Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Concentrations of the major monoaminergic transmitter metabolites HVA, MOPEG and 5-HIAA were determined in the cerebrospinal fluid (CSF) of untreated schizophrenic patients. Patients with aberrated concentrations of 5-HIAA and HVA in CSF had schizophrenia in their families in a frequency significantly higher than that of patients with normal concentrations. These results may indicate the existence of a subgroup of schizophrenic patients having a family disposition for the disorder and an aberrated transmission from central serotonin and dopamine neurons. In young healthy volunteers, aberrated monoamine metabolite concentrations in CSF were also related significantly to a history of psychiatric morbidity in the family. In psychotic patients treated with chlorpromazine significant correlations were obtained between therapeutic outcome on the one hand, and both biochemical effects related to central monoamine metabolism and chlorpromazine concentrations in the CSF on the other hand. Patients with chlorpromazine concentrations above 1 ng/ml in CSF or 40 ng/ml in plasma responded more favourably than patients with concentrations below those levels. The results indicate that biochemical and pharmacokinetic data may be of value for diagnostic classification and prediction of therapeutic outcome in drug-treated schizophrenic patients.
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PMID:Concentrations of monoamine metabolites and chlorpromazine in cerebrospinal fluid for prediction of therapeutic response in psychotic patients treated with neuroleptic drugs. 616 May 94

One hundred and ten patients with Research Diagnostic Criteria (RDC) diagnoses of major depressive disorders were assessed for present or recent suicidal ideation and behavior and for suicidal acts earlier in life before current depression using the Schedule for Affective Disorders and Schizophrenia (SADS). Suicidal scores were correlated uni- and bivariately with levels of CSF monoamine metabolites (HVA, 5HIAA, MHPG), urinary MHPG, the proportion post-/predexamethasone plasma cortisol at 1100 h, and platelet MAO activity (all standardized to same sex, age, height and weight). Results indicate that all 3 monoamine metabolites and their interactions are involved in various aspects of suicidality, at least in unipolar patients. MHPG and 5HIAA (both low or both high) were involved in current or recent suicidal ideation, and low HVA was mainly associated with past potential lethality of suicidal acts. Current hypercortisolism was found in patients that earlier in life had tried to commit dangerous suicides. Bipolar patients (depressives with a history of manic or hypomanic episodes) had earlier in life significantly more, and more dangerous, suicidal attempts than the unipolars.
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PMID:Life at risk: markers of suicidality in depression. 620 42

We followed up a sample of psychiatric patients (diagnoses predominantly schizophrenia and depression) who had participated in in-patient studies of their CSF over the past 15 years. The status of 73 former patients was confirmed, of whom 12 had died. Seven of these patients died at age < or = 40, largely of suicide, homicide, or accidental causes. These seven patients had significantly lower CSF 5-HIAA and HVA than living control patients. There were significant direct correlations between age at death and both CSF 5-HIAA and HVA in the deceased patients. The results offer support for CSF monoamine metabolites relating to early death in a diagnostically diverse sample of psychiatric patients.
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PMID:An association between low levels of 5-HIAA and HVA in cerebrospinal fluid and early mortality in a diagnostically mixed psychiatric sample. 750 65

Neurotensin (NT), a peptide which colocalizes with dopamine in some midbrain and hypothalamic neurons, has been speculated to play a role in schizophrenic illness and in the action of antipsychotic drugs. Previous work suggested a bimodal distribution of NT in patients with schizophrenia, with a subgroup having low drug-free NT concentrations which normalize with neuroleptic treatment. We studied 15 schizophrenic patients with CSF samples collected both off and on neuroleptic medication, 12 with only drug-free (DF) samples, and 10 controls. There was no significant difference in CSF NT concentrations between patients and controls, or between patients off and on medication. However, 7 patients with DFNT CSF concentrations below the patient mean showed an increase with neuroleptic treatment. Moreover, NT was significantly lower for women. Significant correlations with NT concentrations in CSF were found with deficit symptoms in patients, and with the age of the CSF sample for all subjects. There was no correlation between CSF NT concentrations and patient age, duration of illness, or levels of amine metabolites (MHPG, 5HIAA, HVA).
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PMID:CSF concentrations of neurotensin in schizophrenia: an investigation of clinical and biochemical correlates. 751 75

Monoamine neurotransmitter systems are widely thought to be involved in the pathophysiology of affective disorders and schizophrenia and the mechanism of action of antidepressant and antipsychotic drugs. Previous clinical studies have focused on individual monoamine function in isolation, even though a large number of preclinical studies have demonstrated that monoamine neurotransmitter systems interact with one another. In the present paper, preclinical data on monoamine neurotransmitter interactions are reviewed, and two methods for examining monoamine neurotransmitter system interactions in clinical data are presented. One of the best replicated findings in biological psychiatry is that monoamine metabolites in CSF correlate with one another. The degree of correlation may be in part a measure of the degree of interaction between the parent monoamine neurotransmitter systems. Another approach to studying interactions is the use of HVA/5HIAA and HVA/MHPG ratios as an index of interactions between 5HT-DA and NE-DA. When these methods are applied in schizophrenia, patients are found to have decreased monoamine metabolite correlations compared to normal controls. Metabolite correlations increase significantly after antipsychotic treatment, and the HVA/5HIAA and HVA/MPHG ratios also increase, suggesting that neuroleptics may act in part by strengthening interactions between monoamines. BPRS ratings are negatively correlated with HVA/5HIAA and HVA/MHPG so that patients with higher ratios have fewer symptoms, particularly after treatment. These results provide direct experimental support for hypotheses suggesting that interactions between monoamine neurotransmitters are important in schizophrenia. Some of the effects of the atypical neuroleptic, clozapine, on metabolite correlations and ratios are also discussed.
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PMID:Clinical investigation of monoamine neurotransmitter interactions. 783 44

Measurement of plasma concentrations of the dopamine metabolite, homovanillic acid (pHVA), is an indirect tool to assess changes in dopamine turnover. Levels of pHVA have been reported to decrease during treatment with conventional antidopaminergic, neuroleptics, with the decrement correlating with symptomatic improvement in schizophrenic symptoms. Clozapine, an atypical neuroleptic, is the only drug proved to be effective in treatment-refractory patients. However, the mechanism mediating this unique efficacy has not been fully elucidated. This study examined the effect of clozapine on pHVA concentrations in schizophrenic patients. Since clozapine potently binds to alpha 2-adrenergic receptors, plasma norepinephrine (pNE) concentrations were also measured. Twenty-eight treatment-refractory schizophrenic patients (24 men, 4 women) were treated with clozapine (up to 600 mg/day) for 5 weeks, after a minimum 1-week drug-free period. Symptomatology and pHVA and pNE concentrations were measured at the last drug-free day and weekly for 5 weeks. Fourteen patients responded to clozapine treatment, while an equal number did not. Mean pHVA concentrations did not significantly change during treatment with clozapine. Although clozapine tended to lower pHVA concentrations in treatment responders, the effect was small and not significant. Clozapine treatment significantly raised pNE concentrations, but this did not differentiate responders from nonresponders to clozapine. These findings suggest that clozapine's effect on DA turnover is small and that clozapine may be effective in treatment-refractory schizophrenia by mechanisms other than, or in addition to, dopamine receptor blockade. However, since about one-third of NE is metabolized into HVA, the clozapine-induced increase in pNE may have overshadowed a possible lowering effect of clozapine on pHVA.
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PMID:Treatment with clozapine and its effect on plasma homovanillic acid and norepinephrine concentrations in schizophrenia. 848 74

The mesocortical dopamine system is thought to play an important role in the etiology of the stress response. Dopamine (DA) has been shown to accumulate in the rat frontal cortex in response to a wide variety of stressors. Diazepam, an anxiolytic benzodiazepine, can reverse the effects of stress on cortical DA. We investigated the effects of acute and chronic diazepam administration on immobilization stress-induced changes of the DA system in the frontal cortex of the rat. In the first study, 2.5 mg/kg diazepam was administered 20 min prior to 40 min of immobilization stress. Acute diazepam significantly reduced basal levels of extracellular DA and antagonized the stress-induced increase in cortical DA when compared to untreated stressed rats. Acute diazepam did not significantly effect extracellular DOPAC. In the second study, an experimental group of rats was given approximately 2 mg/kg/day diazepam in their drinking water for 3 weeks. This treatment significantly reduced anxiety as assessed by a staircase test for anxiety. Chronic diazepam had no effect on basal levels of cortical DA. However, chronic diazepam treatment also attenuated stress-induced increases in extracellular DA when compared to untreated stressed control rats. Chronic diazepam did not affect stress-induced changes in DOPAC but it did antagonize the effects of stress on HVA. Thus, acute and chronic diazepam treatment can antagonize stress-induced activation of the mesocortical DA system. It is proposed that this effect is produced through an enhancement of GABAergic neurotransmission by diazepam. The role of the dopaminergic system during stress, anxiety, and schizophrenia is discussed.
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PMID:The effect of acute and chronic diazepam treatment on stress-induced changes in cortical dopamine in the rat. 858 19

We investigated the dopamine metabolite plasma homovanillic acid (plasma HVA) levels in 37 catatonic patients on the day of admission before initial medication as well as in 17 healthy controls. In a prospective study catatonic syndrome was diagnosed according to criteria of Lohr and Wiesniwski (1987) and Rosebush et al (1990) whereas comorbid diagnosis was made by Diagnostic and Statistical Manual of Mental Disorders, 3rd ed, revised (DSM III/R) (APA 1987). On the day of admission blood samples were taken before initial medication. Compared to controls (80.1 +/- 40.1 pmol/mliter) catatonic patients showed significantly (P = 0.0286) increased plasma HVA (140.9 +/- 53.6 pmol/mliter). Catatonic patients free of neuroleptic medication (n = 21) differed significantly (p = 0.0416) from controls whereas neuroleptically treated catatonics (n = 16) did not. Our findings of increased plasma HVA in catatonia are explained by an alteration in either mesolimbic or mesocortical dopaminergic function, as is assumed in the case of schizophrenia. As an alternative, it may be due to increased nigrostriatal function, which can lead, as shown in animal experiments with the dopamine agonist amphetamine, to hypokinetic states resembling catatonia in humans.
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PMID:Plasma homovanillic acid concentrations in catatonia. 867 89

For the majority of patients, schizophrenia is a chronic recurrent disease that leads to significant residual morbidity which occurs through a process of behavioral deterioration. The factors that influence the course of schizophrenia after its onset and the ability of treatment to modify the effects of the patient's illness are not well understood. This article examines specific clinical and biological variables that are associated with treatment response and outcome. These variables, which are both trait and state dependent, include premorbid adjustment, age and mode of onset of illness, gender, duration of psychosis, schizophrenia subtype, primary negative symptoms, and extrapyramidal signs including tardive dyskinesia and plasma HVA and brain pathomorphology. In addition, the chronic effects of antipsychotic drug treatment may influence illness course both favorably and adversely as well as potentially altering the neurobiological substrates that mediate expression of the illness and treatment response. Finally, the question of whether the active phase of the illness involves a pathologic process that leads to illness progression is discussed. In light of this discussion, we can speculate that although certain aspects of the illness in terms of its severity and course may be, to an extent, predetermined, a number of factors can exert favorable and unfavorable effects on the course of the illness and its ultimate outcome. One question for the field is to develop therapeutic strategies that minimize the morbidity of the illness in a way that does not introduce iatrogenic consequences to the patient.
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PMID:Factors influencing treatment response and outcome of first-episode schizophrenia: implications for understanding the pathophysiology of schizophrenia. 882 44

During a 10-year period, 120 drugfree DSM-III-R schizophrenic patients were consecutively and unselectively admitted to a ward for young psychotic patients and subjected to a battery of examinations including symptomatology, cerebrospinal fluid (CSF)-biochemistry, computed tomography (CT)-scan, neurophysiologic and psychophysiologic (Electrodermal activity, EDA) parameters before antipsychotic treatment was initiated. After discharge, the patients were longitudinally followed with ratings of outcome (Strauss-Carpenters outcome scale) at years 1, 3, and 5 after index admission. The aim of the study was to find possible early markers for outcome in schizophrenia. At 5 years, 30% of the patients had a good outcome (total score > 13) and 15% a poor outcome (total score < 8). Poor premorbid adjustment and low level of education as well as negative schizophrenic symptomatology at index admission were associated with a poor outcome 5 years later. Positive symptomatology and a family history of schizophrenia did not predict outcome. Patients with a poor outcome (total score < 8) had a significantly more deviant CSF HVA/5-HIAA quotient than those with a very good outcome (total score > 15) as compared with healthy controls. Further, the CSF-peptides neuropeptide Y, dynorphin A, and CRF were predictable for outcome at the 5-year follow-up evaluation. Male schizophrenics who were "nonresponders" on the EDA test showed an almost 100% poor outcome, which was not found in females. In summary, several clinical and biological variables seem to have a predictable value for outcome in schizophrenia and, early identification of them might be a challenge for our future treatment strategies.
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PMID:Clinical and biological markers for outcome in schizophrenia: a review of a longitudinal follow-up study in Uppsala schizophrenia research project. 886 40


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