Biomedical subjects

Volker Arolt

Publications and source records attributed to Volker Arolt.

At least 19 recordsLinked to original sources

PubMed2026

Effects of quetiapine on cognitive functioning in schizophrenia: evidence for the remyelination hypothesis?

Postmortem findings, neuroimaging data, and in-vitro models suggest a decrease in number and density of oligodendrocytes is driving cognitive deficits in schizophrenia (SCZ). Second-generation antipsychotics are discussed to improve oligodendrocyte dysfunction with most conclusive evidence available for quetiapine (QET). We postulate that sustained QET treatment leads to cognitive improvement in SCZ, particularly, in tests with high demands for working memory function. We further hypothesize that these effects are moderated by polygenic factors associated with hippocampus-related brain volumes, general white matter integrity, and/or oligodendroglia-related SCZ risk. Using data of the prospective PsyCourse study, we identified 166 patients with SCZ spectrum disorder receiving QET at one or two consecutive visits plus 166 matched patients without QET. Polygenic scores were calculated for subcortical brain volumes, measures of white matter integrity, and for cell type-specific genetic SCZ risks. QET treatment was consistently associated with improved cognitive function independent of time, specifically, in tests with high, but not with low to medium working memory load. Polygenic analyses did not reveal significant moderation effects. In contrary, low genetic SCZ risk specific for genes related to human oligodendrocyte function was associated with higher cognitive performance independent from QET. While we observed improved cognitive performance under QET in high working memory tests, we did not find evidence that polygenic factors associated with hippocampus-related brain volumes, white matter integrity, or oligodendroglia-related SCZ risk moderate this association. Thus, our tentative findings do not provide evidence for the hypothesis that polygenic estimates of hippocampal remyelination capacities influence the association between QET and cognitive performance in SCZ.

Humans↗

PubMed2007

Association between IL-8 cytokine and cognitive performance in an elderly general population--the MEMO-Study.

OBJECTIVES: To investigate the associations between circulating cytokines and specific neuropsychological domains of cognitive functioning (memory, processing speed and motor function) and general cognitive function (MMSE) in healthy elderly individuals. METHODS: In a cross-sectional study of 369 community dwelling elderly subjects, we examined the relationship between serum IL-1beta, sIL-4R, IL-6, IL-8, IL-10, IL-12 and TNF-alpha concentrations and cognitive performance using an extensive standardized and validated cognitive test battery assessing memory, word fluency, perceptual/cognitive speed, attention and executive functioning, and motor speed. RESULTS: Multivariate analysis adjusted for various confounders and Bonferroni correction for multiple comparisons demonstrated that increased serum concentrations of IL-8 were associated with poor performance in the memory and speed domains and in motor function. No significant associations were found between the remaining cytokines and domains of cognitive functioning. Global cognitive functioning, as measured with MMSE, was not associated with any cytokine. CONCLUSIONS: This study suggests an association between circulating IL-8 concentrations and cognitive dysfunction in the elderly. An interaction between this cytokine and glial cells may help explain the pathophysiological mechanisms leading to cognitive impairment in our study group.

Aged↗

PubMed2007

Cognitive coping style modulates neural responses to emotional faces in healthy humans: a 3-T FMRI study.

Repression designates coping strategies that aim to shield the organism from distressing stimuli by disregarding their aversive characteristics. In contrast, sensitization comprises coping strategies that are employed to reduce situational uncertainty such as analyzing the environment. Functional magnetic resonance imaging was used to study neural correlates of coping styles during the perception of threatening and nonthreatening socially relevant information. Pictures of human faces bearing fearful (ambiguously threatening), angry (unambiguously threatening), happy (nonthreatening), and neutral expressions were presented masked and unmasked. Two groups of subjects were examined who were defined as consistent repressors versus consistent sensitizers with the Mainz Coping Inventory. Sensitizers tended to exhibit stronger neural responses in the amygdala to unmasked fearful faces compared with repressors. Overall, repressors were cortically more responsive to fearful (ambiguously threatening) and happy (nonthreatening) facial expressions than sensitizers, whereas sensitizers presented an enhanced responsivity to angry faces in several prefrontal areas, that is, unambiguously threatening expressions. Results from time series analyses suggest that sensitizers could exhibit less top-down cortical regulation of the amygdala than repressors in the processing of fearful faces. An increased responsivity of the amygdala to ambiguously threatening stimuli may represent a biological determinant of sensitizers' feelings of uncertainty.

Adaptation, Psychological↗

PubMed2006

Amygdala reactivity predicts automatic negative evaluations for facial emotions.

The amygdala is a key structure in a limbic circuit involved in the rapid and unconscious processing of facial emotions. In the present study, the role of the amygdala in automatic, involuntary appraisal processes, which are believed to be a crucial component of emotion processing, was investigated in 23 healthy subjects. Amygdala activity was recorded in response to masked displays of angry, sad, and happy facial expressions using functional magnetic resonance imaging (fMRI). In a subsequent experiment, the subjects performed a masked affective priming task that characterizes automatic emotion processing by investigating the biasing effect of subliminally presented emotional faces on evaluative ratings to subsequently presented neutral stimuli. In the affective priming task, significant valence-congruent evaluation manipulation was observed. Subjects rated neutral targets more positively if they were primed by happy faces. Significant correlations were found between amygdala responses to masked negative facial expressions and negative evaluation shifts elicited by the corresponding emotion quality in the affective priming task. Spontaneous amygdala reactivity to facial emotions appears to be a determinant of automatic negative evaluative response tendencies. This finding might shed some light on how amygdala hyperresponsivity contributes to negative cognitive biases commonly observed in affective disorders.

Adult↗

PubMed2006

Glial cell activation in a subgroup of patients with schizophrenia indicated by increased S100B serum concentrations and elevated myo-inositol.

Post-mortem and in-vivo studies support the hypothesis that astrocytes might be involved in the pathogenesis of schizophrenia. To further substantiate this hypothesis two markers of astroglial activation (myo-inositol, S100B) acquired with independent methods ((1)H-MRS, quantitative immunoassay) were concomitantly measured in schizophrenic patients. Patients with increased S100B levels showed elevated myo-inositol concentrations. This pilot study demonstrates a concomitant elevation of two markers indicating astrocyte activation in a subgroup of schizophrenic patients.

Adult↗

PubMed2006

Cognitive impairment and in vivo metabolites in first-episode neuroleptic-naive and chronic medicated schizophrenic patients: a proton magnetic resonance spectroscopy study.

Involvement of the prefrontal cortex in schizophrenia has been implicated by neuropsychological, as well as neuropathological and imaging studies. Reductions of N-acetylaspartate (NAA), an in vivo marker of neuronal integrity, have repeatedly been detected in the frontal lobes of patients with schizophrenia by proton magnetic resonance spectroscopy (1H-MRS). In chronic medicated patients, a positive correlation between NAA levels of the prefrontal cortex and cognitive functioning has been observed, but to date, there have been no studies in first-episode neuroleptic-naive patients. In this study, single-voxel 1H-MRS was used to investigate neuronal function of the dorsolateral prefrontal cortex in 15 first-episode and 20 chronic schizophrenic patients. Outcomes were compared to 20 age-matched healthy controls to assess the relationship between prefrontal metabolism and neuropsychological performance. Patients with chronic schizophrenia had significant reductions of NAA, glutamate/glutamine, and choline levels compared to first-episode patients and healthy controls. Furthermore, creatine and phosphocreatine were significantly reduced in both patient groups compared to healthy controls. In the neuropsychological tests, chronic schizophrenic patients performed significantly poorer in the Auditory Verbal Learning Task (AVLT) compared to first-episode patients. In both patient groups, NAA levels of the left frontal lobe significantly correlated with performances in verbal learning and memory. These results corroborate data from recent structural and spectroscopic imaging studies of the frontal lobes in schizophrenia, in which cortical gray matter reductions after onset of symptoms as well as reduced levels of NAA in chronic, but not in first-episode schizophrenic patients have been reported.

Adult↗

PubMed2006

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.

Age Factors↗

PubMed2006

The association between depressive mood and cognitive performance in an elderly general population - the MEMO Study.

The aim of this study was to analyse the influence of the severity of depressive symptoms on different domains of cognitive function in the elderly. In a population-based cross-sectional study, 385 participants aged 65-83 years were interviewed with the Center for Epidemiologic Studies Depression Scale (CES-D) and performed a standardized neuropsychological test assessing attention, memory, cognitive speed and motor function. Multivariate linear regression analyses revealed a significant effect of depressive symptoms on a single test (Stroop test 1) and two summary scores (memory and motor function). After full adjustment for education and Mini Mental State Examination, the memory score was partly attenuated. Stratified analysis showed that an increase in CES-D scores led to a larger decline of cognitive test results in participants with mild to moderate depressive symptoms, compared to those with a high degree of depressive symptoms. Our results suggest that depressive mood in older adults is primarily associated with decreased processing speed and motor functioning, but not executive control functions. According to our results depressive mood is not necessarily associated with memory deficits in older adults. Changes in depressive symptoms in milder forms of depressive mood are associated with a larger decline in cognitive function than in severer forms of depressive mood.

Affect↗

PubMed2006

Evidence from increased anticipation of predictive saccades for a dysfunction of fronto-striatal circuits in obsessive-compulsive disorder.

In obsessive-compulsive disorder (OCD), a dysfunction of neuronal circuits involving prefrontal areas and the basal ganglia is discussed that implies specific oculomotor deficits. Performance during reflexive and predictive saccades, antisaccades and predictive smooth pursuit was compared between patients with OCD (n=22), patients with schizophrenia (n=21) and healthy subjects (n=24). Eye movements were recorded by infrared reflection oculography. In both patient groups, higher frequencies of anticipatory saccades with reduced amplitudes in the predictive saccade task were observed. Additionally, reduced smooth pursuit eye velocity and increased frequencies of saccadic intrusions during smooth pursuit as well as increased error rates in the antisaccade task were demonstrated for patients suffering from schizophrenia. Patients with OCD and schizophrenia revealed different patterns of oculomotor impairment: whereas increased anticipation of predictive saccades provides evidence for a dysfunction of the circuit between the frontal eye field and the basal ganglia in both groups, results from the antisaccade task imply additional deficits involving the dorsolateral prefrontal cortex in schizophrenic patients. Furthermore, the cortical network for smooth pursuit (especially the frontal eye field) is also assumed to be disturbed in schizophrenia.

Adult↗

PubMed2006

Subliminal affective priming in clinical depression and comorbid anxiety: a longitudinal investigation.

In the present study, the sequential affective priming paradigm developed by Fazio et al. [Fazio, R.H., Sanbonmatsu, D.M., Powell, M.C., Kardes, F.R., 1986. On the automatic activation of attitudes. Journal of Personality and Social Psychology 50, 229-238.] was applied for the first time to investigate automatic cognitive bias in depressed patients. Unipolar depressed patients (n=22) were tested on admission and after about 7 weeks of inpatient psychotherapy. Half of the patients (n=11) were suffering from a comorbid anxiety disorder. Twenty-two healthy subjects served as controls. Affectively polarized prime words were presented subliminally followed by positive or negative target words, which had to be evaluated. Subjects' affective state was assessed by self-report measures. In the course of psychotherapy, patients recovered significantly. Study groups exhibited qualitatively different affective priming effects: In non-comorbid depressed patients, no affective priming was found. Instead, a highly significant main effect of prime valence emerged, indicating a Stroop-like interference of negative prime words at time 1. This negative bias was associated with depression level at time 1 and could not be found after recovery. Affective priming was observed in controls and comorbid patients, but in opposite directions. Direction and strength of affective priming was directly associated with anxiety level at both times. The affective priming paradigm provides evidence for differential group effects regarding unconscious emotional information processing.

Adult↗

PubMed2006

Amygdala activation during masked presentation of emotional faces predicts conscious detection of threat-related faces.

It has been argued that critical functions of the human amygdala are to modulate the moment-to-moment vigilance level and to enhance the processing and the consolidation of memories of emotionally arousing material. In this functional magnetic resonance study, pictures of human faces bearing fearful, angry, and happy expressions were presented to nine healthy volunteers using a backward masking procedure based on neutral facial expression. Activation of the left and right amygdala in response to the masked fearful faces (compared to neutral faces) was significantly correlated with the number of fearful faces detected. In addition, right but not left amygdala activation in response to the masked angry faces was significantly related to the number of angry faces detected. The present findings underscore the role of the amygdala in the detection and consolidation of memory for marginally perceptible threatening facial expression.

Adult↗

PubMed2006

Unimpaired automatic processing of verbal information in the course of clinical depression.

In this study automatic processing of verbal information was investigated in 22 clinically depressed inpatients and 22 healthy controls in a longitudinal design. A semantic priming task with word pronunciation was administered twice, about 7 weeks apart. Following brief presentations of prime words, subjects had to read target words aloud as quickly as possible. Prime words were directly related, indirectly related, or unrelated to the target words. Stimulus onset asynchrony (SOA) of prime and target was 250 ms. In the course of inpatient treatment, patients recovered significantly. Semantic priming occurred in both study groups for the directly and indirectly related conditions across both testing times. As expected, directly related primes resulted in stronger priming than indirectly related primes. Patients and controls did not differ in semantic priming at either time or relatedness condition. Size of priming was not associated with depression severity, anxiety level, intelligence, medication, or clinical features. We conclude that depression is not characterized by dysfunctional automatic processing of verbal information.

Adult↗

PubMed2006

Memory performance in severely depressed patients treated by electroconvulsive therapy.

OBJECTIVES: Depression is accompanied by disturbed implicit (unconscious) and explicit (conscious) memory functions. The aim was the assessment of immediate and delayed verbal and visual memory functions, concentration/attention during the course of electroconvulsive therapy (ECT) treatment. METHODS: Twenty severely depressed, drug-treatment resistant, elderly patients were assessed with the Wechsler Memory Scale-Revised (WMS-R) before and at the end of the ECT series. RESULTS: Patients revealed deficits in acquisition (immediate verbal and visual memory), attention/concentration, and retrieval of information (delayed memory) before ECT. After ECT, significant improvements were observed in immediate memory but not in delayed memory. Although higher total stimulation levels (millicoulombs) (P = 0.015) were associated with improvements in immediate visual memory, we found that longer duration of convulsions (P = 0.016) as well as lower levels of stimulation at last ECT (P = 0.036) were associated with improvements in immediate verbal memory. Moreover, we found that stimulation energy (millicoulombs) in total and at last ECT was the best predictor among several clinical and ECT parameters of improved visual memory and concentration and decreased verbal and general memory. CONCLUSIONS: Prefrontal cortex-related memory processes, especially immediate memory encoding, improved after ECT, whereas long-term memory remained impaired, indicating that severely depressed patients remain cognitively inferior to normal subjects despite clinically successful treatment. This study may yield a better understanding of the time course of memory alterations in severely depressed patients receiving ECT. Improvement of immediate memory may be essential for establishing normal daily activities of life in the recovery phase of depression.

Major Depressive Disorder↗

PubMed2006

Associations between major depression, bipolar disorders, dysthymia and cardiovascular diseases in the general adult population.

BACKGROUND: Cardiovascular diseases (CVD) and affective disorders are both very prevalent in the general population. However, it is unclear on a population level if the prevalence of different subtypes of affective disorders like unipolar major depression or dysthymia is different in individuals with specific CVDs. METHODS: In 4,181 participants of the general population, lifetime prevalences for affective disorders were assessed through the Composite International Diagnostic Interview and cardiovascular diseases by self-report and subsequent physician-verified diagnosis. Multivariable logistic regression was used in the analysis. RESULTS: Prevalences of unipolar depression, bipolar disorder and dysthymia were significantly higher in participants with coronary heart disease or stroke compared to those without these CVDs. Dysthymia had a stronger (OR = 2.03; 95% CI = 1.21-3.39) association with coronary heart disease than unipolar depression (OR = 1.58; 95% CI = 1.09-2.30) or any depression (OR = 1.92; 95% CI = 1.37-2.70). In contrast, unipolar depression (OR = 2.27; 95% CI = 1.29-3.99) showed a significant OR for the relation with stroke compared to dysthymia that reached no statistical significance. The commonly used category 'any depression' revealed higher odds (OR = 2.50; 95% CI = 1.46-4.28) for the relationship with stroke than unipolar depression or dysthymia, but lower odds than bipolar I disorder (OR = 5.71, 95% CI = 1.23-26.66). CONCLUSIONS: Classification into diagnostic subgroups of affective disorders is important for an improved clinical and pathophysiological understanding of their relationship with CVDs. Dysthymia, in particular, plays an important role regarding the relation of affective disorders and CVDs. Future research on biological models may elucidate the pathophysiological link between subtypes of affective disorders and CVDs.

Adolescent↗

PubMed2005

Masked facial affect priming is associated with therapy response in clinical depression.

In the present study, automatic processing of facial affect in clinical depression was investigated in the course of an inpatient treatment program. Patients suffering from clinical depression (n = 20) and healthy controls (n = 21) completed the facial affective priming task developed by Murphy and Zajonc (1993) twice, about 7 weeks apart. Subjects were instructed to evaluate neutral Chinese ideographs primed by masked displays of sad, happy, and neutral facial affect, including a no-prime condition. In the course of treatment, patients recovered significantly. In acutely depressed patients, no priming based on emotional faces could be found compared to neutral faces at time 1. However, compared to the no-prime condition, negative evaluation shifts elicited by neutral and sad faces were found which were significantly correlated with symptom severity. Patients with persisting high levels of depression after therapy judged ideographs more negatively in all three facial prime conditions at time 1. We conclude that clinically depressed patients are characterized by automatic processing biases for facial affect. An enhanced sensitivity for sad facial expressions and a negatively biased automatic processing of neutral and happy facial affect appears to be associated with depression persistence.

Adult↗

PubMed2005

Visual backward masking: deficits in locating targets are specific to schizophrenia and not related to intellectual decline.

Visual backward masking deficits have been postulated as potential vulnerability markers for schizophrenia. This study investigated the diagnostic specificity of a location and an identification variant of the backward masking task for schizophrenia and analyzed masking performance during the course of the tasks. The influence of schizophrenia patients' intellectual decline on masking performance was also examined. Twenty-eight schizophrenia patients were compared to 28 patients with unipolar depression and 28 healthy controls on a letter location task and a letter identification task applying a low spatial frequency mask. Schizophrenia patients made significantly more detection errors on the location task than depressives at an interstimulus interval (ISI) of 50 ms and healthy controls at ISIs of 16.7, 33.3, 50, and 66.7 ms. Thus, the location masking dysfunction of schizophrenia patients was distinctive at a rather long interstimulus interval (50 ms). On the identification task the performance of schizophrenia patients did not differ from that of the two control groups. Identification but not location masking performance improved during the course of the task for all groups. Intellectual deterioration of schizophrenia patients was not correlated with location or identification masking performance. Schizophrenia patients are characterized by specific impairments in spatial visual processing which appear to be independent of intellectual decline. Potential explanations of the location masking deficit found in schizophrenia are discussed.

Adult↗

PubMed2005

Association of the functional -1019C/G 5-HT1A polymorphism with prefrontal cortex and amygdala activation measured with 3 T fMRI in panic disorder.

Serotonergic genes have been implicated in the pathogenesis of panic disorder and amygdala function in response to fearful stimuli. Regional brain activation on visual presentation of emotional facial stimuli was investigated in 20 patients with panic disorder by means of fMRI at 3 T. All patients were genotyped for the functional -1019C/G 5-HT1A and 5-HTTLPR polymorphisms. In patients homozygous for the 5-HT1A -1019G risk allele (n=5), fearful stimuli were associated with a decreased activation of right prefrontal cortex regions. Patients homozygous for the 5-HT1A -1019G risk allele or patients carrying the short risk allele of the 5-HTTLPR (n=13) showed higher amygdala activation in response to happy faces. This exploratory study suggests a role of the functional -1019C/G 5-HT1A and 5-HTTLPR polymorphisms on prefrontal cortex and amygdala activation patterns in response to emotional facial stimuli. These serotonergic polymorphisms might increase the risk for panic disorder by contributing to an altered processing of emotional stimuli.

Adult↗

PubMed2005

Evidence for glutamatergic neuronal dysfunction in the prefrontal cortex in chronic but not in first-episode patients with schizophrenia: a proton magnetic resonance spectroscopy study.

Based upon pharmacological challenge and postmortem studies, schizophrenia has been hypothesized to be caused by decreased glutamatergic neurotransmission. We investigated the glutamatergic neuronal metabolism of the dorsolateral prefrontal cortex with localized 1H magnetic resonance spectroscopy in 18 first-episode patients, 21 chronic patients with schizophrenia, and 21 age-matched controls. Chronic patients had significantly lower levels of glutamate/glutamine (Glx) and N-acetylaspartate (NAA) compared to healthy controls and first-episode patients. Reduced metabolite levels were not correlated with duration of illness or medication. Our results indicate glutamatergic dysfunction in chronic schizophrenia that could be evidence of a progressive brain disorder.

Adult↗