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IntroductionResting-state EEG (rsEEG) characteristics, such as functional connectivity and network topology, are studied as potential biomarkers in psychiatric research. However, the presence of psychopharmacological treatment in study participants poses a potential confounding factor in biomarker research. To address this concern, our study aims to explore the impact of both single and multi-class psychotropic treatments on aforementioned rsEEG characteristics in a psychiatric population.MethodsRsEEG was analyzed in a real-world cross-sectional sample of 900 hospital-admitted psychiatric patients. Patients were clustered into eight psychopharmacological groups: unmedicated, single-class treatment with antipsychotics (AP), antidepressants (AD) or benzodiazepines (BDZ), and multi-class combinations of these treatments. To assess the associations between psychotropic treatments and the macroscale rsEEG characteristics mentioned above, we employed a general linear model with post-hoc tests. Additionally, Spearman’s rank correlation analyses were performed to explore potential dosage effects.ResultsCompared to unmedicated patients, single-class use of AD was associated with lower functional connectivity in the delta band, while AP was associated with lower functional connectivity in both the delta and alpha bands. Single-class use of BDZ was associated with widespread rsEEG differences, including lower functional connectivity across frequency bands and a different network topology within the beta band relative to unmedicated patients. All of the multi-class groups showed associations with functional connectivity or topology measures, but effects were most pronounced for concomitant use of all three classes of psychotropics. Differences were not only observed in comparison with unmedicated patients, but were also evident in comparisons between single-class, multi-class, and single/multi-class groups. Importantly, multi-class associations with rsEEG characteristics were found even in the absence of single-class associations, suggesting potential cumulative or interaction effects of different classes of psychotropics. Dosage correlations were only found for antipsychotics.ConclusionOur exploratory, cross-sectional study suggests small but significant associations between single and multi-class use of antidepressants, antipsychotics and benzodiazepines and macroscale rsEEG functional connectivity and network topology characteristics. These findings highlight the importance of considering the effects of specific psychotropics, as well as their interactions, when investigating rsEEG biomarkers in a medicated psychiatric population.

BackgroundPsychedelic-assisted therapy [e.g., with lysergic acid diethylamide (LSD)] has shown promising results as treatment for substance use disorders (SUDs). Previous systematic reviews assessing the efficacy of psilocybin in SUDs only included clinical trials conducted in the last 25 years, but they may have missed clinical trials assessing the efficacy of psilocybin that were conducted before the 1980s, given much research has been done with psychedelics in the mid-20th century. In this systematic review, we specifically assessed the efficacy of psilocybin in patients with a SUD or non-substance-related disorder with no publication date restrictions in our search strategy.MethodsA systematic literature search was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines from the earliest published manuscript up to September 2, 2022, in seven electronic databases, including clinical trials in patients with a SUD or non-substance-related disorder evaluating the efficacy of psilocybin.ResultsA total of four studies (six articles, of which two articles were long-term follow-up results from the same trial) were included in this systematic review. Psilocybin-assisted therapy was administered to n = 151 patients in a dose ranging from 6 to 40 mg. Three studies focused on alcohol use disorder, and one study on tobacco use disorder. In a pilot study (n = 10), the percentage of heavy drinking days decreased significantly between baseline and weeks 5–12 (mean difference of 26.0, 95% CI = 8.7–43.2, p = 0.008). In another single-arm study (n = 31), 32% (10/31) became completely abstinent from alcohol (mean duration of follow-up 6 years). In a double-blind, placebo-controlled randomized controlled trial (RCT, n = 95), the percentage of heavy drinking days during the 32-week double-blind period was significantly lower for psilocybin compared to placebo (mean difference of 13.9, 95% CI = 3.0–24.7, p = 0.01). In a pilot study (n = 15), the 7-day point prevalence of smoking abstinence at 26 weeks was 80% (12/15), and at 52 weeks 67% (10/15).ConclusionOnly one RCT and three small clinical trials were identified assessing the efficacy of psilocybin combined with some form of psychotherapy in patients with alcohol and tobacco use disorder. All four clinical trials indicated a beneficial effect of psilocybin-assisted therapy on SUD symptoms. Larger RCTs in patients with SUDs need to evaluate whether psilocybin-assisted therapy is effective in patients with SUD.

Background: Volume increases of the hippocampus after electroconvulsive therapy (ECT) are a robust finding, pointing into the direction of neurogenesis. However, such volumetric increases could also be explained by edema and/or neuroplastic changes (such as angiogenesis). Objectives: If edema explains the volume increase of the hippocampus we hypothesize it would lead to increased mean diffusivity (MD). If neuroplastic would explain the volume increase, it would lead to decreased MD. To investigate angiogenesis as explanation we studied the perfusion fraction f and the pseudodiffusion component D∗ obtained from intravoxel incoherent motion (IVIM) data, and relative perfusion changes obtained from arterial spin labelling (ASL) data. Methods: Using ultra-high field (7 tesla) MRI we acquired IVIM and ASL data. We compared MD, f, D∗ and ASL values for both hippocampi in 21 patients (before and after 10 ECT sessions) and 8 healthy controls (without ECT) in a linear mixed model adjusting for age and gender. Results: We found a significant decrease in MD (which was absent in the healthy controls) in the left and right hippocampus (t = -3.98, p < 0.001). In addition, a decrease in f (t = -4.61, p < 0.001, but not in controls) and no differences in D∗ or ASL perfusion values (both p > 0.05) were found. Conclusions: The decrease in MD in perfusion fraction f suggest that formation of edema nor angiogenesis are responsible for the ECT-induced volume increases in the hippocampus. Also, it supports the hypothesis that hippocampal volume increases might be due to neuroplastic changes.

IntroductionChronic subjective tinnitus is a condition that affects 5.1% to 42.7% of the population, depending on the definition and studied population. Evidence-based treatment options are limited. Cognitive Behavioural Therapy (CBT) has been proven effective to improve quality of life and to diminish tinnitus distress. Positive short-term effects of mindfulness-based interventions on tinnitus distress have been reported; however, the longer term effects remain to be studied.Methods and analysisWe designed a monocentre randomised controlled, non-inferiority trial to compare the effectiveness of mindfulness-based cognitive therapy (MBCT) and CBT in chronic tinnitus patients. Fifty-four patients (≥32 on the Tinnitus Functional Index (TFI), suffering from tinnitus for at least 6 months) will be included in the trial and randomised into one of two intervention groups. One group will receive MBCT, the other group will receive CBT. Our primary objective is to determine whether MBCT is non-inferior to (as good as) CBT on tinnitus distress (TFI) in chronic tinnitus patients at 12 months follow-up after end of therapy. Non-inferiority will be declared if the mean decrease in TFI score for MBCT is no worse than the mean decrease in TFI score in CBT, with statistical variability, with a margin of 13 points. Most secondary objectives (tinnitus severity of problem, tinnitus intrusiveness, quality of life, anxiety, depression, symptoms of psychopathology, perceived tinnitus complaints, coping style (mostly validated questionnaires)) are expected to show non-inferiority to MBCT compared with CBT. We expect a significant difference between MBCT and CBT for mindfulness awareness.Ethics and disseminationThis research protocol was approved by the Institutional Review Board of the UMC Utrecht (NL67838.041.18, V.4, April 2019). The trial results will be made accessible to the public in a peer-review journal.Trial registration numberNL7745.