Obsessive-compulsive disorder (OCD) with schizotypy vs. schizophrenia with OCD: diagnostic dilemmas and therapeutic implications.
ABSTRACT 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.
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ABSTRACT: 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 Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: email@example.com.Brain 12/2014; 138(2). DOI:10.1093/brain/awu360 · 10.23 Impact Factor
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ABSTRACT: 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.Australian and New Zealand Journal of Psychiatry 04/2014; 48(9). DOI:10.1177/0004867414531831 · 3.77 Impact Factor
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ABSTRACT: Obsessive-compulsive symptoms (OCS) are a common phenomenon in patients with schizophrenia and are associated with additional clinical and functional impairments. So far treatment approaches have been limited to mainly pharmacological interventions with restricted effectiveness. Because cognitive behavioural therapy (CBT) is considered treatment of first choice for patients with primary obsessive-compulsive disorder (OCD), it seems compelling to consider it as a treatment option for comorbid OCS in schizophrenia. This research was conducted in order to investigate the theoretical and empirical basis for CBT in the treatment of comorbid OCS/OCD in schizophrenia. A comprehensive review and analysis of published literature was performed. Outcome measures from case-reports and a case-series showed favourable results with a significant reduction of symptom severity in 24/30 patients treated with CBT and exposure and response prevention (ERP) or ERP alone. CBT appears to offer a valuable opportunity to reduce symptom severity in this highly impaired group of patients. Based on these results and with a strong focus on tolerability concerns, suggestions for possible CBT approaches for the comorbid group are proposed. Further research within this field and systematic clinical evaluations are highly desirable.The Cognitive Behaviour Therapist 01/2013; 6. DOI:10.1017/S1754470X13000123