General psychopathology is more important for executive functioning than diagnosis

Within-person increase in pathological worry predicts future depletion of unique executive functioning domains

BACKGROUND

Affective neuroscience and scar theories propose that increased excessive worry, the hallmark symptom of generalized anxiety disorder (GAD), predicts future declines in executive functioning (EF). However, the preponderance of cross-sectional designs used to examine between-person chronic worry-EF relationships has blocked progress on understanding their potentially causal within-person associations. Accordingly, this study used bivariate dual latent change score (LCS) models to test whether within-person increased GAD severity might relate to future reduced EF.

METHODS

Community-dwelling adults (N = 2581, 46 years on average, s.d. = 11.40, 54.71% female) were assessed for GAD symptom severity (Composite International Diagnostic Interview-Short Form) across three waves, spaced about 9 years apart. Three aspects of EF [inhibition, set-shifting, and mixing costs (MCs; a measure related to common EF)], were assessed with stop-and-go switch tasks. Participants responded to 20 normal and 20 reverse single-task block trials and 32 mixed-task switch block trials. EF tests were administered at time 2 (T2) and time 3 (T3), but not at time 1 (T1).

RESULTS

After controlling for T1 depression, LCS models revealed that within-person increased T1 - T2 GAD severity substantially predicted future reduced T2 - T3 inhibition and set-shifting (both indexed by accuracy and latency), and MC (indexed by latency) with moderate-to-large effect sizes (|d| = 0.51-0.96).

CONCLUSIONS

Results largely support scar theories by offering preliminary within-person, naturalistic evidence that heightened excessive worry can negatively predict future distinct aspects of cognitive flexibility. Effectively targeting pathological worry might prevent difficulties arising from executive dysfunction.

The C Factor: Cognitive dysfunction as a transdiagnostic dimension in psychopathology

Research into cognitive functions across psychological disorders suggests that cognitive deficiencies may be present across multiple disorders, potentially pointing to a transdiagnostic phenomenon. More recently, a single dimension model of psychopathology, the p factor, has been proposed, in which cognitive deficits are thought to be an intrinsic construct, assumed to be transdiagnostic. However, no systematic investigation to date tested this hypothesis. The aim of the present study was to systematically review meta-analyses to assess the hypothesis that the C factor (cognitive dysfunction) is transdiagnostic in psychopathology and review potential moderators that may account for such a phenomenon. We conducted a systematic review of meta-analyses examining cognitive function across all disorders for which data were available. Included meta-analyses (n = 82), comprising 97 clinical samples, yielded 1,055 effect sizes. Twelve major disorders/categories (e.g., bipolar disorder, substance use disorders) were included, comprising 29 distinct clinical entities (e.g., euthymic bipolar disorder; alcohol use disorder). Results show that all disorders reviewed are associated with underperformance across cognitive domains, supporting the hypothesis that the C factor (or cognitive dysfunction) is a transdiagnostic factor related to p. To examine moderators that may explain or contribute to c, we first consider important interpretative limitations of neuropsychological data in psychopathology. More crucially, we review oft-neglected motivational and emotional transdiagnostic constructs of p, as prominent contributing constructs to the C factor. These constructs are offered as a roadmap for future research examining these constructs related to p, that contribute, and may account for cognitive dysfunctions in psychopathology.

Cognitive functions in young adults with generalized anxiety disorder

Background:

Anxiety and worry are central symptoms of Generalized Anxiety Disorder (GAD) that have been theorized to negatively impact cognitive functions. However, most of the research has focused on threat-related or emotionally-charged stimuli, and a surprisingly small number of investigations examined ‘cold’ cognitive functions using classic neuropsychological tests. Such investigations are particularly important given that some theoretical models suggest compensatory mechanisms associated with anxiety that in certain circumstances may result in intact performance. The aim of the present study is to assess the neuropsychological profile associated with GAD, using a comprehensive neuropsychological battery.

Methods:

A sample of 23 college students meeting criteria for DSM-5 GAD and 20 control participants completed a psychometrically valid comprehensive computerized neuropsychological battery and clinical questionnaires.

Results:

The GAD sample presented with significantly elevated symptomatic rates of anxiety, worry, depression and stress. However, no significant differences were found on any neuropsychological outcome measures or domain indexes. Effect sizes were small, some of which favored the GAD sample.

Conclusion:

Despite substantial psychopathological burden, GAD exhibited intact cognitive functioning. These results support the Cognitive Control Theory of Anxiety, suggesting that elevated primary anxiety may not impact ‘cold’ cognitive functions in the absence of threat or substantial cognitive load. Given that this is one of the only studies employing a comprehensive neuropsychological battery in GAD, more research is needed in this population to replicate these results and to examine the impact of anxiety on cognitive functions at varying degrees of cognitive load in this population.

The impact of symptom severity on cognitive function in obsessive-compulsive disorder: A meta-analysis

Research on cognitive functions in obsessive-compulsive disorder (OCD) is notoriously heterogeneous with no moderators identified that account for this variability. OCD severity is the primary potential moderator of interest given the longstanding trait versus state debate. Nevertheless, severity has been previously assessed exclusively as a moderator and was not directly and systematically investigated. To address this gap in the literature, the aim of this study was to conduct a systematic meta-analytic review of correlations between cognitive function and symptom severity in OCD samples. Thirty-eight studies were included, allowing for analysis of 132 effects and meta-regression analyses for potential moderators. Small effects were found for the association between cognitive function and symptom severity on major neuropsychological domains, and some subdomains exhibited medium effects for this association. However, several significant methodological and conceptual problems were identified, including the use of the Yale-Brown Obsessive-Compulsive Scale that assesses severity in the past week and not at time of testing, a tendency to not report non-significant correlations, and problematic ecological validity of neuropsychological tests in OCD. In conclusion, we found a small-to-moderate degree of association between OCD symptom severity and cognitive function, but results should be interpreted cautiously given the limitations identified. We offer recommendations that will facilitate future research into this association and move the field beyond the largely stagnant debate about the state versus trait nature of cognitive functioning in OCD, and across disorders.

The association between executive functioning and psychopathology: general or specific?

BACKGROUND

We modeled both psychopathology and executive function (EF) as bi-factor models to study if EF impairments are transdiagnostic or relate to individual syndromes, and concurrently, if such associations are with general EF or specific EF impairments.

METHODS

Data were obtained from the Tracking Adolescents' Individual Lives Survey (TRAILS; N = 2230). Psychopathology was assessed with parent-report questionnaires at ages 11, 14, 16, and 19, and EF with tasks from the Amsterdam Neuropsychological Tasks program at ages 11 and 19. Bi-factor models were fitted to the data using confirmatory factor analysis. Correlations were estimated to study the associations between general or specific components of both psychopathology and EF.

RESULTS

A bi-factor model with a general psychopathology factor, alongside internalizing (INT), externalizing, attention deficit/hyperactivity (ADHD), and autism spectrum (ASD) problem domains, and a bi-factor model with a general EF factor, alongside specific EFs were adequately fitting measurement models. The best-fitting model between EF and psychopathology showed substantial associations of specific EFs with the general psychopathology factor, in addition to distinct patterns of association with ASD, ADHD, and INT problems.

CONCLUSIONS

By studying very diverse psychopathology domains simultaneously, we show how EF impairments cross diagnostic boundaries. In addition to this generic relation, ADHD, ASD, and INT symptomatology show separable profiles of EF impairments. Thus, inconsistent findings in the literature may be explained by substantial transdiagnostic EF impairments. Whether general EF or specific EFs are related to psychopathology needs to be further studied, as differences in fit between these models were small.

Executive function in children with externalizing and comorbid internalizing behavior problems

BACKGROUND

The goal of this study is to investigate differences in executive function (EF) in children with different levels of disruptive behavior problems (DBP).

METHODS

Ninety-three children between 7 and 12 years old with DBP were compared to 63 normally developing peers on a battery of EF tasks that varied in the amount of required emotion regulation ('hot' EF).

RESULTS

Differences in EF were found between DBP and comparison groups as indexed by hot EF tasks. Self-reported emotion scales, in conjunction with physiological recordings of heart rate, confirmed that emotions were elicited during hot EF.

CONCLUSIONS

Results suggest that difficulties in hot EF underlie externalizing problem behaviors in middle childhood.

Neurocognitive development in first episode psychosis 5 years follow-up: associations between illness severity and cognitive course

Cognitive deficits are documented in first-episode psychosis (FEP), but the continuing course is not fully understood. The present study examines the longitudinal development of neurocognitive function in a five year follow-up of FEP-patients, focusing on the relation to illness severity, as measured by relapses and diagnostic subgroups. The study is an extension of previous findings from the TIPS-project, reporting stability over the first two years. Sixty-two FEP patients (53% male, age 28 ± 9 years) were neuropsychologically examined at baseline and at 1, 2, and 5 year follow-ups. The test battery was divided into five indices; Verbal Learning, Executive Function, Impulsivity, Motor Speed, and Working Memory. To investigate the effect of illness severity, the sample was divided in groups based on number of relapses, and diagnostic subgroups, respectively. Impulsivity and Working Memory improved significantly in the first two years, followed by no change over the next three years. Motor Speed decreased significantly from 2 to 5 years. Number of relapses was significantly related to Verbal Learning and Working Memory, showing a small decrease and less improvement, respectively, in patients with two or more episodes. No significant association was found with diagnostic group. Neurocognitive stability as well as change was found in a sample of FEP-patients examined repeatedly over 5 years. Of potential greater importance for understanding how psychotic illnesses progress, is the finding of significant associations between neurocognition and number of relapses but not diagnostic group, indicating that neurocognition is more related to recurring psychotic episodes than to the descriptive diagnosis per se.

Do the same factors predict outcome in schizophrenia and non-schizophrenia syndromes after first-episode psychosis? A two-year follow-up study

OBJECTIVE

The aim of this two-year longitudinal study was to identify the best baseline predictors of functional outcome in first-episode psychosis (FEP). We tested whether the same factors predict functional outcomes in two different subsamples of FEP patients: schizophrenia and non-schizophrenia syndrome groups.

METHODS

Ninety-five patients with FEP underwent a full clinical evaluation (i.e., PANSS, Mania, Depression and Insight). Functional outcome measurements included the WHO Disability Assessment Schedule (DAS-WHO), Global Assessment of Functioning (GAF) and Clinical Global Impression (CGI). Estimation of cognition was obtained by a neuropsychological battery which included attention, processing speed, language, memory and executive functioning.

RESULTS

Greater severity of visuospatial functioning at baseline predicted poorer functional outcome as measured by the three functional scales (GAF, CGI and DAS-WHO) in the pooled FEP sample (explaining ut to the 12%, 9% and 10% of the variance, respectively). Negative symptoms also effectively contributed to predict GAF scores (8%). However, we obtained different predictive values after differentiating sample diagnoses. Processing speed significantly predicted most functional outcome measures in patients with schizophrenia, whereas visuospatial functioning was the only significant predictor of functional outcomes in the non-schizophrenia subgroup.

CONCLUSIONS

Our results suggest that processing speed, visuospatial functioning and negative symptoms significantly (but differentially) predict outcomes in patients with FEP, depending on their clinical progression. For patients without a schizophrenia diagnosis, visuospatial functioning was the best predictor of functional outcome. The performance on processing speed seemed to be a key factor in more severe syndromes. However, only a small proportion of the variance could be explained by the model, so there must be many other factors that have to be considered.

Stroop performance in major depression: selective attention impairment or psychomotor slowness?

BACKGROUND

Numerous neuropsychological studies reported impaired Stroop performance in major depressive disorder (MDD) patients.

METHODS

The present study attempted to identify possible neuropsychological mechanisms involved in this impairment in untreated MDD outpatients (n=75) as compared to healthy subjects (n=83). Inspection Time, Finger Tapping, Simple and Choice Reaction Time were considered as measures of perceptual, motor, psychomotor speed, and response selection, respectively.

RESULTS

MDD patients performed significantly slower than healthy controls in the neutral and the congruent conditions, but not in the incongruent ones. In order to identify predictors of Stroop performance, linear hierarchical regressions analyses were performed. Age, motor and psychomotor speed were predictors of response time and accuracy on Stroop performance. Significant correlations between response time and the number of errors in all three Stroop conditions were found in MDD patients, while such a correlation was obtained in the healthy controls only in the incongruent condition.

LIMITATIONS

Although education was included as a covariate in our analyses, suggesting that the observed effects could not be ascribed to education differences, further testing with education-matched samples is warranted.

CONCLUSIONS

Our study shows that the Stroop task performance is affected by both aging and MDD. Impairment in the Stroop performance can be predicted by psychomotor slowness and by vigilance level in MDD outpatients, but not by impairment of selective attention per se.

Cognitive factors for predicting treatment response in schizophrenic patients: one-year follow-up study

OBJECTIVE

This study was conducted to investigate the cognitive factors that can longitudinally predict the response to treatment in patients with schizophrenia.

METHODS

The subjects were 49 patients with schizophrenia who were newly hospitalized in an acute psychiatry ward and had not been treated with medication for at least 8 weeks prior to the study. The symptoms and cognitive functions of the patients were evaluated at baseline before treatment (T0), at eight weeks after treatment (T1), and one year after treatment (T2). Clinical symptoms were assessed using the PANSS, and cognitive functions were estimated using the Vigilance Test, Cognitrone Test, Wisconsin Card Sorting Test (WCST), and the Korean version of the Memory Assessment Scales (K-MAS).

RESULTS

The patient group showed marked impairments in cognitive function when compared to the normal group, but the patients' clinical symptoms and cognitive functions improved after drug treatment. The patients also showed consistent improvement in verbal and nonverbal memory function as time progressed. Furthermore, there was a significant correlation between clinical symptoms and cognitive functions in the patient group. The cognitive variables that best predicted treatment response and prognosis were total errors on the WCST and immediate list recall component of the K-MAS. It was also shown that the number of total errors on the WCST was a better cognitive predictor than the number of errors in immediate recall.

CONCLUSION

The results of the present study show that the neurocognitive functions of patients with schizophrenia can be stabilized with treatment intervention, that treatment response is related to improvement in cognitive function, and that cognitive domains, especially executive function, can predict treatment response and prognosis in patients with schizophrenia.

Neuropsychological and symptom predictors of aggression on the psychiatric inpatient service

Neuropsychological assessment of executive dysfunction may identify psychiatric patients who may be at high risk for aggressive behavior because impairment of the prefrontal cortex has been indicated as a possible anatomical correlate of aggression. No consensus, however, has been reached on the extent that executive dysfunction contributes to the formation of psychopathology and to aggressive behavior in psychiatric inpatients. We hypothesized a mediating model wherein patients' executive-functioning deficits contribute to the formation of psychopathological symptoms, which then underlies aggressive behavior. To test this model, we examined the relationship between executive functioning, psychiatric symptomatology, and aggressive behavior in 85 psychiatric inpatients presenting over an acute hospital admission using structure equation modeling techniques. The results revealed that psychiatric inpatients' executive function impairment significantly predicted the formation of psychiatric symptomatology, which in turn significantly contributed to the manifestation of aggressive behavior. Executive dysfunction also directly predicted inpatient aggressive behavior. Combining the indirect and direct effects, 59% of our inpatient aggression measure factor variance was accounted for by our measures of executive dysfunction and clinical symptom severity. These findings suggest that neurocognitive deficits underlie both psychiatric symptom formation and aggression. Patients with executive dysfunction may not possess the behavioral inhibition skills needed to cope with the presence of symptoms and other stressful events that accompany acute psychosis and hospitalization that may result, consequently, in increased manifestations of aggressive behavior.

Do symptom dimensions or categorical diagnoses best discriminate between known risk factors for psychosis?

OBJECTIVE

To describe symptom dimensions of psychosis using detailed psychopathological information from epidemiologically defined incident cases which include the full spectrum of functional psychosis across all age ranges. Then, assess the comparative usefulness of the dimensional and categorical representations of psychosis in discriminating between demographic and pre-morbid risk factors.

METHOD

A total of 464 incident cases of psychosis assessed with OPCRIT (Operational Checklist for Psychotic Symptoms) were included in an exploratory factor analysis. Using Regression analyses we modelled the associations of the dimensional and categorical representations of psychosis with antecedent validating variables and compared the subsequent models using the likelihood ratio test.

RESULTS

Factor analysis produced five-symptom dimensions, manic, disorganisation, depressive, delusional and auditory hallucinatory symptoms, explaining 58% of the total variance. Different dimensions were differentially associated with the pre-morbid risk factors. Neither the dimensional nor the categorical representations on their own were sufficient to explain associations with the antecedent validating variables.

CONCLUSION

Neither the dimensional or the diagnostic representation of psychosis was superior in discriminating between known risk factors, combining dimensional measures with categorical diagnoses will probably be more informative in determining the causes and correlates of psychosis.

The relationship between psychological dimensions of depressive symptoms and cognitive functioning in the elderly - the MEMO-Study

Aim of this study was to examine the association of symptom dimensions of depressive symptoms and cognitive functioning in the elderly. In a population-based study with 365 participants 65-83 years of age, dimensions of depressive symptoms were assessed with the four subscales of the CES-D-score and standardized cognitive tests assessing attention, memory, cognitive speed, and motor speed were performed. Compared to men, women scored significantly higher on the subscales for depressed affect and somatic complaints. Older participants had a significantly higher score for interpersonal difficulties. Participants with lower education had higher scores on all four psychological dimensions of depressive symptoms than those with high education (only significant for depressive affect). Individuals scoring high on CES-D subscales for depressive affect and somatic complaints had statistically significant (after Bonferroni adjustment) lower scores in attention and motor function in multivariate analyses. No significant associations between the symptom dimensions of positive affect and interpersonal difficulties with any of the cognitive tests were found in univariate and multivariate analyses (after Bonferroni adjustment). Our findings suggest specific patterns in the relationships between symptom dimensions of depressive symptoms and cognitive dysfunction in the general elderly population. This novel approach might be useful in addressing the heterogeneity of cognitive impairment in depression and in predicting cognitive outcome in depression.

Norwegian Norms and Factor-Structure of Phonemic and Semantic Word List Generation

Word list generation (WLG) tasks are used world wide as measures of executive function, although the tests are sensitive also to deficits in other cognitive functions. Norms derived from English-speaking samples are often used in Norway, even though the consequences of language differences are not yet been assessed. The reliability of WLG testing in Norway is increased by the norms presented in the first part of the study. The validity of WLG tests as measures of executive function is addressed in the second part, by performing a factor-analysis of neuropsychological performance in a mixed psychiatric sample. Education contributed most to performance. There were no sex-differences in overall performance. Factor analysis indicated that phonemic WLG is a more specific measure of executive function than semantic WLG. Semantic WLG correlated higher with basal processing speed, thus being more sensitive to aging. In conclusion the clinical neuropsychologist is advised to control for reduction in basal processing speed before interpreting WLG scores as specific deficits in executive function. The Norwegian norms correspond well with most comparable studies in other languages, thus failing to show any language specific effects.

Severe and persistent mental illness: a useful definition for prioritizing community-based mental health service interventions

OBJECTIVE

There is a lack of consensus on the identification of seriously mentally ill patients (SMI). This study investigates the external and predictive validity of an operationalized definition for the severity and persistency of mental illness applied to a sample of service users attending a community mental health service.

METHOD

The definition is based on the fulfilment of dysfunction (GAF < or = 50) and illness duration (> or = 2 yrs) criteria. The study was conducted with a two-year longitudinal design. External and predictive validity of the SMI definition were assessed against the diagnosis of psychosis.

RESULTS

Our data show evidence for an overall high predictive and external validity of the SMI definition and high sensitivity in predicting those with high burden of mental illness.

CONCLUSIONS

In order to identify people with high levels of psychiatric burden, the SMI working definition seems to be more useful than that simply based on diagnostic criteria.

Neuropsychological test profiles in schizophrenia and non-psychotic depression

OBJECTIVE

The study examined to what degree schizophrenia is characterized by a neuropsychological (NP) test profile specific in shape and level compared with depression and normal functioning.

METHOD

Fifty-three patients with schizophrenia, 45 with non-psychotic depression, and 50 normals were assessed with a comprehensive NP test battery and clinical instruments. NP test scores were factor analyzed into seven composite scores.

RESULTS

Schizophrenia patients performed significantly below normals across all seven composite scores, whereas depression patients were impaired in two. Verbal memory was most impaired. Sixty-two percent of schizophrenia patients were moderately or severely impaired, the corresponding figure for depression was 28%. Impairment was moderately associated with IQ level and clinical symptom load in schizophrenia, but not in depression.

CONCLUSION

Schizophrenia is characterized by deficits across a wide range of NP functions. Thirty-eight percent of the patients are within normal limits. A mild and limited NP disturbance is apparent in depression.

Neuropsychological functions predict 1- and 3-year outcome in first-episode psychosis

OBJECTIVE

To examine neuropsychological performance as a possible predictor of course and outcome in first-episode psychotic (FEP) patients.

METHOD

A group of consecutive FEP patients (n = 120) tested with Wechsler Adult Intelligence Scales-Revised (WAIS-R) at baseline was compared with a healthy group (n = 30) matched for age, education and gender. Relationship between WAIS-R and both Brief Psychiatric Rating Scale and Global Assessment of Function (GAF) ratings were studied at baseline and at 1- and 3-year follow-ups.

RESULTS

The performance of FEP patients was significantly lower (P < 0.001) than that of healthy comparison subjects on all WAIS-R subtests except for Information and Comprehension. The WAIS-R scores of patients with schizophrenia syndromes (DSM-IV) were lower than those of patients with non-schizophrenia syndromes on Block Design. Low WAIS-R Full-Scale IQ scores in FEP patients predicted the presence of negative symptoms at 1-year follow-up and of low GAF ratings at 3-year follow-up.

CONCLUSION

Neurocognitive performance at admission appears to predict various aspects of functional outcome in FEP.

Cortisol level predicts executive and memory function in depression, symptom level predicts psychomotor speed

OBJECTIVE

On a group level depression is related to hypercortisolism and to psychomotor retardation, executive dysfunction and memory impairment. However, intra-group heterogeneity is substantial. Why some are impaired while others remain in the normal range, is not clear. The present study aims at discerning the relative contribution of present symptom severity and hypercortisolism to impairment in the three domains of cognition.

METHOD

Morning saliva cortisol was measured in 26 subjects with recurrent major depression prior to a neuropsychological examination with tests known to be sensitive to cognitive impairment in depression.

RESULTS

Cortisol level correlated with executive dysfunction and post-encoding memory deficits, but not with processing speed. Depression level correlated with processing speed. These patterns remained significant after controlling for confounders through partial correlations.

CONCLUSION

The association between cortisol and cognition is not an artifact of psychiatric symptom load. High level of saliva cortisol is associated with aspects of cognition that can be dissociated from psychomotor retardation, which is dependent on symptom load.