First report of manic-like symptoms in a COVID-19 patient with no previous history of a psychiatric disorder

BACKGROUND

In December 2019, the novel coronavirus (SARS-CoV-2) infection was first reported in Wuhan city, central China, which has spread rapidly. The common clinical features of patients with SARS-CoV-2 infection included fever, fatigue, and damage to the respiratory or digestive system. However, it is still unclear whether SARS-CoV-2 infection could cause damage to the central nervous system (CNS) inducing psychiatric symptoms.

CASE REPORT

Herein, we present the first case of SARS-CoV-2 infection with manic-like symptoms and describe the diagnosis, clinical course, and treatment of the case, focusing on the identifications of SARS-CoV-2 in the specimen of cerebrospinal fluid (CSF). The patient developed manic-like symptoms when his vital signs recovered on illness day 17. After manic-like attack, the detection of SARS-CoV-2 specific IgG antibody in CSF was positive, while the reverse transcriptase-polymerase chain reaction (RT-PCR) on CSF for the SARS-CoV-2 was negative. The patient received Olanzapine for treatment and his mood problems concurrently improved as indicated by scores of Young Manic Rating Scale (YMRS).

LIMITATION

This is a single case report only, and the RT-PCR test for SARS-CoV-2 in CSF was not performed simultaneously when SARS-CoV-2 was positive in samples of sputum and stool.

CONCLUSION

This first case of COVID-19 patient with manic-like symptoms highlights the importance of evaluation of mental health status and may contribute to our understanding of potential risk of CNS impairments by SARS-CoV-2 infection.

Sex difference in cerebrospinal fluid/blood albumin quotients in patients with schizophreniform and affective psychosis

BACKGROUND

The importance of cerebrospinal fluid (CSF) diagnostics for psychiatry is growing. The CSF/blood albumin quotient (QAlb) is considered to be a measure of the blood-CSF barrier function. Recently, systematically higher QAlb in males than in females was described in neurological patients. The aim of this study was to investigate whether a sex difference could also be detected in a well-characterized psychiatric cohort.

METHODS

The patient cohort comprised 989 patients, including 545 females and 444 males with schizophreniform and affective syndromes who underwent CSF diagnostics, including QAlb measurement. The basic CSF findings and antineuronal autoantibody data of this cohort have already been published. This re-analysis employed analysis of covariance with age correction for QAlb mean values and chi2-testing for the number of increased age-corrected QAlb levels to investigate sex differences in QAlb.

RESULTS

The QAlb levels were elevated above reference levels by 18% across all patients, and a comparison between male and female patients revealed a statistically significant sex difference, with increased values in 26% of male patients and a corresponding rate of only 10% in female patients (chi2 = 42.625, p < 0.001). The mean QAlb values were also significantly higher in males (6.52 ± 3.69 × 10-3) than in females (5.23 ± 2.56 × 10-3; F = 52.837, p < 0.001).

DISCUSSION

The main finding of this study was a significantly higher QAlb level in male compared to female patients with psychiatric disorders, complementing previously described sex differences in neurological patient cohorts. This result indicates bias from some general factors associated with sex and could be partly explained by sex differences in body height, which is associated with spine length and thus a longer distance for CSF flow within the subarachnoid space down the spine from the occipital area to the lumbar puncture site in males compared to females. Hormonal influences caused by different estrogen levels and other sex-specific factors could also play a relevant role. The significance of the study is limited by its retrospective design, absence of a healthy control group, and unavailability of exact measures of spine length.

Elevated levels of 8-oxoGuo and 8-oxodG in individuals with severe mental illness - An autopsy-based study

Elevated systemic oxidative stress levels of 8-oxoGuo and 8-oxodG have been reported in individuals with severe mental illness (SMI). As no previous studies have addressed the link between local levels of 8-oxoGuo and 8-oxodG in the central nervous system (CNS), measured in cerebrospinal fluid (CSF), and urinary systemic levels, we employed autopsy-based material to elucidate this aspect. Additionally, we investigated the impact of 8-oxoGuo and 8-oxodG levels on the prevalence of somatic co-morbidities. Based on post mortem samples from deceased individuals with SMI (N = 107), we found significantly elevated urinary levels of both 8-oxoGuo and 8-oxodG compared to mentally healthy living controls. While we found an association between urinary and CSF 8-oxodG levels (r = 0.50, P < 0.001), a similar correlation was not evident for 8-oxoGuo (r = 0.15, P = 0.16). Additionally, the two r-values were significantly different (P < 0.001). Neither marker in urine or CSF was associated with obesity-related variables, metabolic syndrome or type 2 diabetes. The post mortem interval did not affect the results, but the agonal phase seemingly introduced bias. This study provided novel insights into the cellular oxidative stress levels in individuals with SMI. We demonstrated that increased oxidative stress locally and systemically is correlated and is a clear phenomenon in SMI. Although post mortem measurements contain some weaknesses, our study indicates DNA as the main site of oxidative stress modifications in the CNS in SMI. This may provide novel opportunities for treatment modalities. Additionally, our study demonstrated the applicability of post mortem material investigating systemic and local 8-oxoGuo and 8-oxodG levels.

Biomarkers in cerebrospinal fluid of patients with bipolar disorder versus healthy individuals: A systematic review

BACKGROUND

The pathophysiological processes of bipolar disorder (BD) may be detectable by the use of cerebrospinal fluid (CSF) biomarkers.

AIM

We aimed for the first time to review studies of CSF biomarkers in patients with BD compared to healthy control individuals (HC). We investigated the effect of diagnosis, age, gender, clinical state, medication, technical characteristics of tests, fasting state and, cognitive function if applicable.

METHOD

We did a systematic review according to the PRISMA Statement based on comprehensive database searches for studies on cerebrospinal biomarkers in patients with bipolar disorder versus HC. Risk of bias was systematically assessed.

RESULTS

The search strategy identified 410 studies of which thirty-four fulfilled the inclusion criteria. A total of 117 unique biomarkers were investigated, out of which 11 were evaluated in more than one study. Forty biomarkers showed statistically significant differences between BD and HC in single studies. Only the findings of elevated homovanillic acid and 5-hydroxy-indoleacetic acid were replicated across studies. Most studies had a cross sectional design and were influenced by risk of bias mainly due to small sample size, lack of data on mood state at the time of the CSF puncture and not considering potential confounders including age, gender, diagnoses, BMI, life style factors such as smoking, and psychotropic medication.

CONCLUSION

Specific monoamine CSF biomarkers may be related to the pathophysiology of BD. Future studies must aim at increasing the level of evidence by validating the positive findings in prospective studies with stringent methodology.

Zika Virus-Associated Cognitive Impairment in Adolescent, 2016

Incidence of neurologic manifestations associated with Zika virus infection has been increasing. In 2016, neuropsychological and cognitive changes developed in an adolescent after travel to a Zika virus–endemic area. Single-photon emission computed tomography and neuropsychological testing raised the possibility that Zika virus infection may lead to neuropsychiatric and cognitive symptoms.

Increased cerebrospinal fluid complement C5 levels in major depressive disorder and schizophrenia

Inflammation has been implicated in a variety of psychiatric disorders. We aimed to determine whether levels of complement C5 protein in the cerebrospinal fluid (CSF), which may reflect activation of the complement system in the brain, are altered in patients with major psychiatric disorders. Additionally, we examined possible associations of CSF C5 levels with clinical variables. Subjects comprised 89 patients with major depressive disorder (MDD), 66 patients with bipolar disorder (BPD), 96 patients with schizophrenia, and 117 healthy controls, matched for age, sex, and ethnicity (Japanese). Diagnosis was made according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria. CSF C5 levels were measured by enzyme-linked immunosorbent assay. CSF C5 levels were significantly increased in the patients with MDD (p < 0.001) and in the patients with schizophrenia (p = 0.001), compared with the healthy controls. The rate of individuals with an "abnormally high C5 level" (i.e., above the 95th percentile value of the control subjects) was significantly increased in all psychiatric groups, relative to the control group (all p < 0.01). Older age, male sex, and greater body mass index tended to associate with higher C5 levels. There was a significantly positive correlation between C5 levels and chlorpromazine-equivalent dose in the patients with schizophrenia. Thus, we found, for the first time, elevated C5 levels in the CSF of patients with major psychiatric disorders. Our results suggest that the activated complement system may contribute to neurological pathogenesis in a portion of patients with major psychiatric disorders.

Gender effects on brain changes in early-onset psychosis

Progressive loss of cortical gray matter (GM) and increase of cerebrospinal fluid (CSF) have been reported in early-onset psychosis (EOP). EOP typically begins during adolescence, a time when developmental brain trajectories differ by gender. This study aimed to determine gender differences in progression of brain changes in this population. A sample of 61 (21 females) adolescents with a first psychotic episode and a matched sample of 70 (23 females) controls underwent both baseline and 2-year follow-up anatomical brain imaging assessments. Regional GM and CSF volumes were obtained using automated methods based on the Talairach's proportional grid system. At baseline, only male patients showed a clear pattern of alterations in the frontal lobe relative to controls (smaller GM and larger CSF volumes). However, parallel longitudinal changes for male and female patients relative to controls were observed, resulting in a common pattern of brain changes across both genders: rate of left frontal lobe GM volume loss was larger in male (-3.8%) and female patients (-4.2%) than in controls (-0.7% males; -0.4% females). The reverse was found for the CSF volume in the left frontal lobe. While the GM and CSF volumes of females with EOP appear to be within the normal range at initial illness onset, our results point to a similar trajectory of increased/accelerated brain changes in both male and female patients with EOP. The pattern of progression of brain changes in psychosis appears to be independent of gender or structural alterations on appearance of psychotic symptoms.

Microscopic particles in two fractions of fresh cerebrospinal fluid in twins with schizophrenia or bipolar disorder and in healthy controls

Background

Using scanning electron microscopy, microscopic structures have been identified in fresh cerebrospinal fluid (CSF) in patients with schizophrenia and bipolar disorder, but only rarely in control subjects. However, it has not been determined whether these microscopic particles represent state or trait markers, i.e. if their presence is related to clinical manifestations of the disease or if they also can be found in as yet asymptomatic individuals with a genetic liability. This question can be addressed by studying twins discordant or concordant for schizophrenia or bipolar disorder.

Methodology/Principal Findings

We investigated microscopic structures in CSF in 102 individuals: 21 monozygotic and 16 dizygotic twins affected or not affected with schizophrenia, schizoaffective disorder or bipolar disorder and in 65 healthy singleton controls. A first and a second fraction of CSF was freshly applied on filters and examined by scanning electron microscopy technique. Spherical particles with lipid appearance averaging between 0.1 to 8.0 µm in diameter were detected in the center of the filter as well as located in the margins of larger aggregates binding in a viscous state. Structures were found in 12 of 17 probands, 5 of 12 healthy co-twins and 3 of 73 healthy controls. Thus, a positive microscopic finding significantly increased the likelihood of belonging to the proband group (OR = 48, 95% CL: 8.2–550, p<0.0001) and the co-twin-group (OR = 16, 95% CL: 2.0–218, p = 0.006). Age, sex, history of alcohol abuse or anxiety syndrome, somatic disorder and markers of acute inflammatory activity did not account for group differences; nor did exposure to psychotropic medication.

Conclusion

Presence of microscopic particles in CSF may possibly reflect trait dependent genetic or environmental vulnerability in patients with schizophrenia, schizoaffective disorder or bipolar disorder.

No association between a TPH2 promoter polymorphism and mood disorders or monoamine turnover

BACKGROUND

Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in serotonin synthesis. TPH2 is a recently discovered isoform that is expressed predominantly in serotonin neurons. Associations are reported of TPH2 polymorphisms with MDD, bipolar disorder and suicidal behavior. This study examines a single nucleotide polymorphism in the putative promoter region of the TPH2 gene.

METHODS

One hundred nine bipolar, 324 major depressive disorder, and 130 healthy volunteers were genotyped for the rs4131347 (-C8347G) promoter SNP. Association was assessed with diagnosis, suicide attempt status, severity of psychopathology and cerebrospinal fluid monoamine metabolite levels of 5-HIAA, HVA, and MHPG. General linear models and logistic regression tested the effect of genotype*childhood abuse interactions on psychopathology severity and suicide attempt.

RESULTS

There was no association between genotype and either mood disorder, suicide attempt status, psychopathology severity or CSF monoamine metabolite levels.

CONCLUSIONS

No association was detected between the rs4131347 (-C8347G) SNP in the promoter region of the TPH2 gene and mood disorders, suicidal behavior or monoamine function.

Increased anterior cingulate/medial prefrontal cortical glutamate and creatine in bipolar depression

Proton magnetic resonance spectroscopy ((1)HMRS) is an in vivo brain imaging method that can be used to investigate psychotropic drug mechanism of action. This study evaluated baseline (1)HMRS spectra of bipolar depressed patients and whether the level of cerebral metabolites changed after an open trial of lamotrigine, an anti-glutamatergic mood stabilizer. Twenty-three bipolar depressed and 12 control subjects underwent a MRS scan of the anterior cingulate/medial prefrontal cortex. The scan was performed on a GE whole-body 1.5 T MRI scanner using single-voxel PRESS (TE/TR=30/3000 ms, 3 x 3 x 3 cm(3) and post-processed offline with LCModel. Baseline CSF-corrected absolute concentrations of glutamate+glutamine ([Glx]), glutamate ([Glu]), and creatine+phosphocreatine ([Cr]) were significantly higher in bipolar depressed subjects vs healthy controls. The non-melancholic subtype had significantly higher baseline [Glx] and [Glu] levels than the melancholic subtype. Remission with lamotrigine was associated with significantly lower post-treatment glutamine ([Gln]) in comparison to non-remission. These data suggest that non-melancholic bipolar depression is characterized by increased glutamate coupled with increased energy expenditure. Lamotrigine appears to reduce glutamine levels associated with treatment remission. Further study is encouraged to determine if these MR spectroscopic markers can delineate drug mechanism of action and subsequent treatment response.

Antiphospholipid antibodies in blood and cerebrospinal fluids of patients with psychosis

Antiphospholipid antibodies (aPL) have been reported in the cerebrospinal fluids (CSF) of neurology patients but no CSF studies with psychiatric patients exist. We tested serum from 100 hospitalized psychotic patients having hallucinations and/or delusions for aPL. Patients with positive serum aPL findings were asked to submit CSF for aPL testing. Five CSF samples had aPL specificities not found in the patient's serum suggesting the possibility of intrathecal synthesis. Specificity and isotype discordance between CSF and blood aPL in these psychiatric patients implicates a central nervous system independent autoimmune process that may have an underlying association with the pathophysiology of their diseases.

Low cerebrospinal fluid glutamate and glycine in refractory affective disorder

BACKGROUND

Glutamatergic dysregulation has been documented in schizophrenia but has received less systematic study in affective illness.

METHODS

Cerebrospinal fluid (CSF) levels of the excitatory amino acids glutamate (Glu) and aspartate (Asp) and the N-methyl-D-aspartate (NMDA) receptor modulator, glycine (GLY) were measured by high performance liquid chromatography in 32 patients with refractory affective disorder (16 female/16 male, 12 bipolar I, 12 bipolar II, and 8 unipolar) and in 14 age-matched controls.

RESULTS

There was a significant reduction in CSF glutamate and glycine in patients versus controls. A diagnosis by sex interaction was present for CSF glycine with lower levels in female patients compared to female controls. Levels of the excitatory amino acids were highly inter-correlated in patients, but not in controls. In patients studied after 6 weeks of lamotrigine, there was a trend for CSF glutamate levels to increase.

CONCLUSIONS

These data suggest that in patients with refractory affective disorder, excitatory amino acids are dysregulated, as exemplified both by the decreased CSF glutamate and glycine and their high intercorrelation compared to controls. Further controlled study of glutamatergic dysregulation and its relationship to the pathophysiology of affective disorders and potential mechanism of action of mood stabilizers appears indicated.

A prospective study of the association of cerebrospinal fluid monoamine metabolite levels with lethality of suicide attempts in patients with bipolar disorder

OBJECTIVES

Bipolar disorder is a severe illness that is associated with suicidal behavior. A biological predictor of highly lethal suicide attempts in patients with bipolar disorder would be valuable. We hypothesized that cerebrospinal fluid (CSF) monoamine metabolite levels are related to lethality of suicide attempts in bipolar patients and examined the relation between CSF 5-hydroxyindolacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) levels and maximum lethality of suicide attempts at baseline and during a 2-year follow up.

METHODS

Twenty-seven bipolar depressed patients participated in the study. Demographic and clinical parameters were examined and recorded. Lumbar punctures were performed and CSF 5-HIAA, HVA, and MHPG were assayed by high-performance liquid chromatography with electrochemical detection. Following discharge, patients were evaluated after 3 months, 1 year, and 2 years. Each follow-up interview included an in-depth assessment of suicidal behavior during the intervening time period.

RESULTS

Six subjects made suicide attempts during the 2-year follow-up. Bipolar patients who attempted suicide during the follow-up period had higher aggression and hostility scale scores compared to bipolar subjects who did not make a suicide attempt during the follow-up period. CSF 5-HIAA, HVA, and MHPG levels were negatively correlated with the maximum lethality of suicide attempts during the 2-year follow-up period.

CONCLUSIONS

Our finding is the first observation that CSF monoamine metabolite levels may be predictors of lethality of suicide attempts in patients with bipolar disorder. Further studies are necessary to answer the question whether CSF monoamine metabolite levels are clinically useful biochemical predictors of highly lethal suicide attempts or completed suicides.

Relationship of white matter hyperintensities to cerebrospinal fluid glucose polyol pathway metabolites-a pilot study in treatment-resistant affective disorder patients

BACKGROUND

Magnetic resonance imaging (MRI) white matter hyperintensities (WMHs) are found at higher rates in patients with affective disorders, particularly late-life or treatment-resistant disorders. Studies support a vascular pathogenesis for WMHs in late-life onset disorders; however, pathogenesis in typical early-life onset disorders is less clear. Based on associations between diabetes mellitus and both WMHs and affective disorders, this study investigated the relationship between WMHs and brain glucose metabolism by the polyol pathway-a pathway linked to nervous tissue disease in diabetes.

METHODS

Burdens of fluid-attenuated inversion recovery (FLAIR) WMHs were quantified and correlated with cerebrospinal fluid (CSF) concentrations of glucose metabolites in 10 nondiabetic inpatients with treatment-resistant bipolar, unipolar, and schizoaffective disorders and 10 nondiabetic control patients who had been investigated clinically for transient neurological symptoms.

RESULTS

Deep but not periventricular WMH burden correlated positively and significantly with elevated CSF concentrations of sorbitol, the specific polyol pathway metabolite of glucose (rho=0.86, p=0.002), in the affective disorders but not the control group.

LIMITATIONS

This was a pilot study with a relatively small number of subjects; therefore, conclusions are tentative. Controls were not healthy subjects; they were patients with transient neurological symptoms.

CONCLUSIONS

This is the first reported evidence of a relationship between WMHs and increased brain glucose metabolism by the polyol pathway in patients with affective disorders. More extensive studies are necessary to determine whether this preliminary finding represents a pathogenetic relationship.

GABAergic dysfunction in schizophrenia and mood disorders as reflected by decreased levels of glutamic acid decarboxylase 65 and 67 kDa and Reelin proteins in cerebellum

BACKGROUND

Glutamic acid decarboxylase (GAD) is the rate limiting enzyme responsible for conversion of glutamate to gamma-aminobutyric acid (GABA) regulating levels of glutamate and GABA in the mammalian brain. Reelin is an extracellular matrix protein that helps in normal lamination of the embryonic brain and subserves synaptic plasticity in adult brain. Both GAD and Reelin are colocalized to the same GABAergic interneurons in several brain sites. We hypothesized that levels of GAD and Reelin would be altered in cerebellum of subjects with schizophrenia and mood disorders differentially vs. controls.

METHODS

We employed SDS-PAGE and Western blotting to measure levels of GAD isomers 65 and 67 kDa and Reelin isoforms 410-, 330- and 180-kDa proteins as well as beta-actin in cerebellum of subjects with schizophrenia, bipolar disorder and major depression vs. controls (N = 15 per group).

RESULTS

GAD 65- and 67-kDa levels were decreased significantly in bipolar, depressed and schizophrenic subjects (p < 0.05) vs. controls. Reelin 410- and 180-kDa proteins decreased significantly (p < 0.05) in bipolar subjects vs. controls. Reelin 180 kDa was decreased significantly (p < 0.05) in schizophrenics vs. controls. beta-Actin levels did not vary significantly between groups. There were no significant effects of confounding variables on levels of various proteins.

CONCLUSION

This study demonstrates for the first time significant deficits in GABAergic markers Reelin and GAD 65 and 67 proteins in bipolar subjects and global deficits in the latter proteins in schizophrenia and mood disorders, accounting for the reported alterations in CSF/plasma levels of glutamate and GABA in these disorders.

Increased cerebrospinal fluid levels of S100B protein in rat model of mania induced by ouabain

Bipolar disorder is a chronic and severe mental disorder. Recently, new animal models have emerged to further investigate underlying mechanisms of bipolar disorder such as ouabain-induced hyperactivity in rats. In this study, we investigated the cerebrospinal fluid levels of S100B protein as a putative marker of astrocytic activity in bipolar mania induced by intracerebroventricular administration of ouabain in rats. Ouabain induced a two-fold increase in crossing responses in the open field test and increased 30% the cerebrospinal fluid concentration of S100B, as compared to vehicle group. Our findings reinforce the role of astroglial cells in the pathogenesis of bipolar disorder and S100B protein as a marker of bipolar mania.

Biological correlations of suicide and aggressivity in major depressions (with melancholia): 5-hydroxyindoleacetic acid and cortisol in cerebral spinal fluid, dexamethasone suppression test and therapeutic response to 5-hydroxytryptophan

5-Hydroxyindoleacetic acid (5-HIAA) and cortisol in cerebrospinal fluid (CSF), response of the dexamethasone suppression test (DST) and the clinical response to treatment with 5-hydroxytryptophan (5-HTp) plus carbidopa were studied in a group of 21 depressed inpatients (major depression with melancholia) in order to correlate biological findings with psychopathologicalones. A positive correlation was found between strong suicidal thoughts, suicidal attempts and self-aggressivity and low concentration of 5-HIAA in CSF and a less significant but still positive correlation with abnormal DST response and with clinical response to the treatment.

No evident neuronal damage after electroconvulsive therapy

Electroconvulsive therapy (ECT) is regarded as one of the most effective treatments for major depressive disorder but has also been associated with cognitive deficits possibly reflecting brain damage. The aim of this study was therefore to evaluate whether ECT induces cerebral damage as reflected by different biochemical measures. The concentrations in the cerebrospinal fluid (CSF) of three established markers of neuronal/glial degeneration, tau protein (tau), neurofilament (NFL) and S-100 beta protein, were determined in nine patients who fulfilled DSM-IV criteria for major depression. CSF samples were collected before and after a course of six ECT sessions. The CSF/serum (S) albumin ratio reflecting potential blood-brain barrier (BBB) dysfunction was also determined at these time points. The treatment was clinically successful with a significant decline of depressive symptoms in all patients as assessed by the Montgomery-Asberg Rating Scale for Depression. Several patients had signs of BBB dysfunction and/or neuronal damage before the start of treatment. Levels of CSF-tau, CSF-NFL and CSF-S-100 beta levels were not significantly changed by ECT. Also the CSF/S albumin ratio was found to be unchanged after the course of ECT. In conclusion, no biochemical evidence of neuronal/glial damage or BBB dysfunction could be demonstrated following a therapeutic course of ECT.

High serum and cerebrospinal fluid Ca/Mg ratio in recently hospitalized acutely depressed patients

Calcium (Ca) and magnesium (Mg) are involved in many processes related to depression. Evaluations of serum and plasma Ca and Mg levels in depressive disorders do not show consistent results. The few studies that examined their cerebrospinal fluid (CSF) levels tended to find no differences between depressed patients and controls. Because both hypercalcemia and hypomagnesemia are associated with depression, and as Mg may function as a Ca antagonist, it is suggested that the relationship between these cations could be different in depressed patients and controls. We examined CSF and serum Ca and Mg in acutely depressed patients diagnosed as having major depressive disorder or being in a depressive episode of bipolar disorder. Controls were subjects undergoing lumbar puncture as part of an evaluation for headache or suspected meningitis and found to demonstrate no physical or mental disorder. Serum and CSF Ca/Mg ratios were found to be elevated in the depressed patients compared with the controls. A retrospective analysis of previous trials assessing serum/plasma or CSF Ca and Mg does not seem to refute the findings of this study. We further discuss our findings in their relation to the acuteness of the depressive disorders.

Elevated sorbitol concentration in the cerebrospinal fluid of patients with mood disorders

This study was undertaken to test the hypothesis that a specific pathophysiological mechanism of diabetic neuropathy, namely increased polyol pathway flux, could be operative in patients with bipolar and unipolar mood disorders. Numerous studies have shown abnormalities of carbohydrate metabolism, including high rates of diabetes mellitus, in patients with mood disorders. Several studies have found that peripheral neuropathy is a risk factor for depression in diabetics. Furthermore, increased polyol pathway flux results in elevated sorbitol concentrations in peripheral tissues and cerebrospinal fluid (CSF) of diabetics with neuropathy. The purpose of this study was to determine whether sorbitol concentration is elevated in the CSF of non-medically ill patients with mood disorders. Lumbar punctures were performed on 30 subjects - 10 with bipolar mood disorder, 10 with unipolar mood disorder, and 10 age-matched normal controls, and CSF sorbitol concentrations were measured, using a gas chromatographic-mass spectroscopic technique. The mean+/-standard deviation of CSF sorbitol concentrations differed among the three groups as follows: bipolar (22.9+/-4.6 micromoles/l) > unipolar (19.0+/-2.8 micromoles/l)>normal control (15. 6+/-1.9 micromoles/l). One-way ANOVA showed significant (P=0.0002) differences among the three groups. Post-hoc tests indicated a significant (P<0.05) difference between bipolars and normal controls, bipolars and unipolars, and unipolars and normal controls. Further investigation is needed to determine the pathophysiological significance of this novel finding of elevated sorbitol concentration in the CSF of patients with mood disorders.

Increased cerebrospinal fluid glutamine levels in depressed patients

BACKGROUND

There is increasing evidence for an association between alterations of brain glutamatergic neurotransmission and the pathophysiology of affective disorders.

METHODS

We studied the association between cerebrospinal fluid (CSF) metabolites, including glutamine, in unipolar and bipolar depressed patients versus control subjects using a proton magnetic resonance spectroscopy technique. Cerebrospinal fluid samples were obtained from 18 hospitalized patients with acute unmedicated severe depression without medical problems and compared with those of 22 control subjects.

RESULTS

Compared with the control group, the depressed patient group had significantly higher CSF glutamine concentrations, which correlated positively with CSF magnesium levels.

CONCLUSIONS

These findings suggest an abnormality of the brain glial-neuronal glutamine/glutamate cycle associated with N-methyl-D-aspartate receptor systems in patients with depression.

CSF SNAP-25 in schizophrenia and bipolar illness. A pilot study

Research efforts to identify and understand the pathophysiology of schizophrenia and bipolar illness are limited by the inability to study neuronal tissue of living patients. An alternative to sampling brain tissue from living patients is to measure neuronal proteins found in cerebral spinal fluid. One such candidate protein is synaptosomal-associated protein 25kDa. Our hypothesis is that the level of this protein in cerebral spinal fluid may be a marker of neuronal pathology. Cerebral spinal fluid from headache, schizophrenic, bipolar, and control subjects was used to measure the SNAP-25 level by quantitative dot blotting. Schizophrenic subjects had significantly elevated levels of SNAP-25 as compared to headache and control subjects. However, there was no significant difference between the bipolar group and schizophrenic or control groups. This study reports on a potentially useful clinical marker in schizophrenia, and the presence of elevated cerebral spinal fluid SNAP-25 may indicate alterations in neuronal functioning.

Cerebrospinal cytokine levels in patients with acute depression

There is increasing evidence for an association between the alteration of cytokine concentrations in blood and the pathophysiology of depressive disorders. Studies in humans have not investigated CSF cytokine concentrations and their relationship to depressive disorders. This study reports on the association of the CSF concentration of proinflammatory cytokines, IL-1beta, IL-6 and TNFalpha, and major depressive disorders. CSF samples were obtained from 13 hospitalized patients with acute unmedicated severe depression and were compared with 10 control subjects. Compared to the control group, the depressed patient group had higher CSF concentrations of IL-1beta, lower IL-6 and no change in TNFalpha. A positive correlation was found between serum IL-1beta and the severity of depression. These results indicate a unique profile for CSF proinflammatory cytokines in acute depression. These findings merit further investigation and if replicated may possibly offer immunological treatment options for depression.

CSF thyrotropin-releasing hormone gender difference: implications for neurobiology and treatment of depression

In light of the postulated role of thyrotropin-releasing hormone (TRH) as an endogenous anti-depressant, 56 refractory mood-disordered patients and 34 healthy adult control subjects underwent lumbar puncture for cerebrospinal fluid (CSF) TRH analysis. By two-way analysis of variance, there was no difference between CSF TRH in patients (as a group or by diagnostic subtype) and control subjects (n = 90, F = 0.91, df = 2.84, P = 0.41). There was, however, a CSF TRH gender difference (females, 2.95 pg/ml; males, 3.98 pg/ml; n = 90, F = 4.11, df = 1.84, P < 0.05). A post hoc t-test revealed the greatest gender difference in the bipolar group (t = 2.52, P < 0.02). There was no significant difference in CSF TRH in "ill" vs. "well" state (n = 20, P = 0.41). The role of elevated levels of CSF TRH in affectively ill men--or the role of decreased levels of CSF TRH in affectively ill women--remains to be investigated but could be of pathophysiological relevance.

Low levels of transthyretin in the CSF of depressed patients

OBJECTIVE

Transthyretin plays an important role in the transport and distribution of thyroid hormone in the central nervous system (CNS). This study replicated and extended to patients with nonrefractory depressive illness a pilot study indicating that patients with refractory major depression have significantly lower levels of CSF transthyretin than do healthy comparison subjects.

METHOD

Lumbar punctures were performed in drug-free subjects with DSM-III-R major depression (N = 18), DSM-III-R bipolar disorder, depressed phase (N = 1), and healthy comparison subjects (N = 24). CSF concentrations of transthyretin, determined by a quantitative dot-immunobinding assay, of the depressed patients and comparison subjects were compared by analysis of covariance (ANCOVA). The relationship between CSF transthyretin levels and Hamilton Depression Rating Scale scores was determined in a subset of the depressed patients.

RESULTS

CSF concentrations of transthyretin were significantly lower in the depressed patients than in the comparison subjects by ANCOVA. Within the depressed group there was no significant overall correlation between CSF transthyretin levels and Hamilton depression scale scores, but there was a significant inverse correlation in male depressed patients (N = 8) between CSF transthyretin concentrations and Hamilton depression scores.

CONCLUSIONS

Lower CSF transthyretin concentrations in depressed patients may reflect either a stable trait in this population or a state change secondary to depression or other factors. Lower CSF transthyretin concentrations may result in altered CNS thyroid hormone homeostasis. Such alteration could account for certain mood and neurovegetative symptoms of depression and might contribute to failure of standard antidepressant treatment.

Lack of correlation between cerebrospinal fluid thyrotropin-releasing hormone (TRH) and TRH-stimulated thyroid-stimulating hormone in patients with depression

BACKGROUND

It has been proposed that elevated central thyrotropin-releasing hormone (TRH) is associated with the blunted thyroid-stimulating hormone (TSH) response to TRH in patients with depression. Few studies have directly evaluated this relationship between central nervous system and peripheral endocrine systems in the same patient population.

METHODS

15 depressed patients (4 male, 11 female, 12 bipolar, and 3 unipolar) during a double-blind, medication-free period of at least 2 weeks duration, underwent a baseline lumbar puncture followed by a TRH stimulation test. Cerebrospinal fluid (CSF) TRH and serial serum TSH, free thyroxine, triiodothyronine, prolactin, and cortisol were measured. A blunted response to TRH was defined as a delta TSH less than 7 microU/mL.

RESULTS

There was no significant difference in mean CSF TRH between "blunters" (2.82 +/- 1.36 pg/mL) and "non-blunters" (3.97 +/- 0.62 pg/mL, p = .40). There was no evidence of an inverse relationship between CSF TRH and baseline or delta TSH. There was no correlation between CSF TRH and the severity of depression or any other endocrine measure.

CONCLUSIONS

These data are not consistent with the prediction of hypothalamic TRH hypersecretion and subsequent pituitary down-regulation in depression; however, CSF TRH may be from a nonparaventricular nucleus-hypothalamic source (i.e., limbic area, suprachiasmatic nucleus, brain stem-dorsal raphe) and thus, not necessarily related to peripheral neuroendocrine indices.

Simian cytomegalovirus-related stealth virus isolated from the cerebrospinal fluid of a patient with bipolar psychosis and acute encephalopathy

A cytopathic 'stealth' virus was cultured from the cerebrospinal fluid of a patient with a bipolar psychotic disorder who developed a severe encephalopathy leading to a vegetative state. DNA sequencing of a polymerase chain reaction-amplified product from infected cultures has identified the virus as an African green monkey simian cytomegalovirus (SCMV)-related stealth virus. The virus is similar to the SCMV-related stealth virus isolated from a patient with chronic fatigue syndrome. The findings support the concepts that stealth viruses can account for a spectrum of dysfunctional brain diseases and that some of these viruses may have arisen from live polio viral vaccines.

Elevation of CSF somatostatin concentrations in mania

OBJECTIVE

The aim of this study was to compare levels of CSF somatostatin (somatotropin release-inhibiting factor) in drug-free patients with different major psychiatric disorders.

METHOD

CSF somatostatin concentrations were measured in 66 drug-free inpatients with Research Diagnostic Criteria diagnoses of schizophrenia, major depressive disorder, manic disorder, or schizoaffective disorder.

RESULTS

In comparison with both the patients with schizophrenia and the patients with schizoaffective disorder, the manic patients had markedly elevated CSF somatostatin concentrations. The depressed patients had significantly higher levels than the schizophrenic patients.

CONCLUSIONS

Mania is associated with relatively higher CSF somatostatin concentrations.

Cerebrospinal fluid total protein in patients with affective disorders

Cerebrospinal fluid (CSF) total protein was evaluated in 240 patients with affective disorders and compared with findings in 55 normal comparison subjects. Subtype diagnoses were as follows: bipolar I (n = 108, 47 men, 61 women); bipolar type II (n = 67, 26 men, 41 women); and unipolar (n = 65, 22 men, 43 women). Men had significantly elevated values compared with women. In men with bipolar I disorder, mean CSF protein levels were found to be significantly elevated over those in normal subjects, with 31.9% above the traditional normal range cutoff of 45 mg/dl. Moreover, CSF protein levels in male bipolar I patients were found to be positively correlated with severity of depression at the time of the lumbar puncture and with duration of illness. It thus appears that increased protein levels may be associated with illness severity or progression in male patients with bipolar I disorder. Although elevated CSF protein is a nonspecific marker of cerebral pathology, further search for the potential underlying pathophysiological mechanisms related to this finding would now appear to be warranted.

Drug-induced actions on brain neurotransmitter systems and changes in the behaviors and emotions of depressed patients

Despite cumulative evidence that the tricyclic drugs result in significant changes in the functioning of brain serotonergic (5-HT) and nordrenergic (NE) systems, such changes have not been found to be associated with recovery from depression. Based upon evidence that the 5-HT and NE systems were associated with different emotions, it was hypothesized that changes in these systems were associated with different components of behavior in drug-responsive patients and not with changes in the "whole" disorder. Findings from this multihospital study of 104 unipolar and bipolar depressed patients showed early drug-associated reductions in anxiety and hostility in treatment responders to precede changes in motor retardation and depressed mood. Adopting this approach of looking for relationships between changes in components of major depression and changes in neurotransmitter system function, decreases in 5-HT and NE metabolite concentrations in cerebrospinal fluid (CSF) in patients treated with tricyclics, were found to be correlated with changes in specific behaviors. Results indicated the following: (1) drug-induced changes in the 5-HT system to be associated with mood aspects, notably anxiety, and depressed mood; changes in NE primarily with the psychomotor, secondarily with the mood components of the depressed state; (2) the pattern of relationships between changes in 5-HT and in mood in the unipolar was different than that in the bipolar subtype. The results indicate that in determining the relationships of biochemical changes to behavioral ones, that it is important to take into account the type of depression (bipolar or unipolar), as well as examining individually and over time those components that make up the disorder of depression. These results support evidence that tricyclics have multiple behavioral actions, that response is mediated through changes in specific behaviors and that this approach warrants further application in prospective studies of antidepressant drug mechanisms and their therapeutic actions.

CSF neuroactive steroids in affective disorders: pregnenolone, progesterone, and DBI

Recently several steroid compounds have been discovered to act as neuromodulators in diverse central nervous system (CNS) functions. We wondered if neuroactive steroids might be involved in affective illness or in the mode of action of mood-regulating medications such as carbamazepine. Levels of the neuroactive steroids pregnenolone and progesterone, as well as the neuropeptide diazepam binding inhibitor (DBI) (known to promote steroidogenesis), were analyzed from cerebrospinal fluid (CSF) obtained by lumbar puncture (LP) from 27 medication-free subjects with affective illness and 10 healthy volunteers. Mood-disordered subjects who were clinically depressed at the time of the LP had lower CSF pregnenolone (n = 9, 0.16 ng/ml) compared with euthymic volunteers (n = 10, 0.35 ng/ml; p < 0.01). In addition, pregnenolone was lower in all affectively ill subjects (n = 26, 0.21 ng/ml), regardless of mood state on the LP day, than healthy volunteers (p < 0.05). No differences were found for progesterone or DBI levels by mood state or diagnosis. Progesterone, pregnenolone, and DBI did not change significantly or consistently in affectively ill subjects after treatment with carbamazepine. CSF pregnenolone is decreased in subjects with affective illness, particularly during episodes of active depression. Further research into the role of neuroactive steroids in mood regulation is warranted.

Elevated cerebrospinal fluid protein in men with unipolar or bipolar depression

We studied a large sample of rigorously diagnosed, generally unmedicated patients with major depressive disorder (n = 179), bipolar affective disorder (n = 102), or schizophrenia (n = 125) to determine if increased cerebrospinal fluid (CSF) protein is associated with a particular diagnosis or gender. Men had a higher mean CSF protein level than women across all diagnoses (p < 0.001). There were no differences across diagnosis among the female patients. Men with unipolar depression had a higher mean CSF protein content than other male patients (n = 0.029), but depressed bipolar males had an equivalently elevated mean level. Considered apart from unipolar or bipolar diagnosis, the depressive syndrome was strongly associated with increased CSF protein in men (p = 0.004); again, there was no difference across type of illness (depression versus mania) among women. Elevated CSF protein content seems to be associated with illness syndrome rather than diagnosis, and may represent an important finding among men with depression.

CSF and plasma MHPG, and CSF MHPG index: pretreatment levels in diagnostic groups and response to somatic treatments

The authors report a significant positive correlation between levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) in cerebrospinal fluid (CSF) and plasma in drug-free affective disorder patients (major depression, mania, and schizoaffective disorder), but not in schizophrenia. Recent kinetic studies on the relationship between plasma and CSF MHPG discourage the interpretation of independent CSF MHPG levels without correction for the diffusion of MHPG across the blood-brain barrier. The authors therefore examine pretreatment CSF and plasma MHPG levels, and the CSF MHPG index (CSF MHPG corrected for by using simultaneously obtained plasma MHPG according to the method of Kopin et al. [1983]). No significant differences were found in these pretreatment MHPG measures among the four diagnostic groups. Changes in these MHPG indices, and their correlations with behavioral rating scores, are also examined with respect to response to the four major somatic therapies (neuroleptics, lithium, antidepressants, and electroconvulsive therapy).

CSF 5-HIAA predicts suicide risk after attempted suicide

Suicide risk after attempted suicide, as predicted by cerebrospinal fluid (CSF) monoamine metabolite concentrations, was studied in a sample of 92 psychiatric mood disorder inpatients admitted shortly after attempting suicide. The potential of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the CSF to predict suicide risk within the first year after attempted suicide was studied by means of survival analysis after after median split subgrouping. Eleven patients (12%) committed suicide within 1 year after attempted suicide. Eight of these belonged to the below-the-median (< 87 nM) CSF 5-HIAA subgroup, that is, the suicide risk was 17% as compared with 7% among those with above-the-median CSF 5-HIAA. The cumulative number of survived patient-months during the first year after attempted suicide was significantly lower in the low CSF 5-HIAA subgroup. It was concluded that low CSF 5-HIAA predicts short-range suicide risk after attempted suicide in mood disorder psychiatric inpatients. These findings lend further support to the serotonin hypothesis of suicide risk.

Biogenic amines in seasonal affective disorder: effects of light therapy

Wintertime measures of central and peripheral monoamine neurotransmitter system activity in 17 medication-free depressed patients with seasonal affective disorder (SAD) were compared with those in eight healthy volunteers. Mean cerebrospinal fluid (CSF) concentrations of the principal metabolites of norepinephrine (NE), serotonin, and dopamine did not differ between the two groups, nor did mean basal or orthostatically stimulated plasma NE levels. Patients' pretreatment depression ratings were inversely correlated with resting plasma NE concentrations. Fourteen SAD patients were clear responders to 2 weeks of full-spectrum bright light treatment. Neither the transmitter measures nor their interrelatedness was affected significantly by phototherapy.

Cerebrospinal fluid neuropeptides in mood disorder and dementia

Cerebrospinal fluid (CSF) concentrations of immunoreactive corticotropin-releasing hormone (CRH) and somatostatin (SRIF) were measured in female psychiatric inpatients with DSM-III-R diagnoses of major depression, mania, generalized anxiety and somatization disorder. In addition, elderly patients with dementia disorders, with or without concomitant major depression, were also investigated. CSF SRIF was not significantly different among these groups; on the other hand, mean CSF CRH concentrations were significantly higher in major depression and in dementia with depression as compared with neurological controls with no psychiatric disorders. CSF CRH levels in mania, simple dementia, or anxiety or somatization disorder were not significantly different from the controls. Background physical or clinical variables did not account for the differences in CRH concentrations. It is concluded that CSF CRH elevation may be present in some patients with major depression independent of age and an underlying dementia disorder.

Effect of psychotropic drugs on excitatory amino acids in patients undergoing psychosurgery for depression

Samples of ventricular CSF were taken from 52 consecutive patients admitted for psychosurgery for intractable depression. Concentrations of asparagine, aspartate, glutamine, glutamic acid, and serine were determined. Glutamate and aspartate concentrations, implicated in excitotoxic brain damage, were not affected by various types of psychotropic drug treatment. Serine, a modulator of glutamate responses, was significantly elevated in samples from subjects receiving antidepressants. These subjects responded poorly to the operation. Psychotropic drugs are unlikely to be neurotoxic. Nevertheless, antidepressants may influence excitatory neurotransmission.

Cerebrospinal-fluid neuropeptides: a biochemical subgrouping approach

Cerebrospinal-fluid (CSF) corticotropin-releasing hormone, somatostatin, and thyrotropin-releasing hormone were measured by specific radioimmunoassays in 257 hospitalized psychiatry patients suffering from dementia disorders (n = 85), schizophrenia (n = 104), and mood and anxiety disorders (n = 39). Neurological controls (n = 29) were also investigated. Since there were large overlaps of the peptide levels across the nosological groups we subjected the dataset to a three-dimensional normal mixture distribution analysis. We obtained four biochemically separable clusters. Dementia disorders, but not the others, were heterogeneously distributed in these clusters but after eliminating the effects of age and illness duration this difference disappeared. No single clinical, psychological, or background variable emerged as a prominent correlate of the neuropeptide clusters. It is concluded that although CSF neuropeptide concentrations in psychiatric patient populations appear to be separable into distinct, normally distributed subgroups this distinction does not coincide with present nosological classifications.

Lateral ventricle-brain ratio and balance between CSF HVA and 5-HIAA in schizophrenia

OBJECTIVE

Lateral ventricle enlargement in schizophrenia has been positively correlated with poor premorbid competence, negative symptoms, and poor treatment response and negatively correlated with concentrations of homovanillic acid (HVA), a dopaminergic metabolite. The authors provide further evidence of a reciprocal relationship between lateral ventricle size and dopaminergic activity in schizophrenia.

METHOD

They assessed the relationship between lateral ventricle enlargement (ventricle-brain ratio, VBR) and CSF neurotransmitter metabolite concentrations (HVA and 5-hydroxyindoleacetic acid [5-HIAA]) in 45 patients with schizophrenia, 28 with affective disorders (19 patients with major depression and nine with bipolar disorder), and 91 normal comparison subjects.

RESULTS

No group mean differences were significant. Although individual correlations of VBR with HVA and 5-HIAA were not statistically significant, the ratio of HVA to 5-HIAA was significantly correlated with VBR in the patients with schizophrenia, a finding consistent with dopaminergic-serotonergic balance hypotheses.

CONCLUSIONS

These data suggest that it is the balance between HVA and 5-HIAA rather than their absolute levels which is associated with brain morphology and that this relationship between brain chemistry and morphology may be characteristic of the normal range of functioning for these systems. In other words, independent of whether brain morphology and chemistry differentiate psychopathological from nonpsychopathological states, there may be an orderly relationship between lateral ventricle size and the balance between HVA and 5-HIAA balance that is especially prominent in schizophrenia.

CSF GABA in depressed patients and normal controls

The inhibitory neurotransmitter gamma-aminobutyric acid (GABA) has been implicated in the pathophysiology of depression. Therefore, we examined cerebrospinal fluid (CSF) levels of GABA in depressed patients (N = 25) and normal controls (N = 20). There was no significant difference between the groups. However, among the depressed patients the subgroup of unipolar melancholic patients (N = 13) had significantly lower CSF levels of GABA than the rest of the depressed patients (N = 12). There was no significant difference for CSF levels of GABA between depressed patients who were (N = 14) or were not (N = 11) cortisol non-suppressors. It was of interest that among the controls there was a significant negative correlation between CSF levels of GABA and CSF levels of norepinephrine.

[The modulation of postural asymmetry in recipient animals under the influence of the cerebrospinal fluid from patients with manic-depressive psychosis]

Suboccipital administration of cerebrospinal fluid of patients with affective disorders elicits a pose asymmetry in rats-recipients; the character of the pose asymmetry depends on the phase of donor's disease: cerebrospinal fluid of manic patients elicits a relative flexion of the right posterior limb, of depressive patients--a relative flexion of the left posterior limb. High-molecular and low-molecular fractions of the cerebrospinal fluid were active, trypsin treatment led to disappearance of the effect. The results suggest a significant role of protein components of the cerebrospinal fluid in the organization of the symptom of functional asymmetry of the central nervous system under affective disorders.

[The effect of the cerebrospinal fluid from patients with manic and depressive syndromes on the social hierarchical relationships in a group of rats]

Taking into account socio-oriented symptoms of affective disorders, a method of zoosocial hierarchy of rats was used for biological testing of the cerebrospinal fluid of patients with manic and depressive syndromes. Cerebrospinal fluid and its fractions were administered before and after treatment by trypsin into suboccipital cistern of "dominants" and "subordinates" of the community. A change of behaviour was observed, the character of which depended on the phase of donor's psychosis. Low-molecular fraction of the cerebrospinal fluid possessed specific activity, which disappeared after the treatment by trypsin, what allowed to suggest oligopeptide nature of the active factors.

Neuroleptic malignant syndrome: a study of CSF monoamine metabolism

In 8 cases of typical neuroleptic malignant syndrome (NMS), homovanillic acid (HVA), 5-hydroxyindole acetic acid (5-HIAA), noradrenaline (NA), and 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) levels in the cerebrospinal fluid (CSF) were assayed during both the active phase of NMS and after recovery. Compared with levels in normal control subjects the levels of HVA were significantly lower in patients with active NMS. This finding supports the central dopamine blockade theory of NMS pathophysiology. In addition, the levels of HVA were significantly decreased after recovery, suggesting that there may be a decreased dopamine metabolism in patients susceptible to NMS. The levels of 5-HIAA in patients with active NMS and after recovery were also significantly lower than those in normal control group, suggesting a relationship between the development of NMS and a disturbance of serotonin metabolism. The levels of NA in patients with active NMS were significantly higher than in normal subjects, and were within normal range after recovery. The levels of MHPG had a tendency to increase in patients with active NMS, compared with levels during recovery. These findings are a result of increased sympathetic nervous system activity in patients with active NMS; however, they are also observed in other disorders and may well reflect the physical stress caused by NMS.

Cerebrospinal fluid monoamine metabolites and suicidal behavior in depressed patients. A 5-year follow-up study

We carried out a 5-year follow-up study of suicidal behavior among depressed patients who earlier had determinations of cerebrospinal fluid levels of monoamine metabolites. Patients who reattempted suicide during the follow-up had significantly lower cerebrospinal fluid levels of both the serotonin metabolite 5-hydroxyindoleacetic acid and the dopamine metabolite homovanillic acid. The findings were most striking among melancholic patients. These follow-up results suggest that reduced central turnover of serotonin and dopamine may be associated with further suicidal behavior among depressed patients who have previously attempted suicide.

The switch mechanism and the bipolar/unipolar dichotomy

During open trials of intravenous and oral S-adenosyl methionine (SAM) and a placebo-controlled trial of intravenous SAM in 29 patients, 25 patients had SAM and four had placebo (27 courses of SAM, two of the patients receiving two trials a piece). Nine of 11 bipolar patients (all SAM-treated) switched into elevated mood state (hypomania, mania and euphoria) and two did not respond. Six endogenous unipolar patients improved and five did not. No non-endogenous patient or placebo patient responded for more than 14 days. No unipolar patient switched into elated mood. In eleven (38%) trials and nine (33%) patients there was a switch from depression to elation. Biochemical data from the cerebrospinal fluid of eight patients suggested that the role of the dopaminergic system should be further explored.

Elevation of immunoreactive CSF TRH in depressed patients

The concentration of thyrotropin-releasing hormone (TRH), a tripeptide (pyroglutamylhistidylprolin-amide), in the CSF of drug-free patients with DSM-III major depression, somatization disorder, and peripheral neurological disorders was measured with a sensitive and specific radioimmunoassay. The depressed patients had markedly higher CSF TRH concentrations than the other patient groups, and this finding could not be attributed to any demographic variables. The elevation of TRH in CSF provides further evidence of hypothalamic-pituitary-thyroid dysfunction in depression.

CSF biochemical correlates of mixed affective states

To evaluate the question of whether "mixed" bipolar disorder is a distinct entity, we compared selected cerebrospinal fluid (CSF) biochemical parameters from patients with bipolar disorder, mixed, to those with mania and major depression. Fourteen patients in each category (DSM-III) were studied with regard to CSF HVA, 5HIAA, sodium, potassium, calcium, and magnesium levels under carefully controlled conditions. CSF HVA, 5HIAA, and sodium were found to be significantly higher in manics than in major depressives. Discriminant analysis of the biochemical variables of the mixed affective group identified two biochemically distinct and clinically different subgroups of seven patients each, one resembling the manic group and the other the major depressive group. These findings suggest that mixed affective states do not exist as a separate entity, but are composed of two subgroups obtained from the manic and major depressive categories.