Cognitive function in euthymic bipolar I disorder.

Recent reports have suggested the presence of persistent cognitive impairments in patients diagnosed with Bipolar Disorder even after prolonged euthymic phases. In this work, various domains of cognitive function were examined in asymptomatic patients diagnosed with Bipolar I Disorder (BDI) in comparison with healthy subjects. Fifteen otherwise healthy BDI patients with a prior history of psychosis during mania completed a neuropsychological testing battery after a prolonged asymptomatic remission. Their scores were compared to those of individually matched healthy subjects with unpaired two-tailed t-tests at P<0.01. Relationships between cognitive performance measures and clinical variables related to illness severity were also examined with Pearson correlations, P<0.05. We detected poorer performance on measures of verbal learning, executive functioning and motor coordination in BDI patients compared to control volunteers. Scores on tests of executive functioning were negatively correlated with the number of episodes of mania and depression. Social and occupational scores were also associated with a poorer performance on measures of verbal learning and executive function. Euthymic BDI patients, therefore, demonstrate reductions in specific cognitive domains even after prolonged asymptomatic phases. Some of these deficits appear to be associated with a more severe course of illness and poorer social and occupational functioning.

High vesicular monoamine transporter binding in asymptomatic bipolar I disorder: sex differences and cognitive correlates.

OBJECTIVE: It has been hypothesized that anomalies in monoaminergic function underlie some of the manifestations of bipolar disorder. In this study the authors examined the possibility that trait-related abnormalities in the concentration of monoaminergic synaptic terminals may be present in patients with asymptomatic bipolar disorder type I. METHOD: The concentration of a stable presynaptic marker, the vesicular monoamine transporter protein (VMAT2), was quantified with (+)[(11)C]dihydrotetrabenazine (DTBZ) and positron emission tomography. Sixteen asymptomatic patients with bipolar I disorder who had a prior history of mania with psychosis (nine men and seven women) and individually matched healthy subjects were studied. Correlational analyses were conducted to examine the relationship between regional VMAT2 binding, cognitive function, and clinical variables. RESULTS: VMAT2 binding in the thalamus and ventral brainstem of the bipolar patients was higher than that in the comparison subjects. VMAT2 concentrations in these regions correlated with performance on measures of frontal, executive function. In addition, sex differences in VMAT2 binding were detected in the thalamus of the bipolar patients; the male patients had higher binding than the women. No sex differences in binding were observed in the healthy comparison group. CONCLUSIONS: These initial results suggest that higher than normal VMAT2 expression and, by extension, concentration of monoaminergic synaptic terminals, may represent a trait-related abnormality in patients with bipolar I disorder and that male and female patients show different patterns. Also, VMAT2 concentrations may be associated with some of the cognitive deficits encountered in euthymic bipolar disorder.

Modality specificity of memory span tasks among Zaïrian children: A developmental perspective.

Digit span (DS) and visual memory span (VMS) tasks have been shown to be distinct in young children but fail to show modality specificity in older American children and adults (Fastenau, Conant, & Lauer, 1997, 1998). The present study examines the possibility that processing of VMS becomes automatized with written language training. In a sample of 139 Zaïrian children, separate factor analyses on K-ABC data for younger children (6.1-8.5 years) and older children (8.6-12.8 years) yielded two-factor solutions in both cases, which appear to represent verbal and visual-spatial abilities. Modality specificity of the visual span task is supported in both age groups. Findings of modality specificity in both Zaïrian age groups provides support for the theoretical distinction between verbal and visual memory span. Continued modality specificity of visual memory span tasks in older Zaïrian children suggests that the increased verbal loadings of these tasks seen for older American children may reflect differences in written language development.

Longitudinal sensitivity of the Fuld cholinergic profile to Alzheimer's disease.

The diagnostic sensitivity of a profile (Fuld, 1984) thought to mark cholinergic changes in Alzheimer's Disease (AD) was examined in a sample of 53 patients meeting criteria for AD on two occasions and in 19 patients for three occasions. The low obtained sensitivities of the Fuld profile (17%-26%) across testings is consistent with previous studies that used a single time point. The findings also revealed unstable positive and negative profiles over time. There were no performance differences on intellectual or memory measures when comparing subjects identified as positive or negative by the Fuld index. The results demonstrate that the index is insensitive to the dementing process and is a poor diagnostic marker for AD.