary analysis of the ELEKT-D randomized clinical trial of ECT vs ketamine, greater improvement in depression was observed with intravenous ketamine among outpatients with nonpsychotic TRD who had moderately severe or severe depression, suggesting that these patients may consider ketamine over ECT for TRD.

Sildenafil, alone and in combination with imipramine or escitalopram, display antidepressant-like effects in an adrenocorticotropic hormone-induced (ACTH) rodent model of treatment-resistant depression

BACKGROUND

Major depressive disorder (MDD) represents a challenge with high prevalence and limited effectiveness of existing treatments, particularly in cases of treatment-resistant depression (TRD). Innovative strategies and alternative drug targets are therefore necessary. Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is known to exert neuroplastic, anti-inflammatory, and antioxidant properties, and is a promising antidepressant drug candidate.

AIM

To investigate whether sildenafil monotherapy or in combination with a known antidepressant, can elicit antidepressant-like effects in an adrenocorticotropic hormone (ACTH)-induced rodent model of TRD.

METHODS

ACTH-naïve and ACTH-treated male Sprague-Dawley (SD) rats received various sub-acute drug treatments, followed by behavioural tests and biochemical analyses conversant with antidepressant actions.

RESULTS

Sub-chronic ACTH treatment induced significant depressive-like behaviour in rats, evidenced by increased immobility during the forced swim test (FST). Sub-acute sildenafil (10 mg/kg) (SIL-10) (but not SIL-3), and combinations of imipramine (15 mg/kg) (IMI-15) and sildenafil (3 mg/kg) (SIL-3) or escitalopram (15 mg/kg) (ESC-15) and SIL-3, exhibited significant antidepressant-like effects. ACTH treatment significantly elevated hippocampal levels of brain-derived neurotrophic factor (BDNF), serotonin, norepinephrine, kynurenic acid (KYNUA), quinolinic acid (QUINA), and glutathione. The various mono- and combined treatments significantly reversed some of these changes, whereas IMI-15 + SIL-10 significantly increased glutathione disulfide levels. ESC-15 + SIL-3 significantly reduced plasma corticosterone levels.

CONCLUSION

This study suggests that sildenafil shows promise as a treatment for TRD, either as a stand-alone therapy or in combination with a traditional antidepressant. The neurobiological mechanism underlying the antidepressant-like effects of the different sildenafil mono- and combination therapies reflects a multimodal action and cannot be explained in full by changes in the individually measured biomarker levels.

Psilocybin therapy for treatment resistant depression: prediction of clinical outcome by natural language processing

RATIONALE

Therapeutic administration of psychedelics has shown significant potential in historical accounts and recent clinical trials in the treatment of depression and other mood disorders. A recent randomized double-blind phase-IIb study demonstrated the safety and efficacy of COMP360, COMPASS Pathways' proprietary synthetic formulation of psilocybin, in participants with treatment-resistant depression.

OBJECTIVE

While the phase-IIb results are promising, the treatment works for a portion of the population and early prediction of outcome is a key objective as it would allow early identification of those likely to require alternative treatment.

METHODS

Transcripts were made from audio recordings of the psychological support session between participant and therapist 1 day post COMP360 administration. A zero-shot machine learning classifier based on the BART large language model was used to compute two-dimensional sentiment (valence and arousal) for the participant and therapist from the transcript. These scores, combined with the Emotional Breakthrough Index (EBI) and treatment arm were used to predict treatment outcome as measured by MADRS scores. (Code and data are available at https://github.com/compasspathways/Sentiment2D .) RESULTS: Two multinomial logistic regression models were fit to predict responder status at week 3 and through week 12. Cross-validation of these models resulted in 85% and 88% accuracy and AUC values of 88% and 85%.

CONCLUSIONS

A machine learning algorithm using NLP and EBI accurately predicts long-term patient response, allowing rapid prognostication of personalized response to psilocybin treatment and insight into therapeutic model optimization. Further research is required to understand if language data from earlier stages in the therapeutic process hold similar predictive power.

Longitudinal associations between executive function impairments and suicide risk in patients with major depressive disorder: A 1-year follow-up study

Impaired executive function (EF) is a key feature of patients with major depressive disorder (MDD) that several studies have linked to suicidal ideation and suicide attempts. This is the first longitudinal study to examine the association between impaired EF and suicide risk in adult patients with MDD. Longitudinal prospective study with 3 assessment points: baseline, 6 and 12 months. The Columbia-Suicide Severity Rating Scale (C-SSRS) was used to assess suicidality. The Cambridge Neuropsychological Test Automated Battery (CANTAB) was used to assess EF. The association between EF impairments and suicidality was analyzed using mixed-effects models. Out of 167 eligible outpatients, 104 were included in the study. Of these, 72 were re-evaluated at 6 months and 60 at 12 months, obtaining 225 complete observations of the EF. Impaired decision-making and risk-taking behavior were associated with suicidal ideation. Difficulty in impulse control was related to suicidal ideation and to greater severity of suicidal ideation. Impaired spatial planning and working memory was linked to suicide attempts. Our results add to previous literature that the association between EF impairments and suicidality is maintained over the long term, supporting it as a longitudinal risk factor and a possible neurocognitive marker of suicide in patients with MDD.

Neurocognitive effects of subanesthetic serial ketamine infusions in treatment resistant depression

INTRODUCTION

Ketamine treatment prompts a rapid antidepressant response in treatment-resistant depression (TRD). We performed an exploratory investigation of how ketamine treatment in TRD affects different cognitive domains and relates to antidepressant response.

METHODS

Patients with TRD (N = 66; 30 M/35F; age = 39.5 ± 11.1 years) received four ketamine infusions (0.5 mg/kg). Neurocognitive function and depressive symptoms were assessed at baseline, 24 h after the first and fourth ketamine infusion, and 5 weeks following end of treatment. Mixed effect models tested for changes in seven neurocognitive domains and antidepressant response, with post-hoc pairwise comparisons between timepoints, including follow-up. Relationships between change in neurocognitive function and antidepressant response over the course of treatment were tested with Pearson's correlation and mediation analyses. Associations between baseline neurocognitive performance and antidepressant response were tested with Pearson's correlation.

RESULTS

Significant improvements in inhibition, working memory, processing speed, and overall fluid cognition were observed after the first and fourth ketamine infusion. Improvements in processing speed and overall fluid cognition persisted through follow-up. Significant improvements in depressive symptoms reverted towards baseline at follow-up. Baseline working memory and change in inhibition were moderately correlated with antidepressant response, however, improvements in neurocognitive performance were statistically independent from antidepressant response.

CONCLUSION

Antidepressant ketamine leads to improved neurocognitive function, which persist for at least 5 weeks. Neurocognitive improvements observed appear independent of antidepressant response, suggesting ketamine may target overlapping but distinct functional brain systems. Limitations Research investigating repeated serial ketamine treatments is important to determine cognitive safety. This study is a naturalistic design and does not include placebo.

Association of adenosine triphosphate-related genes to major depression and suicidal behavior: Cognition as a potential mediator

BACKGROUND

Soluble epoxide hydrolase (sEH, encoded by EPHX2) and P2X2 (a subtype of ATP receptors) may mediate the antidepressant-like effects of ATP. We sought to determine whether polymorphisms and mRNA expression of EPHX2 and P2X2 are associated with depression and suicidal behavior and how cognition may mediate such associations.

METHOD

We examined 83 single nucleotide polymorphisms (SNPs) of EPHX2 and P2X2. Subjects were MDD suicide attempters (N = 143), MDD non-suicide attempters (N = 248), and healthy volunteers (HV, N = 110). Data on demographics, depression severity, and suicide attempts were collected. Participants completed a set of cognitive tasks. Polymorphisms were genotyped using MALDI-TOF MS within the MassARRAY system. The expression of mRNA was measured using real-time polymerase chain reaction (RT-PCR).

RESULTS

Cognitive function was a significant mediator (p = 0.006) of the genetic effect on depression. Allele C of rs202059124 was associated with depression risk (OR = 11.57, 95%CI: 2.33-209.87, p = 0.0181). A significant relationship was found between P2X2 mRNA expression and depression (OR = 0.68, 95%CI: 0.49-0.94, p = 0.0199). One haploblock (rs9331942 and rs2279590) was associated with suicide attempts: subjects with haplotype GC (frequency = 19.8 %, p = 0.017) and AT (frequency = 35.2 %, p < 0.001) had a lower rate of suicide attempts.

CONCLUSIONS

Our results confirmed that cognitive impairment plays a role in the effect of rs9331949 on depression. Moreover, we confirmed a relationship between P2X2, EPHX2, and MDD in humans and presented preliminary haplotype-based evidence that implicates EPHX2 in suicide.

LIMITATIONS

The main limitation of this study is the limited sample size. More comprehensive and multi-domain cognition tasks and different assessment measures are required in further study.

Current Evidence and Theories in Understanding the Relationship between Cognition and Depression in Childhood and Adolescence: A Narrative Review

The present narrative review has covered the current evidence regarding the role of cognitive impairments during the early phase of major depressive disorder (MDD), attempting to describe the cognitive features in childhood, adolescence and in at-risk individuals. These issues were analyzed considering the trait, scar and state hypotheses of MDD by examining the cold and hot dimensions, the latter explained in relation to the current psychological theoretical models of MDD. This search was performed on several electronic databases up to August 2022. Although the present review is the first to have analyzed both cold and hot cognitive impairments considering the trait, scar and state hypotheses, we found that current evidence did not allow to exclusively confirm the validity of one specific hypothesis since several equivocal and discordant results have been proposed in childhood and adolescence samples. Further studies are needed to better characterize possible cognitive dysfunctions assessing more systematically the impairments of cold, hot and social cognition domains and their possible interaction in a developmental perspective. An increased knowledge on these topics will improve the definition of clinical endophenotypes of enhanced risk to progression to MDD and, to hypothesize preventive and therapeutic strategies to reduce negative influences on psychosocial functioning and well-being.

Lateralized subgenual ACC metabolic connectivity patterns in refractory melancholic depression: does it matter?

Although treatment resistance to antidepressant pharmacotherapy is quite common, the phenomenon of refractory major depressive disorder (rMDD) is not well understood. Nevertheless, the metabolic activity of the subgenual anterior cingulate cortex (sgACC) has been put forward as a possible metabolic biomarker of clinical prediction and response, albeit sgACC lateralization differences in functional connectivity have not yet been extensively examined. Also not in the refractory depressed state. To examine sgACC lateralization differences in metabolic connectivity, we recruited 43 right-handed antidepressant-free unipolar melancholic rMDD patients and 32 right-handed healthy controls to participate in this 18FDG PET study and developed a searchlight-based interregional covariance connectivity approach. Compared to non-depressed individuals, sgACC covariance analysis showed stronger metabolic connections with frontolimbic brain regions known to be affected in the depressed state. Furthermore, whereas the left sgACC showed stronger metabolic connections with ventromedial prefrontal cortical regions, implicated in anhedonia, suicidal ideation, and self-referential processes, the right sgACC showed significantly stronger metabolic connections with posterior hippocampal and cerebellar regions, respectively specialized in memory and social processing. Overall, our results substantiate earlier research that the sgACC is a metabolic key player when clinically depressed and that distinct lateralized sgACC metabolic connectivity patterns are present.

Cognitive factor structure and measurement invariance between healthy controls and patients with major depressive disorder

Cognitive impairments are crucial in functional outcomes of major depressive disorder (MDD). The effectiveness of currently available treatment methods for cognitive deficits is suboptimal. A cognitive test battery is often applied to evaluate cognition with multiple interrelated and difficult-to-interpret outcomes. Generating cognitive factor scores after the confirmation of a common cognitive structure and measurement invariance between healthy controls (HCs) and patients may aid in understanding cognition further. This methodology has been applied for several neuropsychiatric disorders, but not for MDD. Therefore, we conducted a series of exploratory factor analyses (EFA), confirmatory factor analyses (CFA), and multiple groups CFA (MGCFA) for a cognitive test battery in HCs and patients with MDD. The initial EFA of 106 HCs yielded a three-factor model-comprising attention, memory, and executive function. The CFA confirmed the initial model in other 94 HCs with revisions, which reasonably fit the cognitive data of 54 patients with MDD. MGCFA supported the measurement invariance of the determined model between HCs and patients with MDD. The associations of cognitive factor scores with age or education and the effect sizes of group differences in cognitive factor scores externally validated the determined model. In conclusion, this is the first study to demonstrate the measurement invariance of a cognitive model between HCs and patients with MDD using MGCFA. The measurement invariance substantiated valid group comparisons of factor scores and their relationships with other markers. The current results may be applicable for the development of improved treatment strategies for cognitive impairments in MDD.

Functional status and return to work in people with major depression: a 3-year national follow-up study

PURPOSE

Major depressive disorder (MDD) affects a person's function of daily activities, including work participation. Such functional impairments often persist even when other symptoms of MDD are remitted. Increasing evidence highlights the health-promoting effects of returning to work (RTW) in various diseases. However, limited data are available regarding the impact of return to work on functional recovery in MDD. We explored the association between RTW and functional improvements in people with MDD using a large nationally representative database and a 3-year follow-up.

METHODS

Data of people with an MDD diagnosis were selected from the Taiwan Data Bank of Persons with disability for the period between July 11, 2012, and October 31, 2018. We included 4038 adults aged 18-64 years. The World Health Organization Disability Assessment Schedule 2.0 was used for functional assessment. The association between RTW and functional improvements was investigated using a multivariable regression analysis adjusted for confounding variables.

RESULTS

Women aged ≥ 45 years with a lower education level were vulnerable to prolonged unemployment. RTW was significantly associated with better functional improvements in cognition, mobility, self-care, getting along, life activity, and participation than unemployment.

CONCLUSIONS

RTW was positively associated with functional improvements in patients with MDD. A referral system targeting re-employment may be suggested during MDD treatment, especially for individuals at risk of prolonged unemployment.

The effect of selective serotonin reuptake inhibitors on cognitive impairment in patients with depression: A prospective, multicenter, observational study

Whether selective serotonin reuptake inhibitors (SSRIs) can improve cognitive function in depressed patients remains unclear. We aimed to explore the effect of SSRIs on cognitive function and the influencing factors in patients with major depressive disorder (MDD) with impaired cognitive function. We used a neurocognitive test battery to assess five cognitive domains, namely, attention/vigilance, learning, memory, processing speed and executive functioning, and calculated the Global Deficit Score (GDS). A GDS≥0.5 indicated overall cognitive impairment. The changes in the cognitive domains and overall cognitive function were analyzed in MDD patients with a baseline GDS≥0.5 who completed 8 weeks of SSRI treatment. We divided the patients into the cognitive remission and nonremission groups to explore the associated factors. In total, 160 patients (mean age 37.6 ± 10.8 years, 30.6% male) were included in the final analysis. The median (quartiles) of baseline GDS and HRSD₁₇ were 1.4 (0.8, 1.9) and 19.5 (17.0, 23.0), respectively. All five cognitive domains improved after the treatment, while only 41 (25.6%) patients achieved cognitive remission. Recurrence and a higher baseline GDS were risk factors for cognitive nonremission. More aggressive interventions may be needed to promote cognitive remission in clinical practice, especially for patients with severe cognitive impairment and recurrent episodes.

Developing a cognitive dysfunction risk score for use with opioid-dependent persons in drug treatment

BACKGROUND

Cognitive dysfunction is common in persons seeking medication for opioid use disorder (MOUD) and may hinder many addiction-related services. Brief but accurate screening measures are needed to efficiently assess cognitive dysfunction in these resource-limited settings. The study aimed to develop a brief predictive risk score tailored for use among patients in drug treatment.

METHODS

The present study examined predictors of mild cognitive impairment (MCI), objectively assessed via the NIH Toolbox, among 173 patients receiving methadone as MOUD at an urban New England drug treatment facility. Predictors of MCI were identified in one subsample using demographic characteristics, medical chart data, and selected items from the Brief Inventory of Neuro-Cognitive Impairment (BINI). Predictors were cross-validated in a second subsample using logistic regression. Receiver operating curve (ROC) analyses determined an optimal cut-off score for detecting MCI.

RESULTS

A cognitive dysfunction risk score (CDRS) was calculated from patient demographics (age 50+, non-White ethnicity, less than high school education), medical and substance use chart data (history of head injury, overdose, psychiatric diagnosis, past year polysubstance use), and selected self-report items (BINI). The CDRS discriminated acceptably well, with a ROC curve area of 70.6 %, and correctly identified 78 % of MCI cases (sensitivity = 87.5 %; specificity = 55.6 %).

CONCLUSIONS

The CDRS identified patients with cognitive challenges at a level likely to impede treatment engagement and/or key outcomes. The CDRS may assist in efficiently identifying patients with cognitive dysfunction while requiring minimal training and resources. Larger validation studies are needed in other clinical settings.

Effects of Hormonal Contraception Use on Cognitive Functions in Patients With Bulimia Nervosa

Background: Growing evidences indicate that sex hormones have an effect on cognitive functions, and that Bulimia Nervosa (BN) is associated with cognitive impairment. The aim of this study was to determine the effect of hormonal contraception (HC) use on four cognitive functions that are impaired in patients with BN. Methods: This retrospective exploratory study included 103 women with a diagnosis of BN based on the DSM-5 criteria. Their age ranged from 15 to 45 years, and 46.6% were taking HC (oral, transdermal, or intrauterine). Cognition was assessed with the d2 test (attention), Iowa gambling task (IGT; decision making), Brixton spatial anticipation test (set shifting), and Rey-Osterrieth complex figure test (central coherence). Data were analyzed with logistic regression models to estimate the adjusted odds ratios (OR) and 95% confidence intervals (CI) of HC effect on the neuropsychological test scores. Results: In the multivariate model, HC use was significantly associated with better scores for two d2 test indices: F-score [OR = 0.98, 95% CI = (0.95; 0.99)] and final total score ratio [OR = 0.87, 95% CI = (0.77; 0.99)]. HC was also associated with a better understanding of the IGT explicit rules. No difference between the two groups (HC and non-HC use) was detected for set shifting and central coherence. Conclusions: This exploratory study suggests that HC could have effects on the sustained attention and concentration in women with BN. More studies are needed to confirm these results.