Biomedical subjects
Publications and source records attributed to R M Post.
Twenty-one patients with major affective disorder were given the Halstead-Reitan Category Test and had CT brain scans performed in order to measure ventricular-brain ratio (VBR). A significant correlation between ventricular size and cognitive impairment was found. Possible pathophysiological mechanisms that might explain this relationship are discussed.
Methodologic errors have compromised previous attempts to establish the relationship between mood and menstruation in women with the premenstrual syndromes. These syndromes cannot be diagnosed by history and require confirmation with longitudinal, prospective ratings. In this paper we present the characteristic pattern of mood changes in women with and without menstrually-related mood syndrome. The theoretical and diagnostic implications of the pattern differences are discussed.
Twenty affective disorder patients (16 bipolar and 4 unipolar) and 24 normal controls received scans with positron emission tomography (PET) using [18F]2-deoxyglucose (FDG) as a tracer. Subjects received a series of brief electrical stimuli to their right arms during FDG uptake. Patients with bipolar affective illness had significantly lower frontal to occipital glucose metabolic rate ratios (relative hypofrontality) and significantly lower metabolic rates in their basal ganglia in comparison to whole slice metabolism than normal controls. Patients with unipolar illness showed significantly higher frontal to occipital ratios, and also showed relatively decreased metabolism in the basal ganglia. All results in unipolar patients should be considered exploratory due to the small number of patients. Clinical depression ratings correlated negatively with whole slice metabolic rate.
The relationship between a history of attempted suicide and prior course of illness was explored in 87 patients with major affective disorder. Fifty-eight percent of bipolar (n = 67) and 50% of unipolar (n = 20) patients had a history of a suicide attempt. Females were more likely to have made an attempt (67%) than males (42%) and were equally likely to have made a violent attempt. Course of illness and prior history of psychosis were similar in patients with and without a history of an attempt. However, in patients who made an attempt, the severity of the worst attempt was positively correlated with the duration of illness. Greater numbers of prior attempts were associated with greater lethality of the worst attempt. Suicidal ideation for the period of most severe depression in the prior 12 months did not correlate with any measure of lethality of suicide attempt. These data not only suggest the need for further studies of suicide in relationship to the longitudinal course of affective illness, but also the need for continuous reappraisal of suicidal risk in patients with recurrent affective disorders.
A single electroconvulsive shock (ECS) induced a rapid and transient expression of c-fos mRNA in mouse brain. In earclipped sham controls, low but significant expression of c-fos mRNA was also observed. These data suggest that c-fos mRNA may be transiently induced by seizure activity as well as much more subtle and qualitative different stimuli, such as the acute nociceptive stress associated with earclipping.
This article describes the use of the NIMH prospective life-charting methodology (NIMH LCM-p) in the context of a formal double-blind, clinical trial and provides preliminary evidence of its reliability and validity. Subjects included in this report were 30 outpatients with bipolar I and II disorder who completed the first 2 years of a long-term maintenance study: 1 year on carbamazepine or lithium and a crossover to the other in the second year. The LCM-p follows the same types of guidelines and principles utilized in the previously described retrospective life-chart process, allowing for continuity of illness assessment prior and subsequent to study entry. In the LCM-p, daily ratings of severity of mood symptoms based on the degree of associated functional incapacity, provide a more detailed topography of manic and depressive fluctuations. Inter-rater reliability was examined by comparing the severity of daily LCM-p ratings assigned by two raters. In order to assess the validity, we correlated the LCM-p ratings with well-standardized scales, including Hamilton and Beck Depression Ratings, Young Mania Ratings and the Global Assessment Scale (GAS). The Kappa scores for inter-rater reliability demonstrated significant and satisfactory strength of agreement with no fall off over 14 days prior to the rating interview. Strong correlations were found: (1) between the LCM-p average severity for depression rating and the mean Hamilton Depression Rating (r = 0.86, p < .001), and the Beck Depression Inventory (r = 0.73, p < .001); 2) between the LCM-p average severity for mania rating and the Young Mania Rating Scale (r = 0.61, p < .001); and (3) between the LCM-p average severity and the GAS (r = -0.81, p < .001). These preliminary data suggest the reliability and validity of the NIMH-LCM-p in assessing manic and depressive episode severity. It also provides a useful continuous daily measure of affective illness-related symptom fluctuations that allows for detailed prospective assessment of frequency and pattern of illness, treatment response, and continuity with retrospective life chart assessments.
Neural cell adhesion molecule (N-CAM) is a cell recognition molecule, four major isoforms (180, 140, 120, and 105-115 kDa) of which are present in brain. N-CAM has several roles in cellular organization and CNS development. Previously we have found an elevation in CSF N-CAM 120 kDa in the CSF of patients with schizophrenia, bipolar disorder, and depression. We now report an increase in the variable alternative spliced exon (VASE), a 10 amino acid sequence inserted into the fourth N-CAM domain, in the CSF of patients with schizophrenia, but not in bipolar disorder or depression. VASE-immunoreactive (VASE-ir) bands were measured in CSF from patients with schizophrenia (n = 14), bipolar disorder I (n = 7), bipolar disorder II (n = 9), unipolar depression (n = 17) and matched controls (n = 37) by Western immunoblotting. Three VASE-ir bands were distinguished in lumbar CSF corresponding to heavy (165 kDa), medium (155 kDa) and low (140 kDa) MW. A logarithmic transformation was applied to the VASE protein units and analyzed with a MANOVA. There was a 51% and 45% increase in VASE heavy (p = 0.0008) and medium (p = 0.04) MW protein, respectively, in patients with schizophrenia as compared with normal controls. Current neuroleptic treatment in patients with schizophrenia had no effect on CSF VASE concentrations. VASE concentration correlated significantly with behavioral ratings in patients with schizophrenia but not affective disorders. Thus, VASE immunoreactivity is increased in schizophrenia but not in affective disorders. These results provide further evidence of an abnormality of N-CAM protein in chronic schizophrenia and suggest differences between schizophrenia and affective disorders in regulation of N-CAM.
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The study purpose was to determine the extent of neuroleptic exposure in bipolar outpatients maintained on mood-stabilizing medications and any clinical correlates associated with this exposure. Data on medication and severity of illness were gathered from the records (prospective and retrospective) of 70 bipolar patients involved in outpatient research studies at the National Institute of Mental Health (NIMH). The percentage of patients requiring neuroleptic treatment, percentage of time on neuroleptics during the period of observation, total dose of neuroleptics in chlorpromazine (CPZ) equivalency, and number of neuroleptic trials were among the variables calculated. Regression analyses and analyses of variance (ANOVAs) were performed to assess the relationships between neuroleptic exposure and clinical course. Forty-five patients (64.3%) had a neuroleptic trial during the prospective study. Subjects exposed to neuroleptics spent, on average, 15.4% (median, 6.0%) of the time in study on neuroleptic treatment, and were administered, on average, a total of 11,770.5 mg (median, 1,621.9 mg) of neuroleptics (in CPZ equivalency) per year in the prospective study. As expected, bipolar I compared with bipolar II patients had significantly higher neuroleptic exposure by a number of measures. The number of hospitalizations for mania prior to study entry was associated with greater prospective neuroleptic use during the study. Despite maintenance treatment with one or more moodstabilizing agents, we found a relatively high need for adjunctive neuroleptic medication even in this sample of high-functioning bipolar outpatients. These results highlight the need for the study of alternatives, as well as more effective primary mood-stabilizing agents.
The effect of carbamazepine on adenosine receptors in vitro has been well documented, with findings from several groups showing that therapeutic doses of this drug are sufficient to inhibit binding to the major portion of adenosine receptors in brain. In this study, we describe the effects of chronic carbamazepine on central adenosine receptors from several areas of rat brain using [3H]diethylphenylxanthine [( 3H]DPX) and [3H]cyclohexyladenosine [( 3H]CHA) as ligands. Carbamazepine was administered to rats orally in the diet at doses of 2.25 g/kg of diet and 5.0 g/kg of diet for periods of 3 and 11 days, respectively. Carbamazepine-treated animals displayed higher levels of adenosine receptors in virtually all brain areas tested, most of which reached significance in the 11-day treatment group. Scatchard analysis revealed increases in the number of receptors. There was no change in peripheral and central type benzodiazepine receptors or beta-adrenergic receptors in the carbamazepine-treated animals. Therefore, carbamazepine treatment in vivo appears to upregulate adenosine receptors, suggesting that this drug may act as an adenosine antagonist.
Carbamazepine, a drug that is clinically effective in paroxysmal pain syndromes and in epilepsy, also appears to be effective in the treatment of manic-depressive illness. The mechanisms of action of carbamazepine and its endocrine effects remain unclear. Therefore, the hormone responses to sequential stimuli--namely, arginine, thyrotropin-releasing hormone (TRH), and luteinizing hormone-releasing hormone--were studied in six patients with major depressive disorder before and during treatment with carbamazepine. The drug was found to blunt the thyrotropin-stimulating hormone response to TRH and to augment the prolactin response to arginine. The advantages of the experimental design and the implications of the findings for carbamazepine's mechanism of action in affective illness are discussed.
The binding of adenosine agonists and antagonists to the adenosine receptor is differentially affected by both temperature and guanine nucleotides. Agonist binding is facilitated at higher temperatures; the reverse is true for adenosine antagonists. In the present study, we demonstrate the feasibility of utilizing the temperature dependency of agonist/antagonist binding to the adenosine receptor in binding inhibition studies. We show that the anticonvulsant drug carbamazepine (CBZ) and several of its structural analogs behave in a manner identical to that of a series of adenosine antagonists; i.e., they are more potent inhibitors of [3H]cyclohexyladenosine (CHA) binding at 8 degrees C as compared to 37 degrees C and are equipotent as inhibitors of [3H]diethylphenylxanthine (DPX) binding at 0 and 30 degrees. We also show that the potency of CBZ and derivatives as inhibitors of [3H]CHA binding is markedly increased in the presence of 10 microM GppNHp, whereas their potency as inhibitors of [3H]DPX binding is unaffected by this guanine nucleotide. These data in conjunction with past studies support the hypothesis that CBZ and its derivatives act as adenosine antagonists at the level of binding interactions at the adenosine receptor.
The effects of feeding a diet enriched in caffeine or carbamazepine (CBZ) were investigated in rats in a quantitative autoradiographic study of adenosine A1 receptors (labeled by [3H]cyclohexyladenosine, [3H]CHA) and adenylate cyclase (labeled by [3H]forskolin). Although regional distribution of [3H]CHA and [3H]forskolin binding sites differed in some areas, chronic CBZ as well as chronic caffeine upregulated both of them. The changes in receptor densities occurred in the same brain microregions, suggesting that caffeine and CBZ act as antagonists at similar subpopulations of adenosine A1 receptors and [3H]forskolin binding sites. Therefore, a selective interaction of these two drugs with distinct adenosine A1 receptors (and adenylate cyclase) probably does not explain the differential effects of caffeine and CBZ on neuronal activity.
[3H]Nimodipine and high-affinity [125I]omega-conotoxin GVIA (CgTX) binding were investigated in membranes from rat cerebral cortex, cerebellum, and hippocampus after electrically and chemically induced seizures. Animals were decapitated 30 min after a single electroconvulsive shock (ECS) or lidocaine-induced seizure and 24 h after the last of 10 once-daily ECS or six once-daily lidocaine-induced seizures. After a single ECS, [3H]nimodipine and [125I]CgTX binding sites decreased in cerebral cortex (by 10% and 17%, respectively). A downregulation of [3H]nimodipine binding sites in hippocampus occurred after single and repeated lidocaine-induced seizures (by 24% and 11%, respectively), whereas [125I]CgTX binding remained unaltered. An earlier report on changes in [3H]nitrendipine binding after chronic ECS in cortex and hippocampus was not confirmed.
The relationship of the timing of drug administration to anticonvulsant efficacy against amygdala kindled seizures was studied. During kindling development, rats received carbamazepine (CBZ, 15mg/kg) before (CBZ-before) or after each amygdala stimulation (CBZ-after). After kindling to full seizures, when all animals were given CBZ before the stimulation, only the CBZ-after group showed a good anticonvulsant response. The rats that had received CBZ before (during development of kindled seizures) remained unresponsive to CBZ treatment (contingent inefficacy). When drug-naive or CBZ-after animals repeatedly received CBZ before electrical stimulation, they developed tolerance to its anticonvulsant effects (contingent tolerance). The tolerance could be reversed by a period of treatment with CBZ-after or by kindling the animal drug-free, but not by CBZ administration alone or by time off from both drug and seizures. These findings suggest that inefficacy and tolerance to CBZ may be affected by the temporal contingencies of drug administration and that responsiveness can be reinstated by altering these contingencies.
Carbamazepine (CBZ) blocks the development of local anesthetic seizures kindled by cocaine and lidocaine. Cocaine and lidocaine release corticotropin-releasing hormone (CRH) in hypothalamic cell cultures, and this effect is also blocked by CBZ. Because CRH administered intracerebroventricularly (i.c.v.) can produce seizures, its potential role in the development of cocaine seizures and in the anticonvulsant effects of CBZ was studied. CRH (at doses of 5, 10, and 100 micrograms) potentiated cocaine-kindled seizure development and lethality in a dose-related fashion. CRH also reversed the effects of CBZ on cocaine kindling and lethality, but only at the highest doses, which also affected cocaine kindling. Thus, a selective role for CRH in the anticonvulsant effects of CBZ was not demonstrated. The findings suggest a potentially important role for CRH in exacerbating cocaine-seizure evolution and its associated lethality and confirm the inhibition of cocaine kindling and lethality by CBZ.
OBJECTIVE: In this preliminary study, we examined the relationships between prior course and severity of illness and size of the hippocampus, temporal lobes, and third and lateral ventricles in patients with bipolar disorder. BACKGROUND: The few studies that have investigated relationships between course of illness measures and neuroanatomic structures in patients with bipolar disorder found divergent results. METHOD: Twenty-six outpatients, who met Diagnostic and Statistical Manual, Third Edition - Revised (DSM-III-R) criteria for bipolar disorder, received a magnetic resonance imaging (MRI) scan, from which volumes of the temporal lobes, hippocampi, third ventricle, and areas of the lateral ventricles were calculated. Prior course of illness variables were determined using the NIMH Life-Chart Method and were correlated to the volumetric measures of neuroanatomic structures using multiple regression analyses. RESULTS: A longer duration of illness was paradoxically associated with a larger left temporal lobe volume whether patients with a history of substance abuse were removed from the analyses. CONCLUSIONS: Additional studies are needed to both replicate and further examine the association of prior course of illness and larger hippocampal and ventricular volumes in bipolar disorder.
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