Bipolar-ADHD comorbidity: screening for differences in neurocognition and virtual reality-based cognitive performance

OBJECTIVES

Identification of comorbid attention-deficit/hyperactivity disorder (ADHD) in patients with bipolar disorder (BD) is complicated by overlapping cognitive symptoms and methodological challenges. This cross-sectional study investigated whether virtual reality (VR)-based cognitive assessment that mimics daily life cognitive challenges can aid in the detection of sustained attention impairment in BD individuals with comorbid ADHD (BD + ADHD).

METHODS

Forty-nine fully or partially remitted outpatients with BD, of whom 14 (24%) had BD + ADHD, were assessed with the Cognition Assessment in Virtual Reality (CAVIR) test, including a sustained attention test that involves distractions, and the Screen for Cognitive Impairment in Psychiatry (SCIP). Patients were also rated for mood symptoms and functioning and completed questionnaires assessing subjective cognition and quality of life. Patients' cognitive impairment on the SCIP was estimated with reference to n = 100 demographically comparable healthy control participants.

RESULTS

BD + ADHD participants exhibited more pronounced performance deficits on the CAVIR sustained attention test (t(48) = 2.15, p = .037, d = .66). Notably, deficits on this test were proportional to self-reported daily life concentration difficulties in BD + ADHD individuals. Exploratory analyses revealed that BD + ADHD participants also displayed greater impairment on the SCIP working memory- and delayed verbal learning subtests and greater subjective cognitive complaints than BD patients without this comorbidity (p-levels < .001), but only the difference in subjective cognition survived correction for multiple comparisons (F(1,47) = 14.13, p = .005, np2 = 0.24).

CONCLUSION

Screening for deficits in sustained attention with an ecologically valid VR test involving distracting stimuli may be useful for identifying BD + ADHD individuals.

Efficacy and safety of established and off-label ADHD drug therapies for cognitive impairment or attention-deficit hyperactivity disorder symptoms in bipolar disorder: A systematic review by the ISBD Targeting Cognition Task Force

BACKGROUND

Abnormalities in dopamine and norepinephrine signaling are implicated in cognitive impairments in bipolar disorder (BD) and attention-deficit hyperactivity disorder (ADHD). This systematic review by the ISBD Targeting Cognition Task Force therefore aimed to investigate the possible benefits on cognition and/or ADHD symptoms and safety of established and off-label ADHD therapies in BD.

METHODS

We included studies of ADHD medications in BD patients, which involved cognitive and/or safety measures. We followed the procedures of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 statement. Searches were conducted on PubMed, Embase and PsycINFO from inception until June 2023. Two authors reviewed the studies independently using the Revised Cochrane Collaboration's Risk of Bias tool for Randomized trials.

RESULTS

Seventeen studies were identified (N = 2136), investigating armodafinil (k = 4, N = 1581), methylphenidate (k = 4, N = 84), bupropion (k = 4, n = 249), clonidine (k = 1, n = 70), lisdexamphetamine (k = 1, n = 25), mixed amphetamine salts (k = 1, n = 30), or modafinil (k = 2, n = 97). Three studies investigated cognition, four ADHD symptoms, and 10 the safety. Three studies found treatment-related ADHD symptom reduction: two involved methylphenidate and one amphetamine salts. One study found a trend towards pro-cognitive effects of modafinil on some cognitive domains. No increased risk of (hypo)mania was observed. Five studies had low risk of bias, eleven a moderate risk, and one a serious risk of bias.

CONCLUSIONS

Methylphenidate or mixed amphetamine salts may improve ADHD symptoms in BD. However, there is limited evidence regarding the effectiveness on cognition. The medications produced no increased mania risk when used alongside mood stabilizers. Further robust studies are needed to assess cognition in BD patients receiving psychostimulant treatment alongside mood stabilizers.

Effect of erythropoietin on cognitive side-effects of electroconvulsive therapy in depression: A randomized, double-blind, placebo-controlled trial

Electroconvulsive therapy (ECT) is one of the most effective and rapid-acting treatment for severe depression but is associated with cognitive side-effects. Identification of add-on treatments that counteract these side-effects would be very helpful. This randomized, double-blinded, placebo-controlled, parallel-group study investigated the effects of four add-on erythropoietin (EPO; 40,000 IU/ml) or saline (placebo) infusions over 2.5 weeks of ECT (eight ECT sessions) in severely depressed patients with unipolar or bipolar depression. Neuropsychological assessments were conducted pre-ECT, three days after the eighth ECT (week 4), and at a 3-month follow-up. Further, functional magnetic resonance imaging (fMRI) was conducted after the eighth ECT. The primary outcome was change from pre- to post-ECT in a 'speed of complex cognitive processing' composite. Secondary outcomes were verbal and autobiographical memory. Of sixty randomized patients, one dropped out before baseline. Data were thus analysed for 59 patients (EPO, n = 33; saline, n = 26), of whom 28 had fMRI data. No ECT-related decline occurred in the primary global cognition measure (ps≥0.1), and no effect of EPO versus saline was observed on this outcome (ps≥0.3). However post-ECT, EPO-treated patients exhibited faster autobiographical memory recall than saline-treated patients (p = 0.02), which was accompanied by lower memory-related parietal cortex activity. The absence of global cognition changes with ECT and EPO, coupled with the specific impact of EPO on autobiographical memory recall speed and memory-related parietal cortex activity, suggests that assessing autobiographical memory may provide increased sensitivity in evaluating and potentially preventing cognitive side-effects of ECT. TRIAL REGISTRATIONS: ClinicalTrials.gov: NCT03339596, EudraCT no.: 2016-002326-36.

Effect of immersive virtual reality-based cognitive remediation in patients with mood or psychosis spectrum disorders: study protocol for a randomized, controlled, double-blinded trial

BACKGROUND

Cognitive impairments are prevalent across mood disorders and psychosis spectrum disorders, but there is a lack of real-life-like cognitive training programmes. Fully immersive virtual reality has the potential to ensure motivating and engaging cognitive training directly relevant to patients' daily lives. We will examine the effect of a 4-week, intensive virtual reality-based cognitive remediation programme involving daily life challenges on cognition and daily life functioning in patients with mood disorders or psychosis spectrum disorders and explore the neuronal underpinnings of potential treatment efficacy.

METHODS

The trial has a randomized, controlled, double-blinded, parallel-group design. We will include 66 symptomatically stable outpatients with mood disorders or psychosis spectrum disorders aged 18-55 years with objective and subjective cognitive impairment. Assessments encompassing a virtual reality test of daily life cognitive skills, neuropsychological testing, measures of daily life functioning, symptom ratings, questionnaires on subjective cognitive complaints, and quality of life are carried out at baseline, after the end of 4 weeks of treatment and at a 3-month follow-up after treatment completion. Functional magnetic resonance imaging scans are performed at baseline and at the end of treatment. The primary outcome is a broad cognitive composite score comprising five subtasks on a novel ecologically valid virtual reality test of daily life cognitive functions. Two complete data sets for 54 patients will provide a power of 80% to detect a clinically relevant between-group difference in the primary outcome. Behavioural data will be analysed using linear mixed models in SPSS, while MRI data will be analysed with the FMRIB Expert Analysis Tool (FEAT). Treatment-related changes in neural activity from baseline to end of treatment will be investigated for the dorsal prefrontal cortex and hippocampus as the regions of interest.

DISCUSSION

The results will provide insight into whether virtual reality-based cognitive remediation has beneficial effects on cognition and functioning in symptomatically stable patients with mood disorders or psychosis spectrum disorders, which can aid future treatment development.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06038955. Registered on September 15, 2023.

Aberrant resting-state functional connectivity underlies cognitive and functional impairments in remitted patients with bipolar disorder

BACKGROUND

Bipolar disorder (BD) is commonly associated with cognitive impairments, that directly contribute to patients' functional disability. However, there is no effective treatment targeting cognition in BD. A key reason for the lack of pro-cognitive interventions is the limited insight into the brain correlates of cognitive impairments in these patients. This is the first study investigating the resting-state neural underpinnings of cognitive impairments in different neurocognitive subgroups of patients with BD.

METHOD

Patients with BD in full or partial remission and healthy controls (final sample of n = 144 and n = 50, respectively) underwent neuropsychological assessment and resting-state functional magnetic resonance imaging. We classified the patients into cognitively impaired (n = 83) and cognitively normal (n = 61) subgroups using hierarchical cluster analysis of the four cognitive domains. We used independent component analysis (ICA) to investigate the differences between the neurocognitive subgroups and healthy controls in resting-state functional connectivity (rsFC) in the default mode network (DMN), executive central network (ECN), and frontoparietal network (FPN).

RESULTS

Cognitively impaired patients displayed greater positive rsFC within the DMN and less negative rsFC within the ECN than healthy controls. Across cognitively impaired patients, lower positive connectivity within DMN and lower negative rsFC within ECN correlated with worse global cognitive performance.

CONCLUSION

Cognitive impairments in BD seem to be associated with a hyper-connectivity within the DMN, which may explain the failure to suppress task-irrelevant DMN activity during the cognitive performance, and blunted anticorrelation in the ECN. Thus, aberrant connectivity within the DMN and ECN may serve as brain targets for pro-cognitive interventions.

Cerebrospinal fluid erythropoietin, oxidative stress, and cognitive functions in patients with bipolar disorder and healthy control participants: A longitudinal case-control study

Persistent cognitive impairments occur in a large proportion of patients with bipolar disorder (BD) but their underlying pathological cellular processes are unclear. The aims of this longitudinal study of BD and healthy control (HC) participants were to investigate (i) the association of brain erythropoietin (EPO) and oxidative stress with cognitive functions and (ii) the changes in brain EPO during and after affective episodes. Participants underwent neurocognitive testing, lumbar punctures for cerebrospinal fluid (CSF) sampling and provided urine spot tests at baseline (all), after an affective episode (patients) and after one year (all). EPO was assayed in the CSF and oxidative stress metabolites related to RNA and DNA damage (8-dihydroguanosine [8-oxo-Guo], 8-hydroxy-2-deoxyguanosine [8-oxo-dG]) were assayed in the CSF and spot urine. Data was available for analyses for 60 BD and 37 HC participants. In unadjusted primary analyses, verbal memory decreased with increasing concentrations of CSF EPO and oxidative stress. In unadjusted explorative analyses, poorer verbal memory and psychomotor speed were associated with higher levels of oxidative stress. However, no associations between cognitive functions and CSF levels of EPO or oxidative stress were observed after adjustment for multiple testing. CSF EPO concentrations were unchanged during and after affective episodes. While CSF EPO correlated negatively with CSF DNA damage marker 8-oxo-dG, this association rendered non-significant after adjusting for multiple testing. In conclusion, EPO and oxidative stress do not seem to be robustly related to cognitive status in BD. Further insight into the cellular processes involved in cognitive impairments in BD is necessary to pave the way for novel therapeutic strategies to improve patients' cognitive outcomes.

Neurocognitive subgroups among newly diagnosed patients with schizophrenia spectrum or bipolar disorders: A hierarchical cluster analysis

Studies across schizophrenia (SZ) and bipolar disorder (BD) indicate common transdiagnostic neurocognitive subgroups. However, existing studies of patients with long-term illness precludes insight into whether impairments result from effects of chronic illness, medication or other factors. This study aimed to investigate whether neurocognitive subgroups across SZ and BD can be demonstrated during early illness stages. Data from overlapping neuropsychological tests were pooled from cohort studies of antipsychotic-naïve patients with first-episode SZ spectrum disorders (n = 150), recently diagnosed BD (n = 189) or healthy controls (HC) (n = 280). Hierarchical cluster analysis was conducted to examine if transdiagnostic subgroups could be identified based on the neurocognitive profile. Patterns of cognitive impairments and patient characteristics across subgroups were examined. Patients could be clustered into two, three and four subgroups, of which the three-cluster solution (with 83% accuracy) was selected for posthoc analyses. This solution revealed a subgroup covering 39% of patients (predominantly BD) who were cognitively relatively intact, a subgroup of 33% of patients (more equal distributions of SZ and BD) displaying selective deficits, particularly in working memory and processing speed, and a subgroup of 28% (mainly SZ) with global impairments. The globally impaired group exhibited lower estimated premorbid intelligence than the other subgroups. Globally impaired BD patients also showed more functional disability than cognitively relatively intact patients. No differences were observed across subgroups in symptoms or medications. Neurocognitive results can be understood by clustering analysis with similar clustering solutions occurring across diagnoses. The subgroups were not explained by clinical symptoms or medication, suggesting neurodevelopmental origins.

Association between brain serotonin 4 receptor binding and reactivity to emotional faces in depressed and healthy individuals

Brain serotonergic (5-HT) signaling is posited to modulate neural responses to emotional stimuli. Dysfunction in 5-HT signaling is implicated in major depressive disorder (MDD), a disorder associated with significant disturbances in emotion processing. In MDD, recent evidence points to altered 5-HT₄ receptor (5-HT₄R) levels, a promising target for antidepressant treatment. However, how these alterations influence neural processing of emotions in MDD remains poorly understood. This is the first study to examine the association between 5-HT₄R binding and neural responses to emotions in patients with MDD and healthy controls. The study included one hundred and thirty-eight participants, comprising 88 outpatients with MDD from the NeuroPharm clinical trial (ClinicalTrials.gov identifier: NCT02869035) and 50 healthy controls. Participants underwent an [¹¹C]SB207145 positron emission tomography (PET) scan to quantify 5-HT₄R binding (BP_ND) and a functional magnetic resonance imaging (fMRI) scan during which they performed an emotional face matching task. We examined the association between regional 5-HT₄R binding and corticolimbic responses to emotional faces using a linear latent variable model, including whether this association was moderated by depression status. We observed a positive correlation between 5-HT₄R BP_ND and the corticolimbic response to emotional faces across participants (r = 0.20, p = 0.03). This association did not differ between groups (parameter estimate difference = 0.002, 95% CI = -0.008: 0.013, p = 0.72). Thus, in the largest PET/fMRI study of associations between serotonergic signaling and brain function, we found a positive association between 5-HT₄R binding and neural responses to emotions that appear unaltered in MDD. Future clinical trials with novel pharmacological agents targeting 5-HT₄R are needed to confirm whether they ameliorate emotion processing biases in MDD.

The relationship between sleep disturbance and cognitive impairment in mood disorders: A systematic review

BACKGROUND

Cognitive impairment experienced by people with bipolar disorders (BD) or major depressive disorder (MDD) is associated with impaired psychosocial function and poorer quality of life. Sleep disturbance is another core symptom of mood disorders which may be associated with, and perhaps worsen, cognitive impairments. The aim of this systematic review was to critically assess the relationship between sleep disturbance and cognitive impairment in mood disorders.

METHODS

In this systematic review, relevant studies were identified using electronic database searches of PsychINFO, MEDLINE, Embase and Web of Science.

FINDINGS

Fourteen studies were included; eight investigated people with BD, five investigated people with MDD, and one included both people with MDD and people with BD. One study was an intervention for sleep disturbance and the remaining thirteen studies used either a longitudinal or cross-sectional observational design. Ten studies reported a significant association between subjectively measured sleep disturbance and cognitive impairment in people with MDD or BD after adjusting for demographic and clinical covariates, whereas no such association was found in healthy participants. Two studies reported a significant association between objectively measured (actigraphy or polysomnography) sleep abnormalities and cognitive impairment in mood disorders. One study of cognitive behavioural therapy for insomnia modified for BD (CBTI-BD) found an association between improvements in sleep and cognitive performance in BD.

INTERPRETATION

There is preliminary evidence to suggest a significant association between sleep disturbance and cognitive impairment in mood disorders. These findings highlight the need for further research of sleep disturbances and cognitive impairment in people with mood disorders.

Association of neurocognitive function with psychiatric hospitalization and socio-demographic conditions in individuals with bipolar and major depressive disorders

Background

Neurocognitive impairments are associated with poor clinical and employment outcomes in individuals with affective disorders. However, little is known about their associations with long-term clinical outcomes such as psychiatric hospitalizations, and with socio-demographic indicators other than employment. In the largest longitudinal study of neurocognition in affective disorders to date, we investigate the role of neurocognitive impairments on psychiatric hospitalizations and socio-demographic conditions.

Methods

The study included 518 individuals with bipolar or major depressive disorder. Neurocognitive assessments covered executive function and verbal memory domains. Longitudinal data on psychiatric hospitalization and socio-demographic conditions (employment, cohabitation, and marital status) for up to 11 years were obtained using National population-based registers. The primary and secondary outcomes were psychiatric hospitalizations (n = 398) and worsening of socio-demographic conditions (n = 518), in the follow-up period since study inclusion, respectively. Cox regression models were used to examine the association of neurocognition with future psychiatric hospitalizations and the worsening of socio-demographic conditions.

Findings

Clinically significant impairment in verbal memory (z-score ≤ -1; defined by the ISBD Cognition Task Force), but not in executive function, was associated with a higher risk of future hospitalization, when adjusted for age, sex, hospitalization in the year preceding inclusion, depression severity, diagnosis, and type of clinical trial (HR = 1.84, 95% CI:1.05-3.25, p = 0.034; n = 398). The results remained significant even after accounting for illness duration. Neurocognitive impairments were not associated with the worsening of socio-demographic conditions (p ≥ 0.17; n = 518).

Interpretation

Promoting neurocognitive function, especially verbal memory, may mitigate the risk of future psychiatric hospitalization in individuals with affective disorders.

Funding

Lundbeckfonden (R279-2018-1145).

Exenatide once weekly for alcohol use disorder investigated in a randomized, placebo-controlled clinical trial

BACKGROUND

Alcohol use disorder (AUD) is a chronic, relapsing brain disorder that accounts for 5% of deaths annually, and there is an urgent need to develop new targets for therapeutic intervention. The glucagon-like peptide-1 receptor agonist exenatide reduces alcohol consumption in rodents and non-human primates, but its efficacy in patients with AUD is unknown.

METHODS

In a randomized, double-blinded, placebo-controlled clinical trial, treatment-seeking AUD patients were assigned to receive exenatide (2 mg subcutaneously) or placebo once weekly for 26-weeks, in addition to standard cognitive-behavioral therapy. The primary outcome was reduction in number of heavy drinking days. A subgroup also completed fMRI and SPECT brain scans.

RESULTS

A total of 127 patients were enrolled. Our data revealed that although exenatide did not significantly reduce the number of heavy drinking days compared to placebo, it significantly attenuated fMRI alcohol cue-reactivity in the ventral striatum and septal area, which are crucial brain areas for drug reward and addiction. In addition, the dopamine transporter availability was lower in the exenatide group compared to the placebo group. Exploratory analyses revealed that exenatide significantly reduced heavy drinking days and total alcohol intake in a subgroup of obese patients (BMI>30 kg/m2). Adverse events were mainly gastrointestinal.

CONCLUSIONS

This first RCT on the effects of a GLP-1 receptor agonist in AUD provides new important knowledge on the effects of GLP-1 receptor agonists as a novel treatment target in addiction.

TRIAL REGISTRATION

EudraCT: 2016-003343-11 and ClinicalTrials.gov: NCT03232112FUNDING. The Novavi Foundation; The Research Foundation, Mental Health Services, Capital Region of Denmark; The Research Foundation, Capital Region of Denmark; The Ivan Nielsen Foundation; The A.P. Moeller and wife Chastine Mc-Kinney Moellers Family Foundation; The Augustinus Foundation; The Woerzner Foundation; Grosserer L.F Foghts Foundation; The Hartmann Foundation; The Aase and Ejnar Danielsen Foundation; The P.A. Messerschmidt and wife foundation and The Lundbeck Foundation. The funding sources and the manufacturer of exenatide once weekly (Bydureon®, AstraZeneca), had no influence on the trial design or data analysis.

Trajectory of aberrant reward processing in patients with bipolar disorder - A longitudinal fMRI study

BACKGROUND

Bipolar disorder (BD), and especially the mania phenotype, is characterized by heightened reward responsivity and aberrant reward processing. In this longitudinal fMRI study, we investigated neuronal response during reward anticipation as the computed expected value (EV) and outcome evaluation as reward prediction error (RPE) in recently diagnosed patients with BD.

METHODS

Eighty remitted patients with BD and 60 healthy controls (HC) underwent fMRI during which they performed a card guessing task. Of these, 41 patients and 36 HC were re-scanned after 16 months. We compared reward-related neural activity between groups at baseline and longitudinally and assessed the impact of mood relapse.

RESULTS

Patients showed lower RPE signal in areas of the ventrolateral prefrontal cortex (vlPFC) than HC. In these regions, the HC showed decrease in RPE signal over time, which was absent in patients. Patients further exhibited decreased EV signal in the occipital cortex across baseline and follow-up. Patients who remained in remission showed normalization of the EV signal at follow-up. Baseline activity in the identified regions was not associated with subsequent relapse.

LIMITATIONS

Follow-up scans were only available in a relatively small sample. Medication status, follow-up time and BD illness duration prior to diagnosis varied.

CONCLUSIONS

Lower RPE signal in the vlPFC in patients with BD at baseline and its lack of normative reduction over time may represent a trait marker of dysfunctional reward-based learning or habituation. The increase in EV signal in the occipital cortex over time in patients who remained in remission may indicate normalization of reward anticipation activity.

Can magnetic resonance imaging enhance the assessment of potential new treatments for cognitive impairment in mood disorders? A systematic review and position paper by the International Society for Bipolar Disorders Targeting Cognition Task Force

BACKGROUND

Developing treatments for cognitive impairment is key to improving the functioning of people with mood disorders. Neuroimaging may assist in identifying brain-based efficacy markers. This systematic review and position paper by the International Society for Bipolar Disorders Targeting Cognition Task Force examines the evidence from neuroimaging studies of pro-cognitive interventions.

METHODS

We included magnetic resonance imaging (MRI) studies of candidate interventions in people with mood disorders or healthy individuals, following the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis 2020 statement. Searches were conducted on PubMed/MEDLINE, PsycInfo, EMBASE, Cochrane Library, and Clinicaltrials.gov from inception to 30th April 2021. Two independent authors reviewed the studies using the National Heart, Lung, Blood Institutes of Health Quality Assessment Tool for Controlled Intervention Studies and the quality of neuroimaging methodology assessment checklist.

RESULTS

We identified 26 studies (N = 702). Six investigated cognitive remediation or pharmacological treatments in mood disorders (N = 190). In healthy individuals, 14 studies investigated pharmacological interventions (N = 319), 2 cognitive training (N = 73) and 4 neuromodulatory treatments (N = 120). Methodologies were mostly rated as 'fair'. 77% of studies investigated effects with task-based fMRI. Findings varied but most consistently involved treatment-associated cognitive control network (CCN) activity increases with cognitive improvements, or CCN activity decreases with no cognitive change, and increased functional connectivity. In mood disorders, treatment-related default mode network suppression occurred.

CONCLUSIONS

Modulation of CCN and DMN activity is a putative efficacy biomarker. Methodological recommendations are to pre-declare intended analyses and use task-based fMRI, paradigms probing the CCN, longitudinal assessments, mock scanning, and out-of-scanner tests.

Trajectory of cognitive impairments over 1 year after COVID-19 hospitalisation: Pattern, severity, and functional implications

The ongoing Coronavirus Disease (COVID-19) pandemic has so far affected more than 500 million people. Lingering fatigue and cognitive difficulties are key concerns because they impede productivity and quality of life. However, the prevalence and duration of neurocognitive sequelae and association with functional outcomes after COVID-19 are unclear. This longitudinal study explored the frequency, severity and pattern of cognitive impairment and functional implications 1 year after hospitalisation with COVID-19 and its trajectory from 3 months after hospitalisation. Patients who had been hospitalised with COVID-19 from our previously published 3-months study at the Copenhagen University Hospital were re-invited for a 1-year follow-up assessment of cognitive function, functioning and depression symptoms. Twenty-five of the 29 previously assessed patients (86%) were re-assessed after 1 year (11±2 months). Clinically significant cognitive impairments were identified in 48-56 % of patients depending on the cut-off, with verbal learning and executive function being most severely affected. This was comparable to the frequency of impairments observed after 3 months. Objectively measured cognitive impairments scaled with subjective cognitive difficulties, reduced work capacity and poorer quality of life. Further, cognitive impairments after 3 months were associated with the severity of subsequent depressive symptoms after 1 year. In conclusion, the stable cognitive impairments in approximately half of patients hospitalized with COVID-19 and negative implications for work functioning, quality of life and mood symptoms underline the importance of screening for and addressing cognitive sequelae after severe COVID-19.

Randomised controlled cognition trials in remitted patients with mood disorders published between 2015 and 2021: A systematic review by the International Society for Bipolar Disorders Targeting Cognition Task Force

BACKGROUND

Cognitive impairments are an emerging treatment target in mood disorders, but currently there are no evidence-based pro-cognitive treatments indicated for patients in remission. With this systematic review of randomised controlled trials (RCTs), the International Society for Bipolar Disorders (ISBD) Targeting Cognition Task force provides an update of the most promising treatments and methodological recommendations.

METHODS

The review included RCTs of candidate pro-cognitive interventions in fully or partially remitted patients with major depressive disorder or bipolar disorder. We followed the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) 2020 statement. Searches were conducted on PubMed/MEDLINE, PsycInfo, EMBASE and Cochrane Library from January 2015, when two prior systematic reviews were conducted, until February 2021. Two independent authors reviewed the studies with the Revised Cochrane Collaboration's Risk of Bias tool for Randomised trials.

RESULTS

We identified 16 RCTs (N = 859) investigating cognitive remediation (CR; k = 6; N = 311), direct current or repetitive magnetic stimulation (k = 3; N = 127), or pharmacological interventions (k = 7; N = 421). CR showed most consistent cognitive benefits, with two trials showing improvements on primary outcomes. Neuromodulatory interventions revealed no clear efficacy. Among pharmacological interventions, modafinil and lurasidone showed early positive results. Sources of bias included small samples, lack of pre-screening for objective cognitive impairment, no primary outcome and no information on allocation sequence masking.

CONCLUSIONS

Evidence for pro-cognitive treatments in mood disorders is emerging. Recommendations are to increase sample sizes, pre-screen for impairment in targeted domain(s), select one primary outcome, aid transfer to real-world functioning, investigate multimodal interventions and include neuroimaging.

Impaired allocentric spatial memory in patients with affective disorders

BACKGROUND

Memory disturbances are frequent in unipolar depression (UD) and bipolar disorder (BD) and may comprise important predisposing and maintaining factors. Previous studies have demonstrated hippocampal abnormalities in UD and BD but there is a lack of studies specifically assessing hippocampus-dependent memory.

METHODS

We used a virtual task to assess hippocampus-dependent (allocentric) vs non-hipppocampal (egocentric) spatial memory in remitted and partially remitted patients with UD or BD (N = 22) and a healthy control group (N = 32). Participants also completed a range of standard neuropsychological and functional assessments.

RESULTS

Participants in the UD/BD group showed selective impairments on high-load hippocampal (allocentric) memory compared to egocentric memory and this effect was independent of residual mood symptoms. Across both samples, both allocentric and egocentric spatial memory correlated with more general measures of memory and other aspects of cognition measured on standard neuropsychological tests but only high-load allocentric memory showed a significant relationship with functional capacity.

CONCLUSION

Results show a selective impairment in high-load allocentric spatial memory compared to egocentric memory in the patient group, suggesting impaired hippocampal functioning in patients with remitted UD/BD.

Influence of pre-treatment structural brain measures on effects of action-based cognitive remediation on executive function in partially or fully remitted patients with bipolar disorder

Cognitive impairment is an emerging treatment target in patients with bipolar disorder (BD) but so far, no evidence-based treatment options are available. Recent studies indicate promising effects of Cognitive Remediation (CR) interventions, but it is unclear who responds most to these interventions. This report aimed to investigate whether pre-treatment dorsal prefrontal cortex (dPFC) thickness predicts improvement of executive function in response to Action-Based Cognitive Remediation (ABCR) in patients with BD. Complete baseline magnetic resonance imaging (MRI) data were available from 45 partially or fully remitted patients with BD from our randomized controlled ABCR trial (ABCR: n = 25, control group: n = 20). We performed cortical reconstruction and volumetric segmentation using FreeSurfer. Multiple linear regression analysis was conducted to assess the influence of dPFC thickness on ABCR-related executive function improvement, reflected by change in the One Touch Stocking of Cambridge performance from baseline to post-treatment. We also conducted whole brain vertex wise analysis for exploratory purposes. Groups were well-matched for demographic and clinical variables. Less pre-treatment dPFC thickness was associated with greater effect of ABCR on executive function (p = 0.02). Further, whole-brain vertex analysis revealed an association between smaller pre-treatment superior temporal gyrus volume and greater ABCR-related executive function improvement. The observed associations suggest that structural abnormalities in dPFC and superior temporal gyrus are key neurocircuitry treatment targets for CR interventions that target impaired executive function in BD.

Fatigue and cognitive impairment in Post-COVID-19 Syndrome: A systematic review and meta-analysis

IMPORTANCE

COVID-19 is associated with clinically significant symptoms despite resolution of the acute infection (i.e., post-COVID-19 syndrome). Fatigue and cognitive impairment are amongst the most common and debilitating symptoms of post-COVID-19 syndrome.

OBJECTIVE

To quantify the proportion of individuals experiencing fatigue and cognitive impairment 12 or more weeks following COVID-19 diagnosis, and to characterize the inflammatory correlates and functional consequences of post-COVID-19 syndrome.

DATA SOURCES

Systematic searches were conducted without language restrictions from database inception to June 8, 2021 on PubMed/MEDLINE, The Cochrane Library, PsycInfo, Embase, Web of Science, Google/Google Scholar, and select reference lists.

STUDY SELECTION

Primary research articles which evaluated individuals at least 12 weeks after confirmed COVID-19 diagnosis and specifically reported on fatigue, cognitive impairment, inflammatory parameters, and/or functional outcomes were selected.

DATA EXTRACTION & SYNTHESIS

Two reviewers independently extracted published summary data and assessed methodological quality and risk of bias. A meta-analysis of proportions was conducted to pool Freeman-Tukey double arcsine transformed proportions using the random-effects restricted maximum-likelihood model.

MAIN OUTCOMES & MEASURES

The co-primary outcomes were the proportions of individuals reporting fatigue and cognitive impairment, respectively, 12 or more weeks following COVID-19 infection. The secondary outcomes were inflammatory correlates and functional consequences associated with post-COVID-19 syndrome.

RESULTS

The literature search yielded 10,979 studies, and 81 studies were selected for inclusion. The fatigue meta-analysis comprised 68 studies, the cognitive impairment meta-analysis comprised 43 studies, and 48 studies were included in the narrative synthesis. Meta-analysis revealed that the proportion of individuals experiencing fatigue 12 or more weeks following COVID-19 diagnosis was 0.32 (95% CI, 0.27, 0.37; p < 0.001; n = 25,268; I² = 99.1%). The proportion of individuals exhibiting cognitive impairment was 0.22 (95% CI, 0.17, 0.28; p < 0.001; n = 13,232; I² = 98.0). Moreover, narrative synthesis revealed elevations in proinflammatory markers and considerable functional impairment in a subset of individuals.

CONCLUSIONS & RELEVANCE

A significant proportion of individuals experience persistent fatigue and/or cognitive impairment following resolution of acute COVID-19. The frequency and debilitating nature of the foregoing symptoms provides the impetus to characterize the underlying neurobiological substrates and how to best treat these phenomena.

STUDY REGISTRATION

PROSPERO (CRD42021256965).

Cognition in older adults with bipolar disorder: An ISBD task force systematic review and meta-analysis based on a comprehensive neuropsychological assessment

OBJECTIVES

We aim to characterize the cognitive performance in euthymic older adults with bipolar disorder (OABD) through a comprehensive neuropsychological assessment to obtain a detailed neuropsychological profile.

METHODS

We conducted a systematic search in MEDLINE/Pubmed, Cochrane, and PsycInfo databases. Original studies assessing cognitive function in OABD (age ≥50 years ) containing, at a minimum, the domains of attention/processing speed, memory, and executive functions were included. A random-effects meta-analysis was conducted to summarize differences between patients and matched controls in each cognitive domain. We also conducted meta-regressions to estimate the impact of clinical and socio-demographic variables on these differences.

RESULTS

Eight articles, providing data for 328 euthymic OABD patients and 302 healthy controls, were included in the meta-analysis. OABD showed worse performance in comparison with healthy controls, with large significant effect sizes (Hedge's g from -0.77 to -0.89; p < 0.001) in verbal learning and verbal and visual delayed memory. They also displayed statistically significant deficits, with moderate effect size, in processing speed, working memory, immediate memory, cognitive flexibility, verbal fluency, psychomotor function, executive functions, attention, inhibition, and recognition (Hedge's g from -0.52 to -0.76; p < 0.001), but not in language and visuoconstruction domains. None of the examined variables were associated with these deficits.

CONCLUSIONS

Cognitive dysfunction is present in OABD, with important deficits in almost all cognitive domains, especially in the memory domain. Our results highlight the importance of including a routine complete neuropsychological assessment in OABD and also considering therapeutic strategies in OABD.

Cognitive Adverse Effects of Electroconvulsive Therapy: A Discrepancy Between Subjective and Objective Measures?

OBJECTIVES

The character and duration of cognitive adverse effects of electroconvulsive therapy (ECT) are unclear. This study investigated (1) the sensitivity of a short cognitive test battery to cognitive adverse effects of ECT, (2) the relation between subjective and objective cognitive adverse effects, and (3) patient characteristics associated with more subjective than objective adverse effects.

METHODS

Forty-one patients with unipolar or bipolar depression referred to ECT underwent assessments at baseline, 5 to 7 days post-ECT, and 3 months post-ECT. Patients rated their fear of various aspects of ECT on a visual analog scale. At each assessment, patients were evaluated for depressive symptoms, completed the Screen for Cognitive Impairment in Psychiatry (SCIP) and Trail Making Test-Part B (TMT-B), and rated their cognitive difficulties.

RESULTS

Patients feared cognitive adverse effects and lack of treatment efficacy more than other aspects of ECT. The SCIP and TMT-B revealed transient decline in objective cognition after ECT, which was reversed after 3 months. Patients presented with more subjective than objective cognitive difficulties at baseline and more subjective than objective cognitive adverse effects of ECT. This discrepancy was significantly reduced at follow-up. Younger age and poorer objective cognition pretreatment were associated with more subjective than objective cognitive adverse effects 5 to 7 days after ECT.

CONCLUSIONS

The SCIP and TMT-B are sensitive to cognitive adverse effects of ECT. Patients show more subjective than objective cognitive adverse effects of ECT. These insights can be used clinically to inform patients of treatment choice and expected cognitive consequences.

Neuronal underpinnings of cognitive impairment in bipolar disorder: A large data-driven functional magnetic resonance imaging study

OBJECTIVES

Cognitive impairment occurs in approximately 50% of remitted patients with bipolar disorder (BD). However, there exists no treatment with replicated and robust efficacy on cognition in BD. This is partially due to limited insight into the neuronal underpinnings of cognitive impairment in these patients. This is the first study to investigate neuronal underpinnings of cognitive impairment in a large functional magnetic resonance imaging (fMRI) dataset comparing neural activity patterns between distinct neurocognitive subgroups of partially or fully remitted patients with BD.

METHODS

Patients (n = 153) and healthy controls (HC) (n = 52) underwent neuropsychological assessment and fMRI, during which they performed a verbal N-back working memory (WM) task. Based on hierarchical cluster analysis of neuropsychological test performance, patients were grouped into one of two neurocognitive subgroups (cognitively impaired, n = 91; cognitively normal compared to HC, n = 62) that were compared on WM-related neural activity.

RESULTS

Cognitively impaired patients displayed WM-related hypo-activity in left dorsolateral prefrontal cortex and frontal and parietal regions within a cognitive control network (CCN) as well as hyper-activity in the default mode network (DMN) compared to cognitively normal patients. In contrast, cognitively normal patients only exhibited hypo-activity within a small cluster in the superior frontal gyrus relative to HC.

CONCLUSIONS

Cognitive impairment in BD seems to originate from a failure to recruit key regions in the CCN and to suppress task-irrelevant DMN activity during cognitive performance. These results highlight modulation of aberrant dorsal prefrontal and DMN activity as a putative target for pro-cognitive treatment in BD.

Action-based cognitive remediation in bipolar disorder improved verbal memory but had no effect on the neural response during episodic memory encoding

Verbal memory and executive function impairments are common in remitted patients with bipolar disorder (BD). We recently found that Action-Based Cognitive Remediation (ABCR) may improve executive function and verbal memory in BD. Here, we investigated neuronal changes associated with ABCR treatment-related memory improvement in a longitudinal functional MRI (fMRI) study. Forty-five patients with remitted BD (ABCR: n = 26, control treatment: n = 19) completed a picture-encoding task during fMRI and tests of verbal memory and executive function outside the scanner before and after two weeks of ABCR/control treatment. The cognitive assessment was performed again following ten weeks of treatment. Thirty-four healthy controls underwent the same test protocol once for baseline comparisons. Patients showed a moderate improvement in a domain composite of verbal learning and memory both after two weeks and ten weeks of ABCR treatment, which correlated with improved executive function. At baseline, patients showed encoding-related hypoactivity in dorsal prefrontal cortex compared to healthy controls. However, treatment was not associated with significant task-related neuronal activity changes. Improved verbal learning and memory may have occurred through strengthened strategic processing targeted by ABCR. However, picture-encoding paradigms may be suboptimal to capture the neural correlates of this improvement, possibly by failing to engage strategic encoding processes.

Identifying social cognition subgroups in euthymic patients with bipolar disorder: a cluster analytical approach

BACKGROUND

Bipolar disorder (BD) is associated with social cognition (SC) impairments even during remission periods although a large heterogeneity has been described. Our aim was to explore the existence of different profiles on SC in euthymic patients with BD, and further explore the potential impact of distinct variables on SC.

METHODS

Hierarchical cluster analysis was conducted using three SC domains [Theory of Mind (ToM), Emotional Intelligence (EI) and Attributional Bias (AB)]. The sample comprised of 131 individuals, 71 patients with BD and 60 healthy control subjects who were compared in terms of SC performance, demographic, clinical, and neurocognitive variables. A logistic regression model was used to estimate the effect of SC-associated risk factors.

RESULTS

A two-cluster solution was identified with an adjusted-performance group (N = 48, 67.6%) and a low-performance group (N = 23, 32.4%) with mild deficits in ToM and AB domains and with moderate difficulties in EI. Patients with low SC performance were mostly males, showed lower estimated IQ, higher subthreshold depressive symptoms, longer illness duration, and poorer visual memory and attention. Low estimated IQ (OR 0.920, 95% CI 0.863-0.981), male gender (OR 5.661, 95% CI 1.473-21.762), and longer illness duration (OR 1.085, 95% CI 1.006-1.171) contributed the most to the patients clustering. The model explained up to 35% of the variance in SC performance.

CONCLUSIONS

Our results confirmed the existence of two discrete profiles of SC among BD. Nearly two-thirds of patients exhibited adjusted social cognitive abilities. Longer illness duration, male gender, and lower estimated IQ were associated with low SC performance.

Cognition Assessment in Virtual Reality: Validity and feasibility of a novel virtual reality test for real-life cognitive functions in mood disorders and psychosis spectrum disorders

There is a pressing need for measures of real-life cognitive functioning in patients with mood or psychotic disorders in clinical settings and treatment trials targeting cognition. We developed the first immersive virtual reality cognition assessment tool, the Cognition Assessment in Virtual Reality (CAVIR), which assesses verbal memory, processing speed, attention, working memory and planning skills in an interactive virtual reality kitchen scenario. This study investigates the sensitivity and validity of the CAVIR for cognitive impairments in mood and psychotic disorders and its association with functioning and neuropsychological performance. Symptomatically stable patients with mood disorders (MD; n = 40) or psychosis spectrum disorders (PSD; n = 41) and healthy control participants (HC; n = 40) completed the CAVIR and standard neuropsychological tests and were rated for clinical symptoms and daily functioning. We found that the CAVIR was sensitive to cognitive impairments across MD and PSD with large effect sizes (MD: F(73) = 11.61, p < .01, ηp2 = 0.14; PSD: F(72) = 18.24, p < .001, ηp2 = 0.19). There was a moderate to strong positive correlation between performance on the CAVIR and on neuropsychological tests (r(121) = 0.58, p < .001), which prevailed after adjustment for age, years of education and verbal IQ (B = 0.67, p < .001). Lower CAVIR scores correlated moderately with more observer-rated and performance-based functional disability (r(121) = -0.30, p < .01 and r(68) = 0.44, p < .001, respectively), also after adjustment for age, years of education and verbal IQ (B = 0.03, p < .001). In conclusion, the CAVIR is a sensitive and valid instrument for measuring real-life cognitive impairments in mood and psychotic disorders. After further psychometric assessments, the CAVIR can be implemented in clinical settings and trials targeting cognition.

Addressing the 'hypoxia paradox' in severe COVID-19: literature review and report of four cases treated with erythropoietin analogues

BACKGROUND

Since fall 2019, SARS-CoV-2 spread world-wide, causing a major pandemic with estimated ~ 220 million subjects affected as of September 2021. Severe COVID-19 is associated with multiple organ failure, particularly of lung and kidney, but also grave neuropsychiatric manifestations. Overall mortality reaches > 2%. Vaccine development has thrived in thus far unreached dimensions and will be one prerequisite to terminate the pandemic. Despite intensive research, however, few treatment options for modifying COVID-19 course/outcome have emerged since the pandemic outbreak. Additionally, the substantial threat of serious downstream sequelae, called 'long COVID' and 'neuroCOVID', becomes increasingly evident. Among candidates that were suggested but did not yet receive appropriate funding for clinical trials is recombinant human erythropoietin. Based on accumulating experimental and clinical evidence, erythropoietin is expected to (1) improve respiration/organ function, (2) counteract overshooting inflammation, (3) act sustainably neuroprotective/neuroregenerative. Recent counterintuitive findings of decreased serum erythropoietin levels in severe COVID-19 not only support a relative deficiency of erythropoietin in this condition, which can be therapeutically addressed, but also made us coin the term 'hypoxia paradox'. As we review here, this paradox is likely due to uncoupling of physiological hypoxia signaling circuits, mediated by detrimental gene products of SARS-CoV-2 or unfavorable host responses, including microRNAs or dysfunctional mitochondria. Substitution of erythropoietin might overcome this 'hypoxia paradox' caused by deranged signaling and improve survival/functional status of COVID-19 patients and their long-term outcome. As supporting hints, embedded in this review, we present 4 male patients with severe COVID-19 and unfavorable prognosis, including predicted high lethality, who all profoundly improved upon treatment which included erythropoietin analogues.

SHORT CONCLUSION

Substitution of EPO may-among other beneficial EPO effects in severe COVID-19-circumvent downstream consequences of the 'hypoxia paradox'. A double-blind, placebo-controlled, randomized clinical trial for proof-of-concept is warranted.

Effect of Action-Based Cognitive Remediation on cognitive impairment in patients with remitted bipolar disorder: A randomized controlled trial

OBJECTIVES

Cognitive impairment affects many patients with bipolar disorder (BD), and treatments with replicated pro-cognitive effects are lacking. This study aimed to assess the effect of Action-Based Cognitive Remediation (ABCR) vs control treatment on cognitive impairment in patients with BD.

METHODS

Patients with remitted BD with objective cognitive impairment were randomized to 10 weeks of ABCR vs control treatment, and assessed at baseline, after 2 weeks of treatment, at treatment completion and at 6 months follow-up. The primary outcome was a cognitive composite score. Secondary outcomes were executive function and observer-rated functional capacity. Tertiary measures included additional neuropsychological tests, performance-based functional capacity and quality of life. Data were analysed with linear mixed effects models.

RESULTS

In total, 64 participants were randomized; given three dropouts before the baseline assessments, data were analysed for 61 participants (ABCR: n = 32, control: n = 29). There was no effect on ABCR vs control on the primary cognitive composite score (P-values ≥.60). At treatment completion, there was a large effect of ABCR vs control on the secondary executive function measure (treatment effect= -0.16, 95% CI [-0.27, -0.05], P ≤ .01, d = 0.65), and on subjective cognitive functioning (treatment effect = -5.38, 95% CI [-8.13, -2.67], P ≤ .001, d = 0.80), which disappeared at follow-up. There was no treatment-effect on functioning, and no association between cognitive and functional change.

CONCLUSIONS

There was no effect of ABCR on the cognitive composite score. However, there was an effect on executive function and subjective cognitive functioning suggesting that ABCR may be relevant for patients with executive dysfunction.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03295305.

Assessment of the neuronal underpinnings of cognitive impairment in bipolar disorder with a picture encoding paradigm and methodological lessons learnt

BACKGROUND

Mood disorders are often associated with persistent cognitive impairments. However, pro-cognitive treatments are essentially lacking. This is partially because of poor insight into the neurocircuitry abnormalities underlying these deficits and their change with illness progression.

AIMS

This functional magnetic resonance imaging (fMRI) study investigates the neuronal underpinnings of cognitive impairments and neuronal change after mood episodes in remitted patients with bipolar disorder (BD) using a hippocampus-based picture encoding paradigm.

METHODS

Remitted patients with BD (n=153) and healthy controls (n=52) were assessed with neuropsychological tests and underwent fMRI while performing a strategic picture encoding task. A subgroup of patients (n=43) were rescanned after 16 months. We conducted data-driven hierarchical cluster analysis of patients' neuropsychological data and compared encoding-related neuronal activity between the resulting neurocognitive subgroups. For patients with follow-up data, effects of mood episodes were assessed by comparing encoding-related neuronal activity change in BD patients with and without episode(s).

RESULTS

Two neurocognitive subgroups were revealed: 91 patients displayed cognitive impairments while 62 patients were cognitively normal. No neuronal activity differences were observed between neurocognitive subgroups within the dorsal cognitive control network or hippocampus. However, exploratory whole-brain analysis revealed lower activity within a small region of middle temporal gyrus in impaired patients, which significantly correlated with poorer neuropsychological performance. No changes were observed in encoding-related neuronal activity or picture recall accuracy with the occurrence of mood episode(s) during the follow-up period.

CONCLUSION

Memory encoding fMRI paradigms may not capture the neuronal underpinnings of cognitive impairment or effects of mood episodes.

Reduced frontostriatal response to expected value and reward prediction error in remitted monozygotic twins with mood disorders and their unaffected high-risk co-twins

BACKGROUND

Depressive episodes experienced in unipolar (UD) and bipolar (BD) disorders are characterized by anhedonia and have been associated with abnormalities in reward processes related to reward valuation and error prediction. It remains however unclear whether these deficits are associated with familial vulnerability to mood disorders.

METHODS

In a functional magnetic resonance imaging study, we evaluated differences in the expected value (EV) and reward prediction error (RPE) signals in ventral striatum (VS) and prefrontal cortex between three groups of monozygotic twins: affected twins in remission for either UD or BD (n = 53), their high-risk unaffected co-twins (n = 34), and low-risk twins with no family history of mood disorders (n = 25).

RESULTS

Compared to low-risk twins, affected twins showed lower EV signal bilaterally in the frontal poles and lower RPE signal bilaterally in the VS, left frontal pole and superior frontal gyrus. The high-risk group did not show a significant change in the EV or RPE signals in frontostriatal regions, yet both reward signals were consistently lower compared with low-risk twins in all regions where the affected twins showed significant reductions.

CONCLUSION

Our findings strengthen the notion that reduced valuation of expected rewards and reduced error-dependent reward learning may underpin core symptom of depression such as loss of interest in rewarding activities. The trend reduction in reward-related signals in unaffected co-twins warrants further investigation of this effect in larger samples and prospective follow-up to confirm possible association with increased familial vulnerability to mood disorders.

Neuronal and cognitive predictors of improved executive function following action-based cognitive remediation in patients with bipolar disorder

Cognitive impairments in bipolar disorder (BD) are prevalent but effective treatments with replicated and lasting pro-cognitive effects are lacking. Treatment development is hampered by a lack of neurocircuitry biomarkers to predict treatment efficacy. Action-Based Cognitive Remediation (ABCR) improves executive function in BD and this was accompanied by increased dorsal prefrontal cortex (dPFC) response during working memory (WM) after two weeks of treatment. This study investigated whether pre-treatment WM-related dPFC response, executive dysfunction and/or subjective cognitive difficulties predicted ABCR treatment response on executive functions. Forty-five patients with fully or partially remitted BD (ABCR: n = 25, control treatment: n = 20) in our ABCR trial completed a spatial N-back WM task during functional magnetic resonance imaging (fMRI) at baseline. Patients also completed neuropsychological tests and rated their cognitive functions before and after 10 weeks of ABCR or control treatment. Multiple linear regression analyses were conducted to assess whether pre-treatment dPFC response, objective executive impairment and/or subjective cognitive difficulties predicted greater ABCR-related improvements of executive function. We found that treatment-related improvement in executive function was predicted by more WM-related dPFC hypo-activity at baseline (p = 0.03) in linear regression analyses adjusted for age, gender and education. In contrast, there was only a non-significant trend towards more executive dysfunction at baseline predicting greater ABCR-related executive improvement (p = 0.08). Subjective cognitive difficulties at baseline showed no association with treatment effects (p = 0.16). In conclusion, pre-treatment dPFC hypo-activity during WM performance predicts greater effects of ABCR treatment on executive function and may represent a neurocircuitry biomarker for treatment efficacy in this cognitive domain.

Cognitive impairments four months after COVID-19 hospital discharge: Pattern, severity and association with illness variables

The ongoing Coronavirus Disease 2019 (COVID-19) pandemic has affected more than 100 million people and clinics are being established for diagnosing and treating lingering symptoms, so called long-COVID. A key concern are neurological and long-term cognitive complications. At the same time, the prevalence and nature of the cognitive sequalae of COVID-19 are unclear. The present study aimed to investigate the frequency, pattern and severity of cognitive impairments 3-4 months after COVID-19 hospital discharge, their relation to subjective cognitive complaints, quality of life and illness variables. We recruited patients at their follow-up visit at the respiratory outpatient clinic, Copenhagen University Hospital, Bispebjerg, approximately four months after hospitalisation with COVID-19. Patients underwent pulmonary, functional and cognitive assessments. Twenty-nine patients were included. The percentage of patients with clinically significant cognitive impairment ranged from 59% to 65% depending on the applied cut-off for clinical relevance of cognitive impairment, with verbal learning and executive functions being most affected. Objective cognitive impairment scaled with subjective cognitive complaints, lower work function and poorer quality of life. Cognitive impairments were associated with d-dimer levels during acute illness and residual pulmonary dysfunction. In conclusion, these findings provide new evidence for frequent cognitive sequelae of COVID-19 and indicate an association with the severity of the lung affection and potentially restricted cerebral oxygen delivery. Further, the associations with quality of life and functioning call for systematic cognitive screening of patients after recovery from severe COVID-19 illness and implementation of targeted treatments for patients with persistent cognitive impairments.

Change in prefrontal activity and executive functions after action-based cognitive remediation in bipolar disorder: a randomized controlled trial

Cognitive impairment is prevalent in bipolar disorder (BD) but treatments with pro-cognitive effects are lacking. Insight concerning the neurocircuitry of cognitive improvement could provide a biomarker for pro-cognitive effects to advance treatment development. The dorsal prefrontal cortex (dPFC) is a promising region for such treatment target engagement. The aim of this functional magnetic resonance imaging (fMRI) study was to examine the effects of action-based cognitive remediation (ABCR) on early change in the dPFC blood-oxygen-level-dependent response in patients with BD in remission, and whether the observed neural change predicted improved executive functions following 10 weeks of treatment. Forty-five participants with remitted BD (ABCR: n = 26, control treatment: n = 19) completed a spatial n-back working memory task during fMRI and executive function tasks outside the scanner before and after two weeks of ABCR/control treatment, and an additional assessment of executive function at treatment completion. Thirty-four healthy controls underwent a single fMRI and executive function assessment for baseline comparisons. We found an early reversal of pretreatment hypo-activity in the dorsolateral prefrontal cortex (dlPFC) following ABCR vs. control during both high-load (2-back > 1-back) working memory (WM) (F(1,43) = 5.69, p = 0.02, η2 = 0.12) and general WM (2-back > 0-back) (F(1,43) = 5.61, p = 0.02, η2 = 0.12). This dlPFC activity increase predicted improved executive functions at treatment completion (high-load WM: B = -0.45, p = 0.01, general WM: B = -0.41, p < 0.01), independent of changes in subsyndromal symptoms. In conclusion, early dPFC increase may provide a neurocircuitry-based biomarker for pro-cognitive effects. Future cognition trials should include fMRI assessments to confirm the validity of this putative biomarker model across disorders with cognitive impairment.

Processing of infant emotion in mothers with mood disorders and implications for infant development

BACKGROUND

Atypical neurocognitive responses to emotional stimuli are core features of unipolar depression (UD) and bipolar disorder (BD). For mothers with these mood disorders, this may influence interactions with their infants and consequently infant development. The study aimed to investigate psychophysiological and cognitive responses to infant emotional stimuli, and their relation to mother-infant interaction and infant development, in mothers with BD or UD in full or partial remission.

METHODS

Four months after birth, mothers' cognitive responses to emotional infant stimuli were assessed with computerized tasks, while their facial expressions, galvanic skin responses (GSR), gazes, and fixations were recorded. Infant development and mother-infant interactions were also assessed.

RESULTS

We included 76 mothers: 27 with BD, 13 with UD, and 36 without known psychiatric disorders, and their infants. Mothers with BD and UD were in full or partial remission and showed blunted GSR and spent less time looking at infant stimuli (unadjusted p values < 0.03). Mothers with BD showed subtle positive neurocognitive biases (unadjusted p values<0.04) and mothers with UD showed negative biases (unadjusted p values < 0.02). Across all mothers, some measures of atypical infant emotion processing correlated with some measures of delays in infant development and suboptimal mother-infant interaction (unadjusted p values<0.04).

CONCLUSIONS

Mothers with mood disorders in full or partial remission showed atypical cognitive and psychophysiological response to emotional infant stimuli, which could be associated with mother-infant interactions and infant development. The study is explorative, hypothesis generating, and should be replicated in a larger sample. Investigation of the long-term implications of reduced maternal sensitivity is warranted.

Norms for the Screen for Cognitive Impairment in Psychiatry and cognitive trajectories in bipolar disorder

BACKGROUND

The International Society for Bipolar Disorders Targeting Cognition Task Force recommends screening for and monitoring of cognitive impairments in patients with bipolar disorder (BD) with the Screen for Cognitive Impairment in Psychiatry (SCIP). The study aimed to provide the first demographically adjusted norms and change norms for the SCIP and to compare the cognitive trajectory over one year in remitted BD patients with normative cognitive change.

METHODS

Patients with fully or partially remitted BD and healthy controls (HC) were assessed with the SCIP at baseline and at a one-year follow-up. Regression-based models were used to determine demographically adjusted norms and change norms. Using the change models, predicted follow-up scores were calculated for BD and HC, and independent t-tests were used to compare deviations of the observed from the predicted follow-up scores for BD vs. HC to assess differences in cognitive trajectories.

RESULTS

Baseline data were collected for n=273 HC and n=218 BD, and follow-up data for n=139 HC and n=74 BD. Baseline norm models included age, sex and years of education, while change models included baseline SCIP scores and age. Patients with follow-up data showed selective impairments within verbal learning and recall at baseline. They followed the normative cognitive trajectories for all cognitive domains but verbal learning.

LIMITATIONS

Cognition was assessed with a screening tool.

CONCLUSIONS

We recommend implementing demographically adjusted norms and change norms for the SCIP in clinical and research settings. Change norms seem sensitive to subtle and selective cognitive decline over one year in remitted BD.

Effects of psychological and pharmacological interventions on anxiety symptoms in patients with bipolar disorder in full or partial remission: A systematic review

BACKGROUND

Anxiety symptoms are prevalent in bipolar disorder (BD) even during periods of remission and impede treatment efficacy, prognosis and functional capacity. This highlights a pressing clinical need to identify novel effective anxiety treatments. This systematic review aimed to evaluate the evidence within the field.

METHODS

Following PRISMA guidelines, we conducted a systematic search on PubMed, PsycInfo, EMBASE and Cochrane Library for randomised controlled trials (RCTs) targeting anxiety in remitted BD patients.

RESULTS

We identified 10 RCTs investigating the effects of psychological or pharmacological treatments on anxiety in remitted BD patients. Two studies of transdiagnostic personalised cognitive behavioural therapy (CBT) found a treatment-related reduction in anxiety. This evidence was preliminary given small sample size and use of self-report measures in a single-blind trial design, respectively. The remaining six psychological intervention trials provided more preliminary evidence due to several methodological challenges. The two pharmacological studies found anxiolytic effects of add-on olanzapine or methylene blue to lithium treatment, respectively. Nevertheless, this evidence should be interpreted with caution given high drop-out rates and substantial side-effects that may have impeded blinding.

LIMITATIONS

We did not conduct a quantitative meta-analysis.

CONCLUSIONS

There is preliminary evidence for beneficial effects of modified CBT and add-on pharmacotherapy on residual anxiety in BD. Future trials should pre-screen participants for anxiety, define one clinician-rated anxiety measurement as a primary outcome, and employ intention-to-treat analysis to assess treatment effect. This will advance treatment development and enable personalised approaches to address residual anxiety in BD, which has great clinical relevance.

Cognitive processing of infant stimuli in pregnant women with and without affective disorders and the association to postpartum depression

Pregnancy and childbirth are among the strongest risk factors for depression but the neurocognitive mechanisms underlying this enhanced risk are unknown. This study investigated emotional and non-emotional cognition in 57 pregnant women with or without an affective disorder during their third trimester, and the association between cognitive biases and subsequent postpartum depression (PPD). Of the pregnant women, 22 had a diagnosis of unipolar disorder (UD) and seven of bipolar disorder (BD) in full or partial remission, while 28 had no history of affective disorder. We included a control group of 29 healthy non-pregnant women. First, participants were interviewed, completed non-emotional and emotional cognitive tests and lastly filled out questionnaires. The participants were assessed two times after birth: at a home visit shortly after birth, and with a telephone interview to assess PPD in the first six months after birth. Healthy pregnant women rated infant cries less negatively than non-pregnant women, possibly reflecting preparation for motherhood. Pregnant women with UD exhibited a negative bias in ratings of infant cries, whereas pregnant women with BD showed a positive bias in ratings of infant happy faces and recognition of adult facial expressions. Across all pregnant women, more negative ratings of infant cries were associated with enhanced risk of PPD. Negatively biased perception of infant cries during pregnancy may thus signal vulnerability toward PPD.

Hippocampal neurons respond to brain activity with functional hypoxia

Physical activity and cognitive challenge are established non-invasive methods to induce comprehensive brain activation and thereby improve global brain function including mood and emotional well-being in healthy subjects and in patients. However, the mechanisms underlying this experimental and clinical observation and broadly exploited therapeutic tool are still widely obscure. Here we show in the behaving brain that physiological (endogenous) hypoxia is likely a respective lead mechanism, regulating hippocampal plasticity via adaptive gene expression. A refined transgenic approach in mice, utilizing the oxygen-dependent degradation (ODD) domain of HIF-1α fused to CreERT2 recombinase, allows us to demonstrate hypoxic cells in the performing brain under normoxia and motor-cognitive challenge, and spatially map them by light-sheet microscopy, all in comparison to inspiratory hypoxia as strong positive control. We report that a complex motor-cognitive challenge causes hypoxia across essentially all brain areas, with hypoxic neurons particularly abundant in the hippocampus. These data suggest an intriguing model of neuroplasticity, in which a specific task-associated neuronal activity triggers mild hypoxia as a local neuron-specific as well as a brain-wide response, comprising indirectly activated neurons and non-neuronal cells.

Abnormal prefrontal cortex processing of reward prediction errors in recently diagnosed patients with bipolar disorder and their unaffected relatives

OBJECTIVE

Bipolar disorder (BD) has been associated with abnormal reward functioning including pleasure-seeking and impulsivity. Here we sought to clarify whether these changes can be attributed to abnormalities in the neural processing of reward valuation or error prediction. Moreover, we tested whether abnormalities in these processes are associated with familial vulnerability to BD.

METHODS

We obtained functional magnetic resonance imaging data from patients with recently diagnosed BD (n = 85), their unaffected first-degree relatives (n = 44), and healthy control participants (n = 66) while they were performing a monetary card game. We used a region-of-interest approach to test for group differences in the activation of the midbrain, the ventral striatum, and the prefrontal cortex during reward valuation and error prediction.

RESULTS

Patients with BD showed decreased prediction error signal in ventrolateral prefrontal cortex and the unaffected relatives showed decreased prediction error signal in the supplementary motor area in comparison to healthy controls. There were no significant group differences in the activation of the ventral striatum during the task. In healthy controls, prediction error signal in dorsal anterior cingulate cortex correlated with an out-of-scanner measure of motor inhibition but this association was absent in patients and relatives.

CONCLUSIONS

The findings indicate that abnormal reward processing in BD is primarily related to deficits in the engagement of prefrontal regions involved in inhibitory control during error prediction. In contrast, deficient activation in supplementary motor cortex involved in planning of movement emerged as a familial vulnerability to BD.

Women With Borderline Personality Disorder Show Reduced Identification of Emotional Facial Expressions and a Heightened Negativity Bias

Individuals with borderline personality disorder (BPD) frequently display impairments in the identification of emotional facial expressions paralleled by a negativity bias. However, it remains unclear whether misperception of facial expressions is a key psychopathological marker of BPD. To address this question, the authors examined 43 women diagnosed with BPD and 56 healthy female controls using an emotion face identification task and a face dot-probe task together with measures on psychopathology. Compared to controls, women with BPD showed impaired identification of disgusted and angry faces concurrent with a bias to misclassify faces as angry, and a faster preconscious vigilance for fearful relative to happy facial expressions. Increased severity of borderline symptoms and global psychopathology in BPD patients were associated with reduced ability to identify angry facial expressions and a stronger negativity bias to anger. The findings indicate that BPD patients who misperceive face emotions have the greatest mental health issues.

Erythropoietin as candidate for supportive treatment of severe COVID-19

In light of the present therapeutic situation in COVID-19, any measure to improve course and outcome of seriously affected individuals is of utmost importance. We recap here evidence that supports the use of human recombinant erythropoietin (EPO) for ameliorating course and outcome of seriously ill COVID-19 patients. This brief expert review grounds on available subject-relevant literature searched until May 14, 2020, including Medline, Google Scholar, and preprint servers. We delineate in brief sections, each introduced by a summary of respective COVID-19 references, how EPO may target a number of the gravest sequelae of these patients. EPO is expected to: (1) improve respiration at several levels including lung, brainstem, spinal cord and respiratory muscles; (2) counteract overshooting inflammation caused by cytokine storm/ inflammasome; (3) act neuroprotective and neuroregenerative in brain and peripheral nervous system. Based on this accumulating experimental and clinical evidence, we finally provide the research design for a double-blind placebo-controlled randomized clinical trial including severely affected patients, which is planned to start shortly.

Impact of pretreatment interhemispheric hippocampal asymmetry on improvement in verbal learning following erythropoietin treatment in mood disorders: a randomized controlled trial

BACKGROUND

Treatment development that targets cognitive impairment is hampered by a lack of biomarkers that can predict treatment efficacy. Erythropoietin (EPO) improves verbal learning and memory in mood disorders, and this scales with an increase in left hippocampal volume. This study investigated whether pretreatment left hippocampal volume, interhemisphere hippocampal asymmetry or both influenced EPO treatment response with respect to verbal learning.

METHODS

Data were available for 76 of 83 patients with mood disorders from our previous EPO trials (EPO = 37 patients; placebo = 39 patients). We performed cortical reconstruction and volumetric segmentation using FreeSurfer. We conducted multiple linear regression and logistic regression to assess the influence of left hippocampal volume and hippocampal asymmetry on EPO-related memory improvement, as reflected by change in Rey Auditory Verbal Learning Test total recall from baseline to post-treatment. We set up a corresponding exploratory general linear model in FreeSurfer to assess the influence of prefrontal cortex volume on verbal learning improvement, controlling for age, sex and total intracranial volume.

RESULTS

At baseline, more rightward (left < right) hippocampal asymmetry — but not left hippocampal volume per se — was associated with greater effects of EPO versus placebo on verbal learning (p ≤ 0.05). Exploratory analysis indicated that a larger left precentral gyrus surface area was also associated with improvement of verbal learning in the EPO group compared to the placebo group (p = 0.002).

LIMITATIONS

This was a secondary analysis of our original EPO trials.

CONCLUSION

Rightward hippocampal asymmetry may convey a positive effect of EPO treatment efficacy on verbal learning.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT00916552

Characteristics influencing expected cognitive performance during hypoglycaemia in type 2 diabetes

BACKGROUND

Acute hypoglycaemia is associated with cognitive impairment in patients with type 2 diabetes. However, there is limited understanding of the relationship between patients' expected cognitive difficulties and their objectively-measured deficits during non-severe hypoglycaemia.

OBJECTIVE

This report investigates demographic and clinical factors associated with the discrepancy between expected (i.e., self-evaluated) and measurable (i.e., neuropsychological) cognitive functions in patients with type 2 diabetes during acute non-severe hypoglycaemia.

METHODS

We performed an analysis of factors associated with the relationship between expected and measurable cognitive performance for data collected from a cohort of patients with type 2 diabetes (N = 25). Patients attended two experimental visits during which we performed hyper-insulinaemic glucose clamping; (i) non-severe hypoglycaemic clamp (plasma glucose (PG): 3.1 ± 0.3 mmol/L) and (ii) normoglycaemic clamp (PG: 5.8 ± 0.3 mmol/L), as part of a double-blinded cross-over study. During hypoglycaemia, patients' expected cognitive performance was assessed with a visual analogue scale after which objective cognitive functions were assessed with a neuropsychological test battery. We computed a global 'cognitive discrepancy' composite variable with score values on a scale between -10 and +10 using a novel statistical formula that creates a discrepancy score between subjective and objective cognition. Positive values reflect more expected than objectively-measured difficulties, while negative values reflect disproportionately more objectively-measured than expected cognitive difficulties. We used paired samples t-tests to compare degree of cognitive discrepancy between conditions of hypo- and normoglycaemia, while multiple regression analysis was performed to identify factors associated with the degree and direction of the cognitive discrepancy. The significance level for the analyses was p ≤ 0.05 (two-tailed).

RESULTS

Patients generally underestimated their cognitive abilities (M = 1.6, SD = 3.3) during hypoglycaemia compared to normoglycaemia (M = -1.0, SD = 3.5) (p = 0.2), t(23) = 2.9, p < 0.01. Underestimation of cognitive capacity during hypoglycaemia was more pronounced for patients with younger age (β = 0.5, p = 0.02), higher verbal IQ (β = 0.5, p = 0.03), and more hypoglycaemia-related shakiness (β = 0.4, p = 0.03).

LIMITATIONS

The modest sample size limits the generalizability of the findings.

CONCLUSIONS

Patients with type 2 diabetes underestimated their cognitive abilities during non-severe hypoglycaemic states, especially those with younger age, higher IQ, and more hypoglycaemia-related shakiness. These patients may thus have excessive preoccupations with their cognitive difficulties in relation to cognitively challenging daily life situations.

Affective cognition in bipolar disorder: A systematic review by the ISBD targeting cognition task force

BACKGROUND

Impairments in affective cognition are part of the neurocognitive profile and possible treatment targets in bipolar disorder (BD), but the findings are heterogeneous. The International Society of Bipolar Disorder (ISBD) Targeting Cognition Task Force conducted a systematic review to (i) identify the most consistent findings in affective cognition in BD, and (ii) provide suggestions for affective cognitive domains for future study and meta-analyses.

METHODS

The review included original studies reporting behavioral measures of affective cognition in BD patients vs controls following the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement. Searches were conducted on PubMed/MEDLINE, EMBASE, and PsychInfo from inception until November 2018.

RESULTS

A total of 106 articles were included (of which nine included data for several affective domains); 41 studies assessed emotional face processing; 23 studies investigated reactivity to emotional words and images; 3 investigated explicit emotion regulation; 17 assessed implicit emotion regulation; 31 assessed reward processing and affective decision making. In general, findings were inconsistent. The most consistent findings were trait-related difficulties in facial emotion recognition and implicit emotion regulation, and impairments in reward processing and affective decision making during mood episodes. Studies using eye-tracking and facial emotion analysis revealed subtle trait-related abnormalities in emotional reactivity.

CONCLUSION

The ISBD Task Force recommends facial expression recognition, implicit emotion regulation, and reward processing as domains for future research and meta-analyses. An important step to aid comparability between studies in the field would be to reach consensus on an affective cognition test battery for BD.

Whole-Brain Exploratory Analysis of Functional Task Response Following Erythropoietin Treatment in Mood Disorders: A Supervised Machine Learning Approach

A core symptom of mood disorders is cognitive impairment in attention, memory and executive functions. Erythropoietin (EPO) is a candidate treatment for cognitive impairment in unipolar and bipolar disorders (UD and BD) and modulates cognition-related neural activity across a fronto-temporo-parietal network. This report investigates predicting the pharmacological treatment from functional magnetic resonance imaging (fMRI) data using a supervised machine learning approach. A total of 84 patients with UD or BD were included in a randomized double-blind parallel-group study in which they received eight weekly infusions of either EPO (40 000 IU) or saline. Task fMRI data were collected before EPO/saline infusions started (baseline) and 6 weeks after last infusion (follow-up). During the scanning sessions, participants were given an n-back working memory and a picture encoding task. Linear classification models with different regularization techniques were used to predict treatment status from both cross-sectional data (at follow-up) and longitudinal data (difference between baseline and follow-up). For the n-back and picture encoding tasks, data were available and analyzed for 52 (EPO; n = 28, Saline; n = 24) and 59 patients (EPO; n = 31, Saline; n = 28), respectively. We found limited evidence that the classifiers used could predict treatment status at a reliable level of performance (≤60% accuracy) when tested using repeated cross-validation. There was no difference in using cross-sectional versus longitudinal data. Whole-brain multivariate decoding applied to pharmaco-fMRI in small to moderate samples seems to be suboptimal for exploring data driven neuronal treatment mechanisms.

Is aberrant affective cognition an endophenotype for affective disorders? - A monozygotic twin study

BACKGROUND

Identification of endophenotypes can improve prevention, detection and development of new treatments. We therefore investigated whether aberrant affective cognition constitutes an endophenotype for affective disorders by being present in monozygotic (MZ) twins with unipolar or bipolar disorder in partial remission (i.e. affected) and their unaffected co-twins (i.e. high-risk) relative to twins with no family history of affective disorder (i.e. low-risk).

METHODS

We conducted an assessor blind cross-sectional study from 2014 to 2017 of MZ twins using Danish population-based registers in recruitment. Twins attended one test session involving neurocognitive testing, clinical ratings and questionnaires. Main outcomes were attention to and recognition of emotional facial expressions, the memory of emotional self-referential words, emotion regulation and coping strategies.

RESULTS

Participants were 103 affected, 44 high-risk and 36 low-risk MZ twins. Groups were demographically well-balanced and showed comparable non-affective cognitive performance. We observed no aberrant affective cognition in affected and high-risk relative to low-risk twins. However, high-risk twins displayed attentional avoidance of emotional faces (ps ⩽ 0.009) and more use of task-oriented coping strategies (p = 0.01) compared with affected twins. In contrast did affected twins show more emotion-oriented coping than high- and low-risk twins (ps ⩽ 0.004).

CONCLUSIONS

Our findings provide no support of aberrant affective cognition as an endophenotype for affective disorders. High-risk twins' attentional avoidance of emotional faces and greater use of task-oriented coping strategies may reflect compensatory mechanisms.

Clinical characteristics associated with the discrepancy between subjective and objective cognitive impairment in depression

BACKGROUND

Patients with unipolar disorder (UD) commonly experience cognitive dysfunction during symptomatic and remitted phases. However, it is not necessarily the patients with the greatest subjective complaints, who display the largest objectively-measured deficits on neuropsychological tests.

OBJECTIVE

This report investigated the demographic and clinical factors associated with the discrepancy between subjective and objective measures of cognition in two separate depressed patient populations in Denmark and New Zealand, respectively, using a new methodology.

METHODS

Data from 137 depressed patients and 103 healthy controls including neuropsychological test scores, self-reported cognitive difficulties, and ratings of mood were pooled from two studies conducted in Copenhagen, Denmark, and Christchurch, New Zealand, respectively. Cognitive discrepancy scores were calculated using a novel methodology, with positive values indicating disproportionately more subjective than objective difficulties (i.e., "sensitivity") and negative values indicating more objective than subjective impairments (i.e., "stoicism").

RESULTS

In the Danish partially remitted patient sample, greater 'sensitivity' was associated with more subsyndromal depression severity (standardized Beta (std. β )= 0.4, p < 0.01)), illness duration (std. β = 0.4, p < 0.01), and younger age (std. β = 0.6, p < 0.001). This association was replicated in the New Zealand sample of more symptomatic patients (p-values ≤ 0.05).

LIMITATIONS

The cross-sectional design hampered causal inferences. We had obtained different measures of objective and subjective cognition from the two studies.

CONCLUSIONS

Patients with more depressive symptoms and younger age overreported cognitive impairments across all illness states. The use of an objective cognition screener thus seems particularly relevant for these patients to assess whether subjective complaints are accompanied by measurable cognitive deficits.