Sarolta Komlósi

Attention deficit hyperactivity disorder (ADHD): gender- and age-related differences in neurocognition

BACKGROUND Despite the growing recognition that the clinical symptom characteristics associated with attention deficit hyperactivity disorder (ADHD) persist into adulthood in a high proportion of subjects, little is known about the persistence of neurocognitive deficits in ADHD. The objective was twofold: (1) to conduct a meta-analysis of neuropsychological studies to characterize attentional performance in subjects with adult ADHD by examining differences in ADHD versus normal control subjects; and (2) to investigate whether these differences vary as a function of age and gender. METHOD Twenty-five neuropsychological studies comparing subjects with adult ADHD and healthy controls were evaluated. Statistical effect size was determined to characterize the difference between ADHD and control subjects. Meta-regression analysis was applied to investigate whether the difference between ADHD and control subjects varied as a function of age and gender across studies. RESULTS Tests measuring focused and sustained attention yielded an effect size with medium to large magnitude whereas tests of simple attention resulted in a small to medium effect size in terms of poorer attention functioning of ADHD subjects versus controls. On some of the measures (e.g. Stroop interference), a lower level of attention functioning in the ADHD group versus the controls was associated with male gender. CONCLUSIONS Adult ADHD subjects display significantly poorer functioning versus healthy controls on complex but not on simple tasks of attention, and the degree of impairment varies with gender, with males displaying a higher level of impairment.

Pharmacotherapy of adult attention deficit hyperactivity disorder (ADHD): a meta-analysis

Our objective was to conduct a meta-analysis of therapeutic efficacy of pharmacological treatment of adult ADHD based on data from controlled clinical trials. We used the search engines PubMed and Medline to identify relevant clinical trials. Short-term studies with double-blind parallel-group design were selected for the analysis. Altogether, we identified 11 trials that met the criteria, and investigated a total of 1991 subjects, 694 and 1297 of whom were treated with placebo or active medication, respectively. In order to pool efficacy data from studies with different characteristics, including different number of participants, different trial duration and measures of efficacy, the statistical effect sizes for each study had to be calculated. Our findings showed that the pooled effect size across all treatments was in the medium-to-high range (Cohens d=0.65, p<0.0001 vs. placebo), and the effect size for stimulants (Cohens d=0.67, p<0.0001 vs. placebo) was somewhat higher than for non-stimulant medications (Cohens d=0.59, p<0.0001 vs. placebo). The current database of controlled trials for adult ADHD is relatively small, and does not include data for many of the potentially important agents. In addition, effect-size estimates for different classes of medications (i.e. stimulant and non-stimulant medications) were based on separate studies; head-to-head comparisons of various agents are severely lacking. Nonetheless, results of this meta-analysis across all ADHD medications in adult subjects demonstrated statistically significant and clinically robust improvement in symptom severity compared to placebo treatment.

P300 deficits in adults with attention deficit hyperactivity disorder: A meta-analysis

BACKGROUND The P300 (P3) event-related potential (ERP) component, a possible endophenotype for attention deficit hyperactivity disorder (ADHD), has been widely examined in children, but received little attention in adults. Our objective was to conduct a meta-analysis of P3 studies in adults with ADHD. METHOD We searched the Medline and PsycINFO databases for controlled studies examining both adult ADHD and matched healthy controls. Six relevant publications were identified for the meta-analysis, which had comparable data across studies with regard to the amplitude of ERP components related to target detection (P3, P3b). Pooled effect size (ES) for P3 amplitude as well as the association of the ES with age and gender were investigated using meta-regression. RESULTS Comparing the ADHD group versus controls, the pooled effect size for a decrease in P3 amplitude was in the medium range (Cohens d=-0.55, p=0.0006). Additionally, meta-regression revealed that decrease in P3 amplitude significantly varied with the mean age of ADHD patients (p=0.0087), with a gradual increasing of the difference at higher ages. Results also showed a significant association between the ES and gender, indicating a more pronounced reduction of P3 amplitude in the ADHD group versus controls when females were predominantly represented in the sample. CONCLUSIONS To our knowledge, this is the first meta-analysis of P3 characteristics in adults with ADHD. It reveals a significantly decreased P3 amplitude during target detection. Our result that the reduction in P3 amplitude increases with age is interpreted in a neurodevelopmental context.

Emotion-Related Visual Mismatch Responses in Schizophrenia: Impairments and Correlations with Emotion Recognition

Background and Objectives Mismatch negativity (MMN) is an event-related potential (ERP) measure of preattentional sensory processing. While deficits in the auditory MMN are robust electrophysiological findings in schizophrenia, little is known about visual mismatch response and its association with social cognitive functions such as emotion recognition in schizophrenia. Our aim was to study the potential deficit in the visual mismatch response to unexpected facial emotions in schizophrenia and its association with emotion recognition impairments, and to localize the sources of the mismatch signals. Experimental Design The sample comprised 24 patients with schizophrenia and 24 healthy control subjects. Controls were matched individually to patients by gender, age, and education. ERPs were recorded using a high-density 128-channel BioSemi amplifier. Mismatch responses to happy and fearful faces were determined in 2 time windows over six regions of interest (ROIs). Emotion recognition performance and its association with the mismatch response were also investigated. Principal Observations Mismatch signals to both emotional conditions were significantly attenuated in patients compared to controls in central and temporal ROIs. Controls recognized emotions significantly better than patients. The association between overall emotion recognition performance and mismatch response to the happy condition was significant in the 250–360 ms time window in the central ROI. The estimated sources of the mismatch responses for both emotional conditions were localized in frontal regions, where patients showed significantly lower activity. Conclusions Impaired generation of mismatch signals indicate insufficient automatic processing of emotions in patients with schizophrenia, which correlates strongly with decreased emotion recognition.

Fearful face recognition in schizophrenia: An electrophysiological study

BACKGROUND Emotional expressions are important acts of communication, and impairment in facial emotion recognition has been shown to be related to impairments in social cognition in schizophrenia. We used an event-related potential (ERP) paradigm to identify and delineate the temporal characteristics in the electrophysiological cascade related to fearful facial affect processing in patients with schizophrenia as compared to healthy controls. METHODS Twenty-four subjects with schizophrenia and 24 individually matched healthy controls participated in an emotion recognition task. Ekman faces displaying neutral and fearful facial expressions were used as stimuli. ERPs were recorded using a 128-channel EEG system. RESULTS Based on the analysis of Global Field Power (GFP) in the 150-190 ms time window both groups differentiated between fearful and neutral faces. Schizophrenia patients showed an additional differential processing of fearful vs. neutral faces in the 330-450 ms time window, and this ERP effect correlated with psychopathology. CONCLUSIONS Both patients and healthy controls differentiate fearful and neutral faces in early phases of emotion processing. Our results also indicate that schizophrenia patients show increased responsivity to fearful faces at a later processing stage. This could be related to the overrating of negative emotions, and the symptomatology associated with fear processing in patients with schizophrenia.

AS19-02 - Electrophysiological correlates of impaired facial emotion recognition

The ability to read faces is a basic component of social cognition, and has gained considerable interest over the past decades in schizophrenia research. It has been shown to be closely related to psychosocial functioning and quality of life in schizophrenia. Use of event-related potential (ERP) paradigms to measure neural activity during emotion processing has become a major approach in affective neuroscience, since this method captures the exact time course of the emotional information-processing cascade from early to later processing stages with a millisecond-resolution. Emotional stimuli have been shown to elicit an increased processing of perceptual information, and increased attentional allocation. ERP studies of emotion recognition paradigms with schizophrenia patients have rapidly accumulated in the past years. However, results are still divergent and often controversial as to where and when abnormal activation patterns occur in the course of emotion processing as compared to healthy controls. The variability of findings has given room for interpreting results as supporting both a bottom-up, initial sensory-encoding-deficit-view, and also a later, top-down contextual-attentional-deficit view. This presentation will give an overview on findings of emotion recognition deficits as measured by the ERP technique in schizophrenia patients. Finally, we present our own results of fearful face processing and relate electrophysiological results to the clinical symptomatology of fear in schizophrenia. Thus, we attempt to broaden the context of interpreting electrophysiological abnormalities seen in face processing in schizophrenia via linking electrophysiological and clinical findings.

P01-420 - Facial affect recognition: Electrophysiological findings in schizophrenia

Introduction While deficits in facial emotion recognition in schizophrenia have consistently been shown, the underlying neuronal mechanisms remain unclear. Electrophysiological measures, such as event-related brain potentials related to facial emotion recognition yield insight into the time course of recognizing emotional faces. Objectives In our study we aimed to delineate the neurophysiological correlates of facial emotion recognition and to investigate where, when, and what components in the course of emotional information processing show impairment in schizophrenia. Methodology We collected data using a 128-channel EEG recording system for testing an experimental facial emotion recognition paradigm with 20 patients with schizophrenia and 20 matched healthy controls. Subjects were presented fearful and neutral emotional facial expressions on a monitor and asked to make decisions via a button press relating to either the gender or the emotion of the presented face. Results Our findings revealed that ERPs of pateints with schizophrenia significantly differed from those of matched healthy controls in several components and areas characteristic to facial emotion processing, showing differences in both early and late ERP components of emotional face processing. Significant main effects of task (gender vs emotion) and emotion (fear vs neutral) were also found. Conclusion The finding that patients with schizophrenia, as compared to healthy controls, show differences in emotional face processing in several cortical areas and time intervals underlines the hypotheses that a deficit in affect recognition may originate from the impairment of a distributed facial emotion recognition network, including both early perceptual and later phases of facial emotion processing.