Marek Preiss

Cognitive deficits in the euthymic phase of unipolar depression

Although neuropsychological deficits have been reported in patients with major depressive disorder (MDD) during an acute episode, relatively little is known about the persistence of these deficits in remission. This study investigated the performance of attention, executive function and verbal memory during remission from unipolar depressive episodes. We tested the hypothesis that outpatients do not differ in cognitive variables from controls. We did this using a well-defined outpatient sample, consisting of medicated and unmedicated patients, with a history of MDD. Ninety-seven subjects with MDD in remission ranging from young to old were compared with 97 healthy control subjects. Both samples were balanced for age, gender, and education levels. The Auditory Verbal Learning Test (AVLT) and the Trail Making Test (TMT) were used. Patients with remitted MDD, in comparison with controls, were impaired on tasks of attention, executive function and verbal memory. The individual level of depressive symptoms was not related to the cognitive performance. Small- to medium-sized significant correlations exist between cognitive test variables (as represented by Trail Making B and AVLT delayed recall) and level of depressive symptomatology (as measured by MADRS or BDI-II) in the total sample, indicating that higher levels of depressive symptomatology are associated with lower cognitive function. These findings suggest deficits in attention and delayed verbal recall can serve as an indicator for MDD in outpatients.

Probable neuroimmunological link between Toxoplasma and cytomegalovirus infections and personality changes in the human host

BackgroundRecently, a negative association between Toxoplasma-infection and novelty seeking was reported. The authors suggested that changes of personality trait were caused by manipulation activity of the parasite, aimed at increasing the probability of transmission of the parasite from an intermediate to a definitive host. They also suggested that low novelty seeking indicated an increased level of the neurotransmitter dopamine in the brain of infected subjects, a phenomenon already observed in experimentally infected rodents. However, the changes in personality can also be just a byproduct of any neurotropic infection. Moreover, the association between a personality trait and the toxoplasmosis can even be caused by an independent correlation of both the probability of Toxoplasma-infection and the personality trait with the third factor, namely with the size of living place of a subject. To test these two alternative hypotheses, we studied the influence of another neurotropic pathogen, the cytomegalovirus, on the personality of infected subjects, and reanalyzed the original data after the effect of the potential confounder, the size of living place, was controlled.MethodsIn the case-control study, 533 conscripts were tested for toxoplasmosis and presence of anti-cytomegalovirus antibodies and their novelty seeking was examined with Cloningers TCI questionnaire. Possible association between the two infections and TCI dimensions was analyzed.ResultsThe decrease of novelty seeking is associated also with cytomegalovirus infection. After the size of living place was controlled, the effect of toxoplasmosis on novelty seeking increased. Significant difference in novelty seeking was observed only in the largest city, Prague.ConclusionToxoplasma and cytomegalovirus probably induce a decrease of novelty seeking. As the cytomegalovirus spreads in population by direct contact (not by predation as with Toxoplasma), the observed changes are the byproduct of brain infections rather than the result of manipulation activity of a parasite. Four independent lines of indirect evidence, namely direct measurement of neurotransmitter concentration in mice, the nature of behavioral changes in rodents, the nature of personality changes in humans, and the observed association between schizophrenia and toxoplasmosis, suggest that the changes of dopamine concentration in brain could play a role in behavioral changes of infected hosts.

Differences in onset of disease and severity of psychopathology between toxoplasmosis-related and toxoplasmosis-unrelated schizophrenia.

Toxoplasmosis is a lifelong parasitic disease that appears to be associated to schizophrenia. However, no distinguishing attributes in Toxoplasma‐infected schizophrenia patients have been described as yet.

Czech Version of the Trail Making Test: Normative Data and Clinical Utility

The Trail Making Test (TMT) comprises two psychomotor tasks that measure a wide range of visual-perceptual and executive functions. The purpose of this study was to provide Czech normative data and to examine the relationship between derived TMT indices and demographic variables. The TMT was administered to 421 healthy adults. Two clinical groups (n = 126) were evaluated to investigate the clinical utility of the TMT-derived scores: amnestic mild cognitive impairment (n = 90) and Alzheimers disease (n = 36). Statistical analyses showed that age and education, but not gender, were significantly associated with TMT completion times and derived scores. Of all the indices, only the TMT ratio score was insensitive to age. We present normative values for the Czech version of the TMT, providing a reference for measuring individual performance in native Czech speakers. Moreover, we found that accuracy on the TMT was improved with the attenuation of age.

Personalized Cognitive Training in Unipolar and Bipolar Disorder: A Study of Cognitive Functioning

Patients with unipolar depressive disorder and in the depressive phase of bipolar disorder often manifest psychological distress and cognitive deficits, notably in executive control. We used computerized cognitive training in an attempt to reduce psychological affliction, improve everyday coping, and cognitive function. We asked one group of patients (intervention group) to engage in cognitive training three times a week, for 20 min each time, for eight consecutive weeks. A second group of patients (control group) received standard care only. Before the onset of training we administered to all patients self-report questionnaires of mood, mental and psychological health, and everyday coping. We also assessed executive control using a broad computerized neurocognitive battery of tests which yielded, among others, scores in Working Memory, Shifting, Inhibition, Visuomotor Vigilance, Divided Attention, Memory Span, and a Global Executive Function score. All questionnaires and tests were re-administered to the patients who adhered to the study at the end of training. When we compared the groups (between-group comparisons) on the amount of change that had taken place from baseline to post-training, we found significantly reduced depression level for the intervention group. This group also displayed significant improvements in Shifting, Divided Attention, and in the Global executive control score. Further exploration of the data showed that the cognitive improvement did not predict the improvements in mood. Single-group data (within-group comparisons) show that patients in the intervention group were reporting fewer cognitive failures, fewer dysexecutive incidents, and less difficulty in everyday coping. This group had also improved significantly on the six executive control tests and on the Global executive control score. By contrast, the control group improved only on the reports of cognitive failure and on working memory.

Czech version of Rey Auditory Verbal Learning test: Normative data

ABSTRACT The present study provides normative data stratified by age for the Rey Auditory Verbal Learning test Czech version (RAVLT) derived from a sample of 306 cognitively normal subjects (20–85 years). Participants met strict inclusion criteria (absence of any active or past neurological or psychiatric disorder) and performed within normal limits on other neuropsychological measures. Our analyses revealed significant relationships between most RAVLT indices and age and education. Normative data are provided not only for basic RAVLT scores, but for the first time also for a variety of derived (gained/lost access, primacy/recency effect) and error scores. The study confirmed a logarithmic character of the learning slope and is consistent with other studies. It enables the clinician to evaluate more precisely subject’s RAVLT memory performance on a vast number of indices and can be viewed as a concrete example of Quantified Process Approach to neuropsychological assessment.

Post- and peritraumatic stress in disaster survivors: An explorative study about the influence of individual and event characteristics across different types of disasters

Background : Examination of existing research on posttraumatic adjustment after disasters suggests that survivors’ posttraumatic stress levels might be better understood by investigating the influence of the characteristics of the event experienced on how people thought and felt, during the event as well as afterwards. Objective : To compare survivors’ perceived post- and peritraumatic emotional and cognitive reactions across different types of disasters. Additionally, to investigate individual and event characteristics. Design : In a European multi-centre study, 102 survivors of different disasters terror attack, flood, fire and collapse of a building were interviewed about their responses during the event. Survivors’ perceived posttraumatic stress levels were assessed with the Impact of Event Scale-Revised (IES-R). Peritraumatic emotional stress and risk perception were rated retrospectively. Influences of individual characteristics, such as socio-demographic data, and event characteristics, such as time and exposure factors, on post- and peritraumatic outcomes were analyzed. Results : Levels of reported post- and peritraumatic outcomes differed significantly between types of disasters. Type of disaster was a significant predictor of all three outcome variables but the factors gender, education, time since event, injuries and fatalities were only significant for certain outcomes. Conclusion : Results support the hypothesis that there are differences in perceived post- and peritraumatic emotional and cognitive reactions after experiencing different types of disasters. However, it should be noted that these findings were not only explained by the type of disaster itself but also by individual and event characteristics. As the study followed an explorative approach, further research paths are discussed to better understand the relationships between variables. For the abstract in other languages, please see Supplementary files under Reading Tools online

Attentional networks in euthymic patients with unipolar depression.

BACKGROUND The capacity to focus and concentrate or to direct attention supports many aspects of cognitive functioning including short-term memory and higher-level cognitive functions. The purpose was to assess attentional networks in euthymic patients with unipolar depression using the Attentional Network Test (ANT). MATERIALS AND METHODS We investigated performance of attention by virtue of ANT during remission from unipolar depressive disorder and tested a hypothesis that there are no differences between outpatient group (euthymic patients, N=32) and matched controls in attentional variables, the relationship of attentional networks and everyday cognitive failures. RESULTS No differences between the groups in attentional networks were found and no relationship between attentional networks and cognitive failures was found. LIMITATIONS One assessment during remission could be insufficient to recognize long-term pattern of cognitive functions. CONCLUSIONS These data show non-impaired attentional networks possibly explained by sufficient level of remission and ameliorated influence of high education on cognition.

Toxoplasmosis-associated difference in intelligence and personality in men depends on their Rhesus blood group but not ABO blood group.

Background The parasite Toxoplasma gondii influences the behaviour of infected animals and probably also personality of infected humans. Subjects with a Rhesus-positive blood group are protected against certain behavioural effects associated with Toxoplasma infection, including the deterioration of reaction times and personality factor shift. Methodology/Principal Findings Here, we searched for differences in the toxoplasmosis-associated effects between RhD-positive and RhD-negative subjects by testing 502 soldiers with two personality tests and two intelligence tests. The infected subjects expressed lower levels of all potentially pathognomic factors measured with the N-70 questionnaire and in neurasthenia measured with NEO-PI-R. The RhD-positive, Toxoplasma-infected subjects expressed lower while RhD-negative, Toxoplasma-infected subjects expressed higher intelligence than their Toxoplasma-free peers. The observed Toxoplasma-associated differences were always larger in RhD-negative than in RhD-positive subjects. Conclusions RhD phenotype plays an important role in the strength and direction of association between latent toxoplasmosis and not only psychomotor performance, but also personality and intelligence.

Cognitive functions before and 1 year after surgical and endovascular treatment in patients with unruptured intracranial aneurysms

Background and purpose. This prospective study investigated whether surgery or endovascular treatment for unruptured intracranial aneurysms (UIAs) affects cognitive functions. Methods. Four neuropsychological variables from an Auditory Verbal Learning Test (overall capacity of verbal memory and delayed recall) and a Trail Making Test (psychomotor speed and cognitive flexibility) were investigated before and 1 year after treatment for UIAs in 65 patients < 61 years of age. This cohort consists of 15 men and 50 women aged 15–60 (mean age 44.9) years. Results. Group-rate analysis showed a non-significant increase in post-treatment scores in the four neuropsychological variables. In addition, no significant differences were found between the surgical clipping (SC) and endovascular coiling (EC) group. Event-rate analysis demonstrated that two patients from the EC and one from the SC group developed cognitive impairment after treatment. Conclusions. Surgical and endovascular repair for UIAs do not impair cognition in patients without postoperative restrictions in lifestyle.