Obsessive-compulsive disorder among schizophrenic patients: an exploratory study using functional magnetic resonance imaging data

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.

Transdiagnostic Approach to Olfactory Reference Syndrome: Neurobiological Considerations

Olfactory reference syndrome (ORS) describes a constellation of emotional and behavioral symptoms that cause clinically significant distress or impairment arising from the false belief that one is emitting an offensive odor. Despite cases of ORS reported throughout the world over the last century, our knowledge and understanding of ORS remain relatively poor because of the limited literature-mostly case studies and series, but no clinical trials. ORS continues to pose significant diagnostic challenges within our current frameworks of categorizing mental disorders, including the Diagnostic and Statistical Manual of Mental Disorders and International Classification of Diseases. We review the ORS literature and discuss diagnostic parallels and challenges of placing ORS within specific categories. We also review the current research on the neurocircuitry of olfaction and of disorders with potential clinical relevance to patients presenting with ORS. While no primary neuroscientific research has specifically investigated ORS, an overlapping circuitry has been implicated in the neurobiology of obsessive-compulsive, trauma and stressor, and psychotic spectrum disorders, suggesting that the phenomenology of ORS can best be understood through a dimensional, rather than categorical, approach.

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.

Deep Brain Stimulation for Obsessive Compulsive Disorder: Evolution of Surgical Stimulation Target Parallels Changing Model of Dysfunctional Brain Circuits

Obsessive compulsive disorder (OCD) is a common, disabling psychiatric disease characterized by persistent, intrusive thoughts and ritualistic, repetitive behaviors. Deep brain stimulation (DBS) is thought to alleviate OCD symptoms by modulating underlying disturbances in normal cortico-striato-thalamo-cortical (CSTC) circuitry. Stimulation of the ventral portion of the anterior limb of the internal capsule (ALIC) and underlying ventral striatum (“ventral capsule/ventral striatum” or “VC/VS” target) received U.S. FDA approval in 2009 for patients with severe, treatment-refractory OCD. Over the decades, DBS surgical outcome studies have led to an evolution in the electrical stimulation target. In parallel, advancements in neuroimaging techniques have allowed investigators to better visualize and define CSTC circuits underlying the pathophysiology of OCD. A critical analysis of these new data suggests that the therapeutic mechanism of DBS for OCD likely involves neuromodulation of a widespread cortical/subcortical network, accessible by targeting fiber bundles in the ventral ALIC that connect broad network regions. Future studies will include advances in structural and functional imaging, analysis of physiological recordings, and utilization of next-generation DBS devices. These tools will enable patient-specific optimization of DBS therapy, which will hopefully further improve outcomes.

Reduced activity and connectivity of left amygdala in patients with schizophrenia treated with clozapine or olanzapine

Obsessive-compulsive symptoms (OCS) in patients with schizophrenia are a common co-occurring condition, often associated with additional impairments. A subgroup of these patients develops OCS during treatment with second-generation antipsychotics (SGAs), most importantly clozapine and olanzapine. So far, little is known about possible neural mechanism of these SGAs, which seem to aggravate or induce OCS. To investigate the role of SGA treatment on neural activation and connectivity during emotional processing, patients were stratified according to their monotherapy into two groups (group I: clozapine or olanzapine, n = 20; group II: amisulpride or aripiprazole, n = 20). We used an fMRI approach, applying an implicit emotion recognition task. Group comparisons showed significantly higher frequency and severity of comorbid OCS in group I than group II. Task specific activation was attenuated in group I in the left amygdala. Furthermore, functional connectivity from left amygdala to right ventral striatum was reduced in group I. Reduced amygdala activation was associated with OCS severity. Recent literature suggests an involvement of an amygdala-cortico-striatal network in the pathogenesis of obsessive-compulsive disorder. The observed differential activation and connectivity pattern of the amygdala might thus indicate a neural mechanism for the development of SGA-associated OCS in patients with schizophrenia. Further neurobiological research and interventional studies are needed for causal inferences.

Obsessive-compulsive disorder comorbid with schizophrenia and bipolar disorder

Obsessive Compulsive Disorder (OCD) and Obsessive Compulsive Symptoms (OCS) are known to be highly comorbid with bipolar disorder and schizophrenia. Comorbid OCD/OCS influences the course of schizophrenia and bipolar disorder. There is also some evidence to suggest that a diagnosis of OCD may be associated with elevated risk for later development of psychosis and bipolar disorder. Comorbid OCD/OCS is associated with a greater severity of schizophrenia phenotype and poorer prognosis. In addition, certain atypical antipsychotics, clozapine in particular are known to induce or worsen OCS in schizophrenia. OCD when comorbid with bipolar disorder mostly runs an episodic course with worsening and improvement of OCD/OCS in depressive and in manic/hypomanic phases respectively. There is limited systematic data on the treatment of OCD in schizophrenia and bipolar disorder. When OCD presents in the context of schizophrenia, management may include treatment with atypical antipsychotics with limited serotonergic properties, changing the antipsychotic, reduction in the dose of the antipsychotic, addition of cognitive-behavior therapy (CBT), or a specific serotonin reuptake inhibitor (SSRI). When OCD is comorbid with bipolar disorder, mood stabilization is the priority. CBT may be preferred over SSRIs to treat OCD/OCS that persist in between the mood episodes because SSRIs may induce a switch or worsen the course of bipolar disorder. SSRIs when indicated have to be used judiciously under the cover of adequate mood stabilization.

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.

Role of the dorsal anterior cingulate cortex in obsessive-compulsive disorder: converging evidence from cognitive neuroscience and psychiatric neurosurgery

OBJECTIVE Advances in understanding the neurobiological basis of psychiatric disorders will improve the ability to refine neuromodulatory procedures for treatment-refractory patients. One of the core dysfunctions in obsessive-compulsive disorder (OCD) is a deficit in cognitive control, especially involving the dorsal anterior cingulate cortex (dACC). The authors' aim was to derive a neurobiological understanding of the successful treatment of refractory OCD with psychiatric neurosurgical procedures targeting the dACC. METHODS First, the authors systematically conducted a review of the literature on the role of the dACC in OCD by using the search terms "obsessive compulsive disorder" and "anterior cingulate." The neuroscience literature on cognitive control mechanisms in the dACC was then combined with the literature on psychiatric neurosurgical procedures targeting the dACC for the treatment of refractory OCD. RESULTS The authors reviewed 89 studies covering topics that included structural and functional neuroimaging and electrophysiology. The majority of resting-state functional neuroimaging studies demonstrated dACC hyperactivity in patients with OCD relative to that in controls, while task-based studies were more variable. Electrophysiological studies showed altered dACC-related biomarkers of cognitive control, such as error-related negativity in OCD patients. These studies were combined with the cognitive control neurophysiology literature, including the recently elaborated expected value of control theory of dACC function. The authors suggest that a central feature of OCD pathophysiology involves the generation of mis-specified cognitive control signals by the dACC, and they elaborate on this theory and provide suggestions for further study. CONCLUSIONS Although abnormalities in brain structure and function in OCD are distributed across a wide network, the dACC plays a central role. The authors propose a theory of cognitive control dysfunction in OCD that attempts to explain the therapeutic efficacy of dACC neuromodulation. This theoretical framework should help to guide further research into targeted treatments of OCD and other disorders of cognitive control.

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.

How should we manage anxiety in patients with schizophrenia?

OBJECTIVE

We aim to provide a selective clinically focused review of the epidemiology, aetiology and management of comorbid anxiety in people with schizophrenia.

METHOD

The following databases were reviewed: PubMed, Medline and Embase.

RESULTS

Anxiety is highly prevalent throughout course of schizophrenia, but is often not identified or its clinical significance is under-appreciated. Also, there is a paucity of rigorous data to support specific treatment guidelines for people with schizophrenia and concurrent anxiety disorders. Psychological treatments such as cognitive behavioural therapy appear effective if targeted carefully, and preliminary data suggest that mindfulness approaches and progressive muscle relaxation may be beneficial. Pharmacological interventions need to be tailored to the individual and target specific symptom sets. There is a growing evidence base about the neurobiology of schizophrenia and concurrent anxiety symptoms or disorders which will hopefully enhance treatment options.

CONCLUSIONS

Further research is required to guide treatment guidelines for anxiety in people with schizophrenia.

Increased orbitofrontal cortex activation associated with "pro-obsessive" antipsychotic treatment in patients with schizophrenia

BACKGROUND

Patients with schizophrenia have an approximately 10-fold higher risk for obsessive-compulsive symptoms (OCS) than the general population. A large subgroup seems to experience OCS as a consequence of second-generation antipsychotic agents (SGA), such as clozapine. So far little is known about underlying neural mechanisms.

METHODS

To investigate the role of SGA treatment on neural processing related to OCS in patients with schizophrenia, we stratified patients according to their monotherapy into 2 groups (group I: clozapine or olanzapine; group II: amisulpride or aripiprazole). We used an fMRI approach, applying a go/no-go task assessing inhibitory control and an n-back task measuring working memory.

RESULTS

We enrolled 21 patients in group I and 19 patients in group II. Groups did not differ regarding age, sex, education or severity of psychotic symptoms. Frequency and severity of OCS were significantly higher in group I and were associated with pronounced deficits in specific cognitive abilities. Whereas brain activation patterns did not differ during working memory, group I showed significantly increased activation in the orbitofrontal cortex (OFC) during response inhibition. Alterations in OFC activation were associated with the severity of obsessions and mediated the association between SGA treatment and co-occurring OCS on a trend level.

LIMITATIONS

The main limitation of this study is its cross-sectional design.

CONCLUSION

To our knowledge, this is the first imaging study conducted to elucidate SGA effects on neural systems related to OCS. We propose that alterations in brain functioning reflect a pathogenic mechanism in the development of SGA-induced OCS in patients with schizophrenia. Longitudinal studies and randomized interventions are needed to prove the suggested causal interrelations.

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.

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.

Functional neuroimaging in obsessive-compulsive disorder

BACKGROUND AND AIM

Obsessive-compulsive disorder (OCD) is a severe, highly prevalent and chronically disabling psychiatric disorder that usually emerges during childhood or adolescence. This paper aims to review the literature on functional neuroimaging in OCD, analysing the reported dysfunctional connectivity in the corticostriatothalamocortical circuitry.

METHOD

This study included papers published in peer-reviewed journals dealing with functional imaging in OCD.

RESULTS

Striatal dysfunction, mainly of the caudate nucleus, leads to inefficient thalamic gating, resulting in hyperactivity within the orbitofrontal cortex (intrusive thoughts) and the anterior cingulate cortex (non-specific anxiety). Compulsions consist of ritualistic behaviours performed to recruit the inefficient striatum and neutralise unwanted thoughts and anxiety. Functional neuroimaging findings are discussed against the background of specific cognitive impairments, mainly regarding visuospatial processing, executive functioning and motor speed. Cognitive deficits are partial and specific, matching imaging data.

CONCLUSIONS

Several studies have targeted brain regions hypothesised to be involved in the pathogenesis of OCD, showing the existence of dysfunctional connectivity in the corticostriatothalamocortical circuitry. Improvements in spatial resolution of neuroimaging techniques may contribute to a better understanding of the neurocircuitry of OCD and other anxiety disorders.

Obsessive-compulsive symptoms in schizophrenia: their relationship with clinical features and pharmacological treatment

OBJECTIVES

The aim of this study was to evaluate (1) the frequency of obsessive-compulsive symptoms (OCS) in patients with schizophrenia, (2) the impact of OCS on clinical features of schizophrenia, and (3) the association between type of antipsychotic treatment and presence of OCS.

METHODS

OCS were evaluated using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) in 70 patients with schizophrenia. The patients were then divided into two subgroups: those with at least a moderate level of OCS and those with mild or absent OCS. The two subgroups were compared using scores on the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), and the Global Assessment of Functioning Scale (GAF).

RESULTS

Of the 70 patients with schizophrenia who were evaluated, 36 (51.4%) had at least moderate OCS (Y-BOCS score >16). SAPS subscale scores for hallucinations and delusions and GAF scores were found to be significantly higher among patients with at least moderate OCS, compared with those with mild or absent OCS. A significant relationship between at least moderate OCS and treatment with conventional antipsychotics was also observed.

CONCLUSIONS

The presence of OCS seems to have the potential to affect clinical outcomes in schizophrenia and treatment with conventional antipsychotics appears to be correlated with the presence of OCS.

Neuroanatomical, neurochemical, and neurodevelopmental basis of obsessive-compulsive symptoms in schizophrenia

The prevalence of the obsessive-compulsive symptoms in schizophrenia (OCSS) appears to be higher than that expected on the basis of comorbidity rates. Review of brain abnormalities in schizophrenia and obsessive-compulsive disorder (OCD) reveals involvement of similar regions namely the frontal lobe, the basal ganglia, the thalamus, and the cerebellum, in both the disorders. Neurodevelopmental etiopathogenesis has been proposed to explain schizophrenia as well as OCD. Significant overlap in neurotransmitter dysfunction (serotonin, glutamate, and dopamine) has been documented between schizophrenia and OCD. The New-onset obsessive-compulsive (OC) symptoms have been reported with the use of atypical antipsychotics in the schizophrenia patients In this background, OCSS is an emerging area of recent interests. This article attempts to review the literature on the neurobiology of OCSS. Neuroimaging, neuropsychological, and neuromotor abnormalities in OCSS discussed in the context of neurodevelopmental etiopathogenesis suggest glutamate abnormalities in OCSS. Atypical antipsychotic induced OCSS points towards the possible roles of glutamate and serotonin. Dopamine may be responsible for the beneficial role of antipsychotics in the treatment of OCD. In summary, we propose that glutamate, serotonin, and dopamine abnormalities may be the probable basis for OCSS.

Schizo-obsessive and obsessive-compulsive disorder: comparison of clinical characteristics and neurological soft signs

The purpose of the study was to examine whether schizophrenia with obsessive-compulsive disorder (OCD) represents a severe form of OCD-spectrum disorders on the basis of neurological soft signs (NSS) and obsessive-compulsive (OC) symptoms. Sixteen patients with OCD-schizophrenia, 25 OCD patients and 23 healthy controls (HC) were studied. Scales for the Assessment of Positive (SAPS) and Negative Symptoms (SANS), Clinical Global Impressions Scale and Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) were used to assess the schizophrenic and OC symptomatology. NSS were evaluated with the Neurological Evaluation Scale (NES). OCD-schizophrenics had significantly higher scores on total NES than HC. The patients with OCD were more likely to have total Y-BOCS and subscale scores of compulsions than patients with OCD-schizophrenia. The rate of symmetry obsessions and cleaning/washing compulsions were significantly higher in patients with OCD compared to OCD-schizophrenics. We have found no correlation of OC symptoms with schizophrenic symptomatology. Our findings may suggest that OCD-schizophrenia is a distinct subtype of schizophrenia, not a more severe form of OCD-spectrum disorder.

Relationship between obsessive-compulsive symptoms and smoking habits amongst schizophrenic patients

The rate of smoking is especially high among patients with schizophrenia (SCH) and schizoaffective disorder (SCHAFF). Patients with obsessive-compulsive disorder (OCD) smoke less than the general population. OCD symptoms are more frequent among patients with SCH or SCHAFF than in the general population, but it is still unclear whether schizophrenia patients with OC symptoms suffer from SCH and comorbid OCD, or whether they represent a unique subgroup of SCH with presenting OC symptoms. In our study we hypothetised that the current smoking rate of schizophrenia patients with OC symptoms is lower than in schizophrenia patients without OC symptoms. We assessed OC symptoms with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), general state with the Brief Psychiatric Rating Scale (BPRS) and smoking habits with a questionnaire among 66 patients with SCH or SCHAFF. We formed two groups by dividing patients according to their Y-BOCS score. Group I consisted of patients with Y-BOCS scores under 16, while group II consisted of patients with Y-BOCS scores above 16, and we compared the current smoking rates of the two groups. We found that the rates did not differ significantly, so we came to the conclusion that OC symptoms are not in a tight relationship with smoking habits among patients with SCH/SCHAFF.

Obsessive-compulsive and negative symptoms in schizophrenia: associations with coping preference and hope

Although agreement exists regarding the high occurrence of obsessive-compulsive (OC) symptoms in schizophrenia, it is less clear how OC symptoms are related to the traditional symptoms of schizophrenia and co-occurring deficits. One possibility is that there may be two distinct groups of persons with schizophrenia who experience OC symptoms: one group with poor and another with relatively good function. In the present study, the relationships between OC symptoms, coping, and hope were examined among 67 persons with schizophrenia spectrum disorders. First, participants with significant levels of OC symptoms were compared with participants without OC symptoms. Then, participants with significant levels of both OC symptoms and negative symptoms were compared with participants with negative symptoms, but no OC symptoms, and to participants with neither OC symptoms nor negative symptoms. Analysis of variance revealed participants with significant levels of OC symptoms were significantly more likely to experience greater levels of hopelessness and endorse a preference for avoidant focused coping strategies relative to participants without significant OC symptoms. Participants with both negative symptoms and OC symptoms also had less hope and greater preferences for ignoring stressors than participants with negative symptoms but no OC symptoms and participants with neither OC symptoms nor negative symptoms. Implications for theory, practice and research are discussed.

Patterns of obsessive-compulsive symptoms and social function in schizophrenia

Research has alternately found that obsessive and compulsive (OC) symptoms in schizophrenia are associated with graver and lesser levels of negative symptoms. One possible explanation is that there are two distinct groups of persons with OC symptoms: those with cognitive deficits and high levels of negative symptoms and those who generally function well and have low levels of negative symptoms. To examine this question, we performed a cluster analysis on 66 persons with schizophrenia spectrum disorders on the basis of their level of obsessive-compulsive phenomena and global psychosocial function. Four groups were found: high OC/good function (n=9), non-OC/poor function (n=25), non-OC/moderate function (n=20), and high OC/poor function (n=12). A MANCOVA controlling for age found significant group differences on assessments of negative symptoms, executive function and attention among groups. As predicted, the high OC/poor function group had significantly poorer attention than any other group and poorer executive function than either non-OC group. The high OC/good function had lower levels of negative symptoms than either non-OC group. Implications for research and rehabilitation are discussed.

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

Four major brain regions have been repeatedly implicated in the pathophysiology of obsessive compulsive disorder (OCD) in in vivo neuroimaging studies: the caudate nucleus, the orbitofrontal cortex, the anterior cingulate gyrus and the mediodorsal thalamic nucleus. The present review describes the neuroimaging studies on schizophrenia, pertaining to these brain regions. Our working hypothesis is that such common brain regions, if dysfunctional in schizophrenic patients, would be candidates for a neural network subserving the newly emerging syndrome of schizo-obsessive disorder. Findings, though, are controversial. We conclude that further studies, aimed at specific monitoring of these brain regions, in patients suffering from the schizo-obsessive syndrome are warranted.

Obsessive-compulsive disorder in schizophrenia

OBJECTIVE

To examine the differences in demographic and clinical features of patients with schizophrenia, with or without comorbid obsessive-compulsive disorder (OCD).

METHODS

Fifty-two subjects were recruited from clinical services in the city of Edmonton, Alberta and assessed for schizophrenia and OCD with structured clinical interviews and standardized clinical rating scales.

RESULTS

The prevalence of OCD in individuals meeting criteria for schizophrenia was 25%. Those subjects having both schizophrenia and OCD scored significantly higher on the Y-BOCS, Hollingshead scale, and GAF; plus significantly lower PANSS negative symptoms and a trend in increased Parkinsonian symptoms compared with individuals with schizophrenia alone.

CONCLUSION

Our preliminary findings indicate that patients with schizophrenia and OCD vary in selected demographic and clinical measures when compared to patients with schizophrenia alone. Patients with schizophrenia and OCD appear to have less negative symptoms, which may thus be reflected in the decreased GAF scores. It is speculated that patients with schizophrenia and OCD may have a greater propensity to basal ganglia dysfunction than those with schizophrenia alone resulting in increased Parkinsonian symptoms.