Cognitive Functioning in Major Depression – A Summary

The aim of the present paper is to summarize the research during the past decade regarding cognitive functioning in Major Depressive Disorder (MDD). Cognitive impairment in the acute phase of illness has been frequently reported. The findings are shown in different cognitive domains, such as executive functions, attention, memory and psychomotor speed. Fewer reports have investigated cognitive functioning in MDD in longitudinal studies. Some longitudinal reports show that the impairment observed in the acute phase of illness may be long lasting despite symptom reduction and recovery. However, findings regarding cognitive functioning in depression are divergent. Factors that might contribute to the divergent findings, such as depression subtype, severity and comorbidity are discussed. Clinical implications and focus of future research directions is highlighted.In conclusion, depression is associated with cognitive impairment in the acute phase of illness, and some reports indicate that this impairment might be long lasting despite symptom reduction and recovery

Explaining adoption of end of pipe solutions and clean technologies

We estimate firms’ probability of technological adoption based on an unbalanced firm level panel data set from four major sectors during the 2000-2003 period. Technological adoption is measured by environ-mental protection investments (EPIs), and we focus particularly on differences between the decisions to adopt end of pipe solutions and clean technology. We find that the probability of a firm to undertake investments in clean technologies to reduce emissions to air increases if the firm has expenditures for R&D related to environmental protec-tion (green R&D). We also find that firm specific energy expenditures contribute in explaining investments in end of pipe solutions, while this factor is not significant for investments in clean technologies. Furthermore, the results show that the two types of technologies are complements with respect to the investment decision, which indicates that policies that stimulate investments in one type of technology tend to affect investment in the other positively as well. In conclusion, pol-icy makers might want to contemplate environmental policy measures that stimulate green R&D in order to stimulate technological adoption.

Improvement in self-reported cognitive functioning but not in rumination following online working memory training in a two-year follow-up study of remitted major depressive disorder

Self-reported subjective cognitive difficulties (subjective deficits) and rumination are central residual cognitive symptoms following major depressive disorder (MDD). These are risk factors for more a severe course of illness, and despite the considerable relapse risk of MDD, few interventions target the remitted phase, a high-risk period for developing new episodes. Online distribution of interventions could help close this gap. Computerized working memory training (CWMT) shows promising results, but findings are inconclusive regarding which symptoms improve following this intervention, and its long-term effects. This study reports results from a longitudinal open-label two-year follow-up pilot-study of self-reported cognitive residual symptoms following 25 sessions (40 min), five times a week of a digitally delivered CWMT intervention. Ten of 29 patients remitted from MDD completed two-year follow-up assessment. Significant large improvements in self-reported cognitive functioning on the behavior rating inventory of executive function-adult version appeared after two-years (d = 0.98), but no significant improvements were found in rumination (d < 0.308) measured by the ruminative responses scale. The former showed moderate non-significant associations to improvement in CWMT both post-intervention (r = 0.575) and at two-year follow-up (r = 0.308). Strengths in the study included a comprehensive intervention and long follow-up time. Limitations were small sample and no control group. No significant differences between completers and drop-outs were found, however, attrition effects cannot be ruled out and demand characteristics could influence findings. Results suggested lasting improvements in self-reported cognitive functioning following online CWMT. Controlled studies with larger samples should replicate these promising preliminary findings

Facing recovery: Emotional bias in working memory, rumination, relapse, and recurrence of major depression; an experimental paradigm conducted five years after first episode of major depression

Identifying vulnerability factors for relapse of depression is essential in planning preventive interventions. Emotional face processing in major depression (MDD) shows promise as a potential cognitive marker for depression. The current study investigates how working memory (WM) load in face processing relates to rumination and new episodes of MDD in a novel explorative paradigm. It was expected that history of MDD is associated with reduction of the ability to process sad stimuli in high WM load conditions and reduction of the ability to process happy stimuli in low WM conditions. It was further predicted that these relations are associated with rumination and risk for relapse. The experiment was included as a cross sectional part in a follow-up study of a population that previously experienced first episode (FE) depression. The FE (N = 23) and a healthy control group (N = 22) completed a WM face processing task. In the task, three happy or sad faces were presented, processed in either a high or low WM taxing manner, followed by a target stimulus consisting of one of the previous pictures. Response time and accuracy were dependent variables. Rumination and number of relapses or recurrences were measured. The FE group recalled the placement of significantly fewer happy faces in the low WM load condition, and significantly fewer sad faces in the high WM load condition compared to controls. Significantly different scores between groups predicted trait rumination. Poor accuracy in the sad high WM load condition correlated with high degree of rumination. Relapse or recurrence was predicted by rumination. The present study supports an emotional WM deficit in remitted MDD. This suggests that deficits in manipulation of sad faces could represent a trait bias related to rumination and depression.acceptedVersio

Norms matter: U.S. normative data under-estimate cognitive deficits in Norwegians with schizophrenia spectrum disorders

Objective: To illustrate and quantify how using different normative systems influences the accuracy of identifying cognitive impairment in people with schizophrenia spectrum disorders. Participants and methods: A convenience sample of 315 patients between 18 and 38 years of age referred for neuropsychological assessment at a psychiatric inpatient hospital in Bergen, Norway, was included. All completed the Norwegian version of the Repeatable Battery for the Assessment of Neuropsy-chological Status (RBANS). Results: There were statistically significant differences between the Immediate Memory, Visuospatial/Constructional, Language, Delayed Memory, and Total Scale Index scores when comparing the U.S. normative scores with the Scandinavian normative scores. The effect sizes were medium. The patient samples scored higher when using the U.S. normative data, suggesting less cognitive impairment. Conclusions: United States normative data yielded less impaired scores for Norwegians with schizophrenia spectrum disorders. The implications of using U.S. versus Scandinavian normative data are discussed.acceptedVersio

An open pilot study of an internet-delivered intervention targeting self-perceived residual cognitive symptoms after major depressive disorder

Residual cognitive symptoms are associated with reduced daily life functioning, quality of life and represent a risk factor for relapse of major depressive disorder (MDD). There are few studies targeting self-perceived residual cognitive symptoms after MDD. The current open pilot study examines clinical outcomes and feasibility of a novel internet-delivered cognitive enhancement treatment for mood disorders specifically tailored to target self-perceived residual cognitive symptoms after MDD. A total of 43 adults with self-perceived residual cognitive symptoms after MDD were included. Participants were assessed pre- and post-treatment and at 6-month follow-up. The intervention consists of 10 modules that includes psychoeducation, cognitive strategies, and attention training, coupled with weekly therapist guidance. Results showed a significant reduction from pre- to post-treatment in self-perceived residual cognitive symptoms (d = 0.98) and rumination (d = 0.63). Results remained significant at the 6-month follow-up (d = 1.06; d = 0.86). Reliable change in self-perceived residual cognitive symptoms were obtained in 60% of the participants from pre- to post-treatment. Completion rates (86%) and treatment satisfaction (97%) were high. This open pilot study supports that targeting self-perceived residual cognitive symptoms after MDD through internet-delivered cognitive enhancement therapy for mood disorders may be feasible and provide stable reductions in self-perceived residual cognitive symptoms and rumination.publishedVersio

Long-term outcomes of an internet-delivered cognitive enhancement intervention targeting residual cognitive deficits after major depressive disorder: a 2-year follow-up of an open trial

BackgroundCognitive deficits are common and disabling residual symptoms following major depressive disorder (MDD) and are related to increased risk of relapse. Residual cognitive deficits should thus be considered an important target for treatment. However, few have reported long-term outcomes of interventions targeting residual cognitive deficits.ObjectiveThis study aimed to (1) investigate change between pre-treatment and 2-year follow-up assessments in cognitive deficits, rumination, and symptoms of MDD after an internet-delivered intervention targeting residual cognitive deficits; (2) to investigate stability in outcomes between 6-month and 2-year follow-up assessments; (3) to report the number of participants’ experiencing a new episode of MDD in the follow-up period; and (4) to investigate differences in outcomes between those who experienced a new episode of MDD and those who did not.MethodsA total of 43 partly remitted adults were included to test a guided internet-delivered intervention, which consisted of 10 modules involving psychoeducation, cognitive strategies, and attention training. Participants were assessed at pre-treatment, post-treatment, after 6-months, and after 2-years, with measures assessing self-reported residual cognitive deficits, rumination, symptoms of MDD and relapse. Overall, 32 participants completed the 2-year follow-up assessment.ResultsBetween the pre-treatment and 2-year follow-up assessments, there was a reduction in cognitive deficits and rumination, while there was an increase in symptoms of MDD. Cognitive deficits were stable between the 6-month and the 2-year follow-up, while there was an increase in rumination and symptoms of MDD. Thirteen of 32 participants reported a new episode of MDD during the follow-up period. The relapse group reported longer duration of MDD at pre-treatment and showed a difference in all outcomes after 2 years compared to the no-relapse group. The no-relapse group showed improvement in MDD symptoms at post-treatment, while the relapse group did not.ConclusionDelivering cognitive enhancement interventions over the internet is potentially related to stable improvements in residual cognitive deficits. The effects on rumination and symptoms of MDD are less certain. Lack of improvement in MDD symptoms after the intervention period should be investigated as an indicator of relapse. Results should be interpreted with caution due to the lack of control group and sample size

Computerized Working Memory Training in Remission From Major Depressive Disorder: Effects on Emotional Working Memory, Processing Speed, Executive Functions, and Associations With Symptoms

Introduction: Remission from major depressive disorder (MDD) is associated with residual symptoms related to reduced functioning, quality of life, and relapse risk. Previous studies have raised questions about mechanisms involved-in and affected by cognitive training. This study investigated the associations and changes among depressive symptoms, rumination, processing speed (PS), executive functioning (EF), and emotional working memory (e-WM) pre- post computerized working memory training (CWMT). Method: Twenty-nine remitted participants were included in a pre- post pilot study of within-subject effects of online CWMT. A total of 20 participants completed the intervention and pre- post tests of EF and PS, e-WM, in addition to symptom and rumination measures. Associations between changes in symptoms and cognition were investigated pre- post. Associations between improvements in CWMT, depression history, and changes in cognition were explored. Hypotheses and statistics were preregistered before data were analyzed. Results: Manipulation of negatively valanced stimuli in e-WM showed an inverse association with rumination pre-intervention, but the association disappeared post-intervention. Cognitive functioning improved in most conditions with largest effects in EF. Symptoms did not change in the remitted sample. CWMT improvements were related to improvements in some aspects of EF and PS, but also to worse self-reported attention. Depression history was related to less improvement in EF. Limitations: Sample size was small and there was dropout from the study. There was no control group, thus precluding practice and placebo effects and causal relationships. Conclusions: Computerized WM training improves cognitive functions and could influence associations between e-WM and rumination. This could counteract functional impairment following MDD.publishedVersio

Cognitive Impairment and Neurocognitive Profiles in Major Depression—A Clinical Perspective

Increasingly, studies have investigated cognitive functioning from the perspective of acute state- to remitted phases of Major Depressive Disorder (MDD). Some cognitive deficits observed in the symptomatic phase persist in remission as traits or scars. The etiological origin and clinical consequences of the neurocognitive profiles reported in the literature are still unclear and may vary across populations. Deficits are suspected to influence the association between MDD and neurodegenerative disorders and could thus be of particular clinical consequence. The aim of this review is to describe the clinical neuropsychological profile in MDD and how it is related to research during the past decade on cognitive deficits in MDD from a state, trait, and scar perspective. This review, with a clinical perspective, investigates research from the past decade regarding cognitive functioning in MDD in a long-term perspective. We focus on the clinical manifestation of deficits, and the potential neurodegenerative consequences of the neurocognitive profile in MDD. Searches in Medline, PsycINFO and Embase were conducted targeting articles published between 2010 and 2020. Examination of the evidence for long-lasting neurocognitive deficits in major depression within the cognitive domains of Memory, Executive Functions, Attention, and Processing Speed was conducted and was interpreted in the context of the State, Scar and Trait hypotheses. Defining the neurocognitive profiles in MDD will have consequences for personalized evaluation and treatment of residual cognitive symptoms, and etiological understanding of mood disorders, and treatments could potentially reduce or delay the development of neurodegenerative disorders.publishedVersio

Longitudinal relations between impaired executive function and symptoms of psychiatric disorders in childhood

Background Malfunctioning of executive functions correlates with psychopathology in children. However, the directionality, the extent to which the relation varies for various disorders, and whether prospective relations afford causal interpretations are not known. Methods A community sample of Norwegian children (n = 874) was studied biennially from the age of 6 to 14 years. Executive functions were assessed using the Behavior Rating Inventory of Executive Function Teacher-report and symptoms of psychopathology were assessed using the Preschool Age Psychiatric Assessment (age 6; parents) and Child and Adolescent Psychiatric Assessment (ages 8–14; children and parents). Prospective reciprocal relations were examined using a random intercept cross-lagged panel model that adjusts for all unobserved time-invariant confounders. Results Even when time-invariant confounders were accounted for, reduced executive functions predicted increased symptoms of depressive disorders, anxiety disorders, attention-deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD) 2 years later, even when previous changes in these symptoms were adjusted for. The level of prediction (B = .83, 95% CI [.37, 1.3]) was not different for different disorders or ages. Conversely, reduced executive functions were predicted by increased symptoms of all disorders (B = .01, 95% CI [.01, .02]). Conclusions Reduced executive functioning may be involved in the etiology of depression, anxiety, ADHD, and ODD/CD to an equal extent. Moreover, increased depression, anxiety, ADHD, and ODD/CD may negatively impact executive functioning.publishedVersio