Insight and Dissociation in Lucid Dreaming and Psychosis

Dreams and psychosis share several important features regarding symptoms and underlying neurobiology, which is helpful in constructing a testable model of, for example, schizophrenia and delirium. The purpose of the present communication is to discuss two major concepts in dreaming and psychosis that have received much attention in the recent literature: insight and dissociation. Both phenomena are considered functions of higher order consciousness because they involve metacognition in the form of reflective thought and attempted control of negative emotional impact. Insight in dreams is a core criterion for lucid dreams. Lucid dreams are usually accompanied by attempts to control the dream plot and dissociative elements akin to depersonalization and derealization. These concepts are also relevant in psychotic illness. Whereas insightfulness can be considered innocuous in lucid dreaming and even advantageous in psychosis, the concept of dissociation is still unresolved. The present review compares correlates and functions of insight and dissociation in lucid dreaming and psychosis. This is helpful in understanding the two concepts with regard to psychological function as well as neurophysiology

Investigating nuisance effects induced in EEG during tACS application

Transcranial alternating-current stimulation (tACS) in the frequency range of 1–100 Hz has come to be used routinely in electroencephalogram (EEG) studies of brain function through entrainment of neuronal oscillations. It turned out, however, to be highly non-trivial to remove the strong stimulation signal, including its harmonic and non-harmonic distortions, as well as various induced higher-order artifacts from the EEG data recorded during the stimulation. In this paper, we discuss some of the problems encountered and present methodological approaches aimed at overcoming them. To illustrate the mechanisms of artifact induction and the proposed removal strategies, we use data obtained with the help of a schematic demonstrator setup as well as human-subject data

Insight and dissociation in lucid dreaming and psychosis

Dreams and psychosis share several important features regarding symptoms and underlying neurobiology, which is helpful in constructing a testable model of, for example, schizophrenia and delirium. The purpose of the present communication is to discuss two major concepts in dreaming and psychosis that have received much attention in the recent literature: insight and dissociation. Both phenomena are considered functions of higher order consciousness because they involve metacognition in the form of reflective thought and attempted control of negative emotional impact. Insight in dreams is a core criterion for lucid dreams. Lucid dreams are usually accompanied by attempts to control the dream plot and dissociative elements akin to depersonalization and derealization. These concepts are also relevant in psychotic illness. Whereas insightfulness can be considered innocuous in lucid dreaming and even advantageous in psychosis, the concept of dissociation is still unresolved. The present review compares correlates and functions of insight and dissociation in lucid dreaming and psychosis. This is helpful in understanding the two concepts with regard to psychological function as well as neurophysiology

Imaging Dopamine D4 Receptors in the Living Primate Brain: A Positron Emission Tomography Study Using the Novel D1/D4 Antagonist [11C]SDZ GLC 756

The dopamine D4 receptor has lately attracted interest since it has been hypothesized to be involved in the pathogenesis and pharmacotherapy of neuropsychiatric diseases. The present study provides first in vivo evidence of dopamine D4 receptors in primate brain using a [11C]benzo[g]quinoline, the novel radioligand [11C]SDZ GLC 756 ([11C]GLC: in vitro dissociation constants at human receptor clones [nM]: 1.10 at D1; 0.40 at D2; 25 at D3; 0.18 at D4.2; 6.03 at D5). Dynamic positron emission tomography scans were performed on healthy baboons (Papio hamadryas, n 5 3). Specific receptor binding (SB) was calculated for striatum and neocortex (frontal, temporal, parietal, and occipital) based on the differences between the regional and the cerebellar concentration of [11C]. Blockade of D1 and D5 receptors by SCH23390 (1.7 μmol/kg) diminished SB in the striatum by 55 6 4% (mean 6 standard deviation, P , 0.05) and in the frontal cortex by 13 6 8% (P , 0.05) when compared to SB in the unblocked state (SBD1–D5). In the presence of the dopamine antagonists SCH23390 (1.7 μmol/kg) and raclopride (5.7 μmol/kg)—which mask the D1, D2, D3, and D5 subtypes—SB of [11C]GLC to D4 receptors (SBD4) was demonstrated in the striatum and all cortical regions of interest. In the striatum, the ratio of SBD4/SBD1–D5 was 0.13 6 0.07. In the neocortex, SBD4/SBD1–D5 was notably higher (0.77 60.29; mean of all cortical regions of interest). The widespread distribution of dopamine D4 receptors suggests a basic functional role of this receptor subtype in the modulation of cortical and subcortical neuronal activit

Predicting the risk of drug–drug interactions in psychiatric hospitals: a retrospective longitudinal pharmacovigilance study

Objectives The aim was to use routine data available at a patient’s admission to the hospital to predict polypharmacy and drug–drug interactions (DDI) and to evaluate the prediction performance with regard to its usefulness to support the efficient management of benefits and risks of drug prescriptions.Design Retrospective, longitudinal study.Setting We used data from a large multicentred pharmacovigilance project carried out in eight psychiatric hospitals in Hesse, Germany.Participants Inpatient episodes consecutively discharged between 1 October 2017 and 30 September 2018 (year 1) or 1 January 2019 and 31 December 2019 (year 2).Outcome measures The proportion of rightly classified hospital episodes.Methods We used gradient boosting to predict respective outcomes. We tested the performance of our final models in unseen patients from another calendar year and separated the study sites used for training from the study sites used for performance testing.Results A total of 53 909 episodes were included in the study. The models’ performance, as measured by the area under the receiver operating characteristic, was ‘excellent’ (0.83) and ‘acceptable’ (0.72) compared with common benchmarks for the prediction of polypharmacy and DDI, respectively. Both models were substantially better than a naive prediction based solely on basic diagnostic grouping.Conclusion This study has shown that polypharmacy and DDI can be predicted from routine data at patient admission. These predictions could support an efficient management of benefits and risks of hospital prescriptions, for instance by including pharmaceutical supervision early after admission for patients at risk before pharmacological treatment is established

Predictors for symptom re-exacerbation after targeted stepwise drug discontinuation in first-episode schizophrenia Results of the first-episode study within the German research network on schizophrenia

Background: After a first episode in schizophrenia guidelines recommend antipsychotic maintenance treatment (MT) for at least 1 year. Recent RCTs on subsequent targeted intermittent treatment (IT) after stepwise drug discontinuation yielded noticeably higher relapse rates than during MT also in first-episode patients. Nevertheless, about 50% of patients remain stable under IT. Given the potential adverse effects of antipsychotics and the preference of many patients to discontinue drugs, valid predictors for the feasibility of IT are urgently needed to support decision making. Methods: Based on a one-year RCT phase comparing MT with IT in first-episode patients after 1 year of MT, conducted within the German Research Network on Schizophrenia (GRNS), predictors for deterioration under IT in 19 feasible patients were identified by logistic regression analysis. Results: Deterioration occurred in 10 patients (52.6%). Univariate analyses indicated a lower PANSS positive score after acute treatment as well as after one year of MT as significant predictors; in multivariate logistic regression, in addition to the lower PANSS positive score after acute treatment, reaching enduring remission and having had a deterioration both during MT evolved as significant predictors and indicate a higher risk for deterioration. Conclusions: Although limited by the small sample size, our findings suggest that patients who show a favorable response and full and enduring symptom remission during antipsychotic treatment, as well as those with marked deterioration despite MT should rather be recommended to remain on treatment because they are at higher risk for symptom re-exacerbation after (stepwise) drug discontinuation. (C) 2015 Elsevier B.V. All rights reserved