Major depressive disorder is associated with broad impairments on neuropsychological measures of executive function: a meta-analysis and review

Symptom severity of depressive symptoms impacts on social cognition performance in current but not remitted major depressive disorder

The aim of the present study was to investigate the social cognitive functioning of participants with depression when compared with healthy controls, and to assess the impact of symptom severity. One hundred and eight patients with depression (66 remitted and 42 current) and 52 healthy controls were assessed using the Wechsler Advanced Clinical Solutions: Social Perception Subtest, measuring facial affect recognition in isolation and in combination with prosody and body language interpretation. When healthy controls, remitted depression and currently depressed groups were compared, no associations were found on any of the social cognition subscales. Severity of depressive and anxious symptoms predicted performance on all social cognition subscales in currently depressed participants, controlling for age, gender, education and psychotropic medication. Affective depressive symptoms were inversely related to ACS Pairs and Prosody subscales, while somatic symptoms were inversely related to the ACS Affect Recognition and Total scores. There was no association between severity and the WAIS ACS in remitted depression participants. People with MDD exhibiting more severe depressive and anxious symptoms and a cluster of affective symptoms have greater difficulty undertaking complex social cognitive tasks. Given the state like nature to these deficits, these impairments may cause problems with day to day functioning and have implications in targeted therapeutic interventions.

Prevalence of perceived cognitive dysfunction in survivors of a wide range of cancers: results from the 2010 LIVESTRONG survey

PURPOSE

With cancer survivors now numbering over 13 million in the United States, and expected to continue to increase, it is important to consider the needs of this growing population. In the literature, one of the most common complaints by cancer survivors is perceived cognitive dysfunction. Since the preponderance of the research has focused on breast cancer survivors, the purpose of the present study was to explore the prevalence and correlates of perceived cognitive dysfunction in a large sample of cancer survivors with representation across a wide range of different types of cancer.

METHODS

A sample of 3108 post-treatment cancer survivors completed the 2010 LIVESTRONG survey as part of a larger study of cancer survivorship. Respondents completed standardized questions regarding current and past perceived cognitive dysfunction, as well as depressive symptoms, and demographic and medical variables.

RESULTS

Current perceived cognitive dysfunction was reported by nearly half of respondents (45.7%), across a wide range of cancer types, with the highest prevalence among survivors of central nervous system cancers. Receiving chemotherapy and current report of depressive symptoms were both strongly associated with current perceived cognitive dysfunction.

CONCLUSION

These findings contribute to a growing appreciation of the high prevalence of perceived cognitive dysfunction in survivors of a wide range of cancer types and the potential interactive effect of concurrent symptoms of depression. These findings highlight a need to develop more effective means of preventing or reducing cognitive dysfunction in cancer survivors.

IMPLICATIONS FOR CANCER SURVIVORS

Perceived cognitive dysfunction was reported in a wide range of cancer survivors. The potential interactive effect of symptoms of depression suggests the need to develop interventions targeting both cognitive dysfunction and depression to achieve improvements in cognitive functioning.

COGNITION-CHILDHOOD MALTREATMENT INTERACTIONS IN THE PREDICTION OF ANTIDEPRESSANT OUTCOMES IN MAJOR DEPRESSIVE DISORDER PATIENTS: RESULTS FROM THE iSPOT-D TRIAL

BACKGROUND

Childhood maltreatment (CM) history has been associated with poor treatment response in major depressive disorder (MDD), but the mechanisms underlying this relationship remain opaque. Dysfunction in the neural circuits for executive cognition is a putative neurobiological consequence of CM that may contribute importantly to adverse clinical outcomes. We used behavioral and neuroimaging measures of executive functioning to assess their contribution to the relationship between CM and antidepressant response in MDD patients.

METHODS

Ninety eight medication-free MDD outpatients participating in the International Study to Predict Optimized Treatment in Depression were assessed at baseline on behavioral neurocognitive measures and functional magnetic resonance imaging during tasks probing working memory (continuous performance task, CPT) and inhibition (Go/No-go). Seventy seven patients completed 8 weeks of antidepressant treatment. Baseline behavioral and neuroimaging measures were assessed in relation to CM (history of childhood physical, sexual, and/or emotional abuse) and posttreatment depression outcomes.

RESULTS

Patients with maltreatment exhibited decreased modulation of right dorsolateral prefrontal cortex (DLPFC) activity during working memory updating on the CPT, and a corresponding impairment in CPT behavioral performance outside the scanner. No between-group differences were found for imaging or behavior on the Go/No-go test of inhibition. Greater DLPFC activity during CPT significantly predicted posttreatment symptom improvement in patients without maltreatment, whereas the relationship between DLPFC activity and symptom change was nonsignificant, and in the opposite direction, in patients with maltreatment.

CONCLUSIONS

The effect of CM on prefrontal circuitry involved in executive function is a potential predictor of antidepressant outcomes.

Research Review: Neuropsychological test performance in pediatric obsessive-compulsive disorder--a meta-analysis

BACKGROUND

Research into the neuropsychology of pediatric obsessive-compulsive disorder (OCD) reveals inconsistent results, limiting the ability to draw conclusions about possible neurocognitive deficits in youth with OCD. The aim of this study was to conduct a meta-analysis of the available literature.

METHODS

We identified 36 studies, of which 11 studies met inclusion criteria. Results were categorized into nine functional subdomains: planning, response inhibition/interference control, set shifting/cognitive flexibility, verbal memory, nonverbal memory, processing speed, working memory, visuospatial functions, and attention. For each domain, weighted pooled Hedges' g effect size was calculated using random model analyses.

RESULTS

Small effect sizes were found across all subdomains, none of which were found to be statistically significant.

DISCUSSION

Results indicate that youth with OCD do not exhibit noteworthy neuropsychological deficits. This is in line with recent suggestions that OCD may not be characterized by clinically meaningful neuropsychological impairments. However, the small number of available controlled studies highlights the urgent need for more neuropsychological research in this population, as well as for further exploration of the neurodevelopmental hypothesis in pediatric OCD. Finally, the relatively low persistence rates of OCD into adulthood should be taken under consideration, especially in the context of the putative neuropsychological performance differences between adult and pediatric OCD populations.

A computational analysis of flanker interference in depression

BACKGROUND

Depression is characterized by poor executive function, but - counterintuitively - in some studies, it has been associated with highly accurate performance on certain cognitively demanding tasks. The psychological mechanisms responsible for this paradoxical finding are unclear. To address this issue, we applied a drift diffusion model (DDM) to flanker task data from depressed and healthy adults participating in the multi-site Establishing Moderators and Biosignatures of Antidepressant Response for Clinical Care for Depression (EMBARC) study.

METHOD

One hundred unmedicated, depressed adults and 40 healthy controls completed a flanker task. We investigated the effect of flanker interference on accuracy and response time, and used the DDM to examine group differences in three cognitive processes: prepotent response bias (tendency to respond to the distracting flankers), response inhibition (necessary to resist prepotency), and executive control (required for execution of correct response on incongruent trials).

RESULTS

Consistent with prior reports, depressed participants responded more slowly and accurately than controls on incongruent trials. The DDM indicated that although executive control was sluggish in depressed participants, this was more than offset by decreased prepotent response bias. Among the depressed participants, anhedonia was negatively correlated with a parameter indexing the speed of executive control (r = -0.28, p = 0.007).

CONCLUSIONS

Executive control was delayed in depression but this was counterbalanced by reduced prepotent response bias, demonstrating how participants with executive function deficits can nevertheless perform accurately in a cognitive control task. Drawing on data from neural network simulations, we speculate that these results may reflect tonically reduced striatal dopamine in depression.

Impulsive traits and unplanned suicide attempts predict exaggerated prefrontal response to angry faces in the elderly

OBJECTIVE

Abnormal responses to social stimuli are seen in people vulnerable to suicidal behavior, indicating possible disruptions in the neural circuitry mediating the interpretation of socioemotional cues. These disruptions have not been empirically related to psychological and cognitive pathways to suicide. In the present study of older suicide attempters, we examined neural responses to emotional faces and their relationship to impulsivity, one of the components of the suicidal diathesis.

METHODS

Using functional magnetic resonance imaging, we recorded neurohemodynamic responses to angry faces in a carefully characterized sample of 18 depressed elderly with history of suicide attempts, 13 depressed nonsuicidal patients, and 18 healthy individuals, all aged 60+. Impulsivity was assessed with the Social Problem Solving Inventory Impulsivity/Carelessness Style subscale and Barratt Impulsiveness Scale. The Suicide Intent Scale planning subscale was used to describe the degree of planning associated with the most lethal attempt.

RESULTS

Depression and history of attempted suicide were not associated with neural responses to angry faces, failing to replicate earlier studies. Higher impulsivity, however, predicted exaggerated responses to angry faces in fronto-opercular and dorsomedial prefrontal cortex (pcorr <0.05). Poorly planned suicide attempts also predicted increased fronto-opercular responses. Results were robust to effects of medication exposure, comorbid anxiety and addiction, severity of depression, burden of physical illness, and possible brain injury from suicide attempts.

CONCLUSION

Impulsive traits and history of unplanned suicide attempts partly explain the heterogeneity in neural responses to angry faces in depressed elderly. Displays of social emotion command excessive cortical processing in impulsive suicide attempters.

Monitoring and optimising cognitive function in cancer patients: Present knowledge and future directions

The potentially detrimental effects of cancer and related treatments on cognitive functioning are emerging as a key focus of cancer survivorship research. Many patients with central nervous system (CNS) or non-CNS tumours develop cognitive problems during the course of their disease that can result in diminished functional independence. We review the state of knowledge on the cognitive functioning of patients with primary and secondary brain tumours at diagnosis, during and after therapy, and discuss current initiatives to diminish cognitive decline in these patients. Similarly, attention is paid to the cognitive sequelae of cancer and cancer therapies in patients without CNS disease. Disease and treatment effects on cognition are discussed, as well as current insights into the neural substrates and the mechanisms underlying cognitive dysfunction in these patients. In addition, rehabilitation strategies for patients with non-CNS disease confronted with cognitive dysfunction are described. Special attention is given to knowledge gaps in the area of cancer and cognition, in CNS and non-CNS diseases. Finally, we point to the important role for cooperative groups to include cognitive endpoints in clinical trials in order to accelerate our understanding and treatment of cognitive dysfunction related to cancer and cancer therapies.

Trait worry is associated with difficulties in working memory updating

The current study investigated the effects of trait worry, a subcomponent of trait anxiety, on the process of updating information in working memory (WM). A leading theory on anxiety and executive functions, attentional control theory (ACT), states that anxiety is not related to WM updating in emotionally neutral situations. Previous research, however, has focused almost exclusively on WM span tasks that primarily emphasised storage, rather than the updating of WM representations. Moreover, few studies have directly examined the effects of trait worry. In this study, 116 subjects performed a WM updating task that required the memorisation of short lists of words and the within-trial removal of some of these items from WM. Results indicated that levels of trait worry were not related to word-span performance, but were related to performance on trials that required subjects to effectively update WM. Moreover, these effects were observed only for trait worry, not for levels of anxious arousal or comorbid levels of dysphoria. These results support the hypothesis that trait worry is related to WM updating performance and thereby extend ACT in new directions.

Brief report: Executive functions in adolescent offspring of mothers with a history of depression

Deficits in executive functions (EFs) have been documented among individuals with unipolar depression, but controversy exists as to whether such deficits are state-dependent or are trait markers that precede disorder onset. The present study examined whether maternal history of unipolar depression was associated with deficits in EFs in early adolescent offspring, a finding that would support a trait marker conceptualization of EF deficits. Participants were a diverse sample (N = 493) of adolescents and their mothers recruited through local schools. Measures included semi-structured diagnostic interviews of mother and adolescent, mother-report forms assessing demographic information, and tests of executive function. Hierarchical linear regression analyses were conducted to examine the association between maternal depression diagnosis and adolescent offspring performance on tests of EF. Maternal lifetime history of depression was not associated with offspring EF task performance. Findings are not consistent with the conceptualization of impaired executive functions as trait markers of unipolar depression.

Who receives contraception counseling when starting new lupus medications? The potential roles of race, ethnicity, disease activity, and quality of communication

OBJECTIVE

Family planning discussions are an important aspect of medical care for women with systemic lupus erythematosus (SLE) as active disease is a risk factor for poor pregnancy outcomes, and the medications used for treatment can be harmful to the fetus when used during conception and pregnancy. Our objective was to examine the impact of patient perception of quality and type of communication on receiving contraception counseling.

METHODS

Data were derived from patients enrolled in the University of California, San Francisco Lupus Outcomes Study. Individuals participate in a yearly structured telephone interview that includes assessment of contraception counseling when starting new medications, and measures of communication and decision making. Logistic regression was performed to identify predictors of not receiving contraception counseling.

RESULTS

Of the 68 women included in this analysis, one-third did not receive contraception counseling when starting new medications. Older age, white race, depressive symptoms, and higher SLE disease activity were independently associated with not receiving contraception counseling. Participants who did not receive contraception counseling rated their physicians lower in shared decision-making (SDM) communication.

CONCLUSIONS

This study demonstrates a gap in family planning counseling among women with SLE starting new medications. Future studies to address these potential areas of intervention, including education about the need for contraception through menopause, and mechanisms to engage in SDM surrounding contraception are needed to improve quality of care for women with lupus.

Executive Function in Adults With Type 2 Diabetes: A Meta-Analytic Review

OBJECTIVE

To examine the extent to which Type 2 diabetes mellitus (T2DM) is associated with impairments in executive function (EF).

METHODS

Medline, PsychoInfo, and Scopus databases and published references were used to identify articles examining the association between T2DM status (case versus control) and EF decrements. Results from studies were converted to standardized mean differences and compared using random-effects models. Moderator analysis was conducted for age, sex, and diabetes duration using maximum likelihood estimation.

RESULTS

Sixty studies (59 articles) including 9815 individuals with T2DM and 69,254 controls were included. Findings indicated a small but reliable association between T2DM status and EF decrements (d = -0.248, p < .001), observed across all aspects of EF examined: verbal fluency, mental flexibility, inhibition, working memory, and attention. Disease duration significantly moderated the effect of T2DM status on EF.

CONCLUSIONS

T2DM is associated with a mild-to-moderate EF decrements. Such decrements are stronger among those with shorter disease duration.

Executive function and suicidality: A systematic qualitative review

Deficits in executive function (EF) have been proposed as a possible explanation for the "cognitive rigidity" often observed in suicidal individuals. This article provides a systematic review of the existing literature testing the relations between EF and suicidality, across various diagnostic and demographic populations, using the influential multidimensional model of EF proposed by Miyake and colleagues (2000) as an organizing framework. Forty-three journal articles on this topic published before January of 2014 were reviewed. Collectively, results from these studies provide tentative support for an association between EF deficits and suicidality. However, there is some evidence that this association is moderated by other factors (e.g., suicide attempt lethality). Importantly, this relationship may vary across diagnostic groups. Specifically, more studies that used depressive disorder samples reported some positive findings (75%), followed by mixed diagnostic samples (54%). In contrast, fewer positive findings have emerged from studies with bipolar or psychotic disorder samples (29% and 33% respectively), and some even found that suicidality is associated with better EF in individuals with psychotic disorders. Firm conclusions about relationships between specific dimensions of EF and/or aspects of suicidality are difficult to draw this time. Limitations of the existing literature and corresponding directions for future research are discussed.

Course and Predictors of Cognitive Function in Patients With Prostate Cancer Receiving Androgen-Deprivation Therapy: A Controlled Comparison

PURPOSE

Men receiving androgen-deprivation therapy (ADT) for prostate cancer may be at risk for cognitive impairment; however, evidence is mixed in the existing literature. Our study examined the impact of ADT on impaired cognitive performance and explored potential demographic and genetic predictors of impaired performance.

PATIENTS AND METHODS

Patients with prostate cancer were assessed before or within 21 days of starting ADT (n = 58) and 6 and 12 months later. Age- and education-matched patients with prostate cancer treated with prostatectomy only (n = 84) and men without prostate cancer (n = 88) were assessed at similar intervals. Participants provided baseline blood samples for genotyping. Mean-level cognitive performance was compared using mixed models; cognitive impairment was compared using generalized estimating equations.

RESULTS

ADT recipients demonstrated higher rates of impaired cognitive performance over time relative to all controls (P = .01). Groups did not differ at baseline (P > .05); however, ADT recipients were more likely to demonstrate impaired performance within 6 and 12 months (P for both comparisons < .05). Baseline age, cognitive reserve, depressive symptoms, fatigue, and hot flash interference did not moderate the impact of ADT on impaired cognitive performance (P for all comparisons ≥ .09). In exploratory genetic analyses, GNB3 single-nucleotide polymorphism rs1047776 was associated with increased rates of impaired performance over time in the ADT group (P < .001).

CONCLUSION

Men treated with ADT were more likely to demonstrate impaired cognitive performance within 6 months after starting ADT relative to matched controls and to continue to do so within 12 months after starting ADT. If confirmed, findings may have implications for patient education regarding the risks and benefits of ADT.

Large-Scale Network Dysfunction in Major Depressive Disorder: A Meta-analysis of Resting-State Functional Connectivity

IMPORTANCE

Major depressive disorder (MDD) has been linked to imbalanced communication among large-scale brain networks, as reflected by abnormal resting-state functional connectivity (rsFC). However, given variable methods and results across studies, identifying consistent patterns of network dysfunction in MDD has been elusive.

OBJECTIVE

To investigate network dysfunction in MDD through a meta-analysis of rsFC studies.

DATA SOURCES

Seed-based voxelwise rsFC studies comparing individuals with MDD with healthy controls (published before June 30, 2014) were retrieved from electronic databases (PubMed, Web of Science, and EMBASE) and authors contacted for additional data.

STUDY SELECTION

Twenty-seven seed-based voxel-wise rsFC data sets from 25 publications (556 individuals with MDD and 518 healthy controls) were included in the meta-analysis.

DATA EXTRACTION AND SYNTHESIS

Coordinates of seed regions of interest and between-group effects were extracted. Seeds were categorized into seed-networks by their location within a priori functional networks. Multilevel kernel density analysis of between-group effects identified brain systems in which MDD was associated with hyperconnectivity (increased positive or reduced negative connectivity) or hypoconnectivity (increased negative or reduced positive connectivity) with each seed-network.

RESULTS

Major depressive disorder was characterized by hypoconnectivity within the frontoparietal network, a set of regions involved in cognitive control of attention and emotion regulation, and hypoconnectivity between frontoparietal systems and parietal regions of the dorsal attention network involved in attending to the external environment. Major depressive disorder was also associated with hyperconnectivity within the default network, a network believed to support internally oriented and self-referential thought, and hyperconnectivity between frontoparietal control systems and regions of the default network. Finally, the MDD groups exhibited hypoconnectivity between neural systems involved in processing emotion or salience and midline cortical regions that may mediate top-down regulation of such functions.

CONCLUSIONS AND RELEVANCE

Reduced connectivity within frontoparietal control systems and imbalanced connectivity between control systems and networks involved in internal or external attention may reflect depressive biases toward internal thoughts at the cost of engaging with the external world. Meanwhile, altered connectivity between neural systems involved in cognitive control and those that support salience or emotion processing may relate to deficits regulating mood. These findings provide an empirical foundation for a neurocognitive model in which network dysfunction underlies core cognitive and affective abnormalities in depression.

Fronto-parietal and cingulo-opercular network integrity and cognition in health and schizophrenia

Growing evidence suggests that coordinated activity within specific functional brain networks supports cognitive ability, and that abnormalities in brain connectivity may underlie cognitive deficits observed in neuropsychiatric diseases, such as schizophrenia. Two functional networks, the fronto-parietal network (FPN) and cingulo-opercular network (CON), are hypothesized to support top-down control of executive functioning, and have therefore emerged as potential drivers of cognitive impairment in disease-states. Graph theoretic analyses of functional connectivity data can characterize network topology, allowing the relationships between cognitive ability and network integrity to be examined. In the current study we applied graph analysis to pseudo-resting state data in 54 healthy subjects and 46 schizophrenia patients, and measured overall cognitive ability as the shared variance in performance from tasks of episodic memory, verbal memory, processing speed, goal maintenance, and visual integration. We found that, across all participants, cognitive ability was significantly positively associated with the local and global efficiency of the whole brain, FPN, and CON, but not with the efficiency of a comparison network, the auditory network. Additionally, the participation coefficient of the right anterior insula, a major hub within the CON, significantly predicted cognition, and this relationship was independent of CON global efficiency. Surprisingly, we did not observe strong evidence for group differences in any of our network metrics. These data suggest that functionally efficient task control networks support better cognitive ability in both health and schizophrenia, and that the right anterior insula may be a particularly important hub for successful cognitive performance across both health and disease.

Abnormal error processing in depressive states: a translational examination in humans and rats

Depression has been associated with poor performance following errors, but the clinical implications, response to treatment and neurobiological mechanisms of this post-error behavioral adjustment abnormality remain unclear. To fill this gap in knowledge, we tested depressed patients in a partial hospital setting before and after treatment (cognitive behavior therapy combined with medication) using a flanker task. To evaluate the translational relevance of this metric in rodents, we performed a secondary analysis on existing data from rats tested in the 5-choice serial reaction time task after treatment with corticotropin-releasing factor (CRF), a stress peptide that produces depressive-like signs in rodent models relevant to depression. In addition, to examine the effect of treatment on post-error behavior in rodents, we examined a second cohort of rodents treated with JDTic, a kappa-opioid receptor antagonist that produces antidepressant-like effects in laboratory animals. In depressed patients, baseline post-error accuracy was lower than post-correct accuracy, and, as expected, post-error accuracy improved with treatment. Moreover, baseline post-error accuracy predicted attentional control and rumination (but not depressive symptoms) after treatment. In rats, CRF significantly degraded post-error accuracy, but not post-correct accuracy, and this effect was attenuated by JDTic. Our findings demonstrate deficits in post-error accuracy in depressed patients, as well as a rodent model relevant to depression. These deficits respond to intervention in both species. Although post-error behavior predicted treatment-related changes in attentional control and rumination, a relationship to depressive symptoms remains to be demonstrated.

Rumination in major depressive disorder is associated with impaired neural activation during conflict monitoring

Individuals with major depressive disorder (MDD) often ruminate about past experiences, especially those with negative content. These repetitive thoughts may interfere with cognitive processes related to attention and conflict monitoring. However, the temporal nature of these processes as reflected in event-related potentials (ERPs) has not been well-described. We examined behavioral and ERP indices of conflict monitoring during a modified flanker task and the allocation of attention during an attentional blink (AB) task in 33 individuals with MDD and 36 healthy controls, and whether their behavioral performance and ERPs varied with level of rumination. N2 amplitude elicited by the flanker task was significantly reduced in participants with MDD compared to healthy controls. Level of self-reported rumination was also correlated with N2 amplitude. In contrast, P3 amplitude during the AB task was not significantly different between groups, nor was it correlated with rumination. No significant differences were found in behavioral task performance measures between groups or by rumination levels. These findings suggest that rumination in MDD is associated with select deficits in cognitive control, particularly related to conflict monitoring.

Reinforcement learning in depression: A review of computational research

Despite being considered primarily a mood disorder, major depressive disorder (MDD) is characterized by cognitive and decision making deficits. Recent research has employed computational models of reinforcement learning (RL) to address these deficits. The computational approach has the advantage in making explicit predictions about learning and behavior, specifying the process parameters of RL, differentiating between model-free and model-based RL, and the computational model-based functional magnetic resonance imaging and electroencephalography. With these merits there has been an emerging field of computational psychiatry and here we review specific studies that focused on MDD. Considerable evidence suggests that MDD is associated with impaired brain signals of reward prediction error and expected value ('wanting'), decreased reward sensitivity ('liking') and/or learning (be it model-free or model-based), etc., although the causality remains unclear. These parameters may serve as valuable intermediate phenotypes of MDD, linking general clinical symptoms to underlying molecular dysfunctions. We believe future computational research at clinical, systems, and cellular/molecular/genetic levels will propel us toward a better understanding of the disease.

BDNF Val66Met polymorphism and hippocampal volume in neuropsychiatric disorders: A systematic review and meta-analysis

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a neurotrophin involved in neurogenesis and synaptic plasticity in the central nervous system, especially in the hippocampus, and has been implicated in the pathophysiology of several neuropsychiatric disorders. Its Val66Met polymorphism (refSNP Cluster Report: rs6265) is a functionally relevant single nucleotide polymorphism affecting the secretion of BDNF and is implicated in differences in hippocampal volumes.

METHODS

This is a systematic meta-analytical review of findings from imaging genetic studies on the impact of the rs6265 SNP on hippocampal volumes in neuropsychiatric patients with major depressive disorder, anxiety, bipolar disorder or schizophrenia.

RESULTS

The overall sample size of 18 independent clinical cohorts comprised 1695 patients. Our results indicated no significant association of left (Hedge's g=0.08, p=0.12), right (g=0.07, p=0.22) or bilateral (g=0.07, p=0.16) hippocampal volumes with BDNF rs6265 in neuropsychiatric patients. There was no evidence for a publication bias or any demographic, clinical, or methodological moderating effects. Both Val/Val homozygotes (g=0.32, p=0.004) and Met-carriers (g=0.20, p=0.004) from the patient sample had significantly smaller hippocampal volumes than the healthy control sample with the same allele. The magnitude of these effects did not differ between the two genotypes.

CONCLUSION

This meta-analysis suggests that there is no association between this BDNF polymorphism and hippocampal volumes. For each BDNF genotype, the hippocampal volumes were significantly lower in neuropsychiatric patients than in healthy controls.

Corticostriatothalamic reward prediction error signals and executive control in late-life depression

BACKGROUND

Altered corticostriatothalamic encoding of reinforcement is a core feature of depression. Here we examine reinforcement learning in late-life depression in the theoretical framework of the vascular depression hypothesis. This hypothesis attributes the co-occurrence of late-life depression and poor executive control to prefrontal/cingulate disconnection by vascular lesions.

METHOD

Our fMRI study compared 31 patients aged ⩾60 years with major depression to 16 controls. Using a computational model, we estimated neural and behavioral responses to reinforcement in an uncertain, changing environment (probabilistic reversal learning).

RESULTS

Poor executive control and depression each explained distinct variance in corticostriatothalamic response to unexpected rewards. Depression, but not poor executive control, predicted disrupted functional connectivity between the striatum and prefrontal cortex. White-matter hyperintensities predicted diminished corticostriatothalamic responses to reinforcement, but did not mediate effects of depression or executive control. In two independent samples, poor executive control predicted a failure to persist with rewarded actions, an effect distinct from depressive oversensitivity to punishment. The findings were unchanged in a subsample of participants with vascular disease. Results were robust to effects of confounders including psychiatric comorbidities, physical illness, depressive severity, and psychotropic exposure.

CONCLUSIONS

Contrary to the predictions of the vascular depression hypothesis, altered encoding of rewards in late-life depression is dissociable from impaired contingency learning associated with poor executive control. Functional connectivity and behavioral analyses point to a disruption of ascending mesostriatocortical reward signals in late-life depression and a failure of cortical contingency encoding in elderly with poor executive control.

Motor vehicle driving in high incidence psychiatric disability: comparison of drivers with ADHD, depression, and no known psychopathology

Although not often discussed in clinical settings, motor vehicle driving is a complex multitasking endeavor during which a momentary attention lapse can have devastating consequences. Previous research suggests that drivers with high incidence psychiatric disabilities such as ADHD contribute disproportionately to collision rates, which in turn portend myriad adverse social, financial, health, mortality, and legal outcomes. However, self-referral bias and the lack of psychiatric comparison groups constrain the generalizability of these findings. The current study addressed these limitations and examined the unique associations among ADHD, Depression, and adverse driving outcomes, independent of self-selection, driving exposure, and referral bias. The Strategic Highway Research Program (SHRP-2) Naturalistic Driving Study comprises U.S. drivers from six sites selected via probability-based sampling. Groups were defined by Barkley ADHD and psychiatric diagnosis questionnaires, and included ADHD (n = 275), Depression (n = 251), and Healthy Control (n = 1828). Primary outcomes included self-reported traffic collisions, moving violations, collision-related injuries, and collision fault (last 3 years). Accounting for demographic differences, ADHD but not Depression portended increased risk for multiple violations (OR = 2.3) and multiple collisions (OR = 2.2). ADHD but not Depression portended increased risk for collision fault (OR = 2.1). Depression but not ADHD predicted increased risk for self-reported injury following collisions (OR = 2.4). ADHD appears uniquely associated with multiple collisions, multiple violations, and collision fault, whereas Depression is uniquely associated with self-reported injury following a collision. Identification of the specific mechanisms underlying this risk will be critical to designing effective interventions to improve long-term functioning for drivers with high incidence psychiatric disability.

A cognitive-emotional biomarker for predicting remission with antidepressant medications: a report from the iSPOT-D trial

Depression involves impairments in a range of cognitive and emotional capacities. It is unknown whether these functions can inform medication choice when considered as a composite predictive biomarker. We tested whether behavioral tests, grounded in the neurobiology of cognitive and emotional functions, predict outcome with common antidepressants. Medication-free outpatients with nonpsychotic major depressive disorder (N=1008; 665 completers) were assessed before treatment using 13 computerized tests of psychomotor, executive, memory-attention, processing speed, inhibitory, and emotional functions. Matched healthy controls (N=336) provided a normative reference sample for test performance. Depressed participants were then randomized to escitalopram, sertraline, or venlafaxine-extended release, and were assessed using the 16-item Quick Inventory of Depressive Symptomatology (QIDS-SR16) and the 17-item Hamilton Rating Scale for Depression. Given the heterogeneity of depression, analyses were furthermore stratified by pretreatment performance. We then used pattern classification with cross-validation to determine individual patient-level composite predictive biomarkers of antidepressant outcome based on test performance. A subgroup of depressed participants (approximately one-quarter of patients) were found to be impaired across most cognitive tests relative to the healthy norm, from which they could be discriminated with 91% accuracy. These patients with generally impaired cognitive task performance had poorer treatment outcomes. For this impaired subgroup, task performance furthermore predicted remission on the QIDS-SR16 at 72% accuracy specifically following treatment with escitalopram but not the other medications. Therefore, tests of cognitive and emotional functions can form a clinically meaningful composite biomarker that may help drive general treatment outcome prediction for optimal treatment selection in depression, particularly for escitalopram.

The relationship between sleep-wake cycle and cognitive functioning in young people with affective disorders

Although early-stage affective disorders are associated with both cognitive dysfunction and sleep-wake disruptions, relationships between these factors have not been specifically examined in young adults. Sleep and circadian rhythm disturbances in those with affective disorders are considerably heterogeneous, and may not relate to cognitive dysfunction in a simple linear fashion. This study aimed to characterise profiles of sleep and circadian disturbance in young people with affective disorders and examine associations between these profiles and cognitive performance. Actigraphy monitoring was completed in 152 young people (16–30 years; 66% female) with primary diagnoses of affective disorders, and 69 healthy controls (18–30 years; 57% female). Patients also underwent detailed neuropsychological assessment. Actigraphy data were processed to estimate both sleep and circadian parameters. Overall neuropsychological performance in patients was poor on tasks relating to mental flexibility and visual memory. Two hierarchical cluster analyses identified three distinct patient groups based on sleep variables and three based on circadian variables. Sleep clusters included a ‘long sleep’ cluster, a ‘disrupted sleep’ cluster, and a ‘delayed and disrupted sleep’ cluster. Circadian clusters included a ‘strong circadian’ cluster, a ‘weak circadian’ cluster, and a ‘delayed circadian’ cluster. Medication use differed between clusters. The ‘long sleep’ cluster displayed significantly worse visual memory performance compared to the ‘disrupted sleep’ cluster. No other cognitive functions differed between clusters. These results highlight the heterogeneity of sleep and circadian profiles in young people with affective disorders, and provide preliminary evidence in support of a relationship between sleep and visual memory, which may be mediated by use of antipsychotic medication. These findings have implications for the personalisation of treatments and improvement of functioning in young adults early in the course of affective illness.

DEGS2 polymorphism associated with cognition in schizophrenia is associated with gene expression in brain

A genome-wide association study of cognitive deficits in patients with schizophrenia in Japan found association with a missense genetic variant (rs7157599, Asn8Ser) in the delta(4)-desaturase, sphingolipid 2 (DEGS2) gene. A replication analysis using Caucasian samples showed a directionally consistent trend for cognitive association of a proxy single-nucleotide polymorphism (SNP), rs3783332. Although the DEGS2 gene is expressed in human brain, it is unknown how DEGS2 expression varies during human life and whether it is affected by psychiatric disorders and genetic variants. To address these questions, we examined DEGS2 messenger RNA using next-generation sequencing in postmortem dorsolateral prefrontal cortical tissue from a total of 418 Caucasian samples including patients with schizophrenia, bipolar disorder and major depressive disorder. DEGS2 is expressed at very low levels prenatally and increases gradually from birth to adolescence and consistently expressed across adulthood. Rs3783332 genotype was significantly associated with the expression across all subjects (F3,348=10.79, P=1.12 × 10(-)(3)), particularly in control subjects (F1,87=13.14, P=4.86 × 10(-4)). Similar results were found with rs715799 genotype. The carriers of the risk-associated minor allele at both loci showed significantly lower expression compared with subjects homozygous for the non-risk major allele and this was a consistent finding across all diagnostic groups. DEGS2 expression showed no association with diagnostic status after correcting for multiple testing (P>0.05). Our findings demonstrate that a SNP showing genome-wide association study significant association with cognition in schizophrenia is also associated with regulation of DEGS2 expression, implicating a molecular mechanism for the clinical association.

A multivariate twin study of trait mindfulness, depressive symptoms, and anxiety sensitivity

BACKGROUND

Mindfulness-based therapies have been shown to be effective in treating depression and reducing cognitive biases. Anxiety sensitivity is one cognitive bias that may play a role in the association between mindfulness and depressive symptoms. It refers to an enhanced sensitivity toward symptoms of anxiety, with a belief that these are harmful. Currently, little is known about the mechanisms underpinning the association between mindfulness, depression, and anxiety sensitivity. The aim of this study was to examine the role of genetic and environmental factors in trait mindfulness, and its genetic and environmental overlap with depressive symptoms and anxiety sensitivity.

METHODS

Over 2,100 16-year-old twins from a population-based study rated their mindfulness, depressive symptoms, and anxiety sensitivity.

RESULTS

Twin modeling analyses revealed that mindfulness is 32% heritable and 66% due to nonshared environmental factors, with no significant influence of shared environment. Genetic influences explained over half of the moderate phenotypic associations between low mindfulness, depressive symptoms, and anxiety sensitivity. About two-thirds of genetic influences and almost all nonshared environmental influences on mindfulness were independent of depression and anxiety sensitivity.

CONCLUSIONS

This is the first study to show that both genes and environment play an important role in the etiology of mindfulness in adolescence. Future research should identify the specific environmental factors that influence trait mindfulness during development to inform targeted treatment and resilience interventions. Shared genetic liability underpinning the co-occurrence of low mindfulness, depression, and anxiety sensitivity suggests that the biological pathways shared between these traits should also be examined.

Development and Monte Carlo Study of a Procedure for Correcting the Standardized Mean Difference for Measurement Error in the Independent Variable

The standardized mean difference (SMD) is perhaps the most important meta-analytic effect size. It is typically used to represent the difference between treatment and control population means in treatment efficacy research. It is also used to represent differences between populations with different characteristics, such as persons who are depressed and those who are not. Measurement error in the independent variable (IV) attenuates SMDs. In this article, we derive a formula for the SMD that explicitly represents accuracy of classification of persons into populations on the basis of scores on an IV. We suggest an alternate version of the SMD less vulnerable to measurement error in the IV. We derive a novel approach to correcting the SMD for measurement error in the IV and show how this method can also be used to reliability correct the unstandardized mean difference. We compare this reliability correction approach with one suggested by Hunter and Schmidt in a series of Monte Carlo simulations. Finally, we consider how the proposed reliability correction method can be used in meta-analysis and suggest future directions for both research and further theoretical development of the proposed reliability correction method.

Effects of remission speed and improvement of cognitive functions of depressed patients

Major depressive disorder (MDD) presents neuropsychological alterations which improve after the treatment, but it might be mediated by clinical variables. Our goal is to study whether the speed of remission of MDD bears any relation to the improvement of the patients' cognitive functioning after a successful treatment. We carried out clinical and neuropsychological assessments of 51 patients with MDD. After these procedures they underwent a 24-week treatment with fluoxetine, and were assessed again with the same battery used prior to treatment. They were arranged into three groups according to how rapid their symptoms remitted. The patients with a rapid remission presented improvements in working memory, speed of information processing, and some executive functions, unlike the other groups. Rapid remitters also improved in episodic memory and executive functions more than the other patients.

Advancing understanding of executive function impairments and psychopathology: bridging the gap between clinical and cognitive approaches

Executive function (EF) is essential for successfully navigating nearly all of our daily activities. Of critical importance for clinical psychological science, EF impairments are associated with most forms of psychopathology. However, despite the proliferation of research on EF in clinical populations, with notable exceptions clinical and cognitive approaches to EF have remained largely independent, leading to failures to apply theoretical and methodological advances in one field to the other field and hindering progress. First, we review the current state of knowledge of EF impairments associated with psychopathology and limitations to the previous research in light of recent advances in understanding and measuring EF. Next, we offer concrete suggestions for improving EF assessment. Last, we suggest future directions, including integrating modern models of EF with state of the art, hierarchical models of dimensional psychopathology as well as translational implications of EF-informed research on clinical science.

Neuropsychological performance of patients with soft bipolar spectrum disorders

OBJECTIVES

There is much evidence that shows that a substantial number of individuals with DSM-IV-defined unipolar depression (UP) manifest hypomanic sub-syndrome and bipolar diathesis. Other definitions have conceptualized the term soft bipolar spectrum (SBP) for these individuals. Little is known about the cognitive profiles of individuals with SBP. We hypothesized that they are representative of individuals with bipolar II disorder and are different from that of 'strict' UP.

METHODS

Consecutive referrals suffering major depressive episodes were categorically assigned to groups of either bipolar I disorder (n = 98), bipolar II disorder (n = 138), or UP (n = 300). Based on the SBP criteria by Akiskal and Pinto (17), patients with UP were subdivided into 81 SBP and 219 strict UP. We administered self- and clinician-administered scales to evaluate affective temperaments, and neuropsychological tests to assess seven cognitive domains.

RESULTS

Patients with SBP performed significantly better than strict UP patients in the domains of processing speed (p = 0.002), visual-spatial memory (p = 0.017), and verbal working memory (p = 0.017). Compared to patients with bipolar I disorder, patients with SBP were significantly better in set shifting (p < 0.001) and visual-spatial memory (p = 0.042). Patients with SBP performed similarly to patients with bipolar II disorder in all of the cognitive domains tested (p > 0.05). There was a group × cognitive domain interaction effect between bipolar I disorder, bipolar II disorder, SBP, and strict UP groups [Pillai's F = 2.231, df = (18,1437), p = 0.002].

CONCLUSIONS

Our data suggest that patients with SBP differ from patients with UP not only in external validators (e.g., family history of bipolar disorder) and hypomanic symptoms, but also in neuropsychological performance and that the profiles of cognitive functioning were different across bipolar I disorder and 'bipolar II spectrum' that subsumes bipolar II disorder and SBP.

Non-pharmacological strategies for treatment of inpatient depression

OBJECTIVE

To examine the evidence for non-pharmacological interventions in the treatment of moderate to severe depression in an inpatient setting.

METHOD

An integrative review of original research papers was conducted. The electronic databases CINAHL, MEDLINE and PsychINFO were searched using the following search terms: depression, psychosocial, psychosocial intervention, therapy, and inpatient.

RESULTS

Twelve studies were identified in the search for non-psychopharmacological interventions for depression commenced in an inpatient setting. The interventions included psychotherapies, behavioural activation, and chronotherapeutic interventions (controlled exposure to environmental stimuli). These studies suggest it is possible to engage severely depressed inpatients in structured interventions in an inpatient environment. The majority of studies reported favourable outcomes for the interventions compared to a control, but methodological issues were common.

CONCLUSIONS

A diverse range of treatment strategies has been identified in this review. These studies provide evidence that non-pharmacological treatments for depression can be given to enhance outcomes and that research can be undertaken in inpatient settings. Whilst the evidence base has limitations, this review also highlights therapeutic and research opportunities in this area.

Impaired Maturation of Cognitive Control in Adolescents Who Develop Major Depressive Disorder

This study examined whether development of two forms of cognitive control (proactive and reactive) between early and midadolescence was associated with the onset of major depressive disorder (MDD) during the same period and if it prospectively predicted MDD onset between mid- and late adolescence. Adolescents (N = 165) completed 3 waves of assessments, at 12 (T1), 16 (T2), and 18 (T3) years of age. Diagnostic interviews were conducted at each time point to identify three groups of adolescents: "early MDD," those who developed MDD between early (T1) and mid- (T2) adolescence (n = 23); "late MDD," those who developed MDD between mid- (T2) and late (T3) adolescence (n = 20); and "controls," those who did not develop MDD (n = 122). A modified Stroop task was completed at T1 and T2 to examine development of proactive and reactive cognitive control. Adolescents with early MDD exhibited significant declines in reactive control, as well as a trend level decline for proactive control, during this period compared to controls. No significant differences in reactive or proactive control were identified in adolescents with late MDD compared to controls, but they did exhibit significant improvements in proactive control compared to those with early MDD. These findings suggest that normative maturation of reactive, and possibly proactive, cognitive control abilities are impaired in adolescents who develop MDD between early and midadolescence. This has implications for understanding the mechanisms underlying certain forms of behavioral dysregulation that are commonly seen in MDD.

Operant procedures for assessing behavioral flexibility in rats

Executive functions consist of multiple high-level cognitive processes that drive rule generation and behavioral selection. An emergent property of these processes is the ability to adjust behavior in response to changes in one's environment (i.e., behavioral flexibility). These processes are essential to normal human behavior, and may be disrupted in diverse neuropsychiatric conditions, including schizophrenia, alcoholism, depression, stroke, and Alzheimer's disease. Understanding of the neurobiology of executive functions has been greatly advanced by the availability of animal tasks for assessing discrete components of behavioral flexibility, particularly strategy shifting and reversal learning. While several types of tasks have been developed, most are non-automated, labor intensive, and allow testing of only one animal at a time. The recent development of automated, operant-based tasks for assessing behavioral flexibility streamlines testing, standardizes stimulus presentation and data recording, and dramatically improves throughput. Here, we describe automated strategy shifting and reversal tasks, using operant chambers controlled by custom written software programs. Using these tasks, we have shown that the medial prefrontal cortex governs strategy shifting but not reversal learning in the rat, similar to the dissociation observed in humans. Moreover, animals with a neonatal hippocampal lesion, a neurodevelopmental model of schizophrenia, are selectively impaired on the strategy shifting task but not the reversal task. The strategy shifting task also allows the identification of separate types of performance errors, each of which is attributable to distinct neural substrates. The availability of these automated tasks, and the evidence supporting the dissociable contributions of separate prefrontal areas, makes them particularly well-suited assays for the investigation of basic neurobiological processes as well as drug discovery and screening in disease models.

Socioeconomic status and executive function: developmental trajectories and mediation

Childhood socioeconomic status (SES) predicts executive function (EF), but fundamental aspects of this relation remain unknown: the developmental course of the SES disparity, its continued sensitivity to SES changes during that course, and the features of childhood experience responsible for the SES-EF relation. Regarding course, early disparities would be expected to grow during development if caused by accumulating stressors at a given constant level of SES. Alternatively, they would narrow if schooling partly compensates for the effects of earlier deprivation, allowing lower-SES children to 'catch up'. The potential for later childhood SES change to affect EF is also unknown. Regarding mediating factors, previous analyses produced mixed answers, possibly due to correlation amongst candidate mediators. We address these issues with measures of SES, working memory and planning, along with multiple candidate mediators, from the NICHD Study of Early Childcare (n = 1009). Early family income-to-needs and maternal education predicted planning by first grade, and income-to-needs predicted working memory performance at 54 months. Effects of early SES remained consistent through middle childhood, indicating that the relation between early indicators of SES and EF emerges in childhood and persists without narrowing or widening across early and middle childhood. Changes in family income-to-needs were associated with significant changes in planning and trend-level changes in working memory. Mediation analyses supported the role of early childhood home characteristics in explaining the association between SES and EF, while early childhood maternal sensitivity was specifically implicated in the association between maternal education and planning. Early emerging and persistent SES-related differences in EF, partially explained by characteristics of the home and family environment, are thus a potential source of socioeconomic disparities in achievement and health across development.

Concurrent and Short-Term Prospective Relations among Neurocognitive Functioning, Coping, and Depressive Symptoms in Youth

The present short-term longitudinal study examined the concurrent and prospective relations among executive functioning (i.e., working memory and cognitive flexibility), coping (primary and secondary control coping), and depressive symptoms in children. Participants were 192 children between 9 and 15 years old (M age = 12.36 years, SD = 1.77) recruited from the community. Youth were individually administered neuropsychological measures of executive functioning and intelligence and completed self-report measures of executive dysfunction, coping, and depressive symptoms in small groups; the latter two measures were completed again 4 months later (Time 2 [T2]). Linear regression analyses were used to examine direct associations among executive functions, coping, and depressive symptoms, and a bootstrapping procedure was used to test indirect effects of executive functioning on depressive symptoms through coping. Significant prospective relations were found between working memory measured at Time 1 (T1) and both primary and secondary control coping measured at T2, controlling for T1 coping. T1 cognitive flexibility significantly predicted T2 secondary control coping, controlling for T1 coping. Working memory deficits significantly predicted increases in depressive symptoms 4 months later, controlling for T1 depressive symptoms. Bootstrap analyses revealed that primary and secondary control coping each partially mediated the relation between working memory and depressive symptoms; secondary control coping partially mediated the relation between cognitive flexibility and depressive symptoms. Coping may be one pathway through which deficits in executive functioning contribute to children's symptoms of depression.

Is there a "metabolic-mood syndrome"? A review of the relationship between obesity and mood disorders

Obesity and mood disorders are highly prevalent and co-morbid. Epidemiological studies have highlighted the public health relevance of this association, insofar as both conditions and its co-occurrence are associated with a staggering illness-associated burden. Accumulating evidence indicates that obesity and mood disorders are intrinsically linked and share a series of clinical, neurobiological, genetic and environmental factors. The relationship of these conditions has been described as convergent and bidirectional; and some authors have attempted to describe a specific subtype of mood disorders characterized by a higher incidence of obesity and metabolic problems. However, the nature of this association remains poorly understood. There are significant inconsistencies in the studies evaluating metabolic and mood disorders; and, as a result, several questions persist about the validity and the generalizability of the findings. An important limitation in this area of research is the noteworthy phenotypic and pathophysiological heterogeneity of metabolic and mood disorders. Although clinically useful, categorical classifications in both conditions have limited heuristic value and its use hinders a more comprehensive understanding of the association between metabolic and mood disorders. A recent trend in psychiatry is to move toward a domain specific approach, wherein psychopathology constructs are agnostic to DSM-defined diagnostic categories and, instead, there is an effort to categorize domains based on pathogenic substrates, as proposed by the National Institute of Mental Health (NIMH) Research Domain Criteria Project (RDoC). Moreover, the substrates subserving psychopathology seems to be unspecific and extend into other medical illnesses that share in common brain consequences, which includes metabolic disorders. Overall, accumulating evidence indicates that there is a consistent association of multiple abnormalities in neuropsychological constructs, as well as correspondent brain abnormalities, with broad-based metabolic dysfunction, suggesting, therefore, that the existence of a "metabolic-mood syndrome" is possible. Nonetheless, empirical evidence is necessary to support and develop this concept. Future research should focus on dimensional constructs and employ integrative, multidisciplinary and multimodal approaches.

A quantitative meta-analysis of neurocognitive functioning in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is associated with regional alterations in brain structure and function that are hypothesized to contribute to symptoms and cognitive deficits associated with the disorder. We present here the first systematic meta-analysis of neurocognitive outcomes associated with PTSD to examine a broad range of cognitive domains and describe the profile of cognitive deficits, as well as modifying clinical factors and study characteristics. This report is based on data from 60 studies totaling 4,108 participants, including 1,779 with PTSD, 1,446 trauma-exposed comparison participants, and 895 healthy comparison participants without trauma exposure. Effect-size estimates were calculated using a mixed-effects meta-analysis for 9 cognitive domains: attention/working memory, executive functions, verbal learning, verbal memory, visual learning, visual memory, language, speed of information processing, and visuospatial abilities. Analyses revealed significant neurocognitive effects associated with PTSD, although these ranged widely in magnitude, with the largest effect sizes in verbal learning (d = -.62), speed of information processing (d = -.59), attention/working memory (d = -.50), and verbal memory (d =-.46). Effect-size estimates were significantly larger in treatment-seeking than community samples and in studies that did not exclude participants with attention-deficit/hyperactivity disorder, and effect sizes were affected by between-group IQ discrepancies and the gender composition of the PTSD groups. Our findings indicate that consideration of neuropsychological functioning in attention, verbal memory, and speed of information processing may have important implications for the effective clinical management of persons with PTSD. Results are further discussed in the context of cognitive models of PTSD and the limitations of this literature.

Interactive effects of trait and state affect on top-down control of attention

Few studies have investigated how attentional control is affected by transient affective states while taking individual differences in affective traits into consideration. In this study, participants completed a color-word Stroop task immediately after undergoing a positive, neutral or negative affective context manipulation (ACM). Behavioral performance was unaffected by any ACM considered in isolation. For individuals high in trait negative affect (NA), performance was impaired by the negative but not the positive or neutral ACM. Neuroimaging results indicate that activity in primarily top-down control regions of the brain (inferior frontal gyrus and dorsal anterior cingulate cortex) was suppressed in the presence of emotional arousal (both negative and positive ACMs). This effect appears to have been exacerbated or offset by co-occurring activity in other top-down control regions (parietal) and emotion processing regions (orbitofrontal cortex, amygdala and nucleus accumbens) as a function of the valence of state affect (positive or negative) and trait affect (trait NA or trait PA). Neuroimaging results are consistent with behavioral findings. In combination, they indicate both additive and interactive influences of trait and state affect on top-down control of attention.

A meta-analysis of cognitive functions in children and adolescents with major depressive disorder

The cumulative prevalence rates of major depressive disorders (MDD) in children and adolescents averages 9.5 %. The majority of adults with MDD suffer from significant cognitive deficits, but the available neuropsychological data on the cognitive performance of children and adolescents with MDD yielded mixed results. Meta-analytic methods were used to assess the severity of cognitive deficits in children and adolescents with MDD as compared to healthy children and adolescents. We identified 17 studies comparing the intelligence, executive functions, verbal memory and attention of 447 patients with DSM-IV MDD and 1,347 healthy children and adolescents. Children and adolescents with MDD performed 0.194-0.772 (p < 0.001) standard mean differences worse than healthy control subjects in neuropsychological test procedures. The most pronounced deficits of children and adolescents with MDD were seen in inhibition capacity (STD = 0.772; p = 0.002), phonemic verbal fluency (STD = 0.756; p = 0.0001), sustained attention (STD = 0.522; p = 0.000), verbal memory (STD = 0.516; p = 0.0009) and planning (STD = 0.513; p = 0.014). We revealed cognitive deficits of children and adolescents with MDD in various cognitive domains. Long-term studies should investigate how the cognitive deficits of depressed youth affect their academic and social functioning, and whether age, comorbidity and depression severity play a role in this process.

The new DSM-5 diagnosis of mild neurocognitive disorder and its relation to research in mild cognitive impairment

The Diagnostic Statistical Manual-5 (DSM-5) has included a category named the neurocognitive disorder which was formally known in DSM-IV as 'dementia, delirium, amnestic, and other cognitive disorders'. The DSM-5 distinguishes between 'mild' and 'major' neurocognitive disorders. Major neurocognitive disorder replaces the DSM-IV's term 'dementia or other debilitating conditions'. A pivotal addition is 'mild neurocognitive disorder (mNCD)' defined by a noticeable decrement in cognitive functioning that goes beyond normal changes seen in aging. It is a disorder that may progress to dementia - importantly, it may not. Presently, our understanding of mNCD is derived from research on mild cognitive impairment (MCI). Whereas there is currently no clear treatment for mNCD, many experimental therapies now and into the future will focus upon secondary prevention, namely decreasing the risk of progression to major NCD. In this article, we will focus on mNCD by reviewing the relevant literature on MCI. We will review the research on the incidence and prevalence of MCI, conversion rates from MCI to dementia, risk factors for conversion of MCI to dementia, comorbidity of MCI with other neuropsychiatric disorders (NPS), and the development of treatment strategies for neuropsychiatric disorders in MCI. The presence of NPS is common among individuals with MCI and is an important risk for progression to dementia. However, there has been little research on effective treatments for NPS in MCI. Clinicians and investigators must determine if the treatment of the NPS in mNCD will improve quality of life and help reduce the progression of the cognitive impairment.

A quantitative meta-analysis of neurocognitive functioning in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is associated with regional alterations in brain structure and function that are hypothesized to contribute to symptoms and cognitive deficits associated with the disorder. We present here the first systematic meta-analysis of neurocognitive outcomes associated with PTSD to examine a broad range of cognitive domains and describe the profile of cognitive deficits, as well as modifying clinical factors and study characteristics. This report is based on data from 60 studies totaling 4,108 participants, including 1,779 with PTSD, 1,446 trauma-exposed comparison participants, and 895 healthy comparison participants without trauma exposure. Effect-size estimates were calculated using a mixed-effects meta-analysis for 9 cognitive domains: attention/working memory, executive functions, verbal learning, verbal memory, visual learning, visual memory, language, speed of information processing, and visuospatial abilities. Analyses revealed significant neurocognitive effects associated with PTSD, although these ranged widely in magnitude, with the largest effect sizes in verbal learning (d = -.62), speed of information processing (d = -.59), attention/working memory (d = -.50), and verbal memory (d =-.46). Effect-size estimates were significantly larger in treatment-seeking than community samples and in studies that did not exclude participants with attention-deficit/hyperactivity disorder, and effect sizes were affected by between-group IQ discrepancies and the gender composition of the PTSD groups. Our findings indicate that consideration of neuropsychological functioning in attention, verbal memory, and speed of information processing may have important implications for the effective clinical management of persons with PTSD. Results are further discussed in the context of cognitive models of PTSD and the limitations of this literature.

Deficits in behavioural inhibition in substance abuse and addiction: a meta-analysis

AIMS

Deficits in behavioural inhibitory control are attracting increasing attention as a factor behind the development and maintenance of substance dependence. However, evidence for such a deficit is varied in the literature. Here, we synthesised published results to determine whether inhibitory ability is reliably impaired in substance users compared to controls.

METHODS

The meta-analysis used fixed-effects models to integrate results from 97 studies that compared groups with heavy substance use or addiction-like behaviours with healthy control participants on two experimental paradigms commonly used to assess response inhibition: the Go/NoGo task, and the Stop-Signal Task (SST). The primary measures of interest were commission errors to NoGo stimuli and stop-signal reaction time in the SST. Additionally, we examined omission errors to Go stimuli, and reaction time in both tasks. Because inhibition is more difficult when inhibition is required infrequently, we considered papers with rare and equiprobable NoGo stimuli separately.

RESULTS

Inhibitory deficits were apparent for heavy use/dependence on cocaine, MDMA, methamphetamine, tobacco, and alcohol (and, to a lesser extent, non-dependent heavy drinkers), and in pathological gamblers. On the other hand, no evidence for an inhibitory deficit was observed for opioids or cannabis, and contradictory evidence was observed for internet addiction.

CONCLUSIONS

The results are generally consistent with the view that substance use disorders and addiction-like behavioural disorders are associated with impairments in inhibitory control. Implications for treatment of substance use are discussed, along with suggestions for future research arising from the limitations of the extant literature.

Executive Function Deficits in Daily Life Prospectively Predict Increases in Depressive Symptoms

Executive function (EF) deficits are associated with depression. Given that few prospective studies have been conducted, it is unclear whether deficits contribute to depression or result from it. The present study examined whether self-reported EF prospectively predicted worsening of depression symptoms. Time 1 (T1) shifting, inhibition, and working memory (WM) were assessed in relation to T1 and time 2 (T2) depressive symptoms in participants pre-selected to range in risk for depression. Analyses indicated that poorer EF at T1 predicted increases in depressive symptoms and furthermore that this relationship was specific to WM. In contrast, a bidirectional relationship was not evident, as depressive symptoms did not prospectively predict changes in EF. Finally, T1 EF accounted for T2 depressive symptoms beyond two well established predictors of depression: depressive symptoms at T1 and rumination at T2. These findings suggest that EF deficits play an active role in depression onset, maintenance, and/or recurrence.

More rumination and less effective emotion regulation in previously depressed women with preserved executive functions

BACKGROUND

Major depressive disorder is associated with very high recurrence rates, and specific vulnerability factors that increase the risk for repeated episodes should be identified. Impaired executive functions have repeatedly been found in remitted populations. The current study included both neutral and emotional executive tasks, and we expected to find impaired performance in unmedicated previously depressed women compared to controls. Furthermore, we hypothesized that the executive functions inhibition and shifting would be related to the ability to apply cognitive reappraisal and to avoid unhealthy rumination.

METHODS

Inhibition and shifting data derived from neutral and emotional computerized tasks, and questionnaire data on emotion regulation and trait rumination, were obtained from previously depressed (n = 109) and never-depressed women (n = 64) and analyzed in independent samples t-tests. A logistic regression analysis investigated the ability of emotion regulation and rumination to predict depression vulnerability. The associations of executive functions to emotion regulation and rumination were investigated in a series of linear regression analyses. Participants on psychotropic medication were excluded from all analyses of executive performance.

RESULTS

Previously depressed participants, the majority of which had experienced recurrent episodes, matched control participants on both neutral and emotional executive tasks. However, significantly more rumination and expressive suppression, and less cognitive reappraisal, were found in the previously depressed group. Executive function was unrelated to rumination and emotion regulation in this sample.

CONCLUSIONS

Previously depressed women whose executive function was intact were characterized by ruminative tendencies and more frequent use of expressive suppression. Trait rumination and expressive suppression are known to increase depression risk, but were unrelated to executive functions in this population. This indicates that unhealthy emotion regulation strategies may be targeted directly in preventive interventions.