Background: Body dysmorphic disorder (BDD) is a psychiatric disorder characterized by excessive preoccupation with imagined defects in appearance. Optical illusions induce illusory effects that distort the presented stimulus, thus leading to ambiguous percepts. Using electroencephalography (EEG), we investigated whether BDD is related to differentiated perception during illusory percepts. Methods: A total of 18 BDD patients and 18 controls were presented with 39 optical illusions together with a statement testing whether or not they perceived the illusion. After a delay period, they were prompted to answer whether the statement was right/wrong and their degree of confidence in their answer. We investigated differences of BDD patients on task performance and self-reported confidence and analyzed the brain oscillations during decision-making using nonparametric cluster statistics. Results: Behaviorally, the BDD group exhibited reduced confidence when responding incorrectly, potentially attributed to higher levels of doubt. Electrophysiologically, the BDD group showed significantly reduced alpha power at the fronto-central and parietal scalp areas, suggesting impaired allocation of attention. Interestingly, the lower the alpha power of the identified cluster, the higher the BDD severity, as assessed by BDD psychometrics. Conclusions: Results evidenced that alpha power during illusory processing might serve as a quantitative EEG biomarker of BDD, potentially associated with reduced inhibition of task-irrelevant areas.

This retrospective study examined the demographic, clinical and pharmacological factors associated with aggressive behaviour after abrupt discontinuation of medication in schizophrenic patients. The study reports on a survey of 402 schizophrenic patients, who had abruptly discontinued their medication and had been involuntarily hospitalized to Psychiatric Hospital of Attika. The survey utilized the Discontinuation-Emergent Signs and Symptoms Checklist (DESS) to assess the signs and symptoms that patients exhibited (Rosenbaum et al., Biol Psychiatry 1998;44:77), as well the Aggression Scale (Delgado-Escueta et al., New England J Med 1981;305:711) to estimate the aggressive behaviour. Demographic and clinical variables as well as variables related to pharmacological treatment have been also investigated. Analyses revealed that the presence of aggressive behaviour after abrupt drug discontinuation was associated positively with previous history of aggression, male gender , abrupt discontinuation of anticholinergics, delusions, nervousness or anxiety, elevated mood, irritability and negatively with negative symptoms. These predictors can correctly classify 76.3% of patients with aggressive behaviour and 64.0% of patients without aggressive behaviour. These findings suggest that abrupt discontinuation of medication in schizophrenic patients may lead to aggressive behaviour, being connected at least in the acute phase with particular demographic, clinical and pharmacological parameters.

Background: Body dysmorphic disorder (BDD) is a psychiatric disorder characterized by excessive preoccupation with imagined defects in appearance. Optical illusions induce illusory effects that distort the presented stimulus thus leading to ambiguous percepts. Using electroencephalography (EEG), we investigated whether BDD is related to differentiated perception during illusory percepts. Methods: 18 BDD patients and 18 controls were presented with 39 optical illusions together with a statement testing whether or not they perceived the illusion. After a delay period, they were prompted to answer whether the statement is right/wrong and their degree of confidence for their answer. We investigated differences of BDD on task performance and self-reported confidence and analysed the brain oscillations during decision-making using nonparametric cluster statistics. Results: Behaviorally, the BDD group exhibited reduced confidence when responding incorrectly, potentially attributed to higher levels of doubt. Electrophysiologically, the BDD group showed significantly reduced alpha power at mid-central scalp areas, suggesting impaired allocation of attention. Interestingly, the lower the alpha power of the identified cluster, the higher the BDD severity, as assessed by BDD psychometrics. Conclusions: Results evidenced that alpha power during illusory processing might serve as a quantitative EEG biomarker of BDD, potentially associated with reduced inhibition of task-irrelevant areas.