Dirk Jacobsen

Impact of comorbid depressive symptoms on neuropsychological performance in obsessive-compulsive disorder.

There is indirect evidence from previous research that several executive disturbances in obsessive-compulsive disorder (OCD) are mediated by comorbid depressive symptoms. For the present study, the authors investigated whether OCD patients with elevated Hamilton Rating Scale for Depression (HRSD) scores would exhibit deficits in tasks sensitive to the medial and dorsolateral frontal cortex as well as other executive tasks. The 36 OCD patients were split along the median according to their HRSD scores and compared with matched control subjects. Patients with high HRSD scores performed significantly worse than control subjects and patients with low HRSD scores on the Wisconsin Card Sorting Test, the Trail-Making Test (TMT, Part B), and the TMT difference score. Moreover, patients with high HRSD scores exhibited deficits on a (creative) verbal fluency task. It is suggested that comorbid depressive symptoms may have artificially inflated some executive deficit scores in previous studies.

Dimensional structure of the Yale–Brown Obsessive-Compulsive Scale (Y-BOCS)

The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is a widely used instrument to assess obsessive-compulsive symptomatology. The present study provides evidence that the Y-BOCS is best represented by a three-dimensional model comprising severity of obsessions (factor 1), severity of compulsions (factor 2) and resistance to symptoms (factor 3). On the basis of exploratory factor analysis, this structure was found for both baseline (n = 109) and discharge ratings (n = 68) following a multimodal cognitive-behavioral intervention. The factor solution remained essentially unchanged when two optional items (items 1b and 6b) were dropped from analysis. The three-factor structure was replicated with confirmatory factor analysis and showed better fit than previously proposed single- and two-factor models. For future research, we propose a new Y-BOCS scoring algorithm that takes this factor structure into account. A further result was that resistance significantly declined in response to cognitive-behavioral intervention, whereas drug treatment alone did not seem to moderate this variable according to previous research conducted by Kim et al. [Psychiatry Research 51 (1994) 203-211].

Positive schizotypal symptoms predict treatment outcome in obsessive–compulsive disorder

Previous research has suggested that the presence of schizotypal personality disorder may represent a risk factor for treatment failure in obsessive-compulsive disorder (OCD). Relying on a dimensional approach, the present study investigated whether the predictive importance of schizotypal personality is shared by all of its features to the same extent or whether it is confined to a subset of symptoms. Fifty-three patients underwent multi-modal cognitive-behavioral therapy with or without adjunctive antidepressive medication. Therapy response was defined as a 35% decline of the Y-BOCS total score. At baseline assessment, patients were asked to fill out the schizotypal personality questionnaire, the perceptual aberration scale and the Beck depression inventory. Stepwise regression analysis and group comparisons conducted with the schizotypal and depression scales revealed that elevated scores in the positive schizotypal scales, especially perceptual aberrations, were highly predictive for treatment failure. Responders to treatment and non-responders did not significantly differ on other variables or on scores in two scales which measured response biases. The study provides evidence that positive schizotypal symptoms are antecendents for treatment failure in OCD. It needs to be evaluated whether these at-risk individuals benefit from additional intervention, such as the adminstration of low-dose atypical neuroleptics and specifically tailored behavorial intervention.

Neuropsychological correlates of schizophrenic syndromes in patients treated with atypical neuroleptics.

There is widespread evidence that schizophrenic symptomatology is best represented by three syndromes (positive, negative, disorganized). Both the disorganized and negative syndrome have been found to correlate with several neurocognitive dysfunctions. However, previous studies investigated samples predominantly treated with typical neuroleptics, which frequently induce parkinsonian symptoms that are hard to disentangle from primary negative symptoms and may have inflated correlations with neurocognition. A newly developed psychopathological instrument called the Positive and Negative and Disorganized Symptoms Scale (PANADSS) was evaluated in 60 schizophrenic patients. Forty-seven participants treated with atypical neuroleptics performed several neurocognitive tasks.A three-factor solution of schizophrenic symptomatology emerged. Negative symptomatology was associated with diminished creative verbal fluency and digit span backward, whereas disorganization was significantly correlated with impaired Stroop, WCST and Trail-Making Test B performance.Data suggest that disorganization is associated with tasks that demand executive functioning. Previous findings reporting correlations between negative symptomatology and neurocognition may have been confounded by the adverse consequences of typical neuroleptics.

Verbal and Nonverbal Memory Functioning in Posttraumatic Stress Disorder (PTSD)

Although there is evidence for memory impairment in posttraumatic stress disorder (PTSD), it remains unclear whether memory impairment is confined to verbal material or whether memory for nonverbal material is also affected. We examined verbal and nonverbal memory for free recall and recognition in 40 patients with PTSD and 40 healthy controls. Analyses showed that patients with PTSD displayed attenuated memory performance for both short- and long-term recall, which was not further moderated by type of material. The influence of attention, verbal intelligence, and depression was investigated. Our findings suggest that both verbal and nonverbal memory are compromised in PTSD. We would like to thank Alice Behrendt, Dr. Alan Campbell, and Dr. Richard Linscott for help with an earlier version of the manuscript and Christoph Muhtz for his help in recruitment of subjects.

Examination of emotional Stroop interference in obsessive-compulsive disorder

Previous research has produced conflicting findings on whether or not patients with subclinical or manifest obsessive-compulsive disorder (OCD) share an attentional bias for anxiety-related material. In the present study, 35 OCD patients were compared with 20 healthy controls on their performance in an emotional Stroop paradigm. Nine different stimulus conditions were compiled, including sets for depression-related and anxiety-related words as well as stimuli from two constructs with a potential relevance for the pathogenesis and maintenance of OCD symptomatology: responsibility and conscientiousness. Patients did not show enhanced interference for any of the conditions. Syndrome subtype and severity, avoidance and speed of information processing did not moderate results. The present study concurs with most prior research that OCD patients display no interference effect for general threat words. It deserves further consideration, that emotional interference effects in OCD as seen in other anxiety disorders occur when using idiosyncratic word material with a direct relation to the individuals primary concerns.

Extent, profile and specificity of visuospatial impairment in obsessive-compulsive disorder (OCD)

Recent reviews on the neurocognitive profile of patients diagnosed with obsessive-compulsive disorder (OCD) have converged on the assumption that both visuospatial and especially nonverbal memory performance are impaired in OCD. However, as most prior studies have contrasted performance of OCD patients with healthy controls only, no inferences can yet be drawn about the specificity of these deficits to OCD. Further, the administration of complex and multifunctional tasks limit conclusions about clearly defined cognitive deficits. The present study compared 71 OCD patients to 30 healthy and 33 psychiatric control participants on a large battery of visuospatial and nonverbal memory tasks at two time-points. In addition, a visuospatial battery (VS battery), which assesses a wide range of elementary visuospatial functions, was administered. While OCD patients performed worse than healthy controls on some complex tasks (e.g., Block Design), no visuospatial component proved to be impaired specifically in OCD. OCD patients and controls performed similarly on parameters of nonverbal memory. Regarding organizational strategy, OCD patients performed worse than healthy (but not psychiatric) control participants on two out of three Rey-figure trials (copy and immediate). It is suggested that prior research overestimated the severity and significance of visuospatial and nonverbal memory impairment in OCD. The authors would like to thank Dr. Michael Rufer, Dr. Angelique Mundt and Jürgen Orthmann for help with recruitment. The study was supported by a grant of the German Research Foundation (MO 969/1-1).