Biomedical subjects

Christopher F Murphy

Publications and source records attributed to Christopher F Murphy.

7 recordsLinked to original sources

PubMed2006

White-matter integrity predicts stroop performance in patients with geriatric depression.

BACKGROUND: This study tested the hypothesis that microstructural white matter abnormalities in frontostriatal-limbic tracts are associated with poor response inhibition on the Stroop task in depressed elders. METHOD: Fifty-one elders with major depression participated in a 12-week escitalopram trial. Diffusion tensor imaging was used to determine fractional anisotropy (FA) in white matter regions. Executive function (response inhibition) was assessed with the Stroop task. Voxelwise correlational analysis was used to examine the relationship between Stroop performance and fractional anisotropy. RESULTS: Significant associations between FA and Stroop color word interference were evident in multiple frontostriatal-limbic regions, including white matter lateral to the anterior and posterior cingulate cortex and white matter in prefrontal, insular, and parahippocampal regions. CONCLUSIONS: These findings suggest that microstructural white matter abnormalities of frontostriatal-limbic networks are associated with executive dysfunction of late-life depression. This observation provides the rationale for examination of specific frontostriatal-limbic pathways in the pathophysiology of geriatric depression.

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PubMed2006

Attention network dysfunction and treatment response of geriatric depression.

The Attention Network Test was used to assess the efficiency of the executive, orienting and vigilance attention networks and their association to treatment response in older patients with major depression. There were no significant performance differences between depressives and controls. However, within the depressed group, executive-related performance, but not orienting- or vigilance-related performance was correlated with time to remission. The association of executive-attention network efficiency and antidepressant response provides the background for focused structural and functional neuroimaging studies aimed at identifying the functional neuroanatomy of antidepressant response.

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PubMed2006

Structural neuroimaging research methods in geriatric depression.

Geriatric depression consists of complex and heterogeneous behaviors unlikely to be caused by a single brain lesion. However, there is evidence that abnormalities in specific brain structures and their interconnections confer vulnerability to the development of late-life depression. Structural magnetic resonance imaging methods can be used to identify and quantify brain abnormalities predisposing to geriatric depression and in prediction of treatment response. This article reviews several techniques, including morphometric approaches, study of white matter hyperintensities, diffusion tensor imaging, magnetization transfer imaging, t2 relaxography, and spectroscopy, that have been used to examine these brain abnormalities with a focus on the type of information obtained by each method as well as each method's limitations. The authors argue that the available methods provide complementary information and that, when combined judiciously, can increase the knowledge gained from neuroimaging findings and conceptually advance the field of geriatric depression.

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PubMed2005

Executive dysfunction and the course of geriatric depression.

BACKGROUND: Executive dysfunction is common in geriatric depression and persists after improvement of depressive symptoms. This study examined the relationship of executive impairment to the course of depressive symptoms among elderly patients with major depression. METHODS: A total of 112 nondemented elderly patients with major depression participated in an 8-week citalopram trial at a target daily dose of 40 mg. Executive functions were assessed with the initiation/perseveration subscale of the Dementia Rating Scale and the Stroop Color-Word test. Medical burden was rated with the Cumulative Illness Rating Scale. RESULTS: Both abnormal initiation/perseveration and abnormal Stroop Color-Word scores were associated with an unfavorable response of geriatric depression to citalopram. In particular, initiation/perseveration scores below the median (< or =35) and Stroop scores at the lowest quartile (< or =22) predicted limited change in depressive symptoms. Impairment in other Dementia Rating Scale cognitive domains did not significantly influence the outcome of depression. CONCLUSIONS: Executive dysfunction increases the risk for poor response of geriatric depression to citalopram. Because executive functions require frontostriatal-limbic integrity, this observation provides the rationale for investigation of the role of specific frontostriatal-limbic pathways in perpetuating geriatric depression. Depressed elderly patients with executive dysfunction require vigilant clinical attention because they might be at risk to fail treatment with a selective serotonin reuptake inhibiting antidepressant.

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PubMed2002

Frontal white matter microstructure and treatment response of late-life depression: a preliminary study.

OBJECTIVE: This study tested the hypothesis that microstructural abnormalities in white matter areas of the brain containing frontostriatal tracts are associated with a low rate of remission of geriatric depression. METHOD: Thirteen older patients with major depression received open, but controlled, treatment with citalopram at a target daily dose of 40 mg for 12 weeks. Diffusion tensor imaging was used to determine fractional anisotropy in preselected white matter regions. RESULTS: Survival analysis with Cox's proportional hazards model revealed that lower fractional anisotropy of the right and the left frontal white matter regions 15 mm above the anterior commissure-posterior commissure plane was associated with a low remission rate after age was considered. Remission was not significantly associated with fractional anisotropy of lower frontal regions or a temporal region. CONCLUSIONS: Microstructural white matter abnormalities lateral to the anterior cingulate may be associated with a low rate of remission of geriatric depression.

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PubMed2002

Assessing behavioral health using OASIS: part 2: cognitive impairment, problematic behaviors, and anxiety.

This article is the second of a two-part series on assessing behavioral health in adult and elderly home care patients using OASIS. Part 1 presented an assessment approach for depressive symptoms and suicidality. This article presents the assessment of cognitive impairment, problematic behaviors, and anxiety using OASIS as a framework and stresses the importance of direct questioning. Case scenarios and guidelines for referral for further evaluation and possible treatment are provided.

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PubMedDate not supplied

Longitudinal association of initiation/perseveration and severity of geriatric depression.

OBJECTIVE: Many older adults with major depression (MDD) present with impairment in initiation and perseveration (IP) tests. However, it remains unclear how these abnormalities change during the course of depression. METHODS: The authors studied the longitudinal covariation of depression severity and IP functioning in 157 depressed older adults with MDD. Patients with and without baseline IP impairment were studied on three occasions over 1 year. RESULTS: Depression severity was associated with concurrent IP scores; however, despite IP improvement, those with impaired baseline IP functioning did not reach the level of their non-impaired counterparts. CONCLUSION: The persistence of IP abnormalities suggests that these patients require careful treatment planning and follow-up, given that earlier studies noted an association of abnormal IP with disability and poor outcomes of depression treatment.

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