Publications (6)18.96 Total impact
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Article: Are BPI and BPII suicide attempters distinct neuropsychologically?
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ABSTRACT: It is not clear if bipolar disorder I (BPI) and bipolar disorder II (BPII) represent the same disorder on a continuum of severity or two distinct syndromes. Neuropsychological functioning is a means of understanding similarities and differences between diagnostic groups. To compare the neuropsychological functioning of depressed suicide attempters with BPI or BPII and healthy controls. Fifty-one individuals with bipolar disorder (BPI n=32, BPII n=19) and a history of suicide attempt were compared with 58 healthy controls with respect to neuropsychological functioning in the following domains: motor functioning, psychomotor performance, attention, memory, working memory, impulsiveness and language fluency. Participants with BPI and BPII performed significantly more poorly than healthy controls on tests of Digit Symbol Test of psychomotor functioning, the N Back Test of working memory and the Go-No-Go Test of impulsiveness. Participants with BPI were significantly worse than controls but not those with BPII on the Test of Verbal Fluency. Participants with BPII performed significantly worse than either controls or those with BPI on the Simple Reaction Time Motor Test and the Stroop Test of attention. While participants with both BPI and BPII performed more poorly than healthy controls, individuals with BPII also performed more poorly than those with BPI on some tests suggesting that they may have a unique syndrome. The findings have implications for assessment and treatment in bipolar disorder.Journal of Affective Disorders 09/2006; 94(1-3):255-9. · 3.52 Impact Factor -
Article: Etiological heterogeneity and intelligence test scores in patients with schizophrenia.
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ABSTRACT: Previous research has indicated that patients with a family history of schizophrenia show a greater degree of cognitive and neuropsychological impairment than patients without a family history. We examined the neurocognitive performance, using the WAIS-R, of 51 patients with a family history (familial) and 103 patients without a family history (sporadic) to determine if differences exist that may help to explain the heterogeneous neuropsychological profile of the illness. The family history groups did not differ with respect to gender, diagnosis, ethnicity, age, age of onset, education or duration of illness. Multivariate analyses, covarying for age of onset and education, showed the sporadic group performed significantly better than the familial group on the digit symbol and object assembly subtests, with a trend level difference in overall performance IQ score. Additionally, we identified significant gender differences in favor of males for full scale and verbal IQ, the information, digit span, block design, and arithmetic subtests, and at a trend level, the picture assembly subtest. The family history group differences reflect relative dysfunction in visual attention and scanning, visuomotor control, and spatial processing and reasoning. Overall, the results suggest that sporadic patients have better perceptual-organizational skills and faster speed of processing.Journal of Clinical and Experimental Neuropsychology 03/2006; 28(2):167-77. · 2.13 Impact Factor -
Article: Resting neural activity distinguishes subgroups of schizophrenia patients.
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ABSTRACT: Schizophrenia is etiologically heterogeneous. It is anticipated, but unproven, that subgroups will differ in neuropathology and that neuroimaging may reveal these differences. The optimal imaging condition may be at rest, where greater variability is observed than during cognitive tasks, which more consistently reveal hypofrontality. We previously demonstrated symptom and physiologic differences between familial and sporadic schizophrenia patients and hypothesized that the groups would show different resting regional cerebral blood flow (rCBF) patterns. Ten familial and sixteen sporadic schizophrenia patients and nine comparison subjects had single photon emission computed tomography imaging during passive visual fixation. Images were spatially normalized into Talairach coordinates and analyzed for group rCBF differences using SPM with a Z value threshold of 2.80, p < .001. The subgroups had similar age, gender, illness duration, and medication treatment. Sporadic patients had hypofrontality (anterior cingulate, paracingulate cortices, left dorsolateral and inferior-orbitofrontal), whereas familial patients had left temporoparietal hypoperfusion; all of these regions show resting activity in healthy subjects. Both groups hyperperfused the cerebellum/pons and parahippocampal gyrus; additional hyperperfusion for sporadic patients was observed in the fusiform; familial patients also hyperperfused the hippocampus, dentate, uncus, amygdala, thalamus, and putamen. Familial and sporadic schizophrenia patients had different resting rCBF profiles, supporting the hypothesis that certain subgroups have distinct neural underpinnings. Different neuropathologic processes among subgroups of schizophrenia patients may account for the prior contradictory results of resting imaging studies.Biological Psychiatry 12/2004; 56(12):931-7. · 8.28 Impact Factor -
Article: The reliability and clinical correlates of figure-ground perception in schizophrenia.
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ABSTRACT: Schizophrenia subjects are impaired in a number of visual attention paradigms. However, their performance on tests of figure-ground visual perception (FGP), which requires subjects to visually discriminate figures embedded in a rival background, is relatively unstudied. We examined FGP in 63 schizophrenia patients and 27 control subjects and found that the patients performed the FGP test reliably and had significantly lower FGP scores than the control subjects. Figure-ground visual perception was significantly correlated with other neuropsychological test scores and was inversely related to negative symptoms. It was unrelated to antipsychotic medication treatment. Figure-ground visual perception depends on "top down" processing of visual stimuli, and thus this data suggests that dysfunction in the higher-level pathways that modulate visual perceptual processes may also be related to a core defect in schizophrenia.Journal of Neuropsychiatry 02/2004; 16(3):277-83. · 2.51 Impact Factor -
Article: A pilot study of noradrenergic and HPA axis functioning in PTSD vs. panic disorder.
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ABSTRACT: The biological literature in the anxiety disorders has focused on comparisons between patient groups and normal volunteers, with relatively little comparative study of the anxiety disorders. We therefore conducted this pilot study to compare a group of patients with post-traumatic stress disorder (PTSD) (n = 7) to a contiguously studied panic disorder group (n = 17) and healthy control subjects (n = 16) on baseline levels of cortisol and 3-methoxy-4-hydroxyphenylglycol (MHPG), and response to clonidine challenge. Despite the small sample size, highly significant differences were found on the following measures: PTSD patients had lower cortisol, lower MHPG, reduced MHPG volatility to clonidine challenge, and marginally reduced cortisol volatility compared to patients with panic disorder. These biological findings support existing clinical, epidemiologic, family study, and clinical trial findings that distinguish these two disorders as distinct syndromes.Psychiatry Research 08/2002; 110(3):219-30. · 2.52 Impact Factor -
Article: SPECT study of visual fixation in schizophrenia and comparison subjects
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ABSTRACT: Background: The consistent association of impaired eye movements and schizophrenia suggests a relationship between the neurobiology of the illness and visual pursuit systems. Visual fixation (VF), an eye “movement” task at zero velocity, is the simplest such abnormality in schizophrenia patients and their relatives.Methods: We used a VF task for a functional imaging study. Six neuroleptic-free schizophrenia patients and eight gender and mean age matched comparison subjects had SPECT scans with 20 mCi of Tc99-HMPAO, during VF on a simple blue line intersection. MEDX data saved in ANALYZE format for SPM 95 was used to generate paired t-test statistical data for display in Talairach space, with rCBF changes given as Z-scores.Results: Patients, compared to controls, had increased rCBF in both the parahippocampal gyrus (bilaterally) and in the right fusiform gyrus. They had decreased rCBF in the left frontal cortex, including medial and superior frontal gyri and anterior cingulate. Overall, compared to controls, patients had medial temporal lobe hyperperfusion along with left prefrontal hypoperfusion.Conclusions: These findings are consistent with the hypothesized imbalance between the medial temporal and frontal lobes that is postulated for schizophrenia. It was of interest that the relative rCBF differences between schizophrenia patients and controls in this small sample were observable with this cognitively non-demanding visual fixation task.Biological Psychiatry.
