What is obsession? Differentiating obsessive-compulsive disorder and the schizophrenia spectrum

Rethinking the core symptom of schizophrenia: An exploration of disorganized thought centrality in psychosis

BACKGROUND AND HYPOTHESIS

Schizophrenic symptoms are currently classified into several dimensions: positive symptoms, negative symptoms, disorganized thought, cognitive deficits, and general symptoms. This multi-dimensional categorization of symptoms has sparked an ongoing debate in the field: what is the core symptom of schizophrenia? This question remains central to our understanding of the disorder. In our previous research, we demonstrated the centrality of disorganized thought in schizophrenia. Building on this finding, we hypothesized that this centrality is not a feature of all psychotic disorders.

STUDY DESIGN

We analyzed Brief Psychiatric Rating Scale (BPRS) data from 17,414 outpatients using a Variational AutoEncoder (VAE) model. Clustering analysis was performed on the latent representations, followed by network analysis to examine symptom interactions within identified clusters. Analyses were further stratified by age and BPRS item types.

STUDY RESULTS

Clustering analysis revealed four distinct groups, in which one cluster exhibiting characteristics with more severe symptoms (mean BPRS score 99.73 [SD 9.46]), younger age (mean 19.48 [SD 9.31] years), and smaller sample size showed a unique centrality of thought disturbance among five subscale symptoms. This pattern persisted in both adult and adolescent subgroups and when analyzing only verbally reported items.

CONCLUSIONS

Our findings support the specificity of disorganized thought centrality in one particular cluster, distinguishing it from other psychiatric presentations. This study demonstrates the value in analyzing large-scale clinical data to refine our understanding of complex psychiatric disorders, potentially informing future targeted interventions.

Discovering functional interactions among schizophrenia-risk genes by combining behavioral genetics with cell biology

Despite much progress in identifying risk genes for polygenic brain disorders, their core pathogenic mechanisms remain poorly understood. In particular, functions of many proteins encoded by schizophrenia risk genes appear diverse and unrelated, complicating the efforts to establish the causal relationship between genes and behavior. Using various mouse lines, recent studies indicate that alterations of parvalbumin-positive (PV+) GABAergic interneurons can lead to schizophrenia-like behavior. PV+ interneurons display fast spiking and contribute to excitation-inhibition balance and network oscillations via feedback and feedforward inhibition. Here, we first summarize different lines of genetically modified mice that display motor, cognitive, emotional, and social impairments used to model schizophrenia and related mental disorders. We highlight ten genes, encoding either a nuclear, cytosolic, or membrane protein. Next, we discuss their functional relationship in regulating fast spiking and other aspects of PV+ interneurons and in the context of other domains of schizophrenia. Future investigations combining behavioral genetics and cell biology should elucidate functional relationships among risk genes to identify the core pathogenic mechanisms underlying polygenic brain disorders.

Obsessive-compulsive symptoms in individuals at clinical high risk for psychosis: A 2-year longitudinal study

Aim - Recent findings suggest that OCS are prevalent in individuals with early psychosis. However, their clinical relevance still needs to be clarified. This research specifically explored OCS in subjects at Clinical High Risk for Psychosis (CHRP), with the aims of determining their baseline prevalence, examining their 2-year stability, and analyzing their association with sociodemographic data, clinical characteristics and outcomes. Methods - Clinical assessments at baseline and during the 2-year follow-up period included: the Comprehensive Assessment of At-Risk Mental states (CAARMS), the Positive And Negative Syndrome Scale (PANSS), and the Global Assessment of Functioning (GAF). OCS were identified using the CAARMS item 7.6 subscore. Results - Among 180 CHR-P participants, 66 (36.7 %) had OCS at baseline. CHR-P with OCS had higher PANSS scores and greater antidepressant prescription rates. OCS severity levels improved in the first year, but plateaued over two years, correlating with longitudinal changes in GAF and PANSS total scores. OCS improvement was specifically associated with antidepressant use and intensity of individual psychotherapy sessions. CHR-P subjects with OCS had higher service engagement rates. Conclusions - The presence of OCS could characterize a distinct CHR-P subtype with specific clinical and prognostic characteristics, requiring tailored diagnostic and therapeutic approaches. Recognizing the heterogeneity in CHR-P population is crucial for optimizing care.

Conceptual-level disgust conditioning in contamination-based obsessive-compulsive disorder

Pavlovian fear conditioning and extinction represent learning mechanisms underlying exposure-based interventions. While increasing evidence indicates a pivotal role of disgust in the development of contamination-based obsessive-compulsive disorder (C-OCD), dysregulations in conditioned disgust acquisition and maintenance, in particular driven by higher-order conceptual processes, have not been examined. Here, we address this gap by exposing individuals with high (HCC, n = 41) or low (LCC, n = 41) contamination concern to a conceptual-level disgust conditioning and extinction paradigm. Conditioned stimuli (CS+) were images from one conceptual category partially reinforced by unconditioned disgust-eliciting stimuli (US), while images from another category served as non-reinforced conditioned stimuli (CS-). Skin conductance responses (SCRs), US expectancy and CS valence ratings served as primary outcomes to quantify conditioned disgust responses. Relative to LCC, HCC individuals exhibited increased US expectancy and CS+ disgust experience, but comparable SCR levels following disgust acquisition. Despite a decrease in conditioned responses from the acquisition phase to the extinction phase, both groups did not fully extinguish the learned disgust. Importantly, the extinction resilience of acquired disgust was more pronounced in HCC individuals. Together, our findings suggest that individuals with high self-reported contamination concern exhibit increased disgust acquisition and resistance to extinction. The findings provide preliminary evidence on how dysregulated disgust learning mechanism across semantically related concepts may contribute to C-OCD.

Altered cardiac autonomic functioning associates with self-disorders in schizophrenia

Elevated resting heart rate (RHR) and reduced heart rate variability (HRV) are signs of autonomic nervous system dysfunction identified in schizophrenia (SCZ). This dysfunction has been found to manifest prior to the onset of the clinical diagnosis. Yet whether such autonomic dysfunction is associated with vulnerability to schizophrenia remains unknown. This case-control study included recent onset SCZ patients (n = 35) and healthy controls (HC) (n = 33). Patients were scored for self-disorders (SD's) using the EASE manual and all participants underwent a 5-minute resting state electrocardiogram (ECG) recording. Patients were included from outpatient clinics in Denmark. The main measures comprised EASE total scores (SDs), RHR (beats per minute) and three standard HRV measures usually included in testing autonomic nervous system dysfunction: root mean squared of successive differences (RMSSD), standard deviation of normal-to-normal interval (SDNN) and high-frequency/ low frequency ratio (HF/LF). Pearson correlations and linear regression models adjusted for age, sex and medication were used in the SCZ group. The main finding was a positive moderate association between SDs and RHR (r = 0.463; p = 0.005) and a negative association between SDs and HRV (RMSSD) (r = -0.440; p = 0.008) in the SCZ group. Linear regression models found SDs to explain 22 % of the variance of RHR and 19 % in RMSSD. SDs correlated with LF/HF (r = 0.434; p = 0.009), but non-significantly with SDNN. The study provides evidence of an intriguing link between SDs as a susceptibility trait for schizophrenia spectrum disorders and altered cardiac autonomic functioning.

Pseudoneurotic Symptoms in the Schizophrenia Spectrum: A Longitudinal Study of Their Relation to Psychopathology and Clinical Outcomes

BACKGROUND AND HYPOTHESIS

Nonpsychotic symptoms (depression, anxiety, obsessions, etc.) are frequent in schizophrenia-spectrum disorders and are usually conceptualized as comorbidity or transdiagnostic symptoms. However, in twentieth century foundational psychopathological literature, many nonpsychotic symptoms with specific phenomenology (here termed pseudoneurotic symptoms) were considered relatively typical of schizophrenia. In this prospective study, we investigated potential associations of pseudoneurotic symptoms with diagnostic status, functional outcome as well as psychopathological dimensions of schizophrenia.

STUDY DESIGN

First-admitted patients (N = 121) diagnosed with non-affective psychosis, schizotypal disorder, or other mental illness were examined at initial hospitalization and 5 years later with a comprehensive assessment of psychopathology. Informed by the literature, we constructed scales targeting pseudoneurotic symptoms and other, more general, nonpsychotic symptoms.

STUDY RESULTS

Pseudoneurotic symptoms aggregated in schizophrenia-spectrum groups compared to other mental illnesses and occurred at similar levels at baseline and follow-up. They longitudinally predicted poorer social and occupational functioning in schizophrenia-spectrum patients over a 5-year-period but not transition to schizophrenia-spectrum disorders from other mental illnesses. Finally, the level of pseudoneurotic symptoms correlated with disorder of basic self at both assessments and with positive and negative symptoms at follow-up. The scale targeting general nonpsychotic symptoms did not show this pattern of associations.

CONCLUSIONS

The study supports that a group of nonpsychotic symptoms, ie, pseudoneurotic symptoms, are associated with schizophrenia-spectrum disorders and linked with temporally stable psychopathology, particularly disorder of the basic self. Their prospective association with social and occupational functioning needs replication.

Two multimodal neuroimaging subtypes of obsessive-compulsive disorder disclosed by semi-supervised machine learning

BACKGROUND

Obsessive-compulsive disorder (OCD) is a highly heterogeneous mental condition with a diverse symptom. Existing studies classified OCD on the basis of conventional phenomenology-based taxonomy ignoring the fact that the same subtype identified in accordance with clinical symptom may have different mechanisms and treatment responses.

METHODS

This research involved 50 medicine-free patients with OCD and 50 matched healthy controls (HCs). All the participants were subjected to structural and functional magnetic resonance imaging (MRI). Voxel-based morphometry (VBM) and amplitude of low frequency fluctuation (ALFF) were used to evaluate gray matter volume (GMV) and spontaneous neuronal activities at rest respectively. Similarity network fusion (SNF) was utilized to integrate GMVs and spontaneous neuronal activities, and heterogeneity by discriminant analysis was applied to characterise OCD subtypes.

RESULTS

Two OCD subtypes were identified: Subtype 1 exhibited decreased GMVs (i.e., left inferior temporal gyrus, right supplementary motor area and right lingual gyrus) and increased ALFF value (i.e., right orbitofrontal cortex), whereas subtype 2 exhibited increased GMVs (i.e., left cuneus, right precentral gyrus, left postcentral gyrus and left hippocampus) and decreased ALFF value (i.e., right caudate nucleus). Furthermore, the altered GMVs was negatively correlated with abnormal ALFF values in both subtype 1 and 2.

LIMITATIONS

This study requires further validation via a larger, independent dataset and should consider the potential influences of psychotropic medication on OCD patients' brain activities.

CONCLUSIONS

Results revealed two reproducible subtypes of OCD based on underlying multimodal neuroimaging and provided new perspectives on the classification of OCD.

The relationship between obsessive-compulsive symptoms and real-life functioning in schizophrenia: New insights from the multicenter study of the Italian Network for Research on Psychoses

BACKGROUND

Although obsessive-compulsive disorder (OCD) is highly prevalent in schizophrenia, its relationship with patients' real-life functioning is still controversial.

METHODS

The present study aims at investigating the prevalence of OCD in a large cohort of non-preselected schizophrenia patients living in the community and verifying the relationship of OCD, as well as of other psychopathological symptoms, with real-life functioning along a continuum of OCD severity and after controlling for demographic variables.

RESULTS

A sample of 327 outpatients with schizophrenia was enrolled in the study and collapsed into three subgroups according to OCD severity (subclinical, mild-moderate, severe). A series of structural equation modeling (SEM) was performed to analyze in each subgroup the association of obsessive-compulsive symptoms with real-life functioning, assessed through the Specific Levels of Functioning Scale and the UCSD Performance-Based Skills Assessment. Moreover, latent profile analysis (LPA) was performed to infer latent subpopulations. In the subclinical OCD group, obsessive-compulsive symptoms (OCS) were not associated with functioning, whereas in the mild-moderate OCD group, they showed a positive relationship, particularly in the domains of work and everyday life skills. The paucity of patients with severe OCD did not allow performing SEM analysis in this group. Finally, LPA confirmed a subgroup with mild-moderate OCS and more preserved levels of functioning.

CONCLUSIONS

These findings hint at a positive association between mild-moderate OCD and real-life functioning in individuals with schizophrenia and encourage a careful assessment of OCD in personalized programs to sustain daily life activities.

Revisiting Cognitive Deficits in Outpatients with Psychotic Disorders: A Transdiagnostic Comparison of Cognitive Performance While Accounting for Putative Confounding Factors

Recent research suggests that cognitive deficits in individuals with psychotic disorders could be overestimated because poor cognitive test performance is partly attributable to non-cognitive factors. To further test this, we included non-hospitalized individuals with psychotic disorders (PSY, n = 38), individuals with attenuated psychotic symptoms (n = 40), individuals with obsessive-compulsive disorders (n = 39), and healthy controls (n = 38). Relevant cognitive domains were assessed using the MATRICS Consensus Cognitive Battery. Putative confounding non-cognitive factors-heart rate, self-reported stress, negative affect, performance-related beliefs, and actigraphy-derived sleep-were assessed before cognitive testing. A multivariate analysis of covariance was calculated to examine group differences in cognitive performance while controlling for non-cognitive factors. PSY showed decreased test performance in graphomotor speed, attention, and verbal tasks compared to the other groups, whereas non-verbal/visual-spatial tasks were unimpaired. After accounting for non-cognitive factors, group differences diminished in verbal learning, whereas differences in the other domains remained significant. Against our hypotheses, the present findings indicate that some cognitive deficits in PSY cannot be attributed to momentary confounding factors.

Neurocognitive mechanisms of mental imagery-based disgust learning

Disgust imagery represents a potential pathological mechanism for disgust-related disorders. However, it remains controversial as to whether disgust can be conditioned with disgust-evoking mental imagery serving as the unconditioned stimulus (US). Therefore, we examined this using a conditioned learning paradigm in combination with event-related potential (ERP) analysis in 35 healthy college students. The results indicated that the initial neutral face (conditioned stimulus, CS+) became more disgust-evoking, unpleasant, and arousing after pairing with disgust-evoking imagery (disgust CS+), compared to pairing with neutral (neutral CS+) and no (CS-) imagery. Moreover, we observed that mental imagery-based disgust conditioning was resistant to extinction. While the disgust CS + evoked larger P3 and late positive potential amplitudes than CS- during acquisition, no significant differences were found between disgust CS+ and neutral CS+, indicating a dissociation between self-reported and neurophysiological responses. Future studies may additionally acquire facial EMG as an implicit index of conditioned disgust. This study provides the first neurobiological evidence that associative disgust learning can occur without aversive physical stimuli, with implications for understanding how disgust-related disorders may manifest or deteriorate without external perceptual aversive experiences, such as in obsessive-compulsive disorder (OCD).

Self-Disorder in Schizophrenia: A Revised View (2. Theoretical Revision-Hyperreflexivity)

A growing body of research supports the role of self-disorders as core phenotypic features of schizophrenia-spectrum conditions. Self-disorders comprise various alterations of conscious experience whose theoretical understanding continues to present a challenge. This is the second of two articles that aim to clarify the nature of self-disorders in schizophrenia by considering the currently most influential, phenomenological model of schizophrenia: the basic-self-disturbance or ipseity-disorder model (IDM). The previous paper (article 1) presented a state-of-the-art overview of this model and critically assessed its descriptive adequacy with respect to the clinical heterogeneity and variability of the alterations in self- and world-awareness characteristic of schizophrenia. This paper (article 2) proposes a theoretical revision by considering how hyperreflexivity might form the crucial common thread or generating factor that unifies the heterogeneous, and sometimes even contradictory features of schizophrenic self-disorders. We outline implications of our revised model (IDMrevised) for explanatory research, therapeutic practice, and our general understanding of the abnormalities in question.

Clinical features in co-occuring obsessive-compulsive disorder and bipolar disorder: A systematic review and meta-analysis

Obsessive-compulsive disorder (OCD) frequently co-occurs with various psychiatric conditions and may impact as many as one-fifth of individuals diagnosed with bipolar disorder (BD). Despite the expanding body of literature on the coexistence of OCD and BD, there is a notable lack of comprehensive data pertaining to the distinct features of obsessive-compulsive symptoms that define this comorbidity. To bridge this knowledge gap, we conducted a systematic search of PubMed/MEDLINE, Scopus, EMBASE, and PsycINFO until August 7th, 2023. We performed random-effects meta-analyses to compare individuals with both OCD and BD to those with OCD in terms of OCD symptomatology as well as the specific categories of obsessions and compulsions. Out of the 10,393 records initially screened, 17 studies were ultimately incorporated into the qualitative assessment, with 15 of them being included in the quantitative analysis. Individuals with OCD and BD experienced fewer lifetime contamination obsessions (OR=0.71; 95 %CI=0.53, 0.95; p = 0.021) and more sexual obsessions (OR=1.77; 95 %CI=1.03, 3.04; p = 0.04) compared to individuals with OCD without BD. No significant difference was observed for other types of obsessions or compulsions or for the severity of OCD symptoms, although BD type may play a role according to meta-regression analyses. The detection of the presence of sexual or contamination obsessions through a detailed interview may be the focus of clinical attention when assessing OCD in the context of comorbid BD. Sub-phenotyping complex clinical presentation of comorbid psychiatric disorders can aid in making more informed decisions when choosing an appropriate treatment approach.

Anomalies of imagination and development of psychosis: A phenomenological account

In 20th century psychiatry, various disturbances of imagination were discussed in the context of schizophrenia. Today, these notions have almost completely vanished from mainstream psychopathology. However, recent work has suggested that specific phenomena within this area have a relevance for differential diagnosis and early detection of psychosis. This paper first provides an overview of 20th century psychopathological literature, as well as more recent neurocognitive studies, addressing disturbances of imagination and their role for symptom formation in schizophrenia. It then discusses recent empirical investigations of subjective anomalies of imagination in schizophrenia-spectrum disorders and suggests a clinical-phenomenological account of their role in the development of psychotic symptoms. Empirically and conceptually, these subjective anomalies are linked with disturbances of basic self. Patients' descriptions of the development of their anomalous experiences and symptoms indicate that increased spatial (object-like) articulation and instability of the first-personal manifestation of imaginative experience can be involved in the emergence of delusions and hallucinatory phenomena. Finally, a potential link between subjective anomalies of imagination and the neurocognitive construct of source monitoring deficits is discussed.

The Relationship between Childhood Trauma Experiences and Psychotic Vulnerability in Obsessive Compulsive Disorder: An Italian Cross-Sectional Study

People with obsessive compulsive disorder (OCD) are at increased risk of developing psychotic disorders; yet little is known about specific clinical features which might hint at this vulnerability. The present study was aimed at elucidating the pathophysiological mechanism linking OCD to psychosis through the investigation of childhood trauma experiences in adolescents and adults with OCD. One hundred outpatients, aged between 12 and 65 years old, were administered the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and its Child version (CY-BOCS), as well as the Childhood Trauma Questionnaire (CTQ); Cognitive-Perceptual basic symptoms (COPER) and high-risk criterion Cognitive Disturbances (COGDIS) were assessed in the study sample. Greater childhood trauma experiences were found to predict psychotic vulnerability (p = 0.018), as well as more severe OCD symptoms (p = 0.010) and an earlier age of OCD onset (p = 0.050). Participants with psychotic vulnerability reported higher scores on childhood trauma experiences (p = 0.02), specifically in the emotional neglect domain (p = 0.01). In turn, emotional neglect and psychotic vulnerability were found higher in the pediatric group than in the adult group (p = 0.01). Our findings suggest that childhood trauma in people with OCD may represent an indicator of psychotic vulnerability, especially in those with an earlier OCD onset. Research on the pathogenic pathways linking trauma, OCD, and psychosis is needed.

Psychiatric comorbidity: a concept in need of a theory

Despite being a relatively new concept, psychiatric comorbidity, i.e. the co-occurrence of two or more mental disorders, has become widespread in clinical practice and psychiatric research. In this article, we trace the origin of the concept of psychiatric comorbidity, discuss the conceptual literature and point to basic problems concerning inadequate definition of the concept, differential diagnostic issues, and reification of mental disorders. We illustrate how these problems may have consequences for diagnostic assessment in current clinical practice and psychiatric research. To address some of the problems related to psychiatric comorbidity, we discuss potential principles for assessing psychiatric comorbidity. Inspired by Feinstein's original concept of comorbidity in general medicine and his differential diagnostic principles, we emphasize the importance of independence of mental disorders when assessing psychiatric comorbidity. We suggest that knowledge of trait v. state conditions and of the multitudinous clinical manifestations beyond what is captured in the diagnostic manuals may be helpful for assessing the independence of mental disorders and thus psychiatric comorbidity. We further argue that a more hierarchical diagnostic system and explicit exclusionary rules could improve clinical practice and research by reducing informational complexity and combating unwarranted psychiatric comorbidity.

The heterogeneity of attenuated and brief limited psychotic symptoms: association of contents with age, sex, country, religion, comorbidities, and functioning

Introduction

The Attenuated Psychosis Symptoms (APS) syndrome mostly represents the ultra-high-risk state of psychosis but, as does the Brief Intermittent Psychotic Symptoms (BIPS) syndrome, shows a large variance in conversion rates. This may be due to the heterogeneity of APS/BIPS that may be related to the effects of culture, sex, age, and other psychiatric morbidities. Thus, we investigated the different thematic contents of APS and their association with sex, age, country, religion, comorbidity, and functioning to gain a better understanding of the psychosis-risk syndrome.

Method

A sample of 232 clinical high-risk subjects according to the ultra-high risk and basic symptom criteria was recruited as part of a European study conducted in Germany, Italy, Switzerland, and Finland. Case vignettes, originally used for supervision of inclusion criteria, were investigated for APS/BIPS contents, which were compared for sex, age, country, religion, functioning, and comorbidities using chi-squared tests and regression analyses.

Result

We extracted 109 different contents, mainly of APS (96.8%): 63 delusional, 29 hallucinatory, and 17 speech-disorganized contents. Only 20 contents (18.3%) were present in at least 5% of the sample, with paranoid and referential ideas being the most frequent. Thirty-one (28.5%) contents, in particular, bizarre ideas and perceptual abnormalities, demonstrated an association with age, country, comorbidity, or functioning, with regression models of country and obsessive-compulsive disorders explaining most of the variance: 55.8 and 38.3%, respectively. Contents did not differ between religious groups.

Conclusion

Psychosis-risk patients report a wide range of different contents of APS/BIPS, underlining the psychopathological heterogeneity of this group but also revealing a potential core set of contents. Compared to earlier reports on North-American samples, our maximum prevalence rates of contents were considerably lower; this likely being related to a stricter rating of APS/BIPS and cultural influences, in particular, higher schizotypy reported in North-America. The various associations of some APS/BIPS contents with country, age, comorbidities, and functioning might moderate their clinical severity and, consequently, the related risk for psychosis and/or persistent functional disability.

Obsessive-compulsive symptoms in the schizophrenia-spectrum: current developments in psychopathology research

PURPOSE OF REVIEW

Schizophrenia-spectrum disorders (SSD) frequently involve symptoms that usually are ascribed to nonpsychotic disorder spectra, such as obsessive-compulsive symptoms (OCS). These symptoms can cause differential diagnostic challenges, particularly in early illness stages, and must be considered in treatment planning. In this review, we provide an overview of recent literature within the field of OCS in SSD, with a focus on psychopathology research.

RECENT FINDINGS

OCS are seen in approximately a quarter of patients with SSD or at-risk mental state of psychosis. They are associated with more severe clinical features and specific temporal patterns of OCS may be linked with different clinical trajectories. However, the current definitions of OCS have been criticized for their overinclusive nature, which is a limiting step for differential diagnosis and more precise prognostic stratification. Specific phenomenological features, including a link with experiential anomalies (disorders of basic self), have been suggested to provide clinically relevant distinctions.

SUMMARY

The presence of OCS in SSD is associated with more severe clinical features and invites a higher clinical attention and perspectival monitoring. Some findings suggest that more fine-grained psychopathological distinctions might be a viable clinical and research strategy to advance the field in the direction of precision psychiatry.

Obsessive-compulsive symptoms in first episode psychosis and risk states: Systematic review with meta-analysis

BACKGROUND AND HYPOTHESIS

Recent studies have reported high prevalences of obsessive-compulsive symptoms and obsessive-compulsive disorder in at risk and first-episode psychosis patients. This sparked an interest in the effect of these symptoms in the clinical characteristics and outcomes of patients. However these studies have never been formally meta-analyzed.

STUDY DESIGN

Systematic review and meta-analysis of prevalence of obsessive-compulsive symptoms and obsessive-compulsive disorder in at risk and first-episode psychosis patients and comparison of clinical characteristics and outcomes in patients with and without obsessive-compulsive symptoms.

STUDY RESULTS

Obsessive-compulsive disorder was present in 7.9 % (5.9 to 10.0 %) and 10.5 % (8.3 to 12.8 %) and obsessive-compulsive symptoms in 21.4 % (8.3 to 38.2 %) and 34.0 % (26.3 to 42.1 %) of at risk and first episode psychosis patients respectively. The prevalences of obsessive-compulsive symptoms had high heterogeneity due in part to different measurement methods and cut-off values. Similar ages of onset for OCS and psychosis symptoms were found (mean difference - 0.49 years, 95 % CI -1.74 to 0.77). Patients with obsessive-compulsive symptoms had statistically insignificant higher Positive and Negative Syndrome Scale (positive subscale) scores and marginally higher depression scores. There were no differences between both groups in age of onset, Positive and Negative Syndrome Scale (negative subscale) score, risk of conversion to psychosis, anxiety score, suicide rate, and functionality score.

CONCLUSIONS

Obsessive-compulsive disorder and obsessive-compulsive symptoms are very prevalent in at risk and first-episode psychosis patients.

Association between obsessive-compulsive disorder and the risk of schizophrenia using the Korean National Health Insurance Service-National Sample Cohort: a retrospective cohort study

AIMS

Obsessive-compulsive disorder (OCD) and schizophrenia are often reported as co-morbid conditions. However, the evidence of an association between OCD and the risk of schizophrenia is limited. This study investigated the risk of schizophrenia in patients newly diagnosed with OCD using a nationally representative sample cohort in South Korea.

METHODS

Data were obtained from the 2002-2013 Korean National Health Insurance Service-National Sample Cohort of the National Health Insurance Service. Using propensity score matching, 2509 patients with OCD and a control group of 7527 patients were included in the analysis. Chi-squared tests were used to investigate and compare the general characteristics of the study population. The risk of schizophrenia was analysed using the Cox proportional hazard model.

RESULTS

The incidence rate was 45.79/10 000 person-year for patients with OCD and 4.19/10 000 person-year for patients without OCD. Patients with OCD had a higher risk of schizophrenia compared to the control group after adjusting for covariates (hazard ratio = 10.46, 95% confidence interval = 6.07-18.00).

CONCLUSIONS

This study identified an association between the diagnosis of OCD and the risk of schizophrenia in a South Korean national representative cohort. Further research using a prospective design to clarify the causality of OCD in schizophrenia in a controlled environment should be conducted to validate these findings.

Familial risk of psychosis in obsessive-compulsive disorder: Impact on clinical characteristics, comorbidity and treatment response

BACKGROUND

Family studies in obsessive-compulsive disorder (OCD) indicate higher rates of psychosis among their first-degree relatives (FDRs). However, the etiological and clinical relationships between the two disorders remain unclear. We compared the clinical characteristics and pharmacological treatment response in patients diagnosed with OCD with a family history of psychosis (OCD-FHP), with a family history of OCD (OCD-FHO) and those with sporadic OCD (OCD-S).

METHODS

A total of 226 patients who met DSM-IV criteria for OCD (OCD-FHP = 59, OCD-FHO = 112, OCD-S = 55) were included for analysis. All patients were evaluated using the Mini International Neuropsychiatric Interview (MINI 6.0.0), Yale-Brown Obsessive-Compulsive Scale (YBOCS), and the Family Interview for Genetic Studies (FIGS). Treatment response was characterized over naturalistic follow-up.

RESULTS

The three groups did not differ across any demographic or clinical variables other than treatment response. Patients in the OCD-FHP group were found to have received a greater number of trials with serotonin reuptake inhibitors (SRI) [F (2,223) = 7.99, p < 0.001], were more likely to have failed ≥2 trials of SRIs (χ2 = 8.45, p = 0.014), and less likely to have attained remission (χ2 = 6.57, p = 0.037) CONCLUSIONS: We observed that having a relative with psychosis may predispose to treatment resistance in OCD. Further research on the influence of genetic liability to psychosis on treatment response in OCD may offer novel translational leads.

Pseudoneurotic symptoms in the schizophrenia spectrum: An empirical study

BACKGROUND

Nonpsychotic symptoms (depression, anxiety, obsessions etc.) are frequent in schizophrenia-spectrum disorders. Twentieth century foundational psychopathological literature claimed that certain nonpsychotic symptoms (here termed pseudoneurotic symptoms) are relatively closely linked with the schizophrenia-spectrum, despite descriptive overlap with symptoms of other diagnoses. In this study, we investigated the association of pseudoneurotic and other nonpsychotic symptoms with the schizophrenia-spectrum as well as a hypothesis about an association of pseudoneurotic symptoms with disorder of basic self.

METHODS

The sample (N = 226) comprised patients with non-affective psychosis (N = 119), schizotypal personality disorder (N = 51) and other mental illness (N = 56), who were examined with a comprehensive assessment of lifetime psychopathology. Informed by the literature, we constructed scales targeting pseudoneurotic symptoms and other, more general, nonpsychotic symptoms.

RESULTS

Pseudoneurotic symptoms aggregated significantly in schizophrenia-spectrum disorders with an Area under the receiver operating characteristic curve of 0.84 (SE 0.03) for classifying patients with schizophrenia-spectrum disorders versus other mental illness. Patients with non-affective psychosis scored slightly, but significantly, higher on the scale targeting general nonpsychotic symptomatology than the other groups. In multiple regression analysis, pseudoneurotic symptoms were predicted by general nonpsychotic symptoms, disorders of basic self, and negative symptoms but not positive symptoms.

CONCLUSION

The study supports that certain neurotic-like symptoms with specific descriptive features (pseudoneurotic symptoms) are associated with schizophrenia-spectrum disorders. It suggests that pseudoneurotic symptoms are linked with temporally stable schizophrenia psychopathology (disorder of basic self and negative symptoms).