Andrew L. Stoll

Frontal lobe gray matter density decreases in bipolar I disorder.

BACKGROUND This study was conducted to explore differences in gray and white matter density between bipolar and healthy comparison groups using voxel-based morphometry (VBM). METHODS Brain magnetic resonance imaging was performed for 39 subjects with bipolar I disorder and 43 comparison subjects. Images were registered into a proportional stereotaxic space and segmented into gray matter, white mater, and cerebrospinal fluid. Statistical parametric mapping was used to calculate differences in gray and white matter density between groups. RESULTS Bipolar subjects had decreased gray matter density in left anterior cingulate gyrus (Brodmanns area [BA] 32, 7.3% decrease), an adjacent left medial frontal gyrus (BA 10, 6.9% decrease), right inferior frontal gyrus (BA 47, 9.2% decrease), and right precentral gyrus (BA 44, 6.2% decrease), relative to comparison subjects. CONCLUSIONS The observation of a gray matter density decrease in the left anterior cingulate, which processes emotions, in bipolar subjects is consistent with prior reports that used region-of-interest analytic methods. Decreased gray matter density in the right inferior frontal gyrus, which processes nonverbal and intrinsic functions, supports nondominant hemisphere dysfunction as a component of bipolar disorder.

Structural brain abnormalities in first-episode mania.

Using magnetic resonance imaging (MRI), we studied brain morphometric differences between patients with first-episode mania (n = 17) and normal control subjects (n = 16). Patients were admitted for their first psychiatric hospitalization and met DSM-III-R criteria for bipolar disorder, manic or mixed. Diagnoses were made using the Structured Clinical Interview for DSM-III-R. Patients and control subjects were matched for age, gender, height, past history of substance abuse, and handedness, although control subjects had attained higher levels of education. MRI inversion recovery coronal scans were used for measurements. Volumetric measurements were obtained for cerebral hemispheres, lateral and third ventricles, caudate, thalamus, and cingulate gyrus. Patients with first-episode mania demonstrated significantly larger third-ventricular volumes, possibly increased lateral ventricular volumes, and differences in gray/white matter distribution compared with normal control subjects. The possible pathophysiological meaning of these findings is discussed.

Neuroimaging in bipolar disorder: what have we learned?

New technologies are offering increasingly powerful means to obtain structural, chemical, and functional images of the brain during life, often without the use of ionizing radiation. Bipolar disorder, with its clear physiologic features, would appear to be a prime candidate for the application of current brain imaging; however, only a modest number of studies have been reported to date, and most studies have small sample sizes and heterogeneous subject groups. Nonetheless, there are a few consistent findings among these studies, including the following: 1) Structural imaging studies suggest an increased number of white matter hyperintensities in patients with bipolar disorder. These may be lesions unique to bipolar disorder and its treatment, or related to cardiovascular risk factors, which are more common in bipolar patients. Decreased cerebellar size and anomalies of cerebellar blood volume have also been reported. Increased sulcal prominence and enlargement of the lateral and third ventricles are less consistently observed findings. 2) Spectroscopic imaging suggests abnormalities of metabolism of choline-containing compounds in symptomatically ill bipolar patients and, possibly, treatment-induced changes in choline- and myoinositol-containing compounds. Each of these groups of metabolites serves as a component of membrane phospholipids and cellular second-messenger cycles. 3) Metabolic and blood flow studies provide evidence for decreased activity of the prefrontal cortex (PFC) in bipolar patients during depression. It is not clear if these changes are restricted to particular subregions of the PFC, nor if they are reversed with mania. No single pathophysiologic mechanism yet explains these findings, although all might be due to regional alterations in cellular activity and metabolism or changes in cell membrane composition and turnover. The development of imaging technologies has far outpaced their use in bipolar disorder. The promise of future studies is great, with more powerful magnetic resonance scanners, additional ligands for positron emission tomography and single photon emission computed tomography imaging, and improved image generation and processing already available.

The McLean-Harvard first-episode project: 6-month symptomatic and functional outcome in affective and nonaffective psychosis.

BACKGROUND The McLean-Harvard First-Episode Project recruited affective and nonaffective patients at their first lifetime psychiatric hospitalization. METHODS Baseline evaluation and 6-month follow-up in 257 cases yielded recovery outcomes defined by syndromal (absence of DSM-IV criteria for a current episode) and functional (vocational and residential status at least at baseline levels) status. Time to recovery was assessed by survival analysis, and risk factors by multivariate logistic regression. RESULTS Syndromal recovery was attained by 77% of cases over an average of 84 days. By diagnostic group, syndromal recovery rates ranked (p = .001) major affective disorders (81%) > nonaffective acute psychoses (74%) > schizoaffective disorders (70%) > schizophrenia (36%). Functional recovery was significantly associated to syndromal recovery, diagnosis, shorter hospitalization normalized to year, and older age at onset. Average hospital stay declined across the study period, but recovery did not vary with year of entry. CONCLUSIONS Syndromal recovery was achieved by nearly one half of patients within 3 months of a first lifetime hospitalization for a psychotic illness, but functional recovery was not achieved by 6 months in nearly two thirds of patients who had attained syndromal recovery.

Lithium and valproic acid treatment effects on brain chemistry in bipolar disorder

BACKGROUND Prior work reported elevated gray matter (GM) lactate and Glx (glutamate + glutamine + GABA) concentrations in unmedicated patients with bipolar disorder (BP) compared with healthy controls (HC). This study examined whether lithium (Li) and valproic acid (VPA) treatment modulated these chemicals. METHODS A subset of previously reported BP patients were treated with Li (n = 12, 3.6 +/- 1.9 months) or VPA (n = 9, 1.4 +/- 1.7 months) and compared untreated HC subjects (n = 12, 2.9 +/- 2.4 months) using proton echo-planar spectroscopic imaging. Regression analyses (voxel gray/white composition by chemistry) were performed at each time point, and change scores computed. Metabolite relaxation and regions of interest (ROI) were also examined. RESULTS Across treatment, Li-treated BP subjects demonstrated GM Glx decreases (Li-HC, p =.08; Li-VPA p =.04) and GM myo-inositol increases (Li-HC p =.07; Li-VPA p =.12). Other measures were not significant. Serum Li levels were positively correlated with Glx decreases at the trend level. CONCLUSIONS Li treatment of BP was associated with specific GM Glx decreases and myo-inositol increases. Findings are discussed in the context of cellular mechanisms postulated to underlie Li and VPA therapeutic efficacy.

Basal ganglia choline levels in depression and response to fluoxetine treatment: an in vivo proton magnetic resonance spectroscopy study

We have investigated proton magnetic resonance spectra of the basal ganglia in 41 medication-free outpatients with major depression, prior to starting an 8-week standardized trial of open-label fluoxetine, and 22 matched comparison subjects. Upon completing the trial, depressed subjects were classified as treatment responders (n = 18) or nonresponders (n = 23), based on changes in the Hamilton Depression Rating Scale. Depressed subjects had a lower area ratio of the choline resonance to the creatine resonance (Cho/Cr) than comparison subjects. This statistically significant difference between the depressed subjects and comparison subjects was more pronounced in the treatment responders than in the nonresponders. There were no differences in the relative volumes of gray matter or white matter in the voxel used for proton spectroscopy in depressed subjects relative to comparison subjects. These results are consistent with an alteration in the metabolism of cytosolic choline compounds in the basal ganglia of depressed subjects and, in particular, those who are responsive to fluoxetine.

Omega-3 Fatty Acids, Homocysteine, and the Increased Risk of Cardiovascular Mortality in Major Depressive Disorder

Depression is associated with elevated rates of cardiovascular morbidity and mortality. This elevation seems to be due to a significantly increased risk of coronary artery disease and myocardial infarction and, once the ischemic heart disease is established, sudden cardiac death. Recent data suggest that the increased rates of cardiovascular disease in patients with depression may be the result of one or more still-unrecognized underlying physiological factors that predispose a patient to both depression and cardiovascular disease. Two possibly related factors that may have a causal relation with both depressive disorders and cardiovascular disease are an omega-3 fatty acid deficiency and elevated homocysteine levels. We present the available data connecting cardiovascular disease, depression, omega-3 fatty acids, and homocysteine. In addition, we suggest research strategies and some preliminary treatment recommendations that may reduce the increased risk of cardiovascular mortality in patients with major depressive disorder.

Lack of insight in bipolar disorder : the acute manic episode

This study examined the clinical correlates of lack of insight in bipolar disorder. In 28 acutely manic patients interviewed upon hospitalization and/or discharge, mean scores on the Insight and Treatment Attitudes Questionnaire (ITAQ) improved only slightly, from 12.0 on admission to 15.5 on discharge (p = .08), despite marked improvement in other psychiatric symptoms. A reciprocal relationship was found between higher ITAQ scores and involuntary hospitalization (r = -.38). Like schizophrenia, bipolar disorder appears to be a condition in which poor insight is a prominent characteristic.

Neurochemical asymmetries in the albino rat's cortex, striatum, and nucleus accumbens.

The concentrations of dopamine (DA), norepinephrine (NE), serotonin (5-HT), dihydroxyphenylacetic acid (DOPAC), and 5-hydroxyindoleacetic acid (5-HIAA) were measured in the right and left cortex, striatum, and nucleus accumbens of adult Purdue-Wistar rats. There was more DA in the right cortex and accumbens and a greater concentration of NE in the left striatum. There is more 5-HT in the left striatum and right accumbens, more 5-HIAA in the left cortex, as well as a greater 5-HT turnover in the left accumbens. These results are considered in the light of previous findings concerning the relationship of neurochemical asymmetries and behavioral lateralization.

MRI subcortical signal hyperintensities in Mania at first hospitalization

Recently, several investigators have reported an increased frequency of subcortical signal hyperintensities detected with magnetic resonance imaging (MRI) in patients with bipolar disorder as compared to normal controls (Swayze et al 1990; Dupont et al 1987, 1990; Figiel et al 1991). The pathophysiologic significance of these neuroanatomic abnormalities has remained obscure, although it has been suggested that these lesions may be associated with the underlying pathogenetic process (Dupont et al 1987; Figiel et al 1991). However, the effects of illness chronicity (multiple episodes) and treatment on these findings is uncertain and may confound the analysis of these observations. Indeed, Dupont et al (1990) noted that those patients with signal hyperintensities on MRI had significantly more previous hospitalizations, although whether there is a relationship between treatment and subcortical signal hyperintensities is undetermined. Studying patients with bipolar disorder at the onset of the illness (prior to or very early in treatment) could control for these confounding variables and may lead to improved understanding of the pathogenesis of the disorder. If subcortical signal hyperintensities were present at the onset of the illness, then these abnormalities might have etiologic significance. With these considerations in mind, we have examined MRI scans for subcortical hypcfintcnsities from a sample of patients with first-episode mania compared to normal control subjects.