Neuroimaging communality between schizophrenia and obsessive compulsive disorder: a putative basis for schizo-obsessive disorder?

Parental mental disorders in patients with comorbid schizophrenia and obsessive-compulsive disorder: a nationwide family-link study

Schizophrenia is highly comorbid with obsessive-compulsive disorder (OCD); both conditions share numerous pathophysiological etiologies. We, thus, examined the risk of mental disorders in the parents of probands with schizophrenia, OCD, or both conditions. Between 2001 and 2011, we enrolled a nationwide cohort of 69,813 patients with schizophrenia, OCD, or both. The control cohort included 698,130 individuals matched for demographics. Poisson regression models were employed to examine the risk of six mental disorders in their parents, including schizophrenia, bipolar disorder, depressive disorder, OCD, alcohol use disorder, and substance use disorder. We stratified patients into schizophrenia-only, OCD-only, and dual-diagnosis groups, and the dual-diagnosis group was further divided into schizophrenia-first, OCD-first, and simultaneously diagnosed groups. Compared with controls, the schizophrenia, OCD, and dual-diagnosis groups had higher risks for the six mental disorders in their parents (range of odds ratio [OR] 1.50-7.83). The sub-analysis of the dual-diagnosis group showed that the schizophrenia-first, OCD-first, and simultaneously diagnosed groups had higher odds for schizophrenia, bipolar disorder, depressive disorder, and OCD (range of OR 1.64-6.45) in their parents than the control group; the simultaneously diagnosed and OCD-first diagnosed groups had a higher odds of parental substance use disorder, while the schizophrenia-first diagnosed group had a higher odds of parental alcohol use disorder. The interrelationship between OCD and schizophrenia is linked to bipolar disorder, depressive disorder, alcohol use disorder, and substance use disorder. The results have implications for mental health policy and future research.

EEG microstate co-specificity in schizophrenia and obsessive-compulsive disorder

The past 20 years of research on EEG microstates has yielded the hypothesis that the imbalance pattern in the temporal dynamics of microstates C (increased) and D (decreased) is specific to schizophrenia. A similar microstate imbalance has been recently found in obsessive-compulsive disorder (OCD). The aim of the present high-density EEG study was to examine whether this pathological microstate pattern is co-specific to schizophrenia and OCD. We compared microstate temporal dynamics using Bayesian analyses, transition probabilities analyses and the Topographic Electrophysiological State Source-Imaging method for source reconstruction in 24 OCD patients and 28 schizophrenia patients, respectively, free of comorbid psychotic and OCD symptoms, and 27 healthy controls. OCD and schizophrenia patients exhibited the same increased contribution of microstate C, decreased duration and contribution of microstate D and greater D → C transition probabilities, compared with controls. A Bayes factor of 4.424 for the contribution of microstate C, 4.600 and 3.824, respectively, for the duration and contribution of microstate D demonstrated that there was no difference in microstate patterns between the two disorders. Source reconstruction further showed undistinguishable dysregulations between the Salience Network (SN), associated with microstate C, and the Executive Control Network (ECN), associated with microstate D, and between the ECN and cognitive cortico-striato-thalamo-cortical (CSTC) loop in the two disorders. The ECN/CSTC loop dysconnectivity was slightly worsened in schizophrenia. Our findings provide substantial evidence for a common aetiological pathway in schizophrenia and OCD, i.e. microstate co-specificity, and same anomalies in salience and external attention processing, leading to co-expression of symptoms.

Disruption of consciousness depends on insight in OCD and on positive symptoms in schizophrenia

Disruption of conscious access contributes to the advent of psychotic symptoms in schizophrenia but could also explain lack of insight in other psychiatric disorders. In this study, we explored how insight and psychotic symptoms related to disruption of consciousness. We explored consciousness in patients with schizophrenia, patients with obsessive-compulsive disorder (OCD) with good vs. poor insight and matched controls. Participants underwent clinical assessments and performed a visual masking task allowing us to measure individual consciousness threshold. We used a principal component analysis to reduce symptom dimensionality and explored how consciousness measures related to symptomatology. We found that clinical dimensions could be well summarized by a restricted set of principal components which also correlated with the extent of consciousness disruption. More specifically, positive symptoms were associated with impaired conscious access in patients with schizophrenia whereas the level of insight delineated two subtypes of OCD patients, those with poor insight who had consciousness impairments similar to patients with schizophrenia, and those with good insight who resemble healthy controls. Our study provides new insights about consciousness disruption in psychiatric disorders, showing that it relates to positive symptoms in schizophrenia and with insight in OCD. In OCD, it revealed a distinct subgroup sharing neuropathological features with schizophrenia. Our findings refine the mapping between symptoms and cognition, paving the way for a better treatment selection.

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.

Comparison of resting-state spontaneous brain activity between treatment-naive schizophrenia and obsessive-compulsive disorder

BACKGROUND

Schizophrenia (SZ) and obsessive-compulsive disorder (OCD) share many demographic characteristics and severity of clinical symptoms, genetic risk factors, pathophysiological underpinnings, and brain structure and function. However, the differences in the spontaneous brain activity patterns between the two diseases remain unclear. Here this study aimed to compare the features of intrinsic brain activity in treatment-naive participants with SZ and OCD and to explore the relationship between spontaneous brain activity and the severity of symptoms.

METHODS

In this study, 22 treatment-naive participants with SZ, 27 treatment-naive participants with OCD, and sixty healthy controls (HC) underwent a resting-state functional magnetic resonance imaging (fMRI) scan. The amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo) and degree of centrality (DC) were performed to examine the intrinsic brain activity of participants. Additionally, the relationships among spontaneous brain activity, the severity of symptoms, and the duration of illness were explored in SZ and OCD groups.

RESULTS

Compared with SZ group and HC group, participants with OCD had significantly higher ALFF in the right angular gyrus and the left middle frontal gyrus/precentral gyrus and significantly lower ALFF in the left superior temporal gyrus/insula/rolandic operculum and the left postcentral gyrus, while there was no significant difference in ALFF between SZ group and HC group. Compared with HC group, lower ALFF in the right supramarginal gyrus/inferior parietal lobule and lower DC in the right lingual gyrus/calcarine fissure and surrounding cortex of the two patient groups, higher ReHo in OCD group and lower ReHo in SZ group in the right angular gyrus/middle occipital gyrus brain region were documented in the present study. DC in SZ group was significantly higher than that in HC group in the right inferior parietal lobule/angular gyrus, while there were no significant DC differences between OCD group and HC group. In addition, ALFF in the left postcentral gyrus were positively correlated with positive subscale score (r = 0.588, P = 0.013) and general psychopathology subscale score (r = 0.488, P = 0.047) respectively on the Positive and Negative Syndrome Scale (PANSS) in SZ group. ALFF in the left superior temporal gyrus/insula/rolandic operculum of participants with OCD were positively correlated with compulsion subscale score (r = 0.463, P = 0.030) on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The longer the illness duration in SZ group, the smaller the ALFF of the left superior temporal gyrus/insula/rolandic operculum (Rho = 0.-492, P = 0.020). The longer the illness duration in OCD group, the higher the ALFF of the right supramarginal gyrus/inferior parietal lobule (Rho = 0.392, P = 0.043) and the left postcentral gyrus (Rho = 0.385, P = 0.048), and the lower the DC of the right inferior parietal lobule/angular gyrus (Rho = - 0.518, P = 0.006).

CONCLUSION

SZ and OCD show some similarities in spontaneous brain activity in parietal and occipital lobes, but exhibit different patterns of spontaneous brain activity in frontal, temporal, parietal, occipital, and insula brain regions, which might imply different underlying neurobiological mechanisms in the two diseases. Compared with OCD, SZ implicates more significant abnormalities in the functional connections among brain regions.

Predicting the individual risk of psychosis conversion in at-risk mental state (ARMS): a multivariate model reveals the influence of nonpsychotic prodromal symptoms

To improve the prediction of the individual risk of conversion to psychosis in UHR subjects, by considering all CAARMS' symptoms at first presentation and using a multivariate machine learning method known as logistic regression with Elastic-net shrinkage. 46 young individuals who sought help from the specialized outpatient unit at Sainte-Anne hospital and who met CAARMS criteria for UHR were assessed, among whom 27 were reassessed at follow-up (22.4 ± 6.54 months) and included in the analysis. Elastic net logistic regression was trained, using CAARMS items at baseline to predict individual evolution between converters (UHR-P) and non-converters (UHR-NP). Elastic-net was used to select the few CAARMS items that best predict the clinical evolution. All validations and significances of predictive models were computed with non-parametric re-sampling strategies that provide robust estimators even when the distributional assumption cannot be guaranteed. Among the 25 CAARMS items, the Elastic net selected 'obsessive-compulsive symptoms' and 'aggression/dangerous behavior' as risk factors for conversion while 'anhedonia' and 'mood swings/lability' were associated with non-conversion at follow-up. In the ten-fold stratified cross-validation, the classification achieved 81.8% of sensitivity (P = 0.035) and 93.7% of specificity (P = 0.0016). Non-psychotic prodromal symptoms bring valuable information to improve the prediction of conversion to psychosis. Elastic net logistic regression applied to clinical data is a promising way to switch from group prediction to an individualized prediction.

Neural dynamics in co-morbid schizophrenia and OCD: A computational approach

The co-morbidity of obsessive-compulsive disorder (OCD) and schizophrenia is higher than what would be expected by chance and the common underlying neuropathophysiology is not well understood. Repetitive stereotypes and routines can be caused by perseverative thoughts and motor sequences in both of these disorders. We extended a previously published computational model to investigate cortico-striatal network dynamics. Given the considerable overlap in symptom phenomenology and the high degree of co-morbidity between OCD and schizophrenia, we examined the dynamical consequences of functional connectivity variations in the overlapping network. This was achieved by focusing on the emergence of network oscillatory activity and examining parameter sensitivity. Opposing activity levels are present in orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC) in schizophrenia and OCD. We found that with over-compensation of the primary pathology, emergence of the other disorder can occur. The oscillatory behavior is delicately modulated by connections between the OFC/ACC to the ventral and dorsal striatum and by the coupling between the ACC and dorsolateral prefrontal cortex (DLPFC). Modulation on cortical self-inhibition (e.g. serotonin reuptake inhibitor treatment) together with dopaminergic input to the striatum (e.g. anti-dopaminergic medication) has non-trivial complex effects on the network oscillatory behavior, with an optimal modulatory window. Additionally, there are several disruption mechanisms and compensatory processes in the cortico-striato-thalamic network which may contribute to the underlying neuropathophysiology and clinical heterogeneity in schizo-obsessive spectrum disorders. Our mechanistic model predicts that dynamic over-compensation of the primarily occuring neuropathophysiology can lead to the secondary co-morbid disease.

Prevalence of Obsessive-Compulsive Disorder in Patients With Schizophrenia and Outcome on Positive and Negative Symptoms, Cognition, and Quality of Life

The objectives were to examine the prevalence of obsessive-compulsive disorder (OCD) in hospitalized patients with schizophrenia and to compare the clinical, cognitive, and functional characteristics of schizophrenia patients with and without OCD. This cross-sectional study, performed between May and August 2018, enrolled 308 patients (200 men and 108 women). The prevalence of OCD in patients with schizophrenia was 3.2%. An increase in patients having a mild β was significantly associated with higher social relationship score (β = 1.68) and the Memory Functioning Scale-Informant (MFS-I) version (β = 5.67). OCD did not affect the positive and negative symptoms of these patients. The prevalence of OCD in these patients was low (3.2%). Schizophrenia patients with and without OCD have comparable clinical profiles with few exceptions. The existence of OCD may affect the social relationship quality of life and the MFS-I version.

Psychiatric Symptoms in Amyotrophic Lateral Sclerosis: Beyond a Motor Neuron Disorder

The historical view that Amyotrophic Lateral Sclerosis (ALS) as a pure motor disorder has been increasingly challenged by the discovery of cognitive and behavioral changes in the spectrum of Frontotemporal Dementia (FTD). Less recognized and still significant comorbidities that ALS patients may present are prior or concomitant psychiatric illness, such as psychosis and schizophrenia, or mood disorders. These non-motor symptoms disturbances have a close time relationship with disease onset, may constitute part of a larger framework of network disruption in motor neuron disorders, and may impact ALS patients and families, with regards to ethical choices and end-of-life decisions. This review aims at identifying the most common psychiatric alterations related to ALS and its prognosis, looking at a common genetic background and shared structural brain pathology.

The Shared and Distinct White Matter Networks Between Drug-Naive Patients With Obsessive-Compulsive Disorder and Schizophrenia

Background: Obsessive-compulsive disorder (OCD) and schizophrenia (SZ) as two severe mental disorders share many clinical symptoms, and have a tight association on the psychopathological level. However, the neurobiological substrates between these two diseases remain unclear. To the best of our knowledge, no study has directly compared OCD with SZ from the perspective of white matter (WM) networks. Methods: Graph theory and network-based statistic methods were applied to diffusion MRI to investigate and compare the WM topological characteristics among 29 drug-naive OCDs, 29 drug-naive SZs, and 65 demographically-matched healthy controls (NC). Results: Compared to NCs, OCDs showed the alterations of nodal efficiency and strength in orbitofrontal (OFG) and middle frontal gyrus (MFG), while SZs exhibited widely-distributed abnormalities involving the OFG, MFG, fusiform gyrus, heschl gyrus, calcarine, lingual gyrus, putamen, and thalamus, and most of these regions also showed a significant difference from OCDs. Moreover, SZs had significantly fewer connections in striatum and visual/auditory cortices than OCDs. The right putamen consistently showed significant differences between both disorders on nodal characteristics and structural connectivity. Conclusions: SZ and OCD present different level of anatomical impairment and some distinct topological patterns, and the former has more serious and more widespread disruptions. The significant differences between both disorders are observed in many regions involving the frontal, temporal, occipital, and subcortical regions. Particularly, putamen may serve as a potential imaging marker to distinguish these two disorders and may be the key difference in their pathological changes.

Resting-State Default Mode Network Related Functional Connectivity Is Associated With Sustained Attention Deficits in Schizophrenia and Obsessive-Compulsive Disorder

Background: Previous studies have indicated the resting-state default mode network (DMN) related connectivity serving as predictor of sustained attention performance in healthy people. Interestingly, sustained attention deficits as well as DMN-involved functional connectivity (FC) alterations are common in both patients with schizophrenia (SCZ) and with obsessive-compulsive disorder (OCD). Thus, the present study was designed to investigate whether the DMN related resting-state connectivity alterations in these two psychiatric disorders were neural correlates of their sustained attention impairments.

Methods: The study included 17 SCZ patients, 35 OCD patients and 36 healthy controls (HCs). Sustained attention to response task was adopted to assess the sustained attention. Resting-state scan was administrated and seed-based whole-brain FC analyses were performed with seeds located in classical DMN regions including bilateral medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC).

Results: Both SCZ and OCD patients had poorer sustained attention than HCs. Sustained attention deficits in OCD was negatively correlated with their impaired FC of right mPFC-left superior frontal gyrus (SFG) within DMN, and that in SCZ was significantly correlated with their altered FC of left mPFC-bilateral anterior cingulate cortex (ACC) which indicated interaction between DMN and salience network. In addition, the FC between left mPFC and right parietal lobe indicating the interaction between DMN and frontal-parietal network was correlated with sustained attention in both SCZ and OCD.

Conclusion: These findings suggest the importance of DMN-involved connectivity, both within and between networks in underlying sustained attention deficits in OCD and SCZ. Results further support the potential of resting-state FC in complementing information for cognitive deficits in psychiatric disorders.

Schizophrenia and co-morbid obsessive - compulsive disorder: Clinical characteristics

BACKGROUND

Psychiatric co-morbidity is a common condition, partly due to the overlap of symptoms in the categorical diagnosis of mental disorders. The co-occurrence of schizophrenia (SZ) and obsessive compulsive disorder (OCD) is a common and challenging co-morbid condition. Also, the relationship between SZ and OCD remains unclear.

AIM

The aim of this study was to describe the co-morbidity of obsessive-compulsive disorder (OCD) among schizophrenia (SZ) patients and compare clinical characteristics of schizophrenia patients with versus without comorbid OCD.

SUBJECTS AND METHODS

A cohort-study was carried out on 396 patients enrolled between November 2011 to June 2014 at the Department of Psychiatry, Rumeilah Hospital in Qatar. We employed the WHO Composite International Diagnostic Interview (WHO-CIDI), and Structured clinical interview for DSM-5 (SCID-5) for diagnoses, the Yale-Brown Obsessive Compulsive Scale Symptom Checklist for scoring OCD. Patients were grouped in SZ patients with and without comorbid OCD (SZ-OCD vs SZ).

RESULTS

396 subjects were interviewed. Age of SZ-OCD patients was 42.69 ± 14.33 (years old) whereas SZ patients without OCD ranged 41.59 ± 13.59 years old. There were statistically significant differences in clinical characteristics between SZ with and without OCD : age (p = 0.010), BMI (body mass index; p = 0.011), education (p = 0.033), employment (p = 0.019), cigarette smoking (p = 0.039), sheesha smoking (p = 0.008), and prevalence of consanguinity (p = 0.043). In particular, the rate of consanguinity in the current generation was 31.8% [95% CI = 29.1-34.7]. Also, there were statistically significant differences at Hamilton Depression score, General Health Score, Clinical Global Impression- Score, duration of illnesses, and Global Assessment of Functioning (p < 0.001). The results show that anxious, mood and psychotic dimensions rated higher among SZ - OCD ones than SZ only patients.

CONCLUSION

This study confirms that SZ-OCD is a common co-morbidity and prevalence of SZ OCD is higher among patients reporting a degree of consanguinity. Even if this condition is under-recognized in clinical practice, it may significantly change SZ presentation and outcome since psychopathological dimensions report higher scores in the co-morbidity sample.

Obsessive-Compulsive Disorder in Hospitalized Patients with Schizophrenia

Introduction:

Comorbid obsessive-compulsive disorder (OCD) has been reported among patients with schizophrenia in other countries. But, the literature is not well-documented on this issue in Iran (Persia). The present study aimed to investigate the prevalence and severity of OCD and some of its related factors in a group of patients with schizophrenia in Iran.

Methods:

This is a cross-sectional study. A total of 150 hospitalized patients with schizophrenia were recruited at Razi Psychiatric Hospital in Tehran, Iran. Demographic and clinical checklists, as well as the Yale-Brown obsessive-compulsive scale (Y-BOCS), scale for assessment of negative symptoms (SANS), and scale for assessment of positive symptoms (SAPS) were administered to collect data. OCD was the dependent variable and independent variables included age, sex, severity of positive and negative symptoms, duration of schizophrenic disorder, the number of hospitalizations, and antipsychotic medications administered to them. Data were analyzed by analysis of variance (ANOVA), Chi-square, and T-test.

Results:

Overall, 31.3% of patients had OCD with an average severity of 12.81(SD=10.27). The prevalence of OCD was not affected by the number of psychiatric hospitalizations for schizophrenia or the duration of schizophrenic disorder. The severity of OCD significantly reduced as the duration of schizophrenia and the severity of negative symptoms increased.

Conclusion:

OCD was found among a considerable proportion of the study sample. OCD may be associated with exacerbating schizophrenic symptoms. Therefore, psychiatrists should consider the simultaneous treatment of OCD and schizophrenia. Further studies are suggested in this issue.

Schizo-Obsessive Disorder: A Brief Report of Neuroimaging Findings

BACKGROUND

The term 'schizo-obsessive disorder' was coined to describe schizophrenia (SCZ) patients who are also affected by obsessive-compulsive symptoms (OCS) or also meet the criteria for obsessive-compulsive disorder (OCD). Several studies have investigated the clinical and epidemiological features of OCS/OCD in SCZ, but the neuroimaging literature is sparse. The aim of this brief report is to describe some of the most important neuroimaging findings regarding schizo-obsessive disorder.

METHODS

A literature search of the PubMed electronic database was conducted up to July 25, 2015. Search terms included 'schizo-obsessive' combined with the names of specific neuroimaging techniques.

RESULTS

Neuroimaging studies suggest that there may be a specific pattern of neuroanatomic dysfunction in schizo-obsessive patients, but the number of studies is limited and conclusions are preliminary because reports are of an exploratory nature.

CONCLUSIONS

Further neurobiological research is needed to definitely determine whether schizo-obsessive disorder might have unique neuroanatomical and functional alterations.

Evidence for inhibitory deficits in the prefrontal cortex in schizophrenia

Abnormal gamma-aminobutyric acid inhibitory neurotransmission is a key pathophysiological mechanism underlying schizophrenia. Transcranial magnetic stimulation can be combined with electroencephalography to index long-interval cortical inhibition, a measure of GABAergic receptor-mediated inhibitory neurotransmission from the frontal and motor cortex. In previous studies we have reported that schizophrenia is associated with inhibitory deficits in the dorsolateral prefrontal cortex compared to healthy subjects and patients with bipolar disorder. The main objective of the current study was to replicate and extend these initial findings by evaluating long-interval cortical inhibition from the dorsolateral prefrontal cortex in patients with schizophrenia compared to patients with obsessive-compulsive disorder. A total of 111 participants were assessed: 38 patients with schizophrenia (average age: 35.71 years, 25 males, 13 females), 27 patients with obsessive-compulsive disorder (average age: 36.15 years, 11 males, 16 females) and 46 healthy subjects (average age: 33.63 years, 23 females, 23 males). Long-interval cortical inhibition was measured from the dorsolateral prefrontal cortex and motor cortex through combined transcranial magnetic stimulation and electroencephalography. In the dorsolateral prefrontal cortex, long-interval cortical inhibition was significantly reduced in patients with schizophrenia compared to healthy subjects (P = 0.004) and not significantly different between patients with obsessive-compulsive disorder and healthy subjects (P = 0.5445). Long-interval cortical inhibition deficits in the dorsolateral prefrontal cortex were also significantly greater in patients with schizophrenia compared to patients with obsessive-compulsive disorder (P = 0.0465). There were no significant differences in long-interval cortical inhibition across all three groups in the motor cortex. These results demonstrate that long-interval cortical inhibition deficits in the dorsolateral prefrontal cortex are specific to patients with schizophrenia and are not a generalized deficit that is shared by disorders of severe psychopathology.

The clinical characteristics of obsessive compulsive disorder associated with high levels of schizotypy

OBJECTIVES

This study aims to examine the characteristics of obsessive compulsive disorder (OCD) associated with high levels of schizotypy.

METHODS

Using the Schizotypal Personality Questionnaire (SPQ) with 177 individuals with OCD, patients with OCD and high levels of schizotypy (OCD-HS) were compared to patients with OCD and low levels of schizotypy (OCD-LS) on a range of clinical characteristics. Self-report and clinician-administered instruments were used. Results were adjusted for the severity of OCD symptoms, age, marital status and comorbidity using logistic regression.

RESULTS

Patients with OCD-HS were younger and less likely to have been married. OCD-HS was associated with higher rates of symmetry/order obsessions, ordering/arranging compulsions, checking compulsions, co-occurring major depression, post-traumatic stress disorder, substance use disorders and greater general psychopathology. Previously reported associations, such as higher total scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) were not significant when adjusted for differences in demographic variables and comorbidity.

CONCLUSIONS

Patients with OCD-HS were associated with specific OCD symptoms and comorbid conditions and may warrant a specific treatment approach.

Comorbid Obsessive-Compulsive Symptoms in Schizophrenia: Insight into Pathomechanisms Facilitates Treatment

Insight into the biological pathomechanism of a clinical syndrome facilitates the development of effective interventions. This paper applies this perspective to the important clinical problem of obsessive-compulsive symptoms (OCS) occurring during the lifetime diagnosis of schizophrenia. Up to 25% of schizophrenia patients suffer from OCS and about 12% fulfil the diagnostic criteria of obsessive-compulsive disorder (OCD). This is accompanied by marked subjective burden of disease, high levels of anxiety, depression and suicidality, increased neurocognitive impairment, less favourable levels of social and vocational functioning, and greater service utilization. Comorbid patients can be assigned to heterogeneous subgroups. It is assumed that second generation antipsychotics (SGAs), most importantly clozapine, might aggravate or even induce second-onset OCS. Several epidemiological and pharmacological arguments support this assumption. Specific genetic risk factors seem to dispose patients with schizophrenia to develop OCS and risk-conferring polymorphisms has been defined in SLC1A1, BDNF, DLGAP3, and GRIN2B and in interactions between these individual genes. Further research is needed with detailed characterization of large samples. In particular interactions between genetic risk constellations, pharmacological and psychosocial factors should be analysed. Results will further define homogeneous subgroups, which are in need for differential causative interventions. In clinical practise, schizophrenia patients should be carefully monitored for OCS, starting with at-risk mental states of psychosis and longitudinal follow-ups, hopefully leading to the development of multimodal therapeutic interventions.

Stable cognitive deficits in schizophrenia patients with comorbid obsessive-compulsive symptoms: a 12-month longitudinal study

BACKGROUND

Amongst schizophrenia patients, a large subgroup of up to 25% also suffers from comorbid obsessive-compulsive symptoms (OCSs). The association between comorbid OCSs in these patients and neuropsychological impairment remains unclear and somewhat contradictory. Longitudinal approaches investigating the stability of OCS-associated cognitive deficits are missing.

METHODS

Thirty-seven patients with schizophrenia and comorbid OCSs and 43 schizophrenia patients without OCS were assessed with a comprehensive cognitive test battery and compared at baseline and, again, 12 months later.

RESULTS

Schizophrenia patients with comorbid OCSs showed significant pronounced deficits, with increasing effect sizes over the 12-month assessment period in specific cognitive areas such as visuospatial perception and visual memory (WAIS-R block design, Rey-Osterrieth Complex Figure Test), executive functioning (perseveration in the Wisconsin Card Sorting test), and cognitive flexibility (Trail Making test B). These cognitive domains are correlated with OCS severity and are known to be candidate cognitive domains in obsessive-compulsive disorder (OCD).

CONCLUSIONS

OCSs in schizophrenia is associated with specific and longitudinally stable cognitive deficits, strongly arguing for at least partially overlapping neurobiological mechanisms with OCD. Prospective studies involving patients with at-risk mental states for psychosis are necessary to decipher the interaction of cognitive impairment and the clinical manifestations of schizophrenia and OCSs. This might facilitate the definition of patients at high risk for OCSs, an early detection of subclinical levels, therapeutic interventions, and clinical monitoring.

Comorbid obsessive-compulsive symptoms in schizophrenia: contributions of pharmacological and genetic factors

A large subgroup of around 25% of schizophrenia patients suffers from obsessive-compulsive symptoms (OCS) and about 12% fulfill the diagnostic criteria of an obsessive-compulsive disorder (OCD). The additional occurrence of OCS is associated with high subjective burden of disease, additional neurocognitive impairment, poorer social and vocational functioning, greater service utilization and high levels of anxiety and depression. Comorbid patients can be assigned to heterogeneous subgroups. One hypothesis assumes that second generation antipsychotics (SGAs), most importantly clozapine, might aggravate or even induce second-onset OCS. Several arguments support this assumption, most importantly the observed chronological order of first psychotic manifestation, start of treatment with clozapine and onset of OCS. In addition, correlations between OCS-severity and dose and serum levels and duration of clozapine treatment hint toward a dose-dependent side effect. It has been hypothesized that genetic risk-factors dispose patients with schizophrenia to develop OCS. One study in a South Korean sample reported associations with polymorphisms in the gene SLC1A1 (solute carrier family 1A1) and SGA-induced OCS. However, this finding could not be replicated in European patients. Preliminary results also suggest an involvement of polymorphisms in the BDNF gene (brain-derived neurotrophic factor) and an interaction between markers of SLC1A1 and the gene DLGAP3 (disc large associated protein 3) as well as GRIN2B (N-methyl-D-aspartate receptor subunit 2B). Further research of well-defined samples, in particular studies investigating possible interactions of genetic risk-constellations and pharmacodynamic properties, are needed to clarify the assumed development of SGA-induced OCS. Results might improve pathogenic concepts and facilitate the definition of at risk populations, early detection and monitoring of OCS as well as multimodal therapeutic interventions.

Exonic resequencing of the DLGAP3 gene as a candidate gene for schizophrenia

We resequenced the exonic regions of the DLGAP3 gene, which encodes SAP90/PSD95-associated protein 3, in 215 schizophrenic patients and 215 non-psychotic controls. Seven known single-nucleotide polymorphisms (SNPs) were identified, but not associated with schizophrenia. Nevertheless, we identified several rare missense mutations and some of them might be associated with the pathogenesis of schizophrenia.

Obsessive-compulsive disorder in the community: 12-month prevalence, comorbidity and impairment

BACKGROUND

Although subthreshold conditions are associated with impairment in numerous disorders, research on obsessive-compulsive disorder (OCD) below the diagnostic threshold of DSM-IV in the general population is limited.

PURPOSE

To estimate the DSM-IV 12-month prevalence, comorbidity and impairment of OCD, subthreshold OCD (i.e., fulfilling some but not all core DSM-IV criteria), and obsessive-compulsive symptoms (OCS) (i.e., endorsement of OCS without fulfilling any core DSM-IV criteria) in a general population sample.

METHODS

Data from the German National Health Interview and Examination Survey-Mental Health Supplement (N = 4181, age 18-65 years), based on the standardized diagnostic Munich Composite International Diagnostic Interview.

RESULTS

The 12-month prevalence of OCD was 0.7%, subthreshold OCD was 4.5%, and OCS was 8.3%. Subjects in all three groups showed higher comorbidity (odds ratios [ORs] ≥ 3.3), compared to those without OCS. The OCD, subthreshold OCD and OCS were all associated with increased odds of substance abuse/dependence-, mood-, anxiety- and somatoform disorders, with especially strong associations with possible psychotic disorder (ORs ≥ 4.1) and bipolar disorders (ORs ≥ 4.7). Participants in all three groups showed higher impairment (ORs ≥ 3.1) and health-care utilization (ORs ≥ 2.4), compared to those without OCS, even after controlling for covariates.

CONCLUSIONS

Individuals with subthreshold OCD and OCS, not currently captured by DSM-IV OCD criteria, nevertheless show substantial comorbidity, impairment and health-care utilization. This should be taken into account in future conceptualization and classification of OCD and clinical care.

Obsessive-compulsive symptoms in schizophrenia: prevalence, clinical features and treatment. A literature review

OBJECTIVES

To investigate the prevalence of obsessive-compulsive symptoms in schizophrenia, the clinical features of the sub-group of patients with schizophrenia and obsessive-compulsive symptoms and treatment options for these patients.

METHOD

A literature review of studies investigating the prevalence, clinical features and treatment of patients with schizophrenia and obsessive-compulsive symptoms.

RESULTS

The prevalence of obsessive-compulsive symptoms in schizophrenic patients, while generally found to be higher than in the general population, varies widely between different studies. Differences in symptom severity between schizophrenic patients with obsessive-compulsive symptoms and those without have been found, however findings so far have been inconsistent. A number of case reports have implicated atypical antipsychotic medication in the emergence of obsessive-compulsive symptoms. There is evidence to support a combined treatment with an antipsychotic agent and an anti-obsessional agent.

CONCLUSION

Studies investigating the prevalence of obsessive-compulsive symptoms in schizophrenia and their effect on the clinical symptoms have yielded inconsistent results and further studies using larger samples of patients and looking at different subgroups of schizophrenic patients are required. Treatment options need further research to investigate whether the results of relatively small studies can be replicated.

An epidemiologic and clinical overview of medical and psychopathological comorbidities in major psychoses

The presence of comorbidity in major psychoses (e.g., schizophrenia and psychotic subtypes of bipolar disorder and major depressive disorder) seems to be the rule rather than the exception in both DSM-IV and ICD-10. Examining comorbidity in major psychoses, however, requires an investigation into the different levels of comorbidity (either full-blown and subsyndromal) which should be analyzed in both psychopathological and medical fields. On one hand, the high prevalence of psychiatric comorbidity in major psychoses may be the result of the current nosographic systems. On the other hand, it may stem from a common neurobiological substrate. In fact, comorbid psychopathological conditions may share a biological vulnerability, given that dysfunction in specific brain areas may be responsible for different symptoms and syndromes. The high rates of comorbidity in major psychoses require targeted pharmacological treatments in order to effectively act on both the primary diagnosis and comorbid conditions. Nevertheless, few controlled trials in comorbid major psychoses had been carried out and treatment recommendations in this field have mostly an empirical basis. The aim of the present article is to provide a comprehensive and updated overview in relation to epidemiological and clinical issues of comorbidity in major psychoses.

Can obsessions drive you mad? Longitudinal evidence that obsessive-compulsive symptoms worsen the outcome of early psychotic experiences

OBJECTIVE

Although there is substantial comorbidity between psychotic disorder and obsessive-compulsive disorder (OCD), little is known about how these clinical phenotypes, and their subclinical extended phenotypes, covary and impact on each other over time. This study examined cross-sectional and longitudinal associations between both (extended) phenotypes in the general population.

METHOD

Data were obtained from the three waves of the NEMESIS-study. A representative population sample of 7076 participants were assessed using the composite international diagnostic interview (CIDI) at baseline (T(0)), 1 year later at T(1) and again 2 years later at T(2).

RESULTS

At T(0), a lifetime diagnosis of psychotic disorder was present in 1.5% of the entire sample, in 11.5% of the people with any OC symptom and in 23.0% of individuals diagnosed with OCD. OC symptoms at T(0) predicted incident psychotic symptoms at T(2). Similarly, T(0) psychotic symptoms predicted T(2) OC symptoms. The likelihood of persistence of psychotic symptoms or transition to psychotic disorder was higher if early psychosis was accompanied by co-occurring OC symptoms, but not the other way around.

CONCLUSION

OCD and the psychosis phenotype cluster together and predict each other at (sub)clinical level. The co-occurrence of subclinical OC and psychosis may facilitate the formation of a more 'toxic' form of persistent psychosis.

MRI study of the cavum septum pellucidum in obsessive-compulsive disorder

The cavum septum pellucidum (CSP), a putative marker of neurodevelopmental anomaly, has been associated with an increased risk of several psychiatric disorders. The purpose of this study was to evaluate the CSP in patients with obsessive-compulsive disorder (OCD) compared with healthy control subjects. Seventy-one patients with OCD and 71 healthy volunteers matched for age and sex were evaluated with magnetic resonance imaging. We evaluated the CSP using criteria employed in previous studies: presence of the CSP, length of the CSP, and overall size of the CSP, measured in five grades, ranging from grades 0 (no CSP) to 4 (severe CSP). We evaluated OCD symptom severity using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The CSP presence was significantly greater in the OCD group (60.6%) than in control subjects (29.6%), and CSP size grade was significantly larger in the OCD group (chi(2) = 15.609, P = 0.004). CSP length showed no significant group difference. Among patients with OCD, those with a CSP had higher scores on the obsession subscale of the Y-BOCS than those without a CSP (Z = -2.358, P = 0.018), while they did not show significant difference from those without a CSP in the compulsion subscale of the Y-BOCS, age, duration of illness, or age at onset. These results indicate that neurodevelopmental alterations in midline structures might contribute to the pathogenesis of OCD.

A controlled single case study with repeated fMRI measurements during the treatment of a patient with obsessive-compulsive disorder: testing the nonlinear dynamics approach to psychotherapy

There is increasing evidence that obsessive-compulsive disorder (OCD) is associated with a dysfunction of cortico-striato-thalamo-cortical neuronal circuits. In order to examine treatment-related changes in neuronal processes, a drug-naive female patient with OCD (subtype: washing/contamination fear) and an age- and gender-matched healthy control were repeatedly tested using functional magnetic resonance imaging (MRI) during the presentation of a symptom provocation task. Patient-specific visual stimuli of symptom provoking situations were compared with disgust provoking and neutral pictures. FMRI scanning was conducted at the beginning, during and upon completion of an inpatient treatment. During the treatment period of more than eight weeks (combined behavioural and systemic couple therapy) the patient filled out a therapy process questionnaire (TPQ) which was administered daily. Results show a phase transition-like change characterized by a sudden reduction of clinical symptoms as assessed by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) in the middle of the treatment period. Before the discontinuous symptom reduction occurred, the dynamic complexity of the TPQ-time series increased which might be indicative for a critical instability of the system. The fMRI results at the beginning of the treatment suggest strong activities in various brain regions, especially in the anterior cingulate cortex. The results of the second and third acquisition revealed comparably smaller OCD-related neuronal responses. The results may indicate that important clinical changes are taking place during the psychotherapy process which correspond to changing patterns of brain activation as well as to critical instabilities and phase-transition like phenomena in the time-series of the patient's daily self-report data.

Late-onset obsessive compulsive disorder associated with possible gliomatosis cerebri

Onset of obsessive-compulsive disorder (OCD) after the age of 50 years is rare, and should alert the physician to possible "organic" causes of OCD. These include infections, degenerative disorders, brain injury and cerebrovascular lesions, principally involving the frontal lobes and basal ganglia. The current patient had obsessive images, anxiety, auditory hallucinations and seizures following (possible) gliomatosis cerebri, with onset around 69 years of age. The atypical presentation, lesions involving the cortical-basal ganglia-thalamic-cortical circuit and the association with neurological signs/symptoms, was characteristic. However, late-onset OCD has not been commonly reported with diffuse lesions, and the association with gliomatosis cerebri is not known. This patient's case illustrates the need for careful screening of older patients with recently acquired OCD, and for further systematic study of OCD in the broad range of neuropsychiatric disorders affecting the elderly.

Nonclinical obsessive-compulsive symptoms and executive functions in schizophrenia

The impact of nonclinical obsessive-compulsive symptoms (OCS) on neuropsychological functioning in schizophrenia has received little investigation. The authors evaluated whether severity and subtype of OCS are associated with executive functioning in schizophrenia. Twenty-nine patients with schizophrenia and 32 healthy comparison subjects completed questionnaire and performance-based measures of executive functioning. Overall OCS severity in patients was associated with poorer monitoring and cognitive flexibility. Obsessing, hoarding, and checking were related to poorer executive functioning in daily life. Performance-based scores showed few correlations with OCS. Findings indicate that severity of nonclinical OCS subtypes contributes to the heterogeneity of executive functions in schizophrenia.

Relationship between psychotic and obsessive compulsive symptoms in schizophrenia

The presence of obsessive compulsive symptoms (OCSs) in schizophrenia was recognized as early as the first descriptions of the illness. Studies investigating the association between OCSs and schizophrenia have defined their co-occurrence in terms of co-morbidity and compared schizophrenia patients separated into groups according to whether they presented OCSs or not. However, most of these studies did not take both the complexity of the schizophrenia phenomenology and that of OCSs into account. The present research investigates the relationship between schizophrenia symptoms and OCSs using a correlational approach with a dimensional perspective in order to determine how the OCSs contribute to symptom expression in schizophrenia. Fifty nine schizophrenia patients were rated for schizophrenia symptoms (SAPS-SANS) and OCSs (Y-BOCS). Schizophrenia symptoms scores were collapsed into four dimensional scores and OCSs into for other dimensional scores. The latter were entered as explanatory variables to determine their associations with schizophrenia dimension scores using series of stepwise regression models. The results showed a strong positive relationship between Delusions and Obsessions consistent with the view that they reflect manifestations of the similar mechanisms. Similar results indicate an association between Auditory hallucinations and Compulsions also suggesting that they share common mechanisms. On the other hand, there were inverse relationships between Somatic Obsessions and Disorganization and between Hoarding/Collecting Compulsions and Delusions or Auditory hallucinations. These results may reflect that these OCSs have a protective effect against disorganization and psychotic symptoms respectively.

Thalamus surface shape deformity in obsessive-compulsive disorder and schizophrenia

The authors performed a three-dimensional shape deformation analysis to clarify the various patterns of specific thalamic nuclei abnormality using three age-matched and sex-matched groups of 22 patients with obsessive-compulsive disorder (OCD), 22 patients with schizophrenia and 22 control participants. Compared with the healthy volunteers, the anterior, lateral outward surface deformities of the thalamus were significant in OCD patients, whereas the posterior, medial outward deformities of the thalamus were prominent in schizophrenia patients. In terms of thalamic asymmetry, both OCD and schizophrenia patients exhibited the loss of a leftward pattern of asymmetry on the posterior, medial surface of the thalamus. Different patterns of shape abnormality of specific thalamic nuclei may be related to the different phenomenology of OCD and schizophrenia.

The theory of bowl and bugs: a model for the explanation of the coexistence of psychological and biological etiologies in the psychosis

The origin of the psychiatric features of psychotic patients and whether the features are basically psychological or biological has always been an issue of controversy. Some scientists have tried to prove the absolute relevance of these symptoms to psychological etiologies whereas others have insisted on biological causation. However, others have tried to find a link between the two etiologies in the formation of psychiatric symptoms and signs. In this article, a model is proposed for the coexistence and cocausative role of biology and psychology in the formation of symptoms of psychotic patients and as an explanation for the high rate of coexistence of obsessive thoughts in obsessive-compulsive disorder and schizophrenia and their highly reported relevance. These two disorders are put on two sides of a similar spectrum. Through the article, evidence supporting this model from psychological (especially Jungian and modified Freudian views) and neurobiological theories (neuroanatomical, neurotransmitter, and neural network) models is discussed.

COMT Val158Met polymorphism in schizophrenia with obsessive-compulsive disorder: a case-control study

This is the first study of a possible molecular genetic basis for schizophrenia with obsessive-compulsive disorder (OCD). We performed a case-control association study of the catechol-O-methyltransferase (COMT) Val158Met polymorphism in schizophrenia-OCD patients, OCD and healthy controls. One hundred and thirteen schizophrenia-OCD patients, 79 OCD patients and 171 control subjects were genotyped for the Val(158)Met polymorphism in the COMT gene. There was no significant difference in allele and genotype distribution of the COMT gene between schizophrenia-OCD patients and healthy controls. The low-activity Met allele and Met/Met genotype were more frequent in OCD men than in schizophrenia-OCD and control individuals. This difference, however, was not statistically significant following correction for multiple comparisons. These results do not support the hypothesis that the COMT Val158Met gene polymorphism is associated with liability to schizophrenia-OCD.

Obsessive-compulsive disorder (OCD) with schizotypy vs. schizophrenia with OCD: diagnostic dilemmas and therapeutic implications

Although schizophrenia and obsessive-compulsive disorder (OCD) are distinct diagnostic entities, there are substantial areas of overlap between the two disorders in clinical characteristics, affected brain areas and pharmacotherapy. Though OCD patients apparently do not have increased risk for developing schizophrenia, schizotypal personality disorder has consistently been found in OCD patients. Compelling evidence also points to an increased rate of OCD in schizophrenia patients. Accurate diagnosis of both disorders in their "pure" and overlapping forms is necessary in order to evaluate etiological mechanisms underlying schizophrenia and OCD, and to provide adequate treatment and prognosis. In this review, we address some aspects of the current status of research pertinent to the OCD-schizophrenia interface and suggest further steps towards the clinical and etiological identification of homogeneous subgroups on the putative OCD-schizophrenia axis.

Interventions for obsessive compulsive symptoms in people with schizophrenia

This is the protocol for a review and there is no abstract. The objectives are as follows:

1 PRIMARY OBJECTIVES

To evaluate clinically meaningful benefits of interventions used to treat clinically significant obsessive compulsive symptoms occurring in people with schizophrenia with regard to global improvement, changes in mental state, hospitalisation, behaviour and functioning in the short term (less than six weeks), medium term (six weeks to six months) and long term (more than six months). In this review we specifically addressed the efficacy and safety of the following when used to treat clinically significant obsessive compulsive symptoms occurring in people with schizophrenia: 1.1 Conventional and newer (or atypical) antipsychotic drugs 1.2 Conventional and newer antidepressant drugs 1.3 Any other drug or pharmacologically active substance 1.4 Non-pharmacological interventions In future versions of this review we will cover the use of psychosurgery, deep brain stimulation or other invasive interventions for this purpose.

2 SECONDARY OBJECTIVES

To determine whether these interventions would have a differential effect: 2.1 In people with schizophrenia in whom obsessive compulsive symptoms preceded the onset of symptoms of schizophrenia as opposed to those in whom obsessive compulsive symptoms occurred in the prodromal stages or after the symptoms of schizophrenia were firmly established 2.2 In people with obsessive compulsive symptoms as opposed to obsessive compulsive disorder as defined by diagnostic criteria.

Obsessive-compulsive disorder in schizophrenia: clinical characteristics and treatment

There is a considerable overlap of schizophrenia and obsessive-compulsive disorder (OCD) in the structural and functional brain abnormalities involved, role of the dopamine/serotonin neurotransmitter systems, and some demographic and clinical characteristics. Although OCD co-occurs in a substantial proportion of schizophrenia patients, a systematic evaluation of the clinical features and treatment of this population is lacking. This review critically evaluates findings of recent studies pertaining to the rate of occurrence of OCD or obsessive-compulsive symptoms (OCS) in schizophrenia and the clinical characterisation of the schizo-obsessive subtype. Specifically, interrelationships between obsessive-compulsive and schizophrenic symptoms in terms of temporal relationships and their association with specific schizophrenia subtypes and the effect of OCS on the severity of schizophrenia symptoms are addressed. In the absence of evidence-based data, tentative therapeutic approaches in this difficult-to-treat patient subgroup are suggested. These include monotherapy with atypical antipsychotic agents or a combination of either typical or atypical antipsychotics with SSRIs or clomipramine. The clinical characteristics of antipsychotic-induced OCS/OCD are also presented to facilitate identification and management of this rare but clinically significant adverse effect. Finally, future directions of research in schizophrenia-OCD comorbidity relevant to clinical practice are discussed.