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Endophenotypic Marker (endophenotypic + marker)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Visual P3 in Female Alcoholics

ALCOHOLISM, Issue 4 2001
V. Radha Prabhu
Background: The P300 (P3) component of the event related potential has been established as a sensitive risk marker of vulnerability to alcoholism. Most alcoholism studies have focused on men; recent studies indicate that women are equally vulnerable to developing alcoholism. Methods: Visual P3 recorded from 31 electrode positions was evaluated in 44 alcoholic and 60 control women, 24,50 years of age. P3 amplitudes and latencies of the two groups were statistically compared using Analysis of Variance; source localization of surface amplitude values from each group were plotted using a low-resolution brain electromagnetic tomography. Results: The results indicated that alcoholic women had significantly smaller P3 amplitudes in the frontal and central regions compared with controls. Source localization showed lowered activation in alcoholic women in right dorso-lateral prefrontal cortex and the ventro-medial fronto-central regions. Conclusions: The results suggest that P3 is an equally sensitive endophenotypic marker of vulnerability to alcoholism in women. The findings are discussed in terms of functional and physiologic significance of the P3 amplitude in alcoholic women and its relationship to drinking behaviors. [source]

Differential working memory impairment in bipolar disorder and schizophrenia: effects of lifetime history of psychosis

BIPOLAR DISORDERS, Issue 2 2006
David C Glahn
Background:, Although bipolar disorder and schizophrenia have long been viewed as distinct illnesses, there is growing evidence that these two complex diseases share some common genes, which may manifest as overlapping neuropsychological impairments. Although working memory dysfunction has been proposed to be central to the pathophysiology of schizophrenia, it has received less attention in studies of bipolar disorder. Method:, We applied measures of working memory to patients with schizophrenia (n = 15), patients with schizoaffective disorder (n = 15), patients with psychotic (n = 11) and non-psychotic (n = 15) bipolar disorder, and demographically matched healthy subjects (n = 32), in order to determine the extent to which these groups show common or unique impairments. Results:, While patients with bipolar disorder (with and without psychotic features) and those with schizophrenia/schizoaffective disorder were impaired on backward digit span, only patients with a lifetime history of psychotic features, regardless of diagnosis, were impaired on spatial delayed response task. Conclusions:, Backward digit span performance is comparable in bipolar disorder and schizophrenia, and may be an appropriate endophenotypic marker that cuts across diagnostic categories. In contrast, spatial working memory performance clearly distinguishes non-psychotic bipolar disorder patients from patients with functional psychosis. [source]

Abnormal dose-response melatonin suppression by light in bipolar type I patients compared with healthy adult subjects

ACTA NEUROPSYCHIATRICA, Issue 5 2009
Karen T. Hallam
Objective: Among potential endophenotypes proposed for bipolar affective disorder focusing on circadian abnormalities associated with the illness has particularly high face validity. Melatonin sensitivity to light is one circadian endophenotype proposed as useful in bipolar disorder. The aim of this study was to investigate melatonin sensitivity to light over a range of light intensities in order to compare and contrast responses in bipolar I patients with those of healthy adult volunteers. Methods: The study included seven patients (4 females, 3 males) with bipolar I disorder and 34 control participants (22 females, 12 males) with no personal or family history of affective illness. Melatonin sensitivity to light was determined in all patients and participants across a range of light intensities (0, 200, 500 and 1000 lux). Results: The results indicated that patients showed melatonin super-sensitivity to light in comparison with controls, a response that was consistent across the entire light intensity range investigated. Conclusion: The study provides further evidence for a super sensitive response in bipolar I patients and suggests that its potential usefulness as an endophenotypic marker of the illness is deserving of further research. [source]

Memory functioning in familial bipolar I disorder patients and their relatives

BIPOLAR DISORDERS, Issue 2 2009
Seema Quraishi
Objective:, The aim of this study was to compare the memory function of patients with familial bipolar I disorder (BD I) who had shown psychotic features, their non-psychotic, non-bipolar first-degree relatives, and normal controls. Method:, We assessed 38 patients with a lifetime diagnosis of BD I who had experienced psychotic symptoms, 49 of their non-psychotic, non-bipolar first-degree relatives, and 44 controls. Patients and relatives were from families multiply affected with functional psychotic illness. A five-subtest short form of the Wechsler Adult Intelligence Scale,Revised and three Wechsler Memory Scale subtests were administered to all participants. Results:, BD I patients showed deficits in verbal memory and verbal learning but not in visual memory. Compared to controls, relatives showed worse verbal learning at a statistically significant or suggestive level and performed significantly worse in both immediate and delayed verbal memory. Similar to patients, there were no differences between the relatives and control group for visual memory. Conclusion:, Impaired verbal memory and learning were found in patients and their relatives. These deficits may represent candidate endophenotypic markers for bipolar disorder. [source]