Specifying the Neuropsychology of Affective Disorders: Clinical, Demographic and Neurobiological Factors

CERAD-NAB and flexible battery based neuropsychological differentiation of Alzheimer's dementia and depression using machine learning approaches

Depression (DEP) and dementia of the Alzheimer's type (DAT) represent the most common neuropsychiatric disorders in elderly patients. Accurate differential diagnosis is indispensable to ensure appropriate treatment. However, DEP can yet mimic cognitive symptoms of DAT and patients with DAT often also present with depressive symptoms, impeding correct diagnosis. Machine learning (ML) approaches could eventually improve this discrimination using neuropsychological test data, but evidence is still missing. We therefore employed Support Vector Machine (SVM), Naïve Bayes (NB), Random Forest (RF) and conventional Logistic Regression (LR) to retrospectively predict the diagnoses of 189 elderly patients (68 DEP and 121 DAT) based on either the well-established Consortium to Establish a Registry for Alzheimer's Disease neuropsychological assessment battery (CERAD-NAB) or a flexible battery approach (FLEXBAT). The best performing combination consisted of FLEXBAT and NB, correctly classifying 87.0% of patients as either DAT or DEP. However, all accuracies were similar across algorithms and test batteries (83.0% - 87.0%). Accordingly, our study is the first to show that common ML algorithms with their default parameters can accurately differentiate between patients clinically diagnosed with DAT or DEP using neuropsychological test data, but do not necessarily outperform conventional LR.

Dynamic network characteristics of adolescents with major depressive disorder: Attention network mediates the association between anhedonia and attentional deficit

Attention deficit is a critical symptom that impairs social functioning in adolescents with major depressive disorder (MDD). In this study, we aimed to explore the dynamic neural network activity associated with attention deficits and its relationship with clinical outcomes in adolescents with MDD. We included 188 adolescents with MDD and 94 healthy controls. By combining psychophysics, resting-state electroencephalography (EEG), and functional magnetic resonance imaging (fMRI) techniques, we aimed to identify dynamic network features through the investigation of EEG microstate characteristics and related temporal network features in adolescents with MDD. At baseline, microstate analysis revealed that the occurrence of Microstate C in the patient group was lower than that in healthy controls, whereas the duration and coverage of Microstate D increased in the MDD group. Mediation analysis revealed that the probability of transition from Microstate C to D mediated anhedonia and attention deficits in the MDD group. fMRI results showed that the temporal variability of the dorsal attention network (DAN) was significantly weaker in patients with MDD than in healthy controls. Importantly, the temporal variability of DAN mediated the relationship between anhedonia and attention deficits in the patient group. After acute-stage treatment, the response prediction group (RP) showed improvement in Microstates C and D compared to the nonresponse prediction group (NRP). For resting-state fMRI data, the temporal variability of DAN was significantly higher in the RP group than in the NRP group. Overall, this study enriches our understanding of the neural mechanisms underlying attention deficits in patients with MDD and provides novel clinical biomarkers.

Exploring depression in Alzheimer's disease: an Italian Delphi Consensus on phenomenology, diagnosis, and management

BACKGROUND

In Alzheimer's disease (AD), the progressive cognitive impairment is often combined with a variety of neuropsychiatric symptoms, firstly depression. Nevertheless, its diagnosis and management is difficult, since specific diagnostic criteria and guidelines for treatment are still lacking. The aim of this Delphi study is to reach a shared point of view among different Italian specialists on depression in AD.

METHODS

An online Delphi survey with 30 questions regarding epidemiology, diagnosis, clinical features, and treatment of depression in AD was administered anonymously to a panel of 53 expert clinicians.

RESULTS

Consensus was achieved in most cases (86%). In the 80% of statements, a positive consensus was reached, while in 6% a negative consensus was achieved. No consensus was obtained in 14%. Among the most relevant findings, the link between depression and AD is believed to be strong and concerns etiopathogenesis and phenomenology. Further, depression in AD seems to have specific features compared to major depressive disorder (MDD). Regarding diagnosis, the DSM 5 diagnostic criteria for MDD seems to be not able to detect the specific aspects of depression in AD. Concerning treatment, antidepressant drugs are generally considered the main option for depression in dementia, according to previous guidelines. In order to limit side effects, multimodal and SSRI antidepressant are preferred by clinicians. In particular, the procognitive effect of vortioxetine seems to be appealing for the treatment of depression in AD.

CONCLUSIONS

This study highlights some crucial aspects of depression in AD, but more investigations and specific recommendations are needed.

Cognitive improvement in patients with major depressive disorder after personalised multi domain training in the CERT-D study

The CERT-D program offers a new treatment approach addressing disturbed cognitive and psychosocial functioning in major depressive disorder (MDD). The current analysis of a randomised controlled trial (RCT) comprises two objectives: Firstly, evaluating the program's efficacy of a personalised versus standard treatment and secondly, assessing the treatment's persistence longitudinally. Participants (N = 112) were randomised into a personalised or standard treatment group. Both groups received 8 weeks of cognitive training, followed by a three-month follow-up without additional training. The type of personalised training was determined by pre-treatment impairments in the domains of cognition, emotion-processing and social-cognition. Standard training addressed all three domains equivalent. Performance in these domains was assessed repeatedly during RCT and follow-up. Treatment comparisons during the RCT-period showed benefits of personalised versus standard treatment in certain aspects of social-cognition. Conversely, no benefits in the remaining domains were found, contradicting a general advantage of personalisation. Exploratory follow-up analysis on persistence of the program's effects indicated sustained intervention outcomes across the entire sample. A subsequent comparison of clinical outcomes between personalised versus standard treatment over a three-month follow-up period showed similar results. First evidence suggests that existing therapies for MDD could benefit from an adjunct administration of the CERT-D program.

Alteration of the α5 GABA receptor and 5HTT lead to cognitive deficits associated with major depressive-like behaviors in a 14-day combined stress rat model

INTRODUCTION

Current models used to study the pathophysiology of major depressive disorder (MDD) are laborious and time consuming. This study examined the effect of a 14-day combined stress model (CS; corticosterone injection and restraint stress) in male Sprague-Dawley rats and also compare the effect of CS versus 28-day corticosterone treatment on depressive-like behaviour and cognitive deficits.

MATERIEL AND METHODS

Depressive-like behaviours and cognitive deficits were assessed in the forced swim test (FST), sucrose preference (SPT), Morris water maze (MWM) and novel object recognition (NORT) tests. Real-time PCR and ELISA were respectively used to detect expression of the serotonin transporter (5-HTT), serotonin 1 A receptor (5-HT1A), α5 GABAA receptor, and the concentrations of corticosterone (plasma), GABA and acetylcholinesterase (AChE) in the hippocampus and Prefrontal cortex (PFC).Results CS group showed increased immobility time in the FST, time to reach the MWM platform, higher corticosterone level, and increased expressions of hippocampal and PFC 5-HT1A and α5 GABAA receptors, and AChE compared to their control groups. In contrast, reductions in SPT ratio, discrimination index in NORT, time in target quadrant, and hippocampal 5-HTT expression was noted relative to their control group. Compared to the 28-day corticosterone only group, PFC 5-HT1A, Hippocampal 5-HTT were reduced, while PFC 5-HTT, Hippocampal α5 GABAA receptors, and AChE concentrations were higher in the CS group.

CONCLUSION

Our CS model induced depressive-like behaviour with early cognitive deficits in rats affecting both hippocampus and PFC. The CS model may be useful in investigating new and comprehensive treatment strategies for MDD.

Do depressed patients really over-report cognitive impairment?

BACKGROUND

Depressed patients report more severe cognitive impairment than is detectable by neuropsychological tests because they may underestimate their cognitive performance. Alternatively, it is possible that cognitive impairment primarily occurs under everyday life conditions as referred to in most questionnaires. The aim of the present study is to investigate the validity of self-reports in patients with major depression in order to better understand the pronounced impairment in self-reports.

METHODS

We investigated 58 patients with major depression and 28 heathy control participants. We administered the "Screen for Cognitive Impairment in Psychiatry" (SCIP) to assess cognitive performance, the "Questionnaire for Cognitive Complaints" (FLei), and the newly developed scale for "Self-Perception of Cognitive Performance in everyday life and test settings" to ask for the self-assessed cognitive performance in everyday life and in a test situation more specifically.

RESULTS

Depressed patients showed an inferior test performance and reported much more general everyday life related cognitive problems compared to healthy participants. When asked more specifically for their cognitive performance in the test-situation compared to others and compared to everyday life, they did not report more test-related and everyday life related impairment than healthy participants did.

LIMITATIONS

Results might be influenced by comorbidity.

CONCLUSIONS

These results have implications for the assessment of subjective cognitive performance of depressed patients and shed light on the negative effects of general versus more specific recall of autobiographical information.

Everyday memory in patients with depression: An explorative pilot study using an ecological assessment paradigm

BACKGROUND

People with major depressive disorder (MDD) often experience significant memory problems in their daily lives, which, however, frequently do not correspond to standardized memory test (SMT) results. The present pilot study aimed to examine the everyday memory performance of people with MDD by means of an ecological assessment paradigm (EAP).

METHODS

Participants were unexpectedly called one week after their neuropsychological test assessment and asked about their memories of specific details of the former test situation. Associations of this EAP with SMT, subjective everyday memory problems, and symptom coping were exploratively analyzed.

RESULTS

The study involved 22 MDD inpatients (M = 42.5 years, 64% female) and 22 comparable healthy control persons. MDD patients showed a significantly reduced performance in the EAP as well as in the SMT and they reported more memory problems in their daily lives. However, the EAP was not related to SMT results assessed a week before. Moreover, only the EAP was significantly associated with subjective daily memory problems and (distraction) coping style in the MDD group.

CONCLUSIONS

The EAP appears to better reflect the everyday memory problems of persons with depression than standardized test procedures. However, the findings need to be validated by further research with larger samples.

Relations between clinical characteristics and cognitive deficits among adult patients diagnosed with major depressive disorder

OBJECTIVE

The present study examined the relations between clinical characteristics and cognitive deficits in adult patients with major depressive disorder (MDD) from a local outpatient psychiatric clinic in Malaysia.

METHODS

The present sample included 110 participants aged 20-60 years old. Participants were invited to provide their information on sociodemographic variables (age, gender, and educational level) and clinical characteristics (age at onset of depression and duration of illness) and to complete a series of cognitive performance measures including the Trail Making Tests A (psychomotor speed) and B (executive function), the Digit Symbol Substitution Test (attention), and the Auditory Verbal Learning Test (immediate free recall, acquisition phase, and delayed recall). The Mini International Neuropsychiatric Interview Version 6.0 was used to confirm the diagnosis of MDD and the Montgomery-Åsberg Depression Rating Scale was used to assess illness severity.

RESULTS

At the bivariate level, relations of age and educational level to all cognitive deficit domains were significant. At the multivariate level, only educational level and illness severity consistently and significantly predicted all cognitive deficits domains.

CONCLUSIONS

Therapeutic modalities should be individualised whilst considering the impacts of cognitive deficits in an attempt to prevent further deterioration in psychosocial functioning of MDD patients.KEY POINTSCognitive deficits are an elemental component of Major Depressive Disorder (MDD) persisting during a current major depressive episode or during remission, altering individuals' ability to process information and changes the way they perceive and interact with the environment.Cognitive deficits in MDD are evident among the upper-middle income groups in South-Eastern Asian countries warranting more local research as such deficits could lead to functional decline and work performance such as absenteeism and presenteeism.Therapeutic modalities should be individualised by taking the impacts of cognitive deficits into consideration to promote psychosocial functioning of MDD patients.

Dysfunctional serotonergic neuron-astrocyte signaling in depressive-like states

Astrocytes play crucial roles in brain homeostasis and are regulatory elements of neuronal and synaptic physiology. Astrocytic alterations have been found in Major Depressive Disorder (MDD) patients; however, the consequences of astrocyte Ca2+ signaling in MDD are poorly understood. Here, we found that corticosterone-treated juvenile mice (Cort-mice) showed altered astrocytic Ca2+ dynamics in mPFC both in resting conditions and during social interactions, in line with altered mice behavior. Additionally, Cort-mice displayed reduced serotonin (5-HT)-mediated Ca2+ signaling in mPFC astrocytes, and aberrant 5-HT-driven synaptic plasticity in layer 2/3 mPFC neurons. Downregulation of astrocyte Ca2+ signaling in naïve animals mimicked the synaptic deficits found in Cort-mice. Remarkably, boosting astrocyte Ca2+ signaling with Gq-DREADDS restored to the control levels mood and cognitive abilities in Cort-mice. This study highlights the important role of astrocyte Ca2+ signaling for homeostatic control of brain circuits and behavior, but also reveals its potential therapeutic value for depressive-like states.

Brain function changes reveal rapid antidepressant effects of nitrous oxide for treatment-resistant depression:Evidence from task-state EEG

Nitrous oxide has rapid antidepressant effects in patients with treatment-resistant depression (TRD), but its underlying mechanisms of therapeutic actions are not well understood. Moreover, most of the current studies lack objective biological indicators to evaluate the changes of nitrous oxide-induced brain function for TRD. Therefore, this study assessed the effect of nitrous oxide on brain function for TRD based on event-related potential (ERP) components and functional connectivity networks (FCNs) methods. In this randomized, longitudinal, placebo-controlled trial, all TRD participants were divided into two groups to receive either a 1-hour inhalation of nitrous oxide or a placebo treatment, and they took part in the same task-state electroencephalogram (EEG) experiment before and after treatment. The experimental results showed that nitrous oxide improved depressive symptoms better than placebo in terms of 17-Hamilton Depression Rating Scale score (HAMD-17). Statistical analysis based on ERP components showed that nitrous oxide-induced significant differences in amplitude and latency of N1, P1, N2, P2. In addition, increased brain functional connectivity was found after nitrous oxide treatment. And the change of network metrics has a significant correlation with decreased depressive symptoms. These findings may suggest that nitrous oxide improves depression symptoms for TRD by modifying brain function.

Clock Drawing Test: Types of Errors and Accuracy in Early Cognitive Screening

BACKGROUND

Clock Drawing Test (CDT) is a commonly used screening tool for cognitive disorders, known for its ease of administration and scoring. Despite frequent use by clinicians, CDT is criticized for its poor predictive value in mild cases of impairment.

OBJECTIVE

To evaluate CDT as a screening tool for early stage of cognitive impairment in biomarker-verified Alzheimer's disease (AD) and depressive disorder (DD).

METHODS

We analyzed CDT of 172 patients with verified AD, 70 patients with DD, in whom neurodegenerative disorder was excluded using cerebrospinal fluid biomarkers, and 58 healthy older adults. CDT was scored using the semi-quantitative (Shulman) and itemized criteria (adapted from Mendez).

RESULTS

Logistic regression showed that for both DD and AD patients with high Mini-Mental State Examination (MMSE) scores (27 and above) the significant predicting variable is uneven number spacing. As MMSE deteriorates (24-26 points), an additional error of setting clock hands is predictive of the disease. In the low MMSE condition, CDT showed an acceptable discrimination for AD (AUC itemized 0.740, Shulman 0.741) and DD (AUC itemized 0.827, Shulman 0.739) using both scoring methods. In the high MMSE condition, discrimination rates were acceptable using itemized scoring but poor using Shulman scoring for both AD (AUC itemized 0.707, Shulman 0.677) and DD (AUC itemized 0.755, Shulman 0.667) groups.

CONCLUSION

Ideally, modern diagnostic process should take place before the cognitive performance drops beneath the healthy range. This makes CDT of little use when screening patients with very mild cognitive deficits.

Kognitive Beeinträchtigungen alkoholabhängiger Patient_innen im Abstinenzverlauf und die Relevanz depressiver Komorbidität

Zusammenfassung: Hintergrund: Mit dieser Studie wird der Frage nachgegangen, inwieweit sich kognitive Beeinträchtigungen alkoholabhängiger Patient_innen in Abhängigkeit von Abstinenz und Depressivität im Behandlungsverlauf verbessern. Methode: Alkoholabhängige Patient_innen mit ( n = 22) und ohne Depression ( n = 58) wurden neuropsychologisch und hinsichtlich der Depressivität zu drei Zeitpunkten untersucht (nach Entzug und 6 Wochen bzw. 6 Monate später). 33 gesunde Kontrollproband_innen wurden zusätzlich zum ersten Zeitpunkt untersucht. Ergebnisse: Alkoholabhängige Patient_innen zeigten verglichen mit gesunden Kontrollpersonen eine verminderte Leistung im schlussfolgernden Denken. Im Behandlungsverlauf zeigte sich eine trendweise günstigere Entwicklung für abstinente verglichen mit rückfälligen Patient_innen und eine größere Depressivität war mit schwächeren Leistungen assoziiert. Diskussion: Alkoholabhängige Patient_innen leiden an kognitiven Defiziten, die sich z. T. im weiteren Behandlungsverlauf zu verbessern scheinen, v. a. bei Abstinenz.

Genome-wide interaction study with major depression identifies novel variants associated with cognitive function

Major Depressive Disorder (MDD) often is associated with significant cognitive dysfunction. We conducted a meta-analysis of genome-wide interaction of MDD and cognitive function using data from four large European cohorts in a total of 3510 MDD cases and 6057 controls. In addition, we conducted analyses using polygenic risk scores (PRS) based on data from the Psychiatric Genomics Consortium (PGC) on the traits of MDD, Bipolar disorder (BD), Schizophrenia (SCZ), and mood instability (MIN). Functional exploration contained gene expression analyses and Ingenuity Pathway Analysis (IPA®). We identified a set of significantly interacting single nucleotide polymorphisms (SNPs) between MDD and the genome-wide association study (GWAS) of cognitive domains of executive function, processing speed, and global cognition. Several of these SNPs are located in genes expressed in brain, with important roles such as neuronal development (REST), oligodendrocyte maturation (TNFRSF21), and myelination (ARFGEF1). IPA® identified a set of core genes from our dataset that mapped to a wide range of canonical pathways and biological functions (MPO, FOXO1, PDE3A, TSLP, NLRP9, ADAMTS5, ROBO1, REST). Furthermore, IPA® identified upstream regulator molecules and causal networks impacting on the expression of dataset genes, providing a genetic basis for further clinical exploration (vitamin D receptor, beta-estradiol, tadalafil). PRS of MIN and meta-PRS of MDD, MIN and SCZ were significantly associated with all cognitive domains. Our results suggest several genes involved in physiological processes for the development and maintenance of cognition in MDD, as well as potential novel therapeutic agents that could be explored in patients with MDD associated cognitive dysfunction.

Neuropsychological predictors of vocational rehabilitation outcomes in individuals with major depression: A scoping review

BACKGROUND

Major depression is one of the leading causes of disability and limited capacity to work. Neuropsychological impairment is a common symptom in acute and remitted major depression and is associated with poor psychosocial functioning. This scoping review aimed to identify research on the role of neuropsychological functioning in outcomes of vocational rehabilitation programs in individuals with depression.

METHODS

We report on the conduct of this pre-registered (https://osf.io/5yrnf) scoping review in accordance with PRISMA-ScR guidelines. PubMed and PsychInfo were systematically searched for English or German research articles published between 1990 and September 2021 that studied objective neuropsychological tests as predictors of vocational rehabilitation interventions and included participants with depression.

RESULTS

The systematic literature search yielded no studies that specifically targeted subjects with major depression. However, eight articles published since 2016 were included in the review, analyzing data from five trials that evaluated the effectiveness of supported employment in North America and Europe in severe mental illnesses. An estimated 31% of the total number of participants included (n = 3,533) had major depression. Using a variety of cognitive tests and covariates, seven articles found that neuropsychological functioning - especially global cognition scores, verbal and visual learning and memory - significantly predicted vocational outcomes of rehabilitation programs.

CONCLUSION

Despite a lack of studies specifically targeting major depressive disorder, the identified literature suggests that higher baseline neuropsychological functioning predicts better vocational outcomes of supported employment programs in individuals with depression. In clinical practice, additional neuropsychological modules during return-to-work interventions might be helpful for vocational outcomes of such programs.

The relationship between theory of mind and executive functions in major depressive disorders: A review

Patients suffering from major depressive disorder (MDD) experience difficulties in multiple cognitive and affective abilities. A large body of literature has argued that MDD patients show impaired executive functions (EFs) and deficits in theory of mind (ToM), the ability to infer the mental states of others. However, the relationship between ToM and EFs has been poorly investigated. The aim of this review is to provide an overview of studies that evaluated the association between ToM and EFs in patients with MDD diagnosis. A literature review was conducted to identify all published studies in which ToM and EFs measures were administered to individuals with MDD and in which the relationship between these two domains was investigated. Eleven studies were included, and for each study, we discussed the findings related to ToM, EFs, and the nature of the link between these two aspects. Most of the studies reported that patients with MDD, compared with healthy controls, showed significant impairments in both ToM and EFs abilities. Moreover, this review indicates the presence of a significant association between these two domains in MDD patients, supporting the evidences that executive functioning is important to perform ToM tasks. Although the results that emerged are interesting, the relationship between ToM and EFs in MDD needs further investigation.

Decision Making under Risk in Patients Suffering from Schizophrenia or Depression

Studies have reported difficulties in decision making for patients with schizophrenia or depression. Here, we investigated whether there are differences between schizophrenia patients, depressed patients, and healthy individuals (HC) when decisions are to be made under risk and cognitive flexibility is required. We were also interested in the relationships between decision making, cognitive functioning, and disease severity. Thirty HC, 28 schizophrenia patients, and 28 depressed patients underwent structured clinical assessments and were assessed by the Positive and Negative Syndrome Scale or Hamilton Rating Scale. They performed the Probability-Associated Gambling (PAG) Task and a neuropsychological test battery. Both patient groups obtained lower scores than HC in memory and executive function measures. In the PAG task, relative to HC, depressed patients made slower decisions but showed a comparable number of advantageous decisions or strategy flexibility. Schizophrenia patients were slower, riskier, and less flexible compared to HC. For them, the decision making behavior correlated with the symptom severity. In both groups, decision making scores correlated with memory and executive function scores. Patients with schizophrenia or depression may have difficulties under risk when quick and flexible decisions are required. These difficulties may be more pronounced in patients who have marked cognitive deficits or severe clinical symptoms.

Amyloid Plaques and Symptoms of Depression Links to Medical Help-Seeking due to Subjective Cognitive Decline

Background:

Subjective cognitive decline (SCD) is associated with an increased risk of Alzheimer’s disease (AD). However, patients reporting SCD to their general practitioner are not always referred to a memory clinic.

Objective:

To investigate whether prior history of medical help-seeking is associated with AD biomarker abnormality, worse cognitive performance, and/or depressive symptoms in SCD.

Methods:

We compared levels of cerebrospinal fluid (CSF) Aβ_1 - 42, cognitive performance, and depressive symptoms (15-item Geriatric Depression Scale, GDS-15) between healthy controls (n = 88), SCD with a history of medical help seeking (SCD-HS, n = 67), and SCD non help-seekers (SCD-NHS, n = 44). Cases with evidence of amyloid plaques (CSF Aβ_1 - 42 ≤708 ng/l) and symptoms of depression (GDS-15≥6) were determined in both SCD groups.

Results:

The SCD-HS group had lower CSF Aβ_1 - 42 (p < 0.01), lower word list learning and memory recall (p < 0.0001), and an increased level of depressive symptoms (p < 0.0001) compared to controls and SCD-NHS cases. The SCD-HS group had more cases with symptoms of depression (n = 12, 18%) and amyloid plaques (n = 18, 27%) compared to SCD-NHS (n = 1, 2% and n = 7, 16%, respectively). None of the SCD-HS cases and only one SCD-NHS case had concurrent symptoms of depression and amyloid plaques. The SCD-HS cases showed equal word list learning and memory performance regardless of amyloid status or symptoms of depression.

Conclusion:

Medical help-seeking in SCD is associated with an increased risk of AD pathology or symptoms of depression. However, subtle memory deficits are seen in SCD help-seekers, also without amyloid plaques or symptoms of depression.

Cognitive profiles in persons with depressive disorder and Alzheimer's disease

Alzheimer’s disease and depressive disorder are frequent in old age. Both may be associated with depressed mood and cognitive impairment. Therefore, finding a strategy to clarify the diagnosis underlying subjective complaints of impaired cognition and depressed mood in older persons is of utmost interest. We conducted a cross-sectional retrospective observational clinical cohort study using patient records from 2014 to 2018. From 3758 patients, we included patients aged 60 years and older with a Mini-Mental-Status Examination score of 24 and above. Final analysis included all patients in whom Alzheimer’s disease biomarker analysis was performed (cerebrospinal fluid markers of Alzheimer’s disease or positron emission tomography imaging; n = 179) and patients with depressive disorder in whom Alzheimer’s disease was ruled out by analysis of biomarkers suggestive of Alzheimer’s disease (n = 70). With case–control matching for age, education and gender, performance of patients with Alzheimer’s disease was worse in acquisition, consolidation and recall of verbal information and false-positive answers. None of the results, however, sufficed to differentially diagnose individual patients with Alzheimer’s disease or depressive disorder. With more severe symptoms of depression, patients with biomarker-verified Alzheimer’s disease performed worse in executive testing but were not additionally impaired in verbal episodic memory performance. We conclude that distinguishing between Alzheimer’s disease and depressive disorder is unreliable on clinical grounds and behavioural testing alone. Diagnosing the cause of subjective complaints about deteriorating cognitive function or depressed mood requires additional biomarker assessment, whereas cognitive assessment is needed to define appropriate targets of symptomatic treatment in patients with Alzheimer’s disease and depressive disorder.

A Longitudinal 5-Year Follow-Up Study of Cognitive Function After First Episode Major Depressive Disorder: Exploring State, Scar and Trait Effects

Major depression (MDD) is associated with cognitive deficits in processing speed and executive function (EF) following first episode (FE). It is unclear whether deficits are state or trait related. Studies following FE MDD over longer periods are lacking, making it uncertain how cognition and symptoms develop after the initial episode. The present study assessed cognitive function and symptoms 5 years following FE MDD. In addition, the study explored relationships between MDD symptoms, rumination, and cognitive deficits with regards to the trait, state, and scar perspective. Twenty-three participants with previous FE MDD, and 20 matched control participants were compared on Delis-Kaplan Executive Function System measures of processing speed and EF, in a 5-year longitudinal follow-up study. Correlations between current symptoms- and history of MDD, rumination, cognition were investigated. Findings indicated that cognitive deficits persisted with no clear signs of exacerbation after initial episode. Inhibition appeared independent of current and previous symptoms of depression. Processing speed was related to depressive- symptoms and rumination. In conclusion, results indicated persisting, stable deficits in both EFs and processing speed. Findings further suggest that depressive symptoms could be related to deficits in processing speed, indicating state effects. There was limited support for worsening of cognition after initial episode. Some aspects of EF like Inhibition could show persistent deficits independent of depressive symptoms indicating trait effects.

Dysregulation of inflammation, neurobiology, and cognitive function in PTSD: an integrative review

Compelling evidence from animal and human research suggest a strong link between inflammation and posttraumatic stress disorder (PTSD). Furthermore, recent findings support compromised neurocognitive function as a key feature of PTSD, particularly with deficits in attention and processing speed, executive function, and memory. These cognitive domains are supported by brain structures and neural pathways that are disrupted in PTSD and which are implicated in fear learning and extinction processes. The disruption of these supporting structures potentially results from their interaction with inflammation. Thus, the converging evidence supports a model of inflammatory dysregulation and cognitive dysfunction as combined mechanisms underpinning PTSD symptomatology. In this review, we summarize evidence of dysregulated inflammation in PTSD and further explore how the neurobiological underpinnings of PTSD, in the context of fear learning and extinction acquisition and recall, may interact with inflammation. We then present evidence for cognitive dysfunction in PTSD, highlighting findings from human work. Potential therapeutic approaches utilizing novel pharmacological and behavioral interventions that target inflammation and cognition also are discussed.

Memory deficits in patients with major depression: yes, they are trying hard enough!

Background: Cognitive impairment is a common symptom of patients with Major Depression (MDD) with negative clinical and social effects. With this study we investigated the question of whether MDD patients' effort to memorize items is reduced and whether this reduction is related to patients' memory impairment.Research design and methods: Twenty-two patients with MDD and 28 healthy control participants took part in the study. Both groups did not differ with respect to age, gender, and basic education. MDD was confirmed by the Mini Diagnostic Interview for Mental Disorders (Mini-DIPS). Willingness to make an effort was assessed by the Amsterdam Short-Term Memory Test (ASTM). Logical Memory (LM) from the Wechsler Memory Scale (WMS IV) was used to assess verbal memory.Results: With respect to the willingness to make an effort, all MDD-patients performed above the cutoff and did not perform worse than healthy control participants. Depression appears to have a negative impact on recall and recognition of verbal information, but the effect on recall was larger.Conclusions: These findings support studies indicating no motivational deficits in patients with depression during standardized neuropsychological testing. Reduced motivation is not a plausible explanation for depressive patients' cognitive deficits assessed with neuropsychological tests.

Higher BDNF plasma levels are associated with a normalization of memory dysfunctions during an antidepressant treatment

One important symptom of patients with major depressive disorder (MDD) is memory dysfunction. However, little is known about the relationship between memory performance and depression severity, about the course of memory performance during antidepressant treatment as well as about the relationship between memory performance and brain-derived neurotrophic factor (BDNF). Memory function [learning and delayed recall) was assessed in 173 MDD patients (mean age 39.7 ± 11.3 years] treated by a pre-defined treatment algorithm within the early medication change (EMC) study at baseline, days 28 and 56. Depression severity was assessed in weekly intervals, BDNF plasma levels were measured at baseline, days 14 and 56, BDNF exon IV and p11 methylation status at baseline. Linear mixed regression models revealed that the course of depression severity was not associated with the course of learning or delayed recall in the total group. 63 (36%) of the investigated patients showed memory deficits (percent range ≤ 16) at baseline. Of those, 26(41%) patients experienced a normalization of their memory deficits during treatment. Patients with a normalization of their delayed recall performance had significantly higher plasma BDNF levels (p = 0.040) from baseline to day 56 than patients with persistent deficits. Baseline BDNF exon IV promoter and p11 gene methylation status were not associated with memory performance. Our results corroborate a concomitant amelioration of learning and delayed recall dysfunctions with successful antidepressant therapy in a subgroup of patients and support a role of BDNF in the neural mechanisms underlying the normalization of memory dysfunctions in MDD. ClinicalTrials.gov number: NCT00974155; EudraCT: 2008-008280-96.

Decoding rumination: A machine learning approach to a transdiagnostic sample of outpatients with anxiety, mood and psychotic disorders

OBJECTIVE

To employ machine learning algorithms to examine patterns of rumination from RDoC perspective and to determine which variables predict high levels of maladaptive rumination across a transdiagnostic sample.

METHOD

Sample of 200 consecutive, consenting outpatient referrals with clinical diagnoses of schizophrenia, schizoaffective, bipolar, depression, anxiety disorders, obsessive compulsive and post-traumatic stress. Machine learning algorithms used a range of variables including sociodemographics, serum levels of immune markers (IL-6, IL-1β, IL-10, TNF-α and CCL11) and BDNF, psychiatric symptoms and disorders, history of suicide and hospitalizations, functionality, medication use and comorbidities.

RESULTS

The best model (with recursive feature elimination) included the following variables: socioeconomic status, illness severity, worry, generalized anxiety and depressive symptoms, and current diagnosis of panic disorder. Linear support vector machine learning differentiated individuals with high levels of rumination from those ones with low (AUC = 0.83, sensitivity = 75, specificity = 71).

CONCLUSIONS

Rumination is known to be associated with poor prognosis in mental health. This study suggests that rumination is a maladaptive coping style associated not only with worry, distress and illness severity, but also with socioeconomic status. Also, rumination demonstrated a specific association with panic disorder.

The Newly Normed SKT Reveals Differences in Neuropsychological Profiles of Patients with MCI, Mild Dementia and Depression

The SKT (Syndrom-Kurztest) is a short cognitive performance test assessing deficits of memory and attention in the sense of speed of information processing. The new standardization of the SKT (2015) aimed at improving its sensitivity for early cognitive decline due to dementia in subjects aged 60 or older. The goal of this article is to demonstrate how the neuropsychological test profile of the SKT can be used to provide valuable information for a differential diagnosis between MCI (mild cognitive impairment), dementia and depression. n = 549 patients attending a memory clinic (Nuremberg, Germany) were diagnosed according to ICD-10 and tested with the SKT. The SKT consists of nine subtests, three for the assessment of memory and six for measuring attention in the sense of speed of information processing. The result of the SKT test procedure is a total score, which indicates the severity of overall cognitive impairment. Besides the summary score, two subscores for memory and attention can be interpreted. Using the level of depression as a covariate, statistical comparisons of SKT test profiles between the three patient groups revealed that depressed patients showed more pronounced deficits than MCI patients in all six attention subtests. On the other hand, MCI patients displayed significantly greater mnestic impairment than the depressed group, which was indicated by significant differences in the memory subscore. MCI and dementia patients showed similar deficit patterns dominated by impairment of memory (delayed recall) with MCI patients demonstrating less overall impairment. In sum, the SKT neuropsychological test profiles provided indicators for a differential diagnosis between MCI and beginning dementia vs. depression.

Plasma brain-derived neurotrophic factor (pBDNF) and executive dysfunctions in patients with major depressive disorder

Objectives: Executive dysfunctions are frequently seen in patients with major depressive disorder (MDD) and normalise in many cases during effective antidepressant therapy. This study investigated whether a normalisation of executive dysfunctions during antidepressant treatment correlates with or can be predicted by clinical parameters or levels of brain-derived neurotrophic factor (BDNF).Methods: In 110 MDD patients with executive dysfunctions (percentile <16), executive functions and plasma BDNF levels were analysed at baseline, and days 14 and 56 of an antidepressant treatment. BDNF exon IV and P11 methylation status was studied at baseline.Results: Eighty patients (73%) experienced a normalisation of executive dysfunctions, while 30 (27%) suffered from persistent dysfunctions until day 56. Patients with persistent dysfunctions had significantly higher HAMD scores at days 14 and 56, and lower plasma BDNF levels at each time point than patients with a normalisation of dysfunctions (F₁= 10.18; P = 0.002). This was seen for verbal fluency, but not processing speed. BDNF exon IV and p11 promoter methylation was not associated with test performance.Conclusions: Our results corroborate a concomitant amelioration of executive dysfunctions with successful antidepressant therapy and support a role of BDNF in the neural mechanisms underlying the normalisation of executive dysfunctions in MDD.ClinicalTrials.gov number: NCT00974155; EudraCT: 2008-008280-96.

[Depressed, biased, forgetful: The interaction of emotional and cognitive dysfunctions in depression]

Major depressive disorder is characterized by changes in the emotional state, e. g. the diminished experience of positive emotions, as well as cognitive impairments such as concentration and memory difficulties. These emotional and cognitive dysfunctions are closely interrelated and play a key role for the development and maintenance of depressive symptoms. For instance, patients with depression show negatively biased information processing that affects attention and memory as well as their reaction to feedback. In addition, there is an increased motivation to avoid negatively evaluated conditions and at the same time a reduced motivation to approach positive goals. Furthermore, depressed patients often show a specific style of thinking, called rumination, which involves repeated, intensive thinking about the causes, consequences and symptoms of one's own negative feelings. In this review, the different relationships between emotional, motivational and cognitive symptoms of depressive patients will be presented and the influence of their interaction on cognitive performance will be discussed. The highlighted clinical relevance of emotional-cognitive dysfunctions should be considered more often in therapeutic interventions for depressed patients.

Exploration of Major Cognitive Deficits in Medication-Free Patients With Major Depressive Disorder

Background: Major depressive disorder (MDD) is associated with a wide range of cognitive deficits. However, it remains unclear whether there will be a major cognitive deficit independently caused by depression at acute episodes of MDD. Method: A comprehensive neurocognitive test battery was used to assess the executive function, processing speed, attention, and memory in 162 MDD patients and 142 healthy controls (HCs). A multivariate analysis of variance, hierarchical regression analyses and general linear regression analyses were used to explore the possible major cognitive deficits and their predictor variables. Results: MDD patients showed extensive impairment in all four cognitive domains. Impairment of executive function and processing speed were found to persist even with other cognitive domains and clinical variables being accounted for. Executive function and processing speed were further predicted by total disease duration and depression severity, respectively. Conclusions: Executive function and processing speed may be two distinct major deficits at acute episodes of MDD. Furthermore, the executive function is likely originated from the cumulative effect of disease duration and processing speed is possibly derived from the temporary effect of current depressive episode.

The clinical relationship between cognitive impairment and psychosocial functioning in major depressive disorder: A systematic review

Cognitive deficits are frequently observed in major depressive disorder (MDD), as well as impaired long-term psychosocial functioning. However, the relationship between cognitive deficits and psychosocial functioning in MDD is under-investigated. We aim to systematically review the literature on the relationship between specific cognitive impairments and psychosocial functioning in MDD. We systematically reviewed English-language literature in PubMed, PsychINFO, Scopus and Web of Science using search terms related to psychosocial functioning. Additional studies were identified by searching reference lists. Following our inclusion/exclusion criteria, 28 studies were reviewed. Inclusion criteria included age (> 18), MDD diagnosed by standard tools (e.g., DSM-IV), use of cognitive and psychosocial assessments. Cross-sectional studies indicated that cognitive deficits in domains of executive functioning, attention, memory, and global cognition are associated with psychosocial dysfunction in domains of as quality of life, and social, occupational, and global functioning. The cognition-functioning relationship was also observed in longitudinal studies, showing that only specific cognitive domains affected psychosocial outcomes over the long-term course of illness. Older age and greater MDD symptom severity appear to enhance cognition-psychosocial dysfunction relationship, however little is known regarding the role of a number of other clinical factors (e.g., psychosis, illness duration).

Associations between Depressive Symptomatology and Neurocognitive Impairment in HIV/AIDS

OBJECTIVE

Mood disorders and neurocognitive impairments are debilitating conditions among patients with HIV/AIDS. How these comorbidities interact and their relationships to systemic factors remain uncertain. Herein, we investigated factors contributing to depressive symptomatology (DS) in a prospective cohort of patients with HIV/AIDS in active care that included neuropsychological assessment.

METHODS

Among patients with HIV/AIDS receiving combination antiretroviral therapy (cART) and ongoing clinical assessments including measures of sleep, health-related quality of life (HQoL), neuropsychological testing, and mood evaluation (Patient Health Questionnaire-9 [PHQ-9]) were performed. Univariate and multivariate analyses were applied to the data.

RESULTS

In 265 persons, 3 categories of DS were established: minimal (PHQ-9: 0-4; n = 146), mild (PHQ-9: 5-9; n = 62), and moderate to severe (PHQ-9: 10+; n = 57). Low education, unemployment, diabetes, reduced adherence to treatment, HIV-associated neurocognitive disorders (HAND), low health-related quality of life (HQoL), reduced sleep times, and domestic violence were associated with higher PHQ-9 scores. Motor impairment was also associated with more severe DS. In a multinomial logistic regression model, only poor HQoL and shorter sleep duration were predictive of moderate to severe depression. In this multivariate model, the diagnosis of HAND and neuropsychological performance (NPz) were not predictive of DS.

CONCLUSIONS

Symptoms of depression are common (45%) in patients with HIV/AIDS and represent a substantial comorbidity associated with multiple risk factors. Our results suggest that past or present immunosuppression and HAND are not linked to DS. In contrast, sleep quality and HQoL are important variables to consider in screening for mood disturbances among patients with HIV/AIDS and distinguishing them from neurocognitive impairments.

Early improvement of executive test performance during antidepressant treatment predicts treatment outcome in patients with Major Depressive Disorder

Executive dysfunctions frequently occur in patients with Major Depressive Disorder and have been shown to improve during effective antidepressant treatment. However, the time course of improvement and its relationship to treatment outcome is unknown. The aim of the study was to assess the test performance and clinical outcome by repetitive assessments of executive test procedures during antidepressant treatment. Executive test performance was assessed in 209 –patients with Major Depressive Disorder (mean age 39.3 ± 11.4 years) and 84 healthy controls five times in biweekly intervals from baseline to week 8. Patients were treated by a defined treatment algorithm within the early medication change study (EMC trial; ClinicalTrials.gov NCT00974155), controls did not receive any intervention. Cognitive domains were processing speed, cognitive flexibility, phonemic and semantic verbal fluency. Intelligence was assessed at baseline. Depression severity was tested once a week by the Hamilton Depression Rating Scale (HAMD₁₇). 130 patients (62%) showed executive dysfunctions in at least one of four tests at baseline. Linear mixed regression models revealed that the course of depression severity was associated to the course of cognitive flexibility (p = 0.004) and semantic verbal fluency (p = 0.020). Cognitive flexibility and semantic verbal fluency may be candidates easily to apply for therapy response prediction in clinical routine, which should be tested in further prospective studies.

Trial registration: ClinicalTrials.gov NCT00974155

EudraCT: 2008-008280-96

When Cognitive Decline and Depression Coexist in the Elderly: CSF Biomarkers Analysis Can Differentiate Alzheimer's Disease from Late-Life Depression

Late-life depression (LLD) and Alzheimer's Disease (AD) are the two most frequent neuropsychiatric disorders affecting elderly. LLD and AD may clinically present with depressive and cognitive symptoms. Therefore, when cognitive decline is coupled with depression in the elderly, the differential diagnosis between LLD and AD could be challenging. The aim of the present study was to evaluate in a population of elderly patients affected by depression and dementia the usefulness of CSF AD biomarkers (tau proteins and β-amyloid₄₂–Aβ₄₂) and 2-[18F]fluoro-2-deoxy-d-glucose positron emission tomography (18FFDG-PET) in early differentiating LLD from AD. Two hundred and fifty-six depressed and demented patients, after performing CSF AD biomarkers and 18FFDG-PET, were distributed in two groups on the basis of the current diagnostic guidelines for AD (n = 201) and LLD (n = 55). Patients were then observed for 2 years to verify the early diagnosis. After the 2 year follow-up we compared AD and LLD patients' CSF and 18FFDG-PET data obtained at baseline to a group of age- and sex-matched controls. We found CSF Aβ₄₂ levels significantly higher in LLD compared to AD patients. Remarkably, CSF Aβ₄₂ levels of LLD patients (range between 550 and 1204 pg/mL) did not overlap with those of AD patients (range between 82 and 528 pg/mL). Moreover, we documented no differences in CSF AD biomarkers (Aβ₄₂ and tau proteins) when comparing LLD patients to controls. In addition, AD patients showed the significant reduction of 18FFDG-PET uptake in temporo-parietal regions compared to both controls and LLD. Conversely, LLD and control groups did not differ at 18FFDG-PET analysis, although LLD patients showed heterogeneous patterns of glucose hypometabolism involving cortical and subcortical brain areas. It is noteworthy that at the end of the clinical follow-up, patients owing to AD group showed the expected significant decline of cognitive performances, whereas patients assigned to LLD group improved cognition as depressive symptoms recovered. Hence, in case of co-existence of cognitive impairment and depression in the elderly, we propose CSF AD biomarkers analysis to early differentiate LLD from AD and properly target the patient's therapeutic strategy and clinical follow-up.

Cognition in depression: Can we THINC-it better?

BACKGROUND

Cognitive compromise is a common experience for patients with depression and other mood disorders. Depressed patients sustain deficits in working memory and attentional distortions in emotional processing and negative attention biases, which may contribute to maintaining their depressive state.

METHODS

The Mood Assessment and Classification (MAC) Committee comprised academic psychiatrists with clinical expertise in the management of mood disorders. The independently convened committee met to discuss contentious aspects of mood disorders diagnosis and assessment with the express aim of informing clinical practice and future research.

RESULTS

The Committee specifically identified cognition as an important aspect for clinicians to consider in the context of depression and mood disorders. This article highlights some of the barriers to assessment and proposes tools that have the potential to be implemented in clinical practice.

LIMITATIONS

The conclusions drawn within this article are based on expert opinion. We have noted the limitations of the literature that informs this opinion.

CONCLUSIONS

As cognitive ability has been closely linked to patients' ability to achieve functional recovery, it is imperative that clinicians are able to identify patients with cognitive deficits and are equipped with tools to conduct effective cognitive assessments. Examining cognitive factors may generate a deeper understanding of the pathogenesis of depression and mood disorders which can ultimately be used to inform treatment.

A Network Meta-Analysis Comparing Effects of Various Antidepressant Classes on the Digit Symbol Substitution Test (DSST) as a Measure of Cognitive Dysfunction in Patients with Major Depressive Disorder

BACKGROUND

Major depressive disorder is a common condition that often includes cognitive dysfunction. A systematic literature review of studies and a network meta-analysis were carried out to assess the relative effect of antidepressants on cognitive dysfunction in major depressive disorder.

METHODS

MEDLINE, Embase, Cochrane, CDSR, and PsychINFO databases; clinical trial registries; and relevant conference abstracts were searched for randomized controlled trials assessing the effects of antidepressants/placebo on cognition. A network meta-analysis comparing antidepressants was conducted using a random effects model.

RESULTS

The database search retrieved 11337 citations, of which 72 randomized controlled trials from 103 publications met the inclusion criteria. The review identified 86 cognitive tests assessing the effect of antidepressants on cognitive functioning. However, the Digit Symbol Substitution Test, which targets multiple domains of cognition and is recognized as being sensitive to change, was the only test that was used across 12 of the included randomized controlled trials and that allowed the construction of a stable network suitable for the network meta-analysis. The interventions assessed included selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and other non-selective serotonin reuptake inhibitors/serotonin-norepinephrine reuptake inhibitors. The network meta-analysis using the Digit Symbol Substitution Test showed that vortioxetine was the only antidepressant that improved cognitive dysfunction on the Digit Symbol Substitution Test vs placebo {standardized mean difference: 0.325 (95% CI = 0.120; 0.529, P=.009}. Compared with other antidepressants, vortioxetine was statistically more efficacious on the Digit Symbol Substitution Test vs escitalopram, nortriptyline, and the selective serotonin reuptake inhibitor and tricyclic antidepressant classes.

CONCLUSIONS

This study highlighted the large variability in measures used to assess cognitive functioning. The findings on the Digit Symbol Substitution Test indicate differential effects of various antidepressants on improving cognitive function in patients with major depressive disorder.

Neurobiological mechanisms of exercise and psychotherapy in depression: The SPeED study-Rationale, design, and methodological issues

BACKGROUND/AIMS

Even though cognitive behavioral therapy has become a relatively effective treatment for major depressive disorder and cognitive behavioral therapy-related changes of dysfunctional neural activations were shown in recent studies, remission rates still remain at an insufficient level. Therefore, the implementation of effective augmentation strategies is needed. In recent meta-analyses, exercise therapy (especially endurance exercise) was reported to be an effective intervention in major depressive disorder. Despite these findings, underlying mechanisms of the antidepressant effect of exercise especially in combination with cognitive behavioral therapy have rarely been studied to date and an investigation of its neural underpinnings is lacking. A better understanding of the psychological and neural mechanisms of exercise and cognitive behavioral therapy would be important for developing optimal treatment strategies in depression. The SPeED study (Sport/Exercise Therapy and Psychotherapy-evaluating treatment Effects in Depressive patients) is a randomized controlled trial to investigate underlying physiological, neurobiological, and psychological mechanisms of the augmentation of cognitive behavioral therapy with endurance exercise. It is investigated if a preceding endurance exercise program will enhance the effect of a subsequent cognitive behavioral therapy.

METHODS

This study will include 105 patients diagnosed with a mild or moderate depressive episode according to the Diagnostic and Statistical Manual of Mental Disorders (4th ed.). The participants are randomized into one of three groups: a high-intensive or a low-intensive endurance exercise group or a waiting list control group. After the exercise program/waiting period, all patients receive an outpatient cognitive behavioral therapy treatment according to a standardized therapy manual. At four measurement points, major depressive disorder symptoms (Beck Depression Inventory, Hamilton Rating Scale for Depression), (neuro)biological measures (neural activations during working memory, monetary incentive delay task, and emotion regulation, as well as cortisol levels and brain-derived neurotrophic factor), neuropsychological test performance, and questionnaires (psychological needs, self-efficacy, and quality of life) are assessed.

RESULTS

In this article, we report the design of the SPeED study and refer to important methodological issues such as including both high- and low-intensity endurance exercise groups to allow the investigation of dose-response effects and physiological components of the therapy effects.

CONCLUSION

The main aims of this research project are to study effects of endurance exercise and cognitive behavioral therapy on depressive symptoms and to investigate underlying physiological and neurobiological mechanisms of these effects. Results may provide important implications for the development of effective treatment strategies in major depressive disorder, specifically concerning the augmentation of cognitive behavioral therapy by endurance exercise.

The relationship between neuropsychological performance and depression in patients with traumatic brain injury

Traumatic brain injury is a multi-faceted condition that affects individuals on physical, cognitive, and emotional levels. The study investigated the relationship between depression and neuropsychological performance in a group with traumatic brain injury. A retrospective review was conducted on 75 participants who completed neuropsychological assessments. Information on clinical characteristics, sociodemographic information, neuropsychological outcomes, and Beck Depression Inventory scores were included in the analysis. Results indicated that 36% of the participants reported experiencing severe symptoms of depression, 28% moderate symptoms of depression, and 36% mild/minimal symptoms of depression. Performance on the Rey Auditory Verbal Learning Test indicated inverse relationships with depression scores suggesting that traumatic brain injury patients with lower depression scores perform better on verbal memory tasks. Similarly, findings for the written and oral versions of the Symbol Digit Modalities Test reflected inverse correlations with depression scores, indicating that lower depression scores are correlated with increased processing speed and capacity. A significant positive association between the time taken to complete the Trail Making Test Trail A and Trail B and depression scores was found, suggesting that higher depression scores in this sample were related to slower performance speed and lower executive performance. When specific clinical and sociodemographic variables were included as covariates in a partial correlational analysis, neuropsychological performance indicators and depression scores remained significant for Symbol Digit Modalities Test (oral and written), the Rey Auditory Verbal Learning Test Retrieval and Recognition trials, and Trail Making Test (Trail B). This study indicates that in a traumatic brain injury cohort, depression levels are significantly associated with specific neuropsychological performance measures. The findings of this study have implications for psychosocial treatment planning after a traumatic brain injury and contribute to our understandings of the inter-relationship between cognition and emotion.

Neuropsychological changes in melancholic and atypical depression: A systematic review

There is not a consensus as to whether neuropsychological profiling can distinguish depressive subtypes. We aimed to systematically review and critically analyse the literature on cognitive function in patients with melancholic and atypical depression. We searched in databases PubMed, SCOPUS, Web of Knowledge and PsycInfo for papers comparing the neuropsychological performance of melancholic patients (MEL) to non-melancholic depressive patients (NMEL), including atypical depressives, and healthy controls (HC). All studies were scrutinised to determine the main methodological characteristics and particularly possible sources of bias influencing the results reported, using the STROBE statement checklist. We also provide effect size of the results reported for contrasts between MEL; patients and NMEL patients. Seventeen studies were included; most of them demonstrated higher neuropsychological impairments of MEL patients compared to both NMEL patients and HC on tasks requiring memory, executive function, attention and reaction time. Detailed analysis of the methodologies used in the studies revealed significant variability especially regarding the participants' sociodemographic characteristics, clinical characteristics of patients and differences in neuropsychological assessment. These findings suggest that MEL may have a distinct and impaired cognitive performance compared to NMEL depressive patients on tasks involving verbal and visual memory, executive function, sustained attention and span, as well as psychomotor speed, this last especially when cognitive load is increased. Additional studies with adequate control of potentially confounding variables will help to clarify further differences in the neuropsychological functioning of depressive subtypes.

Memory performance of patients with major depression in an everyday life situation

Although patients with major depressive disorder (MDD) report severe memory impairment in their everyday life, memory tests indicate only moderate deficits. In order to clarify these conflicting observations, the present study aimed at the investigation of MDD patients' memory performance in a real everyday life situation. The study included 20 MDD patients and 20 healthy control subjects. Nonverbal memory was assessed by means of the Rey Complex Figure Test whereas verbal memory was assessed by the recall of a 20-item wordlist with supermarket products. For the assessment of everyday life memory, subjects had to purchase as many products as possible of the 20-item wordlist in a real supermarket. Furthermore, subjects were asked for memory complaints. MDD patients' performance in the supermarket resembled memory test results and was not significantly impaired. MDD patients' self-reports, however, indicated severe memory problems that clearly fell below their performance in the supermarket. This study helped to identify everyday life-related factors that do not impair MDD patients' cognitive performance beyond their performance in standard laboratory testing situations. These factors may not be relevant for remediation programs that are specifically developed for depressed patients.

How can Continuous Performance Test help to assess inattention when mood and ADHD symptoms coexist?

Depression and attention-deficit/hyperactivity disorder (ADHD) are prevalent, and often comorbid, disorders, with varying severity levels among patients. Inattention is a symptom present in both disorders, which often makes their differential diagnosis difficult in clinical practice (depression only versus comorbidity). This study aimed to investigate the influence of depressive symptoms on attention performance using one of the most common tasks in clinical practice, the continuous performance test (CPT). Ninety-three college students (60 men, 33 women) with a mean age of 24 years old were investigated with self-reports and semi-structured interviews for ADHD; the Beck Depression Inventory (BDI) was used for depression ratings. Attention measures were derived from the CPT. There was no correlation between depression and ADHD symptoms; in addition, depression was not correlated with any of the CPT scores; ADHD symptomatology was the only predictor of changes in those CPT variables (commission and omission errors and d prime). ADHD-associated impairment on the CPT was not augmented by the presence of depressive symptoms, making neuropsychological results on this test helpful for the differential diagnosis. When attention deficits are observed in individuals with mild or moderate depression, they are most likely not attributed to depression.

Clinical, Functional, and Biological Correlates of Cognitive Dimensions in Major Depressive Disorder - Rationale, Design, and Characteristics of the Cognitive Function and Mood Study (CoFaM-Study)

Cross-sectional and longitudinal studies exploring clinical, functional, and biological correlates of major depressive disorder are frequent. In this type of research, depression is most commonly defined as a categorical diagnosis based on studies using diagnostic instruments. Given the phenotypic and biological heterogeneity of depression, we chose to focus the phenotypic assessments on three cognitive dimensions of depression including (a) cognitive performance, (b) emotion processing, and (c) social cognitive functioning. Hence, the overall aim of the study is to investigate the long-term clinical course of these cognitive dimensions in depression and its functional (psychosocial) correlates. We also aim to identify biological "genomic" correlates of these three cognitive dimensions of depression. To address the above overall aim, we created the Cognition and Mood Study (CoFaMS) with the key objective to investigate the clinical, functional, and biological correlates of cognitive dimensions of depression by employing a prospective study design and including a healthy control group. The study commenced in April 2015, including patients with a primary diagnosis of a major depressive episode of major depressive disorder or bipolar disorder according to DSM-IV-TR criteria. The assessments cover the three cognitive dimensions of depression (cognitive performance, emotion processing, and social cognition), cognitive function screening instrument, plus functional scales to assess general, work place, and psychosocial function, depression symptom scales, and clinical course of illness. Blood is collected for comprehensive genomic discovery analyses of biological correlates of cognitive dimensions of depression. The CoFaM-Study represents an innovative approach focusing on cognitive dimensions of depression and its functional and biological "genomic" correlates. The CoFaMS team welcomes collaborations with both national and international researchers.

Visuospatial planning in unmedicated major depressive disorder and bipolar disorder: distinct and common neural correlates

BACKGROUND

Cognitive impairments are an important feature of both remitted and depressed major depressive disorder (MDD) and bipolar disorder (BD). In particular, deficits in executive functioning may hamper everyday functioning. Identifying the neural substrates of impaired executive functioning would improve our understanding of the pathophysiology underlying these disorders, and may eventually aid in discriminating between MDD and BD, which is often difficult during depression and remission. To date, mostly medicated MDD and BD subjects have been investigated, which may have influenced results. Therefore, we investigated executive functioning in medication-free depressed and remitted MDD and BD subjects.

METHOD

We used the Tower of London (ToL) visuospatial planning task to assess behavioural performance and blood oxygen-level dependent responses in 35 healthy controls, 21 remitted MDD, 23 remitted BD, 19 depressed MDD and nine depressed BD subjects.

RESULTS

Visuospatial planning per se was associated with increased frontostriatal activity in depressed BD compared to depressed MDD. In addition, post-hoc analyses indicated that visuospatial planning load was associated with increased parietal activity in depressed compared to remitted subjects, and BD compared to MDD subjects. Task performance did not significantly differ between groups.

CONCLUSIONS

More severely affected, medication-free mood disorder patients require greater parietal activity to perform in visuospatial planning, which may be compensatory to maintain relatively normal performance. State-dependent frontostriatal hyperactivity during planning may be a specific BD characteristic, providing clues for further characterization of differential pathophysiology in MDD v. BD. This could potentially provide a biomarker to aid in the differentiation of these disorders.

The interrelationship between attentional and executive deficits in major depressive disorder

OBJECTIVE

Cognitive dysfunction is an established feature of major depressive disorder (MDD). However, it remains unclear whether deficits in different cognitive domains are relatively independent or originate from a circumscribed 'primary deficit'. This study tested the hypothesis that a deficit in attention represents a primary deficit in depression.

METHOD

Neuropsychological function was assessed in 30 depressed patients with MDD and 34 control participants. Cognitive composites were derived from a minimum of three tests and included attention, executive function, visuospatial memory and verbal memory. A multivariate analysis of variance was used to assess group differences in overall cognitive performance, and multiple regression models were used to evaluate the role of attention in deficits in other domains.

RESULTS

The cognitive deficit in the depressed sample was found to be characterized by poorer performance in attention and executive function. When evaluating the interrelationship between the two deficits, the attentional deficit was found to persist when variability in executive function was statistically accounted for, whilst the executive deficit was eliminated when attention was accounted for.

CONCLUSION

The results demonstrated that the attentional deficit could not be explained by deficits in executive function, which provides support for a primary attention deficit in depression.

Assessing the Construct Validity and Internal Reliability of the Screening Tool Test Your Memory in Patients with Chronic Pain

Patients with chronic pain often complain about cognitive difficulties, and since these symptoms represent an additional source of suffering and distress, evaluating the cognitive status of these patients with valid and reliable tests should be an important part of their overall assessment. Although cognitive impairment is a critical characteristic of pain, there is no specific measure designed to detect these effects in this population. The objective was to analyze the psychometric properties of the “Test Your Memory” (TYM) test in patients with chronic pain of three different origins. A cross-sectional study was carried out on 72 subjects free of pain and 254 patients suffering from different types of chronic pain: neuropathic pain (104), musculoskeletal pain (99) and fibromyalgia (51). The construct validity of the TYM was assessed using the Mini-Mental State Examination (MMSE), Hospital Anxiety and Depression Scale (HADs), Index-9 from MOS-sleep, SF-12, and through the intensity (Visual Analogical Scale) and duration of pain. An exploratory factor analysis was also performed and internal reliability was assessed using Cronbach’s alpha. After adjusting for potential confounders the TYM could distinguish between pain and pain-free patients, and it was correlated with the: MMSE (0.89, p<0.001); HAD-anxiety (-0.50, p<0.001) and HAD-depression scales (-0.52, p<0.001); MOS-sleep Index-9 (-0.49, p<0.001); and the physical (0.49, p < .001) and mental components (0.55, p < .001) of SF-12. The exploratory structure of the TYM showed an 8-factor solution that explained 53% of the variance, and Cronbach’s alpha was 0.66. The TYM is a valid and reliable screening instrument to assess cognitive function in chronic pain patients that will be of particular value in clinical situations.

Die Bedeutung kognitiver Beeinträchtigungen bei depressiven Patienten

Zusammenfassung. Beeinträchtigungen der Exekutivfunktionen, der Aufmerksamkeit und des Gedächtnisses sind einige der häufigsten und hartnäckigsten Symptome depressiver Störungen. Bisher konnte allerdings kein eindeutiges Profil dieser Defizite identifiziert werden, wahrscheinlich auch deshalb, weil die Defizite von verschiedenen klinischen und demografischen Faktoren, wie dem Depressionssubtypus, Grübeln, Komorbiditäten und Alter beeinflusst werden. Die kognitiven Beeinträchtigungen verbessern sich mit der Remission der Störung, häufig findet jedoch keine vollständige Rückbildung statt. Sie sind klinisch sehr relevant und gehen einher mit Suizidalität, reduzierten Therapieeffekten und negativen Auswirkungen auf Alltagsaktivitäten. Aus diesen Gründen ergibt sich für betroffene Patienten die Notwendigkeit einer neuropsychologischen Behandlung. Erste Ergebnisse lassen hoffen, dass die kognitiven Beeinträchtigungen mithilfe neuropsychologischer Therapie, Achtsamkeitstraining, psychopharmakologischer Therapie und weiteren neurobiologischen Behandlungen, wie z. B. der repetitiven transkraniellen Magnetstimulation, erfolgreich behandelt werden können.

Cognitive remission: a novel objective for the treatment of major depression?

BACKGROUND

Cognitive dysfunction in major depressive disorder (MDD) encompasses several domains, including but not limited to executive function, verbal memory, and attention. Furthermore, cognitive dysfunction is a frequent residual manifestation in depression and may persist during the remitted phase. Cognitive deficits may also impede functional recovery, including workforce performance, in patients with MDD. The overarching aims of this opinion article are to critically evaluate the effects of available antidepressants as well as novel therapeutic targets on neurocognitive dysfunction in MDD.

DISCUSSION

Conventional antidepressant drugs mitigate cognitive dysfunction in some people with MDD. However, a significant proportion of MDD patients continue to experience significant cognitive impairment. Two multicenter randomized controlled trials (RCTs) reported that vortioxetine, a multimodal antidepressant, has significant precognitive effects in MDD unrelated to mood improvement. Lisdexamfetamine dimesylate was shown to alleviate executive dysfunction in an RCT of adults after full or partial remission of MDD. Preliminary evidence also indicates that erythropoietin may alleviate cognitive dysfunction in MDD. Several other novel agents may be repurposed as cognitive enhancers for MDD treatment, including minocycline, insulin, antidiabetic agents, angiotensin-converting enzyme inhibitors, S-adenosyl methionine, acetyl-L-carnitine, alpha lipoic acid, omega-3 fatty acids, melatonin, modafinil, galantamine, scopolamine, N-acetylcysteine, curcumin, statins, and coenzyme Q10. The management of cognitive dysfunction remains an unmet need in the treatment of MDD. However, it is hoped that the development of novel therapeutic targets will contribute to 'cognitive remission', which may aid functional recovery in MDD.