Effects of neuroleptic treatment on symptoms of schizophrenia and plasma homovanillic acid concentrations

Effect of Switching to Brexpiprazole on Plasma Homovanillic Acid Levels and Antipsychotic-Related Side Effects in Patients with Schizophrenia or Schizoaffective Disorder

OBJECTIVE

Although switching antipsychotics is a common strategy in the treatment of schizophrenia, caution is needed because of the risk of worsening of psychosis, particularly when switching to a dopamine D2 partial agonist. Homovanillic acid (HVA), a dopamine metabolite, is thought to be a possible indicator of the response to antipsychotics. We examined the effects of switching to brexpiprazole monotherapy from other antipsychotics on plasma HVA levels and side effects during maintenance treatment of schizophrenia.

METHODS

The antipsychotics of 37 Japanese patients with schizophrenia or schizoaffective disorder were switched to brexpiprazole for the improvement of side effects. We evaluated clinical symptoms and extrapyramidal symptoms (EPS) and took fasting blood samples at baseline and endpoint (eight weeks after completing the switch) to measure plasma levels of HVA, prolactin, and metabolic parameters.

RESULTS

Switching to brexpiprazole significantly decreased the Drug-Induced Extrapyramidal Symptoms Scale total score (p=0.008), prolactin levels (p<0.001), body weight (p=0.046), and body-mass index (p=0.034), and increased HDL cholesterol (p=0.008). On the other hand, switching to brexpiprazole did not change plasma levels of HVA or Positive and Negative Syndrome Scale scores.

CONCLUSION

Switching to brexpiprazole significantly improved EPS, high prolactin levels, and metabolic side effects without elevating plasma HVA levels. Brexpiprazole may stabilize dopaminergic neural transmission and could be a useful strategy to decrease the burden in patients with schizophrenia during the maintenance phase. Because of the small sample size, further studies with larger sample sizes are needed to confirm and extend our results.

Antidopaminergic medication in healthy subjects provokes subjective and objective mental impairments tightly correlated with perturbation of biogenic monoamine metabolism and prolactin secretion

OBJECTIVES

Off-label prescription of antipsychotics to patients without psychotic symptoms has become a routine matter for many psychiatrists and also some general practitioners. Nonetheless, little is known about the possibly detrimental effects of antidopaminergic medications on general psychopathology, subjective mental state, or a possible association with physiological parameters in nonpsychotic individuals.

METHODS

In this randomized, single-blinded study, groups of healthy volunteers (n=18) received low doses of reserpine, aripiprazole, haloperidol, or placebo on 7 successive days. Relevant physiological parameters (plasma prolactin, concentrations of catecholamine metabolites in plasma, and 24-hour urine) and each subject's mental state (Positive and Negative Syndrome Scale, Hamilton Rating Scale for Depression, visual analogue scale, Beck Depression Inventory II) were assessed at the start and end of the trial.

RESULTS

Of the three active treatments, only reserpine caused a significant increase in some plasma- and urine-catecholamine metabolites, but all three medications evoked objective and subjective changes in general psychopathology scores, which correlated with individual increases in plasma homovanillic acid concentrations. Both objective and subjective impairments were significantly more pronounced in the subgroup with greatest increase of plasma prolactin. Subjects experiencing the most pronounced side effects under haloperidol, which compelled them to drop out, showed significantly higher prolactin concentration increases than those who tolerated haloperidol well.

CONCLUSION

We found consistent associations between altered markers of dopamine transmission and several objective and subjective mental impairments in healthy volunteers after 1 week's treatment with antidopaminergic medications. These findings should draw attention to a more intensive risk-benefit evaluation in cases of off-label prescription of antipsychotic medications.

Agomelatine Protection in an LPS-Induced Psychosis-Relevant Behavior Model

BACKGROUND The aim of this study was to investigate the effect of agomelatine in a psychosis-relevant behavior model. MATERIAL AND METHODS We used 18 adult male Wistar rats in this study. Twelve rats given LPS for endotoxemia were randomly divided into 2 groups (n=6). Group I was treated with 1 mL/kg 0.9% NaCl i.p. and Group II was treated with 40 mg/kg agomelatine. Six normal rats served as the control group and were not given LPS for endotoxemia. Cylindrical steel cages containing vertical and horizontal metal bars with top cover were used. Rats were put in these cages for the purpose of orientation for 10 min. Apomorphine was given to rats removed from cages, and then they were immediately put back in the cages for the purpose of observing stereotyped conduct. Brain HVA levels and plasma TNF-a levels were evaluated in tissue homogenates using ELISA. The proportion of malondialdehyde (MDA) was measured in samples taken from plasma for detection of lipid peroxidation similar to thiobarbituric acid reactive substances. RESULTS LPS induced-plasma TNF-α, brain TNF-α, and plasma MDA levels were significantly lower in the LPS+agomelatine group compared to the LPS+saline group (p<0.05). HVA levels and stereotype scores were significantly lower in the LPS+agomelatine group compared to the LPS+saline group (p <0.001). CONCLUSIONS Agomelatine reduced TNF-α, HVA, MDA levels, and the stereotype score in relevant models of psychosis. Our results suggest that the anti-inflammatory effect of agomelatine involved oxidant cleansing properties and that its effects on the metabolism of dopamine can play an important role in the model of psychosis.

Variability of plasma homovanillic acid over 13 months in patients with schizophrenia; relationship with the clinical response and the Wisconsin card sort test

In the present study we have measured, on a monthly basis, the concentration of plasma homovanillic acid (pHVA) in schizophrenic patients during 13 months of their pharmacological treatment. The average pHVA values of each patient were within the range of 7.30-17.70 ng/ml and the coefficients of variation for each patient (CV %) were within the range of 13-33%. Half of the patients that showed higher pHVA CV% values also showed higher scores on the Brief Psychiatric Rating Scale at the beginning of the study, and improved more after 6 months, when compared to the remaining 50% with lower CV% values. There was no significant relationship between the scores of the Wisconsin Card Sort Test and the concentration or the CV% of the pHVA of each patient. A greater variability in the pHVA may be associated with a greater plasticity of the dopaminergic system and a better clinical response.

Plasma homovanillic acid differences in clinical subgroups of first episode schizophrenic patients

This study evaluates the relationship between plasma homovanillic acid (pHVA) levels, which have been used to study the role of central dopamine in schizophrenia, and the positive/negative syndrome in first episode schizophrenic patients before and after antipsychotic treatment. Forty neuroleptic-naive first episode schizophrenic patients were monitored at baseline and on days 7, 14 and 28. Clinical status was evaluated with the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), and the Brief Psychotic Rating Scale. Plasma HVA levels were also measured. Patients were divided into predominantly positive or negative syndrome groups by subtracting SAPS from SANS scores, at baseline. A healthy control group was also enrolled. Schizophrenic patients as a group had significantly higher pHVA levels than controls at baseline (20.50+/-11.85 vs. 13.04+/-7.22 ng/ml). Moreover, 12 predominantly negative syndrome patients had similar mean baseline pHVA levels (21.30+/-12.36 ng/ml) to those of 28 predominantly positive syndrome patients (19.40+/-11.33 ng/ml). During follow-up, there was a different evolution of pHVA levels in the predominantly positive syndrome group than in the predominantly negative syndrome group, with a significantly greater global reduction of pHVA levels in the former. Although both groups showed clinical improvement following 4 weeks of treatment with risperidone, pHVA levels at endpoint were lower (13.29+/-5.91 ng/ml) than at baseline in patients in the predominantly positive syndrome group, while among those in the predominantly negative syndrome group there was no difference in pHVA levels before and after treatment (21.02+/-13.06 ng/ml). The different pHVA level profiles observed in predominantly positive and negative syndrome first episode patients after 4 weeks of treatment with risperidone suggest that each syndrome may have a different underlying neurobiology.

Inter- and intra-individual variability in the levels of plasma homovanillic acid in schizophrenic patients

BACKGROUND

Changes in the levels of homovanillic acid in blood plasma (pHVA) may reflect changes which occur in the brain. In healthy individuals, this concentration of pHVA is stable over time.

METHODS

Over the course of one month, we studied 98 acute schizophrenic patients who had not been taking any medication but were administered neuroleptics upon hospital admission, together with 23 chronic schizophrenic patients on long-term treatment from whom medication was withdrawn. Blood samples were taken at regular intervals from each individual and the concentration of plasma homovanillic acid was measured.

RESULTS

We found relative stable values of pHVA with an intraclass correlation coefficient of 0.363 in acute patients and 0.638 (p<0.0001) in chronic patients, although no differences were found in mean values (13.79 and 14.18 microg/L, respectively) or in the variation range (7.20 to 26.7 microg/L and 6.96 to 29.96 microg/L respectively). The index of individuality was calculated to be 1.36 in acute patients and 0.74 in chronic patients.

CONCLUSIONS

Despite the wide range of values in the concentration of pHVA and the presence of pharmacological stimuli, we found a certain reproducibility in the levels of this dopamine metabolite. These findings are consistent with the idea that the dopaminergic activity is characterized by a constitutive value which would be under genetic control. The higher stability observed in chronic patients may reflect a weaker, age-related dopaminergic plasticity; conversely, it may indicate that a lack of plasticity in response to a pharmacological stimulus may be an indicator of poorer prognosis.

Neuropsychological impairments in neuroleptic-responder vs. -nonresponder schizophrenic patients and healthy volunteers

To determine whether two groups of schizophrenic patients representing the two extremes of the neuroleptic response-spectrum (consistent responders vs. consistent nonresponders) differ with respect to their neuropsychological profile. Neuroleptic-responder (R; n=36) and -nonresponder (NR; n=39) schizophrenic patients were recruited according to a priori defined criteria of responsiveness to typical neuroleptics. Seven neuropsychological domains were assessed and compared between groups: attention-vigilance, abstraction-flexibility, spatial organization, visual-motor processing, visual memory, verbal abilities, and verbal memory and learning. All measures were standardized using the scores of 36 healthy volunteers. NR schizophrenic patients performed worse in all neuropsychological domains compared to normal controls and R schizophrenic patients. However, only performances on visual memory, verbal abilities, and verbal memory and learning were significantly poorer in NR compared to R patients. Only the latter domain significantly differentiated NR patients from the other two groups. R patients performed at an intermediate level in all domains. This report of differences in neuropsychological profile between neuroleptic-responder and -nonresponder schizophrenic patients adds to the growing evidence supporting the value of distinguishing schizophrenic patients on the basis of their therapeutic response to neuroleptics.

ADHD and reading disabilities: a cluster analytic approach for distinguishing subgroups

Data suggest that children with reading disability (RD) and non-RD children with attention-deficit/hyperactivity disorder (ADHD) may comprise distinct subgroups. Research has been hampered by variance in definitional criteria, which results in the study of different subgroups of children. Using cluster analysis, this study empirically divided children with ADHD (N = 54), based on their Full Scale IQ (FSIQ) and reading ability. Four distinct subgroups emerged in which cognitive, behavioral, and neurochemical function was compared. Cluster 1 was of average FSIQ and reading scores; Cluster 2 was of average FSIQ but showed impairment in reading; Cluster 3 had high FSIQ and reading scores; and Cluster 4 had low scores in both domains. The groups had different patterns of cognitive, behavioral, and neurochemical function, as determined by discrepancies in Verbal-Performance IQ, academic achievement scores, parent aggression ratings, and a measure of noradrenergic function. These distinctions are discussed with regard to etiology, treatment, and long-term outcome.

Determination of norepinephrine in small volume plasma samples by stable-isotope dilution gas chromatography-tandem mass spectrometry with negative ion chemical ionization

A stable-isotope based gas chromatography-tandem mass spectrometry-negative ion chemical ionization method was developed for the determination of norepinephrine (NE) levels in small volumes (25-100 microl) of plasma. NE was stabilized in plasma by the addition of semicarbazide and spiked with deuterium-labeled norepinephrine internal standard. The analytes were isolated from the plasma by solid-phase extraction using phenylboronic acid columns and derivatized using pentafluoropropionic anhydride. The derivatized analytes were chromatographed on a capillary column and detected by tandem mass spectrometry with negative ion chemical ionization. Unparalleled sensitivity and selectivity were obtained using this detection scheme, allowing the unambiguous analysis of trace levels of NE in small-volume plasma samples. Linear standard curves were obtained for NE over a mass range from 1 to 200 pg per sample. The method had a limit of quantitation of 10 pg NE/ml plasma when using a 100-microl sample aliquot (1 pg/sample). Accuracy for the analysis of plasma samples spiked with 10 to 200 pg NE/ml typically ranged from 100+/-10%, with RSD values of less than 10%. The methodology was applied to determine the effect of clonidine on plasma NE levels in conscious spontaneously hypertensive rats. Administration of clonidine (30 microg/kg) produced an approximately 80% reduction in plasma NE accompanied by a 30% reduction in heart and mean arterial pressure that persisted >90 min after drug administration. The ability to take multiple samples from individual rats allowed the time course for the effect of clonidine to be mapped out using only one group of animals.

Genetic antecedents of dopamine dysfunction in schizophrenia

BACKGROUND

Relatives of schizophrenic probands frequently manifest attenuated features of this illness including the negative symptoms and the milder positive psychotic symptoms. These two symptom dimensions are hypothesized to be associated with decreased and increased brain dopamine (DA) functions, respectively, raising the possibility that DA abnormalities may be present in the relatives of schizophrenic probands.

METHODS

Plasma homovanillic acid (HVA), the major DA metabolite and an indicator of brain DA activity, was measured in nonpsychotic, physically healthy first-degree relatives (n = 55) of schizophrenic probands and in normal subjects (n = 20) without a family history of schizophrenia.

RESULTS

Plasma HVA inversely correlated with negative symptoms and positively correlated with attenuated positive symptoms. Also, relatives had decreased plasma HVA compared to normal subjects, consistent with the fact that these relatives are characterized by negative symptoms. These findings were not related to major peripheral factors that could affect plasma HVA suggesting that the findings may reflect changes in brain DA activity.

CONCLUSIONS

Negative symptoms indicating a genetic diathesis to schizophrenia in relatives may have a biologic basis in reduced DA activity and the DA dysfunction of schizophrenia may have genetic antecedents. This opens an important new avenue for further study of DA in this illness.

Neurodevelopmental evaluation of 9-month-old infants exposed to low levels of lead in utero: involvement of monoamine neurotransmitters

The objective of this work is to investigate the neurotoxicty of low-level lead exposure in utero on infants and the possible involvement of dopaminergic and serotonergic neurotransmitters. The correlation analysis for cord blood lead level, the concentrations of dopamine metabolite homovanillic acid (HVA) and serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cord plasma and the neurodevelopmental scales of infants were conducted on 244 9-month-old children. Both score of sociability subscale and 5-HIAA concentration were correlated with cord blood lead level. The sociability score was negatively correlated with the concentration of HVA, whereas both the coordination score and the global score were negatively correlated with the concentration of 5-HIAA. With partial correlation analysis, after taking HVA into account, the significant negative correlation between the sociability score and the cord blood lead level that existed in the linear correlation analysis disappeared, and the score of global scale correlated negatively with lead level in cord blood. When taking 5-HIAA into account, the scores of all the neurodevelopmental subscales except the language subscale were significantly negatively correlated with lead level in cord blood. The results indicated that low-level lead exposure in utero could produce a neurotoxic effect on the developing serotonergic system in infants. The neurotoxicity of low-level lead exposure in utero may affect the sociability of infants. Serotonergic activity was shown to have a potential effect on neurodevelopmental assessment. It may interfere with the association between low-level lead exposure in utero and other neurodevelopmental performances of 9-month-old children.

Pretreatment plasma homovanillic acid in schizophrenia and schizoaffective disorder: the influence of demographic variables and the inpatient drug-free period

BACKGROUND

The relationship between plasma homovanillic acid (pHVA) and schizophrenic symptoms has not been conclusively determined. We reexamine pHVA levels in a new sample of patients with emphasis on demographic variables and the drug-free period.

METHODS

Plasma HVA levels were studied in 54 schizophrenic and schizoaffective-disordered, drug-free inpatients suffering from a psychotic exacerbation.

RESULTS

A significant correlation was observed between pHVA levels and the number of inpatient drug-free days in the total sample, as well as the schizophrenic patient subsample. Further, pHVA was significantly and positively correlated with the duration of illness in the schizophrenic patient subsample. Plasma HVA correlations with behavior, as measured by Brief Psychiatric Rating Scale factors (anxiety/depression and hostility/suspiciousness), emerged only when considering schizophrenic patients drug-free for more than 2 weeks. No correlation was found between pHVA and the age of illness onset or the duration of the delay of treatment of the first psychotic episode.

CONCLUSIONS

The effects of antipsychotic withdrawal on levels of pHVA in clinical populations may have to be examined and controlled for in future studies attempting to study the relationship between this metabolite and behavior in acutely ill, drug-free schizophrenic patients.

Pretreatment plasma HVA predicts neuroleptic response in manic psychosis

Elevated pretreatment plasma free homovanillic acid (HVA) predicted acute response to neuroleptic treatment in patients with manic psychosis. These findings suggest that plasma HVA may be a useful predictor of a successful short-term response in manic as well as schizophrenic psychoses, and that elevated pre-synaptic dopaminergic release may play a role in more than one group of psychotic disorders.

Plasma 3-methoxy-4-hydroxyphenylglycol and homovanillic acid measurements in deficit and nondeficit forms of schizophrenia

BACKGROUND

Discrepancies in the biochemical research on negative symptoms in schizophrenia may be ascribed to the lack of differentiation into primary and secondary negative symptoms. We have used Carpenter's criteria to define the deficit syndrome of schizophrenia as the presence of enduring and primary negative symptoms and measured catecholaminergic parameters in deficit as compared with nondeficit schizophrenics.

METHODS

We have investigated plasma homovanillic acid (pHVA) and 3-methoxy-4-hydroxyphenylglycol (pMHPG) concentrations in 34 DSM-III-R neuroleptic-treated schizophrenic patients who were classified into deficit (n = 14) and nondeficit (n = 20) forms of schizophrenia. All these patients were in a stable clinical and therapeutic status for the preceding 12 months.

RESULTS

The 14 deficit schizophrenic patients had lower plasma levels of pHVA and higher plasma concentrations of pMHPG from 9 AM to 12 AM as compared with the 20 nondeficit schizophrenic patients. The two groups did not differ on any demographic, therapeutic, or clinical variable considered.

CONCLUSIONS

Our data are consistent with the postulated distinct pathophysiological basis for the deficit syndrome of schizophrenia and suggest that opposite alterations in the pHVA or pMHPG levels may reflect specific changes in noradrenergic and dopaminergic functions in these deficit patients.

Association of plasma homovanillic acid with behavioral symptoms in patients diagnosed with dementia: a preliminary report

Neuroleptic treatment of psychotic symptoms or agitated behavior in elderly patients diagnosed with dementia is associated with reduced efficacy and increased rates of neuroleptic-induced parkinsonism in comparison to younger patients with schizophrenia. We report the first study to examine the relationship between an in vivo measure of dopaminergic function, plasma homovanillic acid (pHVA), and ratings of psychosis, agitation, and parkinsonism before and after neuroleptic treatment in dementia patients. Pretreatment pHVA was significantly correlated with parkinsonian rigidity, with a trend observed with agitation and hostility. Though mean pHVA did not change during perphenazine treatment, intraindividual change in pHVA at day 15 was correlated with improvement in hostility, with a similar trend for improvement in agitation. These preliminary findings are consistent with reports associating dopaminergic function with agitated, but not psychotic, symptoms in patients diagnosed with dementia, and with a reduced responsivity of dopaminergic systems to neuroleptic treatment in these patients.

Noradrenergic mechanisms in ADHD children with and without reading disabilities: a replication and extension

OBJECTIVE

To examine noradrenergic (NA) function in children with attention-deficit hyperactivity disorder (ADHD) by replicating and expanding upon a previous finding that ADHD children with and without reading disabilities (RD) differ in plasma levels of the NA metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG).

METHOD

Plasma levels of MHPG were compared in ADHD children who were subdivided on the basis of the presence or absence of RD. Subsequently, this replication sample was combined with a previously studied sample to further explore the relationship between plasma MHPG levels and measures of cognitive function in children with ADHD.

RESULTS

Plasma levels of MHPG were significantly lower in ADHD children without RD, compared with those with RD, replicating a published finding. Analyses in the combined sample indicated that, among children with ADHD, plasma MHPG levels were inversely associated with measures of academic achievement and verbal processing, but not parent or teacher ratings of behavior or continuous performance test measures of attention and impulsivity.

CONCLUSIONS

These data indicate that children with ADHD are not homogeneous with regard to NA function and that neurochemical variation is closely associated with differences in clinical characteristics of the children.

Relationship between 3-methoxy-4-hydroxyphenylglycol and homovanillic acid in saliva and plasma of healthy volunteers

Plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) levels may reflect changes in central noradrenergic and dopaminergic activity, respectively. The relationship between MHPG and HVA in saliva and plasma was investigated to evaluate the utility of salivary metabolite measurement as a relatively noninvasive and useful alternative to plasma analysis. MHPG and HVA in saliva and plasma, collected concurrently, from 12 healthy volunteers, were measured by high-performance liquid chromatography. Concentration of free MHPG in saliva correlated significantly with plasma free MHPG. Salivary free MHPG was significantly higher than in plasma. Enzymatic hydrolysis of conjugated MHPG corroborated other work that plasma free MHPG, MHPG-glucuronide, and MHPG-sulfate were in roughly equal proportions. Unpredictably, in saliva, free MHPG was greater than 80% of the total. Salivary and plasma free HVA concentrations also correlated significantly, but salivary HVA levels were significantly lower than in plasma. Conjugated HVA was consistently less than 10% of total both in saliva and plasma. These findings suggest that salivary MHPG and HVA can reflect plasma metabolite levels. Although local factors may influence their formation and concentration in saliva, large changes in plasma free MHPG or HVA could be reflected by parallel changes in saliva.

New dopaminergic and non-dopaminergic theories in schizophrenia and their therapeutic impact

The dopamine (DA) hypothesis of schizophrenia, postulating that schizophrenia is characterized by increased dopamine function, has been the most influential theory on the pathogenesis of schizophrenia. It has recently been revised based on the appreciation that the core symptoms of schizophrenia may not be the positive (psychotic) symptoms, but rather the negative symptoms and the cognitive deficits found in schizophrenic patients. This revision has prompted the hypothesis that schizophrenia is characterized by both decreased prefrontal dopamine activity (causing deficit symptoms) and increased dopamine activity in mesolimbic dopamine neurons (causing positive symptoms). Notwithstanding this revision of a role for dopamine in schizophrenia, it has become increasingly evident that dysfunction of other monoaminergic systems may be as important in contributing to the pathophysiology of schizophrenia. Specifically, the putative role of serotonin (5-hydroxytryptamine, 5-HT) in schizophrenia is gaining considerable attention. Several observations, such as the ability of the 5-HT antagonist, ritanserin, to alleviate schizophrenic symptoms and, when added to haloperidol (Haldol®), to decrease its extrapyramidal side-effects (EPS), have stimulated studies into a role of 5-HT in schizophrenia. The finding that clozapine (Leponex®), clinically superior to conventional neuroleptics, is a weak DA2 antagonist but a potent 5-HT1c and 5-HT2 antagonist has further stimulated 5-HT-related research in schizophrenia.

First-episode neuroleptic-free schizophrenics: concentrations of monoamines and their metabolites in plasma and their correlations with clinical responses to haloperidol treatment

Thirty-two first-episode neuroleptic-free schizophrenics were treated with neuroleptics for 8 weeks. The monoamines and their metabolites, dopamine, norepinephrine, serotonin, homovanillic acid (HVA), 3-methoxy-4-hydroxy-phenylglycol(MHPG), and 5-hydroxyindoleacetic acid (5-HIAA) in plasma were measured to examine the association with treatment responses and psychopathology assessed according to the brief psychiatry rating scale (BPRS). No differences were noted in the pretreatment concentrations of monoamines and their metabolites between patients and healthy controls; however, during treatment the concentrations of HVA and MHPG were significantly reduced only in the schizophrenics who responded to treatment. Moreover, the HVA and MHPG reductions correlated significantly with improvements in BPRS scores. Since their plasma levels reflect to some extent central dopaminergic and noradrenergic activities, respectively, the present findings suggest the involvement of these systems in the pathogenesis of schizophrenia as well as the usefulness of such measurements as predictors of responsiveness to neuroleptics.

Changes in plasma prolactin and catecholamine metabolite levels following acute needle stick in children

Changes in plasma levels of prolactin (PRL), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) following insertion of an indwelling catheter into a forearm vein were assessed in 11 boys with attention-deficit hyperactivity disorder. Results indicated decreases in plasma PRL and HVA, but not MHPG, from the time of needle stick until 105 min post-insertion. These data indicate a significant increase in plasma PRL and HVA in children following needle stick which gradually decreases over a 1.5-2-h period. These stress-induced changes indicate that values obtained immediately after needle insertion cannot be assumed to accurately reflect baseline levels.

A study of the potential confounding effects of diet, caffeine, nicotine and lorazepam on the stability of plasma and urinary homovanillic acid levels in patients with schizophrenia

Ten men inpatients who met DSM-III-R criteria for schizophrenia participated. On five occasions at least one week apart, each subject had an intravenous line placed at 0730 after an overnight fast. On each occasion blood samples were drawn at 0800 and hourly thereafter through 1200 noon for measurement of plasma homovanillic acid (HVA). Total four-hour urine collections were obtained for measurement of urinary HVA. Subjects received five experimental conditions, in randomized sequence: no intervention, smoking one cigarette per hour, drinking one caffeinated cola per hour, lorazepam 2 mg IV push, or a high monoamine meal. Baseline (0800) plasma HVA measures showed only minor intrinsic variability. The average standard deviation in baseline plasma HVA over five occasions of measurement was low relative to the changes in HVA produced during treatment with antipsychotic medications. The high monoamine meal significantly elevated plasma HVA, with a similar trend for urinary HVA. Neither caffeine, nicotine, nor lorazepam significantly affected plasma or urinary HVA.

Empirical evaluation of the factorial structure of clinical symptoms in schizophrenia: effects of typical neuroleptics on the brief psychiatric rating scale

There has been little investigation of the effect of neuroleptic medication on the structure of symptoms in schizophrenia. In this study, 135 male schizophrenic patients were rated with the Brief Psychiatric Rating Scale (BPRS) after 4 weeks of treatment with typical neuroleptic medication and after 2 weeks free of neuroleptics, with the order of assessment varying across patients. Confirmatory factor analyses (CFA) found that there were no differences in symptom structure across medication status and no differences in the structure of symptoms in treatment responders and nonresponders. The typical 5-factor BPRS model fit the data poorly and the fit improved considerably through deletion of items measuring symptoms not associated with schizophrenia, suggesting that some of the symptoms that contribute to a total BPRS score may be adding primarily error variance. Although the sample size in this study is limited, the results suggest that using total BPRS scores to measure severity of schizophrenic symptoms should be reconsidered.

Plasma homovanillic acid concentrations in catatonia

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.

Plasma homovanillic acid levels and therapeutic outcome in schizophrenics: comparisons of neuroleptic-naive first-episode patients and patients with disease exacerbation due to neuroleptic discontinuance

Plasma homovanillic acid (pHVA) levels were measured and the Brief Psychiatric Rating Scale (BPRS) scores were evaluated in 26 schizophrenic patients who had either never been medicated (neuroleptic-naive, first-episode subjects) or whose condition had become exacerbated following neuroleptic discontinuance (exacerbated subjects). All the subjects received medication with a fixed dose of a neuroleptic (haloperidol or fluphenazine, both 9 mg/day) for the first week and variable doses for the subsequent 4 weeks. In the neuroleptic-naive subjects, pHVA levels increased significantly 1 week after starting the protocol; this increase correlated significantly with clinical improvement of the BPRS positive symptom scores at week 5. In the neuroleptic-naive subjects, pHVA levels had declined to the baseline level by week 5. In the exacerbated subjects, there were no significant correlations between pHVA level changes at week 1 and later improvements of the BPRS positive symptom scores. These results suggest that the rise in pHVA levels occurring within 1 week after starting a fixed neuroleptic dose may predict a favorable clinical response in neuroleptic-naive schizophrenic patients.

Catatonia: short-term response to lorazepam and dopaminergic metabolism

Therapeutic response to lorazepam and dopaminergic metabolism were investigated in 18 neuroleptically naive acute catatonic patients. They were diagnosed as catatonic according to criteria by Lohr and Rosebush and treated exclusively with lorazepam (2-4 mg) during the first 24 h. Dopaminergic metabolism (plasma HVA, plasma MHPG), anxiety (HAM-A) and parkinsonic/dyskinetic movements (SEPS, AIMS) were measured under standard conditions before initial treatment with lorazepam (day 0) and 24 h after initial treatment (day 1). On day 0 responders to lorazepam treatment (complete remission of catatonic syndrome after 24 h according to Rosebush and Lohr) showed significantly higher (P = 0.004) plasma HVA (130.4 +/- 51.2 pmol/ml; means +/- SD) than non-responders (no remission of catatonic syndrome after 24 h; 73.2 +/- 40.5 pmol/ml; means +/- SD). On day 1 plasma HVA did not differ any more significantly between both groups Clinically, responders showed significantly higher HAM-A (P = 0.025) and AIMS (P = 0.022) scores as well as significantly lower SEPS (P = 0.049) scores than non-responders on day 0. Hence catatonic short-term responders and nonresponders to lorazepam can be distinguished with regard to plasma HVA, anxiety and dyskinetic/parkinsonic movements.

Time course of the corticosteroid-dopaminergic interaction during metyrapone and dexamethasone administration

Recent studies performed with depressed patients and normal subjects suggest that corticosteroids may alter dopaminergic activity. We measured the time course of the interaction between corticosteroid and plasma homovanillic acid (HVA) levels in 10 young healthy subjects after the administration of 2 mg of dexamethasone in session 1 and after the administration of 4.5 g of metyrapone in session 2. Plasma levels of adrenocorticotropic hormone (ACTH), 11-desoxycortisol, cortisol, HVA, and prolactin (PRL) were measured at 08:00, 09:00, 12:00, 15:00, and 16:00 h on a baseline day and during both drug-administration sessions. Dexamethasone administration resulted in a significant decrease in plasma levels of ACTH, 11-desoxycortisol, and cortisol at all time points and to a significant decrease in PRL secretion in the early morning. Plasma HVA levels were unchanged after dexamethasone administration. Metyrapone administration resulted in a significant decrease in cortisol levels and a significant increase in ACTH and 11-desoxycortisol levels. Plasma HVA levels were significantly increased in the early morning, while PRL levels were unaltered. These results are discussed in relation to the neurochemical and behavioral changes associated with steroid administration and interpreted with regard to a possible association between HVA and PRL in the effects of corticosteroids on dopaminergic activity.

Decreased DOPAC in the anterior cingulate cortex of individuals with schizophrenia

The dopamine metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), was found to be decreased in the anterior cingulate cortex of individuals with schizophrenia compared with normal controls. The finding does not appear to be solely related to the presence of antipsychotic medications, age, postmortem interval, or freezer time. No changes in norepinephrine and its metabolites were found.

Treatment of obsessive-compulsive symptoms in schizophrenic patients with clomipramine

Recent studies show that obsessive-compulsive symptoms may occur in many patients with schizophrenia and may predict a poor prognosis. Pilot studies have shown that some schizophrenic patients may improve if a serotonin reuptake blocker is added to their neuroleptic. We have performed a pilot, double-blind, crossover study of clomipramine (CMI) or placebo, added to maintenance psychotropic medication. Six schizophrenic patients with obsessive-compulsive symptoms were studied in a double-blind CMI versus placebo crossover protocol. The patients met DSM-III-R criteria for chronic schizophrenia, experienced obsessive-compulsive symptoms, and had been previously stabilized on their psychiatric medication. The patients were rated at baseline and longitudinally through the study with the Positive and Negative Symptom Scale for Schizophrenia (PANSS) and the Yale Brown Obsessive-Compulsive Scale (YBOCS). An analysis of covariance was used to compare the drug versus placebo effect at the final visit with the baseline rating as a covariate. Ratings on both the YBOCS and the PANSS showed that patients improved significantly more on CMI than on placebo. No patients experienced an exacerbation of psychotic symptoms. Preliminary findings from this double-blind, crossover, pilot study of CMI and placebo, designed to assess the effect of CMI in the treatment of schizophrenic patients with obsessive symptoms, suggest that CMI is superior to placebo in the treatment of obsessions and compulsions and improves overall schizophrenic symptoms. Further studies with larger samples and longer follow-up period are necessary to confirm these preliminary findings.

Positron emission tomography and plasma biochemistry findings in schizophrenic patients before and after electroconvulsive therapy

The clinical effects of electroconvulsive therapy (ECT) on the morbidity of paranoid schizophrenic patients were assessed by positron emission tomography (PET) and plasma biochemistry studies before and after ECT. The present study included five patients whose average age was 41.4 years. The average duration of illness was 23.0 years. To avoid any effect of changes in drugs on PET, no changes were made in the medication of any of the five patients during the study period. ECT improved the clinical symptoms in every patient. Regional cerebral blood flow (rCBF) on PET in both temporal lobes and the left cerebellum was higher in paranoid schizophrenia before ECT than in normal subjects, and rCBF after ECT in both frontal lobes, the right temporal lobe and the right putamen was lower than before ECT as mental symptoms improved. These findings suggest high cerebral blood flow volume in paranoid schizophrenia. Plasma biochemistry studies revealed a lower level of 3-methoxy-4-hydroxyphenylglycol (MHPG) after ECT than before ECT, but a higher level of prolactin existed.

Longitudinal changes in symptoms and plasma homovanillic acid levels in chronically medicated schizophrenic patients

A correlation has been noted between the changes in plasma homovanillic acid concentrations and changes in psychiatric symptoms induced by neuroleptic treatment. Our objective was to determine whether plasma homovanillic acid concentration changed in accordance with the changes in symptoms over time. Twenty-eight chronically medicated schizophrenic inpatients received the same treatment regimen for 1 year. Symptoms and plasma homovanillic acid concentrations were examined every month and whenever conditions deteriorated. Plasma homovanillic acid concentrations were significantly higher in the patients in the worst condition than in the patients in the best condition. Further, when comparing the best and worst conditions of both the positive and negative symptoms, the change in psychiatric rating of positive and negative symptoms was correlated significantly with the change in plasma homovanillic acid level. These results suggest that a change in plasma homovanillic acid concentration can be produced not only by neuroleptic-induced dopaminergic blocking but also by a change in positive and negative symptoms of schizophrenia.

Effects of raclopride treatment on plasma and CSF HVA: relationships with clinical improvement in male schizophrenics

Thirty-two acutely psychotic, male schizophrenic patients received raclopride, at 2, 6, or 12 mg/day, or haloperidol, 15 mg/day for 4 weeks after randomized, double-blind assignment. Twenty-six patients, including 19 who had been assigned one of the three doses of raclopride, completed the study. Raclopride, particularly at 12 mg/day, increased CSF homovanillic acid (HVA) at 4 weeks, and plasma HVA at 2 days, of treatment. The clinical response to raclopride was significantly correlated with plasma raclopride concentrations and baseline plasma HVA concentrations. Although raclopride is a substituted benzamide with atypical properties in animals, these results suggest that the doses of raclopride required for clinical efficacy and elevation of clinical indices of brain dopamine turnover are similar.

A comparison of plasma homovanillic acid in the deficit and nondeficit subtypes of schizophrenia

Plasma homovanillic acid (pHVA) was measured over a 13 hr-period in 16 DMS-III-R schizophrenic patients, all treated with neuroleptic drugs and in a stable clinical and therapeutic status for the preceeding 12 months. Patients were categorized into deficit (n = 9) and nondeficit (n = 7) forms of schizophrenia according to the Schedule for the Deficit Syndrome (SDS) criteria. As compared to the nondeficit group, deficit patients display significantly lower mean pHVA concentrations from 9 AM to 12 AM and a lack of diurnal variations. None of the demographic, clinical, and therapeutic variables can explain these biological differences. These data suggest a specific biochemical basis for the deficit syndrome of schizophrenia as defined by the SDS criteria, that is, primary, enduring, negative symptoms.

Comparative study of dopamine metabolism with local cerebral glucose utilization in rat brain following the administration of haloperidol decanoate

The effects of haloperidol decanoate on dopamine (DA) metabolism in discrete regions of rat brain were investigated and compared with changes in local cerebral glucose utilization (LCGU). The concentration of DA and its metabolite, homovanillic acid, and the alpha-methyl-p-tyrosine (alpha-MT)-induced decline of DA were measured in 6 brain regions by a high-performance liquid chromatographic assay. LCGU in 26 brain regions were examined by [14C]2-deoxy-D-glucose autoradiography. At 24-hr after intramuscular injection of haloperidol decanoate (60 mg eq/kg to haloperidol), the concentration of homovanillic acid in the prefrontal cortex, caudate-putamen, accumbens nucleus, lateral amygdala, and medial thalamus showed significant increase compared with control values. On day 21, the increase in these regions was significantly attenuated with no significant difference from the controls. Furthermore, chronic haloperidol rats showed alpha-MT-induced decline of DA to a similar extent in the control rats. LCGU on day 21 showed significant decrease in the parietal cortex, and a tendency toward decrease in the prefrontal cortex, lateral amygdala and medial thalamus compared with the controls. There was no significant change in LCGU in the caudate-putamen or accumbens nucleus. Chronic haloperidol would thus appear to affect energy metabolism mainly in the cortico-thalamo-limbic circuits, and this may not correspond well to presynaptic DA metabolism.

Rapid measurement of the monoamine content in small volumes of rat plasma

A method for the simultaneous measurement of serotonin, catecholamines, and their metabolites, 5-hydroxy-indoleacetic acid, homovanillic acid, and 3, 4-dihydroxyphenylacetic acid, by ultrafiltration and microbore high-performance liquid chromatography with dual electrochemical detection in small plasma volumes was established. Unlike the traditional assays which require at least 1-2 ml of plasma for each measurement, the present method uses only a 20-microliters sample volume. Since blood loss is minimal, repeated blood sampling from a single animal as a rat becomes practicable. The present microassay provides low detection limits (signal-to-noise ratio = 3) for all analytes (0.2-0.5 pg per 5-microliters injection or 50-120 pg/ml plasma). Isocratic separation of these analytes on a microbore column is achieved within 15 min. This rapid and sensitive method can be used as a routine research tool in various physiological or pharmacokinetic studies especially in small animals.

Rapid assay of the monoamine content in small volumes of rat plasma

A method for the simultaneous measurement of serotonin catecholamines, and their metabolites in rat plasma by ultrafiltration and microbore liquid chromatography with electrochemical detection (LC-ED) in small volumes is established. Prior to the LC assay, sixteen plasma ultrafiltrates are readily prepared within 30 min in the present study. The present method, applying a dual-electrode detection technique, provides an additional reliable assignment or measurement of peaks by identifying the peaks on the basis of their redox ratios. In addition, the important early-eluting peaks and interfering peaks are eliminated in the cathodic chromatogram resulting in a reliable measurement of norepinephrine, epinephrine, and 3,4-dihydroxyphenylacetic acid. Isocratic separation of serotonin, catecholamines, and their metabolites by a microbore column is achieved within 15 min. Hence, theoretically, over 90 analyses can be performed in a working day. The limit of detection (signal-to-noise ratio = 3) of this method is ca. 0.2-0.5 pg per injection for all analytes. The required volume of the plasma samples can be less than 100 microliters. Hence, the remainder of the plasma sample can be analysed for other substances. This rapid, simple, and sensitive method can thus be used as a research tool in the simultaneous measurement of rat plasma serotonin, catecholamines, and their metabolites.

Influence of renal clearance on peripheral homovanillic acid measurements in healthy subjects and schizophrenic patients

In order to investigate the effect of renal clearance on plasma homovanillic acid (HVA) concentrations, we examined plasma concentration and urinary excretion of HVA and creatinine per 4 h over 24 h in eight male schizophrenic patients and eight healthy male subjects. Renal clearances of HVA and of creatinine were determined per 4 h period. No significant differences were found between groups in the total 24 h excretion of either HVA or creatinine. Although differences between groups in plasma HVA concentrations and urinary HVA excretion per 4 h did not reach statistical significance, the renal clearance of HVA was significantly lower in the patient group than in the control group. There was no difference between groups in creatinine clearance. Diurnal changes were seen in the renal clearance of HVA and creatinine in both groups. Renal HVA clearance decreased from 23.00-07.00 h, with a coincident decrease in urinary HVA excretion and an increase in plasma HVA concentration. We provide evidence that renal clearance is an important determinant of plasma HVA concentration, and should be considered when interpreting plasma HVA data.

Plasma homovanillic acid in neuroleptic responsive and nonresponsive schizophrenics

Changes in plasma homovanillic acid (HVA) were investigated in neuroleptic responsive and nonresponsive schizophrenics in order to delineate parameters of dopamine regulation, which may underlie differences in neuroleptic responsivity. Nineteen schizophrenics were treated with haloperidol for 6 weeks. HVA was sampled at baseline, 24 hr after initial neuroleptic dose, and after 6 weeks of treatment. Subjects were pretreated with debrisoquin in order to reduce the peripheral production of HVA. The responders had an initial rise in HVA at 24 hr after first neuroleptic dose, followed by a decline back to baseline over the 6 weeks of treatment. The nonresponders' HVA failed to rise at 24 hr after first neuroleptic dose. At 6 weeks of treatment their HVA had fallen to significantly below baseline. Thus, a rise in HVA 24 hr after the first dose of neuroleptic predicted treatment response; a fall in HVA at 6 weeks to below pretreatment values was associated with neuroleptic nonresponse.

Rapid and reliable high-performance liquid chromatographic method for analysing human plasma serotonin, 5-hydroxyindoleacetic acid, homovanillic acid and 3,4-dihydroxyphenylacetic acid

The simultaneous measurement of homovanillic acid, 3,4-dihydroxyphenylacetic acid, serotonin and 5-hydroxyindoleacetic acid in human plasma by an ultrafiltration and microbore high-performance liquid chromatography-electrochemical detection technique is established. Conventional preparation of blood is very tedious and time-consuming, but isocratic separation of the analytes in plasma ultrafiltrates using a microbore column could be achieved within 10 min. Hence, theoretically, over 140 analyses can be performed in a working day. The detection limit (signal-to-noise ratio = 3) of this method is about 0.1-0.5 pg per injection for all analytes. The required volume of plasma samples can be less than 100 microliters. Hence, blood loss is minimal, especially in repeated blood sampling. This rapid, simple and sensitive method can, therefore, be used as a routine clinical tool in the simultaneous measurement of plasma homovanillic acid, 3,4-dihydroxyphenylacetic acid, serotonin and 5-hydroxyindoleacetic acid.

Early response to haloperidol treatment in chronic schizophrenia

This study examined the time-course of treatment response to haloperidol in chronic schizophrenia. Furthermore the predictive value of baseline psychopathology and early therapeutic changes for the identification of the eventual treatment outcome was examined. After a two-week drug-free period forty-three chronic schizophrenic patients were treated with haloperidol for five weeks. Psychopathology was assessed on the last drug-free day and on the third and eighth day from the initiation of treatment, and then at weekly intervals. At the end of the study based on a priori criteria patients were classified as responders or non-responders to haloperidol. Seventeen patients met criteria for treatment response at the end of five weeks of treatment, while 26 did not. Already by the third day of treatment, in the responders there was a significant decrease in total BPRS and in the subscales scores for psychosis, tension and anergia, but not for hostility-suspiciousness and depression. These decreases represented approximately half of the eventual improvement obtained by the end of the study. Discriminant function analysis showed that severity of symptoms at baseline and improvement by day 3 correctly classified overall outcome in 72% of the cases.

A multidimensional (pharmacokinetic and clinical-biological) approach to neuroleptic response in schizophrenia. With particular reference to drug resistance

Despite the undisputable effectiveness of the available neuroleptic medications (NDs), short and long term outcome of schizophrenic disorders is often unsatisfactory and drug resistance phenomena are not uncommon. The causes of variability in the response seem to be primarily due to the heterogeneity of schizophrenic syndromes in terms of clinical history, symptoms, and biological patterns. The high non-compliance rate is an important source of therapeutic failure particularly during long-term treatment. The lacking or poor response to NDs can be linked to peculiar drug disposition patterns, which lead generally to inadequate plasma concentrations (too low or too high). To deal with pharmacokinetic aspects two main topics are discussed in this paper: (A) the interindividual differences in bioavailability and metabolism and (B) the plasma level-clinical response relationship. The knowledge of these aspects can significantly contribute to reducing some pseudo-drug resistance phenomena. Moreover, the need to combine these data with the new acquisitions on the pathophysiology of these disorders is emphasized, to deal properly with the complexity of drug response mechanisms during therapy with NDs. New heuristic paradigms for schizophrenic disorders, stemming from the evidences of their heterogeneity, in terms of clinical course, outcome and biological findings, should be considered in relation to response. Accordingly, the concept of 'therapeutic window' (as conceived in the '70s) for NDs (as for antidepressants) needs to be reexamined in relation to recent clinical, neurochemical and neuromorphological data. Finally, the indications for NDs monitoring (particularly for drugs like haloperidol and fluphenazine) are reported, suggesting that a multidimensional operational strategy could be particularly suitable to deal with drug resistance problems.

Lithium in combination with perphenazine: effect on plasma monoamine metabolites

The addition of lithium to perphenazine altered the pattern of plasma homovanillic acid (HVA) during the course of treatment for acute psychosis. In the perphenazine-treated group plasma HVA declined significantly by days 7-9 of treatment, whereas in the perphenazine-plus-lithium group plasma HVA tended to increase. The pattern for plasma methoxyhydroxyphenethyl-glycol (MHPG) was not significantly different for the two groups. The addition of lithium to a neuroleptic may enhance the metabolism of dopamine.