Detection of viral antibodies in camel sera using magnetic particle spectroscopy.

Pandemics like SARS-Cov-2 very frequently have their origin in different animals and in particular herds of camels could be a source of zoonotic diseases. This study took advantage on a highly sensitive and adaptable method for the fast and reliable detection of viral antibodies in camels using low-cost equipment. Magnetic nanoparticles (MNP) have high variability in their functionalization with different peptides and proteins. We confirm that 3-aminopropyl triethoxysilane (APTES)-coated MNP could be functionalized with viral proteins. The protein loading could be confirmed by simple loading controls using FACS-analysis (p < 0.05). Complementary combination of antigen and antibody yields in a significant signal increase could be proven by both FACS and COMPASS. However, COMPASS needs only a few seconds for the measurement. In COMPASS, the phase φn on selected critical point of the fifth higher harmonic (n = 5th). Here, positive sera display highly significant signal increase over the control or negative sera. Furthermore, a clear distinction could be made in antibody detection as an immune response to closely related viruses (SARS-CoV2 and MERS). Using modified MNPs along with COMPASS offers a fast and reliable method that is less cost intensive than current technologies and offers the possibility to be quickly adapted in case of new occurring viral infections. KEY POINTS: • COMPASS (critical offset magnetic particle spectroscopy) allows the fast detection of antibodies. • Magnetic nanoparticles can be adapted by exchange of the linked bait molecule. • Antibodies could be detected in camel sera without washing steps within seconds.

Critical Offset Magnetic PArticle SpectroScopy for rapid and highly sensitive medical point-of-care diagnostics.

Magnetic nanoparticles (MNPs) have been adapted for many applications, e.g., bioassays for the detection of biomarkers such as antibodies, by controlled engineering of specific surface properties. Specific measurement of such binding states is of high interest but currently limited to highly sensitive techniques such as ELISA or flow cytometry, which are relatively inflexible, difficult to handle, expensive and time-consuming. Here we report a method named COMPASS (Critical-Offset-Magnetic-Particle-SpectroScopy), which is based on a critical offset magnetic field, enabling sensitive detection to minimal changes in mobility of MNP ensembles, e.g., resulting from SARS-CoV-2 antibodies binding to the S antigen on the surface of functionalized MNPs. With a sensitivity of 0.33 fmole/50 µl (≙7 pM) for SARS-CoV-2-S1 antibodies, measured with a low-cost portable COMPASS device, the proposed technique is competitive with respect to sensitivity while providing flexibility, robustness, and a measurement time of seconds per sample. In addition, initial results with blood serum demonstrate high specificity.

An apprenticeship model in the training of psychotherapy students. Study protocol for a randomized controlled trial and qualitative investigation.

BACKGROUND: One approach towards advancing the quality of mental health care is to improve psychotherapists' skills through education and training. Recently, psychotherapy training has benefitted from adapting training methods from other professions (e.g., deliberate practice). The apprenticeship model has a long history in skill trades and medicine, but has yet to be adopted in training mental health professionals. This study aims to investigate the impact of apprenticeship training on clinical psychology students' skills. METHODS: In a pragmatic mixed-methods trial, 120 first year students in a Master's degree clinical psychology program will be randomized to either training-as-usual or training-as-usual plus psychotherapy apprenticeship. In the intervention group, students will participate, over a period of 10 weeks, in weekly treatment sessions together with licensed therapists at outpatient mental health and substance use treatment clinics. Outcomes are assessed post-intervention and at two-year follow-up. The main outcome measure is the Facilitative Interpersonal Skills (FIS) performance test. Additional self-report measures tap self-efficacy, self-compassion, worry, rumination, and stress. Weekly reflection log entries written by the students will be qualitatively analyzed in order to gain an in-depth understanding of the learning process. Students' and therapists' experiences with the intervention will be explored in focus group interviews. DISCUSSION: To the best of our knowledge, this is the first controlled study to investigate the impact of apprenticeship as an isolated training component in the education of clinical psychologists. The study is designed so as to yield a comprehensive understanding of an approach which could prove to be a valuable supplement to the existing educational methods in this field and ultimately, contribute to improve the quality of mental health care.

Effects of image homogeneity on stenosis visualization at 7 T in a coronary artery phantom study: With and without B1-shimming and parallel transmission.

BACKGROUND: To investigate the effects of B1-shimming and radiofrequency (RF) parallel transmission (pTX) on the visualization and quantification of the degree of stenosis in a coronary artery phantom using 7 Tesla (7 T) magnetic resonance imaging (MRI). METHODS: Stenosis phantoms with different grades of stenosis (0%, 20%, 40%, 60%, 80%, and 100%; 5 mm inner vessel diameter) were produced using 3D printing (clear resin). Phantoms were imaged with four different concentrations of diluted Gd-DOTA representing established arterial concentrations after intravenous injection in humans. Samples were centrally positioned in a thorax phantom of 30 cm diameter filled with a custom-made liquid featuring dielectric properties of muscle tissue. MRI was performed on a 7 T whole-body system. 2D-gradient-echo sequences were acquired with an 8-channel transmit 16-channel receive (8 Tx / 16 Rx) cardiac array prototype coil with and without pTX mode. Measurements were compared to those obtained with identical scan parameters using a commercially available 1 Tx / 16 Rx single transmit coil (sTX). To assess reproducibility, measurements (n = 15) were repeated at different horizontal angles with respect to the B0-field. RESULTS: B1-shimming and pTX markedly improved flip angle homogeneity across the thorax phantom yielding a distinctly increased signal-to-noise ratio (SNR) averaged over a whole slice relative to non-manipulated RF fields. Images without B1-shimming showed shading artifacts due to local B1+-field inhomogeneities, which hampered stenosis quantification in severe cases. In contrast, B1-shimming and pTX provided superior image homogeneity. Compared with a conventional sTX coil higher grade stenoses (60% and 80%) were graded significantly (p<0.01) more precise. Mild to moderate grade stenoses did not show significant differences. Overall, SNR was distinctly higher with B1-shimming and pTX than with the conventional sTX coil (inside the stenosis phantoms 14%, outside the phantoms 32%). Both full and half concentration (10.2 mM and 5.1 mM) of a conventional Gd-DOTA dose for humans were equally suitable for stenosis evaluation in this phantom study. CONCLUSIONS: B1-shimming and pTX at 7 T can distinctly improve image homogeneity and therefore provide considerably more accurate MR image analysis, which is beneficial for imaging of small vessel structures.

Vasa vasorum of proximal cerebral arteries after dural crossing - potential imaging confounder in diagnosing intracranial vasculitis in elderly subjects on black-blood MRI.

OBJECTIVES: Vessel wall enhancement (VWE) may be commonly seen on MRI images of asymptomatic subjects. This study aimed to characterize the VWE of the proximal internal carotid (ICA) and vertebral arteries (VA) in a non-vasculitic elderly patient cohort. METHODS: Cranial MRI scans at 3 Tesla were performed in 43 patients (aged ≥ 50 years) with known malignancy for exclusion of cerebral metastases. For vessel wall imaging (VWI), a high-resolution compressed-sensing black-blood 3D T1-weighted fast (turbo) spin echo sequence (T1 CS-SPACE prototype) was applied post gadolinium with an isotropic resolution of 0.55 mm. Bilateral proximal intradural ICA and VA segments were evaluated for presence, morphology, and longitudinal extension of VWE. RESULTS: Concentric VWE of the proximal intradural ICA was found in 13 (30%) patients, and of the proximal intradural VA in 39 (91%) patients. Mean longitudinal extension of VWE after dural entry was 13 mm in the VA and 2 mm in the ICA. In 14 of 39 patients (36%) with proximal intradural VWE, morphology of VWE was suggestive of the mere presence of vasa vasorum. In 25 patients (64 %), morphology indicated atherosclerotic lesions in addition to vasa vasorum. CONCLUSIONS: Vasa vasorum may account for concentric VWE within the proximal 2 mm of the ICA and 13 mm of the VA after dural entry in elderly subjects. Concentric VWE in these locations should not be confused with large artery vasculitis. Distal to these segments, VWE may be more likely related to pathologic conditions such as vasculitis. KEY POINTS: • Vasa vasorum may account for concentric VWE within the proximal 2 mm of the ICA and 13 mm of the VA after dural entry in non-vasculitic elderly people. • Concentric enhancement within the proximal 2 mm of the intradural ICA and within the proximal 13 mm of the intradural VA portions should not be misinterpreted as vasculitis. • Distal of this, VWE is likely related to pathologic conditions, in case of concentric VWE suggestive of vasculitis.

Intracranial vessel wall imaging framework - Data acquisition, processing, and visualization.

OBJECTIVE: Assessment of vessel walls is an integral part in diagnosis and disease monitoring of vascular diseases such as vasculitis. Vessel wall imaging (VWI), in particular of intracranial arteries, is the domain of Magnetic Resonance Imaging (MRI) - but still remains a challenge. The tortuous anatomy of intracranial arteries and the need for high resolution within clinically acceptable scan times require special technical conditions regarding the hardware and software environments. MATERIALS AND METHODS: In this work a dedicated framework for intracranial VWI is presented offering an optimized, black-blood 3D T1-weighted post-contrast Compressed Sensing (CS)-accelerated MRI sequence prototype combined with dedicated 3D-GUI supported post-processing tool for the CPR visualization of tortuous arbitrary vessel structures. RESULTS: Using CS accelerated MRI sequence, the scanning time for high-resolution 3D black-blood CS-space data could be reduced to under 10 min. These data are adequate for a further processing to extract straightened visualizations (curved planar reformats - CPR). First patient data sets could be acquired in clinical environment. CONCLUSION: A highly versatile framework for VWI visualization was demonstrated utilizing a post-processing tool to extract CPR reformats from high-resolution 3D black-blood CS-SPACE data, enabling simplified and optimized assessment of intracranial arteries in intracranial vascular disorders, especially in suspected intracranial vasculitis, by stretching their tortuous course. The processing time from about 15-20 min per patient (data acquisition and further processing) allows the integration into clinical routine.

Near real-time magnetic particle imaging for visual assessment of vascular stenosis in a phantom model.

PURPOSE: This study aimed to investigate the potential of magnetic particle imaging (MPI) to quantify artificial stenoses in vessel phantoms in near real-time. METHODS: Custom-made stenosis phantoms with different degrees of stenosis (0%, 25%, 50%, 75%, and 100%; length 40 mm, inner diameter 8 mm, Polyoxymethylene) were filled with diluted Ferucarbotran (superparamagnetic iron-oxide nanoparticle (SPION) tracer agent, 500 mmol (Fe)/l). A traveling wave MPI scanner (spatial resolution ~ 2 mm, gradient strength ~ 1.5 T/m, field of view: 65 mm length and 29 mm diameter, frequencies f1 = 1050 Hz and f2 = 12150 Hz) was used to acquire images of the phantoms (200 ms total acquisition time per image, 10 averages). Standardized grey scaling was used for comparability. All measured stenoses (n = 80) were graded manually using a dedicated software tool. RESULTS: MPI allowed for accurate visualization of stenoses at a frame rate of 5frames per second. Less severe stenoses were detected more precisely than higher-grade stenoses and came with smaller standard deviations. In particular, the 0%, 25%, 50%, 75%, and 100% stenosis phantom were measured as 3.7 ± 2.7% (mean ± standarddeviation), 18.6 ± 1.8%, 52.8 ± 3.7%, 77.8 ± 14.8% and 100 ± 0%. Geometrical distortions occurred around the center of the high-grade stenosis and led to higher standard deviations compared to lower grade stenoses. In the frame of this study the MPI signal depended linearly on the SPION concentration down to 0.05 mmol (Fe)/l. CONCLUSION: Near real-time MPI accurately visualized and quantified different stenosis grades in vascular phantoms.

High-resolution Compressed-sensing T1 Black-blood MRI : A New Multipurpose Sequence in Vascular Neuroimaging?

BACKGROUND AND PURPOSE: In vasculopathies of the central nervous system, reliable and timely diagnosis is important against the background of significant morbidity and sequelae in cases of incorrect diagnosis or delayed treatment. Magnetic resonance imaging (MRI) plays a major role in the detection and monitoring of intracranial and extracranial vascular pathologies of different etiologies, in particular for evaluation of the vessel wall in addition to luminal information, thus allowing differentiation between various vasculopathies. Compressed-sensing black-blood MRI combines high image quality with relatively short acquisition time and offers promising potential in the context of neurovascular vessel wall imaging in clinical routine. This case review gives an overview of its application in the diagnosis of various intracranial and extracranial entities. METHODS: An optimized high-resolution compressed-sensing black-blood 3D T1-weighted fast (turbo) spin echo technique (T1 CS-SPACE prototype) precontrast and postcontrast application at 3T was used for the evaluation of various vascular conditions in neuroradiology. RESULTS: In this article seven cases of intracranial and extracranial arterial and venous vasculopathies with representative imaging findings in high-resolution compressed-sensing black-blood MRI are presented. CONCLUSION: High-resolution 3D T1 CS-SPACE black-blood MRI is capable of imaging various vascular entities in high detail with whole head coverage and low susceptibility for motion artifacts and within acceptable scan times. It represents a highly versatile, non-invasive technique for the visualization and differentiation of a wide variety of neurovascular arterial and venous disorders.

Parallel magnetic particle imaging.

Magnetic Particle Imaging (MPI) is a promising tomographic method to visualize the distribution of superparamagnetic materials in three-dimensions. For encoding, a strong gradient represented by a field free point (FFP) or a field free line (FFL) is steered rapidly through the field of view (FOV), acquiring the signal successively. Conventional MPI scanners only provide a single FFP or FFL to sample the entire scan volume, which limits the size of the FOV and/or the temporal resolution. The alternative scanner concept of Traveling Wave MPI (TWMPI) uses a dynamic linear gradient array (dLGA) for dynamic FFP generation along the symmetry axis. The TWMPI scanner is capable of creating multiple FFPs simultaneously, and usually care is taken to locate only a single FFP in the desired FOV. In this manuscript, the concept of parallel MPI utilizing multiple FFPs simultaneously is introduced. For that, conceptual simulations are presented followed by reconstruction approaches for visualization of parallel MPI signals. In addition, an initial parallel MPI experiment with simultaneous acquisition of signals from two FFPs inside the FOV of the same scanner using two receive chains is demonstrated. This allows scanning a doubled FOV within the same acquisition time without sacrificing resolution compared to the standard TWMPI scanner.

Superspeed Bolus Visualization for Vascular Magnetic Particle Imaging.

Magnetic Particle Imaging (MPI) is a fast imaging technique to visualize the distribution of superparamagnetic iron-oxide nanoparticles (SPIONs). For spatial encoding, a field free area is moved rapidly through the field of view (FOV) generating localized signal. Fast moving samples, e.g., a bolus of SPIONs traveling through the large veins in the human body carried by blood flow with velocities in the order of ~45 cm/s, cause temporal blurring in MPI measurements using common sequences and reconstruction techniques. This hampers the evaluation of dynamics of fast moving samples. In this manuscript, a first study on fast moving samples visualized within an MPI scanner is demonstrated. By optimizing parameters for imaging and reconstruction, the dynamics of a fast moving bolus at different velocities can be visualized with high temporal resolution without blurring artifacts.

Early maladaptive schemas impact on long-term outcome in patients treated with group behavioral therapy for obsessive-compulsive disorder.

BACKGROUND: Some studies have previously found that certain elevated early maladaptive schemas (EMSs) are negative predictors for outcome for patients with obsessive-compulsive disorder (OCD) treated with Cognitive-Behavioral Therapy (CBT) or Exposure and Response Prevention (ERP). The current study explores whether EMS were related to reductions in OCD symptom severity at long-term follow-up (Mean = 8 years) after group ERP for patients with OCD. The central hypothesis was that patients with no response to treatment or patients who relapsed during the follow-up period were more likely to have elevated pre-treatment EMSs compared to those who responded to initial treatment and maintained gains over time. We also investigated whether there were any differences in change over time of overall EMS between patients who were recovered versus patients who were not recovered at extended follow-up. METHODS: Young Schema Questionnaire -Short Form (YSQ-SF), Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Beck Depression Inventory (BDI) were measured in 40 OCD patients in a general outpatient clinic before and after group ERP, after 12-months and at extended follow-up. To analyze the predictors, a multiple regression analyses was conducted. Changes in overall EMS was analyzed by mixed models procedures. RESULTS: The major finding is that patients with high pre-treatment YSQ-SF total scores were less likely to respond to initial treatment or were more likely to relapse between post-treatment and the extended follow-up. The YSQ-SF total score at pre-treatment explained 10.5% of the variance of extended long-term follow-up outcome. The entire sample experienced a significant reduction in overall EMS over time with largest reduction from pre- to post-test. There were no statistically significant differences in total EMS change trajectories between the patients who were recovered at the extended follow-up compared to those who were not. CONCLUSION: The results from the present study suggest that patients with higher pre-treatment EMSs score are less likely to recover in the long-term after receiving group ERP for OCD. A combined treatment that also targets early maladaptive schemas may be a more effective approach for OCD patients with elevated EMS who don't respond to standard ERP.

Magnetic Particle Imaging meets Computed Tomography: first simultaneous imaging.

Magnetic Particle Imaging (MPI) is a promising new tomographic modality for fast as well as three-dimensional visualization of magnetic material. For anatomical or structural information an additional imaging modality such as computed tomography (CT) is required. In this paper, the first hybrid MPI-CT scanner for multimodal imaging providing simultaneous data acquisition is presented.

Magnetic Particle Imaging-Guided Stenting.

Purpose:To assess the feasibility of magnetic particle imaging (MPI) to guide stenting in a phantom model. Materials and Methods: MPI is a new tomographic imaging method based on the background-free magnetic field detection of a tracer agent composed of superparamagnetic iron oxide nanoparticles (SPIOs). All experiments were conducted on a custom-built MPI scanner (field of view: 29-mm diameter, 65-mm length; isotropic spatial resolution 1-1.5-mm). Stenosis phantoms (n=3) consisted of polyvinyl chloride (PVC) tubes (8-mm inner diameter) prepared with centrally aligned cable binders to form a ~50% stenosis. A dedicated image reconstruction algorithm allowed precise tracking of endovascular instruments at 8 frames/s with a latency time of ~115 ms. A custom-made MPI-visible lacquer was used to manually label conventional guidewires, balloon catheters, and stainless steel balloon-expandable stents. Vascular stenoses were visualized by injecting a diluted SPIO tracer (ferucarbotran, 10 mmol iron/L) into the vessel phantoms. Balloon angioplasty and stent placement were performed by inflating balloon catheters and stent delivery balloons with diluted ferucarbotran. Results: After deployment of the stent, the markers on its ends were clearly visible. The applied lacquer markers were thin enough to not relevantly alter gliding properties of the devices while withstanding friction during the experiments. Placing an optimized flexible lacquer formulation on the preexisting radiopaque stent markers provided enough stability to withstand stent expansion. Final MPA confirmed successful stenosis treatment, facilitated by the disappearance of the lacquer markers on the stent due to differences in SPIO concentration. Thus, the in-stent lumen could be visualized without interference by the signal from the markers. Conclusion: Near real-time visualization of MPI-guided stenting of stenoses in a phantom model is feasible. Optimized MPI-visible markers can withstand the expansion process of stents.

Three-Week Inpatient Treatment of Obsessive-Compulsive Disorder: A 6-Month Follow-Up Study.

Background: Specialized inpatient or residential treatment might be an alternative treatment approach for patients with obsessive-compulsive disorder (OCD) that do not respond satisfactorily to the standard outpatient treatment formats. Method: The aim of this open trial was to investigate the 6-month effectiveness of a 3-week inpatient treatment of OCD, where exposure with response prevention (ERP) was the main treatment intervention. The sample consisted of 187 adult patients with OCD, all with previous treatment attempts for OCD. Results: The sample showed significant reductions in symptoms of OCD and depression. The effect sizes were large for obsessive-compulsive symptoms and moderate to large for depressive symptoms. At discharge, 79.7% of the intent-to-treat (ITT) group were classified as treatment responders (≥35% reduction in Y-BOCS scores). However, some participants experienced relapse, as 61.5% of the ITT group were classified as treatment responders at 6-month follow-up. Antidepressant use appeared not to influence the outcome. Only pre-treatment levels of obsessive-compulsive symptoms emerged as a significant predictor of relapse. Conclusion: The 3-week inpatient programme produced similar treatment effects as previous inpatient and residential studies of longer duration (2 - 3 months). The results suggest that patients with severe OCD can be treated efficiently using this brief inpatient format. However, better relapse prevention interventions are needed.

Magnetic Particle Imaging Guided Real-Time Percutaneous Transluminal Angioplasty in a Phantom Model.

PURPOSE: To investigate the potential of real-time magnetic particle imaging (MPI) to guide percutaneous transluminal angioplasty (PTA) of vascular stenoses in a phantom model. MATERIALS AND METHODS: Experiments were conducted on a custom-built MPI scanner. Vascular stenosis phantoms consisted of polyvinyl chloride tubes (inner diameter 8 mm) prepared with a centrally aligned cable tie to form ~ 50% stenoses. MPI angiography for visualization of stenoses was performed using the superparamagnetic iron oxide nanoparticle-based contrast agent Ferucarbotran (10 mmol (Fe)/l). Balloon catheters and guidewires for PTA were visualized using custom-made lacquer markers based on Ferucarbotran. Stenosis dilation (n = 3) was performed by manually inflating the PTA balloon with diluted Ferucarbotran. An online reconstruction framework was implemented for real-time imaging with very short latency time. RESULTS: Visualization of stenosis phantoms and guidance of interventional instruments in real-time (4 frames/s, ~ 100 ms latency time) was possible using an online reconstruction algorithm. Labeling of guidewires and balloon catheters allowed for precise visualization of instrument positions. CONCLUSION: Real-time MPI-guided PTA in a phantom model is feasible.

Explaining depression symptoms in patients with social anxiety disorder: Do maladaptive metacognitive beliefs play a role?

Social anxiety disorder (SAD) is a major risk factor for developing symptoms of depression. Severity of social anxiety has previously been identified as a risk factor, and cognitive models emphasize dysfunctional schemas and self-processing as the key vulnerability factors underlying general distress in SAD. However, in the metacognitive model, depressive and other symptoms are related to metacognitive beliefs. The aim of this study was therefore to test the relative contribution of metacognitions when controlling for SAD severity and factors postulated in cognitive models. In a cross-sectional design, 102 patients diagnosed with primary SAD were included. We found that negative metacognitive beliefs concerning uncontrollability and danger and low confidence in memory emerged as the only factors explaining depressive symptoms in the regression model, suggesting that metacognitive beliefs are associated with increased depressive symptoms in SAD patients.

Paroxetine, Cognitive Therapy or Their Combination in the Treatment of Social Anxiety Disorder with and without Avoidant Personality Disorder: A Randomized Clinical Trial.

BACKGROUND: The most efficacious treatments for social anxiety disorder (SAD) are the SSRIs and cognitive therapy (CT). Combined treatment is advocated for SAD but has not been evaluated in randomized trials using CT and SSRI. Our aim was to evaluate whether one treatment is more effective than the other and whether combined treatment is more effective than the single treatments. METHODS: A total of 102 patients were randomly assigned to paroxetine, CT, the combination of CT and paroxetine, or pill placebo. The medication treatment lasted 26 weeks. Of the 102 patients, 54% fulfilled the criteria for an additional diagnosis of avoidant personality disorder. Outcomes were measured at posttreatment and 12-month follow-up assessments. RESULTS: CT was superior to paroxetine alone and to pill placebo at the end of treatment, but it was not superior to the combination treatment. At the 12-month follow-up, the CT group maintained benefits and was significantly better than placebo and paroxetine alone, whereas there were no significant differences among combination treatment, paroxetine alone, and placebo. Recovery rates at 12 months were much higher in the CT group (68%) compared to 40% in the combination group, 24% in the paroxetine group, and 4% in the pill placebo group. CONCLUSIONS: CT was the most effective treatment for SAD at both posttreatment and follow-up compared to paroxetine and better than combined treatment at the 12-month follow-up on the Liebowitz Social Anxiety Scale. Combined treatment provided no advantage over single treatments; rather there was less effect of the combined treatment compared to CT alone.

Psychotic and schizotypal symptoms in non-psychotic patients with obsessive-compulsive disorder.

BACKGROUND: Research is scarce with regard to the role of psychotic and schizotypal symptoms in treatment of obsessive-compulsive disorder (OCD). The aim of the current study was to investigate the occurrence and specificity of psychotic and schizotypal symptoms among non-psychotic OCD patients, and to examine whether such symptoms was associated with response to exposure and response prevention (ERP), and whether ERP for OCD had an impact on psychotic and schizotypal symptoms. METHODS: Non-psychotic OCD patients (n = 133) and a general non-psychotic psychiatric outpatient sample (n = 110) were assessed using self-report inventories before and after psychological treatment. RESULTS: Non-psychotic OCD patients did not report greater degree of psychotic or schizotypal symptoms than the control group. Psychotic and schizotypal symptoms were not associated with OCD symptoms before or after ERP. Psychotic and schizotypal symptom were significantly reduced following ERP. CONCLUSIONS: Psychotic and schizotypal symptoms seem to be equally prevalent among non-psychotic OCD patients and non-psychotic psychiatric controls. These symptoms were more linked to depressive symptoms than OCD symptoms. In non-psychotic OCD patients, ERP seems sufficient in reducing OCD symptoms despite the presence of psychotic- and schizotypal symptoms, and reductions in psychotic- and schizotypal symptoms were observed following ERP.