Comparative Analysis of Cognitive Function in Schizophrenia with and without Obsessive Compulsive Disorder

IQ and socio-occupational functioning in relation to obsessive-compulsive symptoms severity in a clinical sample of adolescents

Obsessive-compulsive disorder (OCD) is often comorbid with other psychiatric conditions, leading to severely impaired functioning and poor quality of life. Until now, the relationship between obsessive-compulsive symptoms (OCS) and functioning has been studied mainly through a categorical approach (i.e., presence/absence of the disorder), leaving more dimensional analyses almost unexplored. Therefore, the present study investigates the association between OCS and both intellectual functioning (IQ) and socio-occupational functioning across different levels of OCS severity. 341 help-seeking adolescents (65% female, mean age = 15.37 years, SD = 1.37) with different psychopathologies underwent an in-depth clinical examination using the Comprehensive Assessment of At Risk Mental States (CAARMS), through which OCS were also evaluated, and the Kiddie-Schedule for Affective Disorder and Schizophrenia - Present and Lifetime - DSM-5 (K-SADS-PL). Cognitive functioning was assessed using a full IQ test (WISC-IV or WAIS-IV), and socio-occupational functioning was assessed using the Social and Occupational Functioning Assessment Scale (SOFAS). A negative quadratic curvilinear (i.e. inverted U-shape) relationship was found between OCS severity and IQ (β=-1.11, p < .05), and a negative linear relationship was observed between OCS severity and socio-occupational functioning (β=-1.32, p < .01). While the association with IQ remained significant after controlling for sociodemographic variables and psychopathology symptoms (β=-0.471, p = .005), the association with socio-occupational functioning did not (β=-0.034, p = .487). These results indicate that OCS are differentially associated with IQ depending on their severity within the adolescent psychiatric population. In particular, mild OCS appear to be associated with a higher IQ relative to no OCS or severe OCS.

Clinical profile of schizophrenia comorbid with obsessive-compulsive symptoms: A comparative study

OBJECTIVE

Describe and compare the clinical profile of schizophrenic patients with and without obsessive-compulsive symptoms and obsessive-compulsive disorder (OCD) patients.

METHODS

A descriptive and analytical cross-sectional study was carried out at the psychiatry department of Hassan II University Hospital in Fez over 12 months to compare three groups of patients: "schizo-obsessive" (n=32), "schizophrenia" (n=34), and "OCD" (n=46). All participants (n=112) were assessed using the mini-international neuropsychiatric interview (MINI), the Yale-Brown obsessive-compulsive scale (Y-BOCS), the Brown assessment of beliefs scale (BABS), the Hamilton anxiety rating scale (HAM-A), the Beck's depression inventory (BDI-II), the positive and negative syndrome scale (PANSS), and the clinical global impressions-severity scale (CGI-S).

RESULTS

The "schizo-obsessive" group differed from the "schizophrenia" group in: more severe psychotic symptoms (mean=64.16±17.049, P<0.001), higher anxiety (mean=8.87±5,655, P<0.001) and depression (mean=7.50±5.989, P<0.001) scores, more prevalent suicide attempts (46.9%), higher illness severity score (mean=5.13±1.157, P=0.02), and more professional disinsertion (78.1%). The "schizo-obsessive" group (mean= 14.47±3.388) had significantly poor insight (P<0.001) compared to the "OCD" group (mean= 8.35±4.542). There were similarities in the obsessive and compulsive themes between the "schizo-obsessive" and the "OCD" groups, with no significant difference of severity (P=0.26).

CONCLUSION

A careful assessment of obsessive symptomatology is essential in schizophrenia for better patient management and prognosis.

A diffusion tensor imaging study in schizophrenia patients with clozapine induced obsessive compulsive symptoms

OBJECTIVE

The aim of this study was to evaluate brain connectivity by diffusion tensor imaging (DTI) in schizophrenia patients with clozapine-induced obsessive compulsive symptoms (OCS).

METHODS

Eighteen schizophrenia patients, nine of which had clozapine-induced OCS (Clz-OCS (+)), 9 without OCS (Clz-OCS (-)) and 9 healthy controls were included. Psychopathology was evaluated with Positive and Negative Syndrome Scale and Yale-Brown Obsession and Compulsion Scale in the patient groups. All groups were assesed with neurocognitive tests and DTI.

RESULTS

Tract-Based Spatial Statistics based comparison of DTI revealed lower fractional anisotropy in the genu of corpus callosum (CC), right cingulum, left frontal white matter (WM) in the Clz-OCS (+) group, compared to controls. Fractional anisotropy was found to be lower in the bilateral occipital WM and higher in the bilateral medial temporal regions, anterior limb of internal capsule, cingulum, frontoparietal peripheral WM, right external capsule and genu of CC in Clz-OCS (+) patients compared to Clz-OCS (-).

CONCLUSIONS

WM integrity in several pathways such as cortico-striato-thalamo-cortical circuitry and orbito-frontal tracts seems to be affected differently in patients with Clz-OCS (+). Different neuroplastic effects of clozapine leading to occurrence of OCS in a subgroup of patients is possible, and needs further evaluation by longitudinal follow-up studies.

Obsessive-Compulsive Disorder and Schizophrenia: Conceptualization, Assessment and Cognitive Behavioral Treatment

There is little doubt that schizophrenia (SZ) and obsessive-compulsive disorder (OCD) are among the most severe disorders to impact humanity. They are both common, significantly disabling and have the tendency to strike during critical developmental periods in a young person's life. Schizophrenia affects approximately 1% of the global population and OCD has a lifetime prevalence of between 2% and 3% in the general population. The comorbidities in both SZ and OCD are common and frequently diagnosed, and research has generally found that comorbidities are associated with conditions that are more complex to diagnose and treat, and often result in less favorable prognoses. We review the research that has taken place regarding the co-occurrence of SZ and OCD, discuss it's theoretical conceptulization and clinical differentiation and diagnosis. We then propose recommendations for the best practice of cognitive behavioral therapy in this difficult population, as well as areas that need exploration for future research.

Meta-analysis of cognitive functioning in patients with psychotic disorders and obsessive-compulsive symptoms

Obsessive-compulsive symptoms (OCS) in psychotic disorders are associated with unfavorable outcomes, whether this extends to cognitive function remains unclear. We conducted meta-analyses on several cognitive domains to investigate overall group differences between patients with a psychotic disorder and co-occurring OCS (OCS +) and those without OCS (OCS-). We used meta-regression to assess possible confounding effects. No overall associations between OCS + and OCS- in any of the 17 investigated cognitive domains were found. We predominantly found large heterogeneity in effect size and direction among studies. Post-hoc analyses of processing speed tasks not purely based on reaction-time showed worse performance in the OCS + group with a small effect size (SMD = - 0.190; p = 0.029). Meta-regression revealed advanced age was significantly correlated with worse performance of the OCS + group in processing speed (R² = 0.7), working memory (R² = 0.11), cognitive inhibition (R² = 0.59), and cognitive flexibility (R² = 0.34). Patients fulfilling the criteria for an obsessive-compulsive disorder showed less impairment in cognitive inhibition compared to the OCS + group (R² = 0.63). Overall, comorbid OCS were not associated with cognitive impairment. However, large heterogeneity between studies highlights the complex nature of factors influencing cognition in people with psychotic disorder and comorbid OCS and warrants further research into possible moderating factors.

Long-Term Outcomes and Predictors of Childhood-Onset Schizophrenia: A Naturalistic Study of 6-year Follow-Up in China

Objectives: The long-term outcome of childhood-onset schizophrenia (COS) and its influencing factors remain unclear. The current study aimed to assess the long-term outcomes of COS and identify possible outcome predictors. Methods: We retrospectively investigated 276 patients with COS. Diagnosis made according to the ICD-10 criteria for schizophrenia, and the age of the first onset was ≤ 14 years. Follow-up was completed for 170 patients, with a median follow-up period of 5.6 years. Outcome variables included occupational/education status and readmission. Spearman correlation was performed to assess the relationship between predictors and outcome variables. Binary logistic regression was conducted to detect possible predictor variables for outcome variables. Results: At the end of the follow-up, 89 patients (52.3%) were at school, 70 patients (41.2%) were employed, and only 11 patients (6.5%) were dropped out of school or unemployed. The duration to the first admission and depressive symptoms were identified as predictors of occupational/educational status. The length of follow-up and obsessive-compulsive symptoms (OCS) were distinguished as predictors of readmission. Duration to the first admission and length of follow-up were risk factors, and depressive symptoms and OCS were protective factors for the outcomes of COS. Conclusion: We found a favorable long-term outcome on occupational/education status in COS, and depressive symptoms and OCS may be associated with more positive long-term outcomes in COS. Our findings suggest that COS patients may benefit from early intervention and require appropriate treatment.

Schizophrenia with and without obsessive-compulsive symptoms: a comparative analysis of performance on trail making test and disability on WHODAS

BACKGROUND

Presence of obsessive-compulsive symptoms (OCS) affects performance on tests of some cognitive functions, such as the trail making test (TMT), and may affect the level of disability in schizophrenia (SZ).

AIMS

The aim of the present study was to compare performance on TMT and disability on WHO Disability Assessment Schedule (WHODAS) in persons with SZ with and without OCS in a cross-sectional study.

METHODS

Persons with SZ (n=200) fulfilling DSM-V (Diagnostic and Statistical Manual) diagnostic criteria were assessed on Yale Brown Obsessive Compulsive Scale (YBOCS) and divided into two groups based on presence or absence of OCS. TMT and WHODAS V.2.0 were applied. The two groups as a whole, as well as a subsample matched on age, gender and age of onset were compared.

RESULTS

Out of 200 persons with SZ, 37 (18.5%) reported OCS. The OCS group took a significantly longer mean time to complete TMT-A (Z=-3.02, p=0.003) as well as TMT-B (Z=-3.551, p<0.001). Significant correlations were found between TMT-A and total YBOCS Scores (r=0.351, p=0.033), as well as TMT-A and YBOCS compulsion scores (r=0.404, p=0.013) but not with TMT-B Scores. The OCS group reported greater disability in all domains separately as well as on average WHODAS Scores (Z=-5.969, p<0.001). Significant correlations were found between YBOCS obsession scores and YBOCS total scores with average WHODAS Scores (r=0.614, p<0.001 and r=0.406, p=0.013, respectively). We obtained essentially similar results with the matched subsample as well as with the entire group.

CONCLUSION

Persons with SZ and comorbid OCS had significantly poorer performance on TMTs and greater disability in comparison to persons with SZ alone. Magnitude of disability correlated with severity of OCS.

Altered grey matter volume and white matter integrity in individuals with high schizo-obsessive traits, high schizotypal traits and obsessive-compulsive symptoms

Altered brain structures have been found in patients with schizo-obsessive disorder, schizophrenia and obsessive-compulsive disorder in previous studies. However, it is unclear whether similar brain changes are also found in individuals with high schizo-obsessive traits (SOT), high schizotypal traits (SCT) and obsessive-compulsive symptoms (OCS). We examined grey matter volume (GMV) and white matter integrity (WMI, including fractional anisotropy, mean diffusivity, axial diffusivity and radial diffusivity) in 26 individuals with high SOT, 30 individuals with high SCT, 25 individuals with OCS and 30 individuals with low trait scores (LT) in this study. Correlation analysis between GMV, WMI, Schizotypal Personality Questionnaire (SPQ) scores and Obsessive-Compulsive Inventory-Revised (OCI-R) scores in the subclinical groups was also carried out. We found that the SOT group exhibited increased GMV at the right superior occipital gyrus and the left postcentral gyrus compared with the LT group. The SCT group exhibited increased GMV at the right precentral gyrus and the bilateral cuneus compared with the LT group, and decreased fractional anisotropy at the anterior corona radiata compared with the other three groups. The OCS group exhibited increased GMV at the left superior temporal gyrus and decreased GMV at the left pre-supplementary motor area compared with the LT group. These findings highlight specific brain changes in individuals with high SOT, high SCT and OCS, and may thus provide new insights into the neurobiological changes that occur in sub-clinical populations of these disorders.

Lifetime psychopathological characteristics associated with comorbid obsessive-compulsive disorder in clinically stable patients with chronic schizophrenia

Obsessive-compulsive symptoms (OCS) commonly occur in the course of schizophrenia. The aim of this study was to investigate the rate of obsessive-compulsive disorder (OCD) in patients with chronic schizophrenia and evaluate lifetime correlates of the comorbidity. Subjects were clinically stable patients with chronic schizophrenia (n = 320). Patients having comorbid OCD and those without OCD were compared in terms of symptoms dimensions and cognitive function. OCD was found in 20.6 % of subjects. Earlier age at onset, male gender, higher level of education, comorbid panic disorder, and specific phobia were associated with comorbid OCD. In terms of lifetime symptoms, depression (p = 0.001) and anxiety (p = 0.014) showed significant association with the comorbidity, which corroborates with our previous study findings regarding OCD in bipolar disorder. In addition, decreased emotional response (p = 0.016), less formal thought disorder (p = 0.007), and less prodromal impairment (p = 0.005) were independently associated with the comorbidity. The OCD group showed better performance in working memory domain (p = 0.027) while other cognitive domains did not show any significant difference between the two groups. Association of OCSs with depressive symptoms and other comorbid anxiety disorders seems to be a common finding across schizophrenia and bipolar disorder. This study also suggests that comorbidity of OCD in schizophrenia is associated with less impairment of thought process and cognitive function throughout the disease course.

Identifying Schizo-Obsessive Comorbidity by Tract-Based Spatial Statistics and Probabilistic Tractography

A phenomenon in schizophrenia patients that deserves attention is the high comorbidity rate with obsessive-compulsive disorder (OCD). Little is known about the neurobiological basis of schizo-obsessive comorbidity (SOC). We aimed to investigate whether specific changes in white matter exist in patients with SOC and the relationship between such abnormalities and clinical parameters. Twenty-eight patients with SOC, 28 schizophrenia patients, 30 OCD patients, and 30 demographically matched healthy controls were recruited. Using Tract-based Spatial Statistics and Probabilistic Tractography, we examined the pattern of white matter abnormalities in these participants. We also used ANOVA and Support Vector Classification of various white matter indices and structural connection probability to further examine white matter changes among the 4 groups. We found that patients with SOC had decreased fractional anisotropy (FA) and increased radial diffusivity in the right sagittal stratum and the left crescent of the fornix/stria terminalis compared with healthy controls. We also found changed connection probability in the Default Mode Network, the Subcortical Network, the Attention Network, the Task Control Network, the Visual Network, the Somatosensory Network, and the cerebellum in the SOC group compared with the other 3 groups. The classification results further revealed that FA features could differentiate the SOC group from the other 3 groups with an accuracy of .78. These findings highlight the specific white matter abnormalities found in patients with SOC.

The "Obsessive Paradox": The Complex Relationship Between Cognitive and Obsessive Dimensions in Schizophrenia

The objective of the study was to investigate the relationship between cognitive functions and obsessive-compulsive dimension in schizophrenia and a possible moderating effect of schizophrenia symptom dimensions on this association. Sixty-one schizophrenia patients were administered the Positive and Negative Syndrome Scale, the Yale-Brown Obsessive-Compulsive Scale (YBOCS), and the Matrics Consensus Cognitive Battery. A U-shaped curve described a gradual transition from an inverse association to a positive relationship between YBOCS and processing speed scores, along a severity gradient of obsessive dimension. This effect ("the obsessive paradox") was not moderated by other symptom dimensions. The present study suggests that severe obsessive-compulsive symptoms may participate to counterbalance processing speed impairment independently from other symptom dimensions. These results highlight the complexity of the relationship between cognitive and obsessive dimensions in schizophrenia.

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.

Prevalence and clinical correlations of obsessive-compulsive symptoms in schizophrenia

INTRODUCTION

Obsessive compulsive symptoms are often present in persons with schizophrenia. Adequately powered studies to evaluate the effect of such symptoms in the course of the disorder, are few.

AIM

We aimed to estimate the prevalence and type of obsessive-compulsive symptoms in persons with schizophrenia.

METHODS

We evaluated 200 outpatients with schizophrenia (DSM-V) on the Positive and Negative Symptom Scale (PANSS) and the Yale Brown Obsessive Compulsive Scale (YBOCS). Participants with or without obsessive compulsive symptoms were matched on age, gender and age of onset of schizophrenia. Appropriate analysis by comparisons and correlations were performed.

RESULTS

Prevalence of obsessive-compulsive symptoms was 18.5% (n = 37/200). Most common obsession was contamination and compulsion was cleaning/washing with a prevalence of 51.35% and 63.33% respectively. There were no significant differences between the two groups on age, gender, marital status, residence, age of onset or total duration of illness of schizophrenia. The OC symptoms group had significantly higher general psychopathology and PANSS total scores. There was significant positive correlation between YBOCS total obsession scores (To) and total PANSS scores (r = 0.358) (p = 0.030), as well as PANSS general psychopathology subscale scores (Gt) (r = 0.395) (p = 0.016) and finally between total YBOCS scores (To + Tc) and PANSS positive subscale scores (Pt)(r = 0.344) (p = 0.037).

CONCLUSION

There was a significant subgroup of schizophrenia patients (almost one fifth) who complained of obsessive-compulsive symptoms. This group reported significantly higher general psychopathology and could thus be said to be more seriously ill, in an adequately powered cross sectional study.

Comparison of neurocognitive domains in patients with schizophrenia with and without co-morbid obsessive compulsive disorder

BACKGROUND

Neurocognitive deficits have been well documented in patients with schizophrenia. Research has shown that a significant proportion of patients with schizophrenia have co-morbid obsessive-compulsive symptoms/disorder (OCS/OCD). However, the impact of OCS/OCD on various neurocognitive domains in patients with schizophrenia is less understood.

METHODS

40 patients with schizophrenia and comorbid OCD (Group-I) were matched with 39 patients with schizophrenia without OCD (Group-II) and were assessed on Trail making test A and B (TMT-A/B), Controlled Oral Word Association test (COWA), Stroop test and Tower of London (TOL). Psychopathology was assessed by using Positive and Negative syndrome Scale (PANSS). Severity of OCD was assessed by using Yale-Brown Obsessive Compulsive Scale (Y-BOCS).

RESULTS

Compared to patients without comorbid OCD, those with comorbid OCD had more severe cognitive deficits, with medium to large effect sizes. Significant differences were noted in the domains of processing speed (TMT-A; p = 0.018), verbal fluency (COWA; p < 0.001), cognitive flexibility (TMT-B; p = 0.006) and in executive functioning (TOL-2 moves, 3 moves and 4 moves problems). There was significant associations in Group I Y-BOCS total score with the domains of verbal fluency (perseveration words, p = 0.006, variant words, p = 0.036), cognitive processing and selective attention (Stroop score, p = 0.04) and executive functioning (significance noted in 2 moves problems only).

CONCLUSIONS

Co-morbid OCD in schizophrenia is associated with more neurocognitive impairment as compared with schizophrenia without OCD. Accordingly, more intensive interventions must be carried out to address the neurocognitive deficits in patients of schizophrenia with OCD.

Neuropsychological profile of schizophrenia with and without obsessive compulsive disorder

Neuropsychological profile of schizophrenia with obsessive compulsive disorder (OCD) in comparison with that of schizophrenia without OCD is understudied and the results are inconsistent. We hypothesize that patients having schizophrenia with OCD ('schizo-obsessive disorder') may have unique neuropsychological deficits in comparison with those with schizophrenia alone, particularly with respect to executive functions. Thirty patients with schizo-obsessive disorder and 30 individually matched patients with schizophrenia without any obsessive-compulsive symptoms formed the sample of the study. Neuropsychological assessment included tests for attention, executive functions and memory. Patients with schizo-obsessive disorder did not differ from those with schizophrenia alone with respect to measures of attention, executive functions and memory. Our findings do not support unique neuropsychological profile of schizo-obsessive disorder. Studying a larger sample of drug-naive patients in a longitudinal design may provide us more insights in to this.

Schizo-obsessive spectrum disorders: an update

The presence of obsessive-compulsive symptoms (OCS) and obsessive-compulsive disorders (OCD) in schizophrenia is frequent, and a new clinical entity has been proposed for those who show the dual diagnosis: the schizo-obsessive disorder. This review scrutinizes the literature across the main academic databases, and provides an update on different aspects of schizo-obsessive spectrum disorders, which include schizophrenia, schizotypal personality disorder (SPD) with OCD, OCD with poor insight, schizophrenia with OCS, and schizophrenia with OCD (schizo-obsessive disorder). An epidemiological discussion on the discrepancies observed in the prevalence of OCS and OCD in schizophrenia across time is provided, followed by an overview of the main clinical and phenomenological features of the disorder in comparison to the primary conditions under a spectral perspective. An updated and comparative analysis of the main genetic, neurobiological, neurocognitive, and pharmacological treatment aspects for the schizo-obsessive spectrum is provided, and a discussion on endophenotypic markers is introduced in order to better understand its substrate. There is sufficient evidence in the literature to demonstrate the clinical relevance of the schizo-obsessive spectrum, although little is known about the neurobiology, genetics, and neurocognitive aspects of these groups. The pharmacological treatment of these patients is still challenging, and efforts to search for possible specific endophenotypic markers would open new avenues in the knowledge of schizo-obsessive spectrum.

Obsessive compulsive symptoms are associated with better functioning independently of cognition in schizophrenia

OBJECTIVES

Although the relationship of obsessive-compulsive symptoms (OCSs) with both cognition and social functioning (SF) has already been the focus of research in schizophrenia, the moderation of the relationship of OCSs with SF by cognition has not been explored to date. We investigated the association of OCSs with SF and its interaction with cognition in schizophrenia.

METHODS

We recruited 110 schizophrenia patients and assessed OCSs (Yale-Brown Scale), schizophrenia symptoms (Positive and Negative Syndrome Scale), SF (Strauss-Carpenter Scale) and cognition. 51 patients had one obsessive-compulsive symptom or more, whereas 59 patients had no obsessive compulsive-symptom, according to the Yale-Brown Scale. We mainly investigated: a) the predictive effect of OCSs on SF, controlling for cognition, illness duration and symptoms' severity and b) the moderating effect of cognition on the OCSs-SF relationship.

RESULTS

The mean score of OCSs for patients having at least one symptom was 13.43 (SD=8.32). Higher OCSs predicted increased SF (B=0.98, t=2.41, df=88, p=0.018). This relationship was driven by the association of compulsions with job functioning (B=0.074, t=2.029, df=88, p=0.046). Patients without OCSs demonstrated worse functioning compared with those having at least one obsessive-compulsive symptom (mean difference=2.496, t=3.732, df=88, p<0.001). We failed to find evidence that cognition moderates the effect of OCSs on SF.

CONCLUSION

There may be a beneficial effect of OCSs on SF in patients with schizophrenia which is independent of their cognitive performance.

Longitudinal association between cognitive performance and obsessive-compulsive symptoms in patients with psychosis and unaffected siblings

OBJECTIVE

Obsessive-compulsive symptoms (OCS) frequently occur in psychotic disorders. Cross-sectional associations between OCS and cognitive impairment have led to different causal explanations. Whereas one assumes that higher cognitive impairment reflects a risk factor for psychotic patients to develop OCS, another suggests that deficits reflect a consequence of OCS. This study investigated the longitudinal interrelation between OCS and cognitive functioning.

METHOD

Baseline and follow-up data from 622 patients and 670 un-affected siblings from the 'Genetic Risk and Outcome in Psychosis' study were analyzed. Participants were allocated to groups according to the presence or absence of OCS at assessments and compared on several cognitive domains.

RESULTS

Cross-sectional comparisons revealed no group differences in cognitive performance. Longitudinal analyses comparing the groups with changes in OCS revealed one significant group effect with more problems in set-shifting abilities in patient who reported OCS development at follow-up. Significant time and interaction effects were mainly due to improvement in immediate verbal recall and digit-symbol coding in patients and siblings who reported remission of OCS.

CONCLUSION

Although insight into causality needs further exploration, our results do not confirm the hypothesis of pre-existing cognitive risk constellations. Findings suggest that remission of comorbid OCS results in improved immediate verbal recall and processing speed.

Associations of obsessive-compulsive symptoms with clinical and neurocognitive features in schizophrenia according to stage of illness

This study aimed to investigate the association of obsessive-compulsive symptoms with clinical and neurocognitive features in patients with schizophrenia. This study enrolled 163 people with schizophrenia who were receiving risperidone monotherapy. Comorbid obsessive-compulsive symptoms were assessed using the Yale-Brown Obsessive-Compulsive Scale, and subjects with a score ≥ 10 constituted the obsessive-compulsive symptom group (n=30, 18.4%). The learning index was significantly higher in patients with obsessive-compulsive symptoms than in those without such symptoms after adjusting for age, stage (early and chronic), duration of illness, and CDSS score. However, there was no significant interaction between obsessive-compulsive symptoms and stage of illness. Scores on Positive and Negative Syndrome Scale, Calgary Depression Scale for Schizophrenia, and Beck Depression Inventory were significantly higher in the obsessive-compulsive symptom group. In addition, the Subjective Well-being under Neuroleptic Treatment score was significantly lower in the obsessive-compulsive symptom group. In conclusion, comorbid obsessive-compulsive symptoms in patients with schizophrenia were associated with a higher learning ability without a significant interaction with stage of illness. However, schizophrenia patients with obsessive-compulsive symptoms had more severe psychotic and depressive symptoms and poorer quality of life.

Prevalence and clinical correlates of obsessive-compulsive disorder in schizophrenia

Obsessive compulsive symptoms frequently occur in a substantial proportion of patients with schizophrenia. The term schizoobsessive has been proposed to delineate this subgroup of schizophrenia patients who present with obsessive-compulsive symptoms/disorder. However, whether this co-occurrence is more than just co-morbidity and represents a distinct subgroup remains controversial. A striking variation is noted across studies examining prevalence of obsessive-compulsive symptoms/disorder in schizophrenia patients and their impact on clinical profile of schizophrenia. Hence, in this study, we examined the prevalence of obsessive-compulsive symptoms/disorder in a large sample of consecutively hospitalized schizophrenia patients and compared the clinical and functional characteristics of schizophrenia patients with and without obsessive-compulsive symptoms/disorder. We evaluated 200 consecutive subjects with the DSM-IV diagnosis of schizophrenia using the Structured Clinical Interview for DSM-IV Axis I disorders, Positive and Negative Syndrome Scale, Yale-Brown Obsessive-Compulsive Scale, Brown Assessment of Beliefs Scale, Clinical Global Impression-Severity scale, Global Assessment of Functioning Scale, Family Interview for Genetic Studies and World Health Organization Quality of Life scale. The prevalence of obsessive-compulsive symptoms in patients with schizophrenia was 24% (n=48); 37 of them had obsessive-compulsive disorder (OCD) and 11 had obsessive-compulsive symptoms not amounting to a clinical diagnosis of OCD (OCS). Schizophrenia patients with OCS/OCD had an earlier age at onset of schizophrenia symptoms, lower positive symptoms score, higher co-morbidity with Axis II disorders, higher occurrence of OCD in family and better quality of life. Findings of the study indicate a higher prevalence of OCS/OCD in schizophrenia. Schizophrenia patients with and without OCS/OCD have comparable clinical profile with few exceptions. High rates of OCD in first degree relatives suggest possible genetic contributions and differences in neurobiology. Finally, evidence to consider schizoobsessive as a distinct diagnostic entity is inconclusive and warrants further studies.

Neuropsychological profile and treatment-related features among patients with comorbidity between schizophrenia spectrum disorder and obsessive–compulsive disorder: is there evidence for a “schizo-obsessive” subtype?

Epidemiological studies have found that obsessive–compulsive disorder (OCD) is estimated to occur in 12% of patients with schizophrenia. Whether this “schizo-obsessive” subgroup may be posited as a clinical entity with a distinct neuropsychological profile and treatment-related features remains unclear. A sample of 30 patients who met DSM-IV criteria for both schizophrenia/schizoaffective disorder and OCD was compared with 30 OCD subjects and with 37 patients with schizophrenia/schizoaffective disorder. Neuropsychological domains were measured by the Wechsler Adult Intelligence Scale - Third Edition (WAIS-III), the Trail Making Test (TMT), and the verbal fluency test (FAS). Treatment-related variables were assessed with the Clinical Global Improvement scale (CGI), the Drug Attitude Inventory (DAI), and dosage/type of antipsychotic medications. One-way analysis of variance revealed statistically significant differences among the three groups in “working memory,” “block design,” “semantic fluency,” TMT-A, and TMT-B. However, the Bonferroni correction showed no statistical differences between both psychotic groups. In addition, there were no significant differences among the three groups in the CGI and DAI, although “schizo-obsessive” patients tended to display slightly higher scores on these variables than the other groups. Overall, these findings do not support the hypothesis that comorbidity between schizophrenia spectrum disorders and OCD may reflect a distinct clinical entity. However, further research with larger sample sizes and a more comprehensive clinical assessment are needed. Our findings also underscore the fact that divergences among assessment instruments, as well as confounding variables, may influence results on neuropsychological domains.

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.

Machine learning fMRI classifier delineates subgroups of schizophrenia patients

BACKGROUND

The search for a validated neuroimaging-based brain marker in psychiatry has thus far been fraught with both clinical and methodological difficulties. The present study aimed to apply a novel data-driven machine-learning approach to functional Magnetic Resonance Imaging (fMRI) data obtained during a cognitive task in order to delineate the neural mechanisms involved in two schizophrenia subgroups: schizophrenia patients with and without Obsessive-Compulsive Disorder (OCD).

METHODS

16 schizophrenia patients with OCD ("schizo-obsessive"), 17 pure schizophrenia patients, and 20 healthy controls underwent fMRI while performing a working memory task. A whole brain search for activation clusters of cognitive load was performed using a recently developed data-driven multi-voxel pattern analysis (MVPA) approach, termed Searchlight Based Feature Extraction (SBFE), and which yields a robust fMRI-based classifier.

RESULTS

The SBFE successfully classified the two schizophrenia groups with 91% accuracy based on activations in the right intraparietal sulcus (r-IPS), which further correlated with reduced symptom severity among schizo-obsessive patients.

CONCLUSIONS

The results indicate that this novel SBFE approach can successfully delineate between symptom dimensions in the context of complex psychiatric morbidity.

Does co-morbid obsessive-compulsive disorder modify the abnormal language processing in schizophrenia patients? An FMRI study

Background: Impaired language processing is one of the most replicated findings in functional brain studies of schizophrenia (SCH). This is demonstrated by reduced activations in left prefrontal language areas (i.e., BA44/45, the inferior frontal gyrus, IFG) presented as decreased language lateralization. This finding was documented both in chronic as well as in first-episode SCH patients, arguing for a neurobiological marker for SCH. In a previous study, we demonstrated the specificity of this finding to SCH patients when compared to obsessive–compulsive disorder (OCD) patients in whom language processing was similar to healthy controls. Since a sizable proportion of SCH patients also meet DSM-IV criteria for OCD, we further sought to elucidate whether OCD attenuates abnormal prefrontal language lateralization in this unique group of schizo-obsessive patients compared to their non-OCD-SCH counterparts.

Methods: We used functional magnetic resonance imaging (fMRI) to investigate regional activation and language lateralization in the left and right IFG and inter-hemispheric functional connectivity (FC) during a language task of auditory verb generation in 14 SCH patients with OCD, compared to 17 SCH patients without OCD, 13 OCD patients and 14 healthy controls.

Results: No between-group differences were found in the behavioral measurements of word generation. However, while OCD patients were indistinguishable from healthy volunteers, a similarly reduced lateralization in the IFG and diminished inter-hemispheric FC was noted in the two SCH groups with and without OCD.

Conclusion: The co-occurrence of OCD in SCH does not attenuate abnormal processing of language as reflected by regional IFG activity and FC. These results further support the notion that these language processing abnormalities are characteristic of SCH and that SCH–OCD combined psychopathology is more akin to SCH than to OCD.

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.

Can cognitive deficits differentiate between schizophrenia with and without obsessive-compulsive symptoms?

BACKGROUND

The frequent occurrence of obsessive-compulsive symptoms (OCS) in the course of schizophrenia and their impact on the functional outcome of the illness underlie the suggestion that the presence of OCS represents a separate subtype of schizophrenia, with a distinct clinical presentation and prognosis and specific neurobiological characteristics. This study investigated whether the presence of OCS in schizophrenia is associated with worse cognitive functioning in the domains of processing speed, executive functions and visuospatial memory. We also explored whether the degree of impairment in any of these cognitive domains could predict group membership (i.e. Schizophrenia with OCS [Sch-OCS] and Schizophrenia without OCS) and if there was a relationship between cognitive functioning and severity of OCS within the Sch-OCS group.

METHODS

Forty patients with schizophrenia, 20 with and 20 without OCS, individually matched for age, gender, years of education and severity of psychotic symptoms and 20 healthy controls underwent a comprehensive neuropsychological assessment.

RESULTS

Only lower performance in processing speed discriminated patients with OCS from patients without OCS. Processing speed impairment not only classified patients in OCS or non-OCS group but was also independent of the severity of OCS symptoms.

CONCLUSIONS

The notion of additive effects of both schizophrenia and OCD on the structural and functional integrity of the brain circuits that support cognitive functions warrants further investigation in longitudinal neuropsychological and neuroimaging studies with larger samples and sufficient variation in the severity of OCS.

The obsessive compulsive spectrum in schizophrenia, a meta-analysis and meta-regression exploring prevalence rates

AIMS

The aims of this study were to conduct a meta-analysis and meta-regression to estimate the prevalence rates for obsessive compulsive symptoms (OCS) and obsessive compulsive disorder (OCD) in schizophrenia, and to investigate what influences these prevalence rates.

METHOD

Studies were identified via an online OVID database search, including PsychInfo, Embase and Medline until December 2009.

RESULTS

Forty-three studies summarizing outcomes for 3978 subjects met inclusion criteria. The mean OCD prevalence is 12.3%, slightly increasing to 13.6% after adjustment in meta-regression. The prevalence rate of OCS, defined as any obsession or compulsion is 30.7% (30.3% adjusted). Higher severity of OCS, DIGS assessment, and Sub-Saharan African origin of study are associated with a lower OCS/OCD prevalence rate, use of DSM-IV edition, Y-BOCS assessment and longer schizophrenia history are associated with a higher prevalence rate.

CONCLUSION

The prevalence of OCS and OCD in schizophrenia is substantial, specifically in more chronic patient populations and is influenced by the method of assessment.

The effect of obsessive-compulsive symptomatology on executive functions in schizophrenia: a systematic review and meta-analysis

The presence of obsessive-compulsive symptoms (OCS) and obsessive-compulsive disorder (OCD) is frequent in patients with schizophrenia and has been associated with greater functional impairment. The impact of these features on cognitive function is unclear. In this article, we performed a systematic review and meta-analysis to assess the effect of OCS/OCD on executive functions in schizophrenia patients. Results indicate that schizophrenia patients with OCS/OCD were more impaired in abstract thinking than schizophrenia patients without OCS/OCD. This finding provides support to the double jeopardy hypothesis and may partially explain the greater functional impairment shown in schizo-obsessive patients compared to those with schizophrenia. Inconsistent results were found for set-shifting, cognitive flexibility, cognitive inhibition and verbal fluency, as indicated by the high statistical heterogeneity found. Potential sources of heterogeneity such as definition of OCS/OCD, age of onset, severity of negative symptoms and premorbid intelligence were planned to be explored but there was an insufficient number of studies to perform these analyses. Our findings highlight the complexity of the relationship between OCS/OCD and schizophrenia and warrant further investigation of the cognitive function of schizo-obsessive patients.

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.

Is a schizo-obsessive subtype associated with cognitive impairment? Results from a large cross-sectional study in patients with psychosis and their unaffected relatives

The current study investigated whether candidate cognitive endophenotypes may be used to validate a schizo-obsessive subtype. Using within-subject random effect regression analyses and cross-trait cross-relative analyses, we evaluated the association between obsessive-compulsive symptoms (OCSs) and cognitive performance in 984 patients with nonaffective psychosis (22.5% with OCSs), 973 unaffected siblings (7.7% with OCSs), 851 parents (4.2% with OCSs), and 573 controls (4.5% with OCSs). No significant within-subject associations between OCSs and cognitive functioning were found for patients and siblings. Severity of OCSs was associated with worse set-shifting ability in parents and worse processing speed in controls, but effect sizes were small (0.10 and 0.05 respectively). Cross-trait cross-relative analyses yielded no significant results. Contrary to our expectations, neither within-subject analyses nor cross-relative analyses yielded a clear association between OCSs and cognitive performance. Results do not support a schizo-obsessive subtype associated with cognitive impairment.

Comparison of putative intermediate phenotypes in schizophrenia patients with and without obsessive-compulsive disorder: examining evidence for the schizo-obsessive subtype

Obsessive-compulsive symptoms or obsessive-compulsive disorder (OCD) is estimated to occur in up to 30% of patients with schizophrenia. Whether this subgroup of patients is cognitively, affectively, or physiologically distinct remains unclear. 204 schizophrenia patients, 15 who also met criteria for a diagnosis of OCD, and 147 healthy controls were examined on several intermediate phenotypes. The patient groups did not differ from each other except that the co-morbid group exhibited an elevated rate of eye-tracking dysfunction. Results suggest that OCD-co-morbid patients did not comprise a distinct subgroup based on the measures studied here, although systematic assessment of larger cohorts is warranted.

Clinical and neurocognitive profiles of subjects at high risk for psychosis with and without obsessive-compulsive symptoms

OBJECTIVE

Obsessive-compulsive symptoms (OCS), which are common in psychotic-spectrum illnesses, are of clinical interest because of their association with poor prognosis or cognitive dysfunction. However, few studies on the clinical and neurocognitive implications of OCS in individuals at ultra-high risk for psychosis (UHR) have been conducted.

METHOD

Sixty-five UHR subjects [24 with OCS (UHR+OCS), 41 without OCS (UHR-OCS)], and 40 healthy controls were assessed using clinical scales and neurocognitive tests.

RESULTS

Those with UHR+OCS showed more severe clinical symptoms and poorer global functioning as compared to both healthy controls and the UHR-OCS group, according to the results of the Global Assessment of Functioning, the Comprehensive Assessment of At-Risk Mental States, and the Positive and Negative Syndrome Scale (total, negative, and general scores). In the neurocognitive domain, those in the UHR-OCS group showed notably greater latency in the Stroop task and more confabulation errors in immediate recall in the Rey-Osterrieth Complex Figure Test compared with those in UHR+OCS group, whose performance levels were similar to those of the healthy control group.

CONCLUSIONS

The OCS manifested in UHR individuals was associated with a more severe clinical symptomatic presentation, including lower global functioning and more psychotic symptoms. On the other hand, those with UHR-OCS performed more poorly on some cognitive tests. The features that distinguish the groups can be used for developing prognoses and intervention strategies for the heterogeneous UHR group.

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.