Plasma homovanillic acid in the prodromal phase of schizophrenia

Actualities in immunological markers and electrochemical sensors for determination of dopamine and its metabolites in psychotic disorders (Review)

Psychotic disorders represent a serious health concern. At this moment, anamnestic data, international criteria for diagnosis/classification from the Diagnostic and Statistical Manual of Mental Disorders-5 and the International Classification of Diseases-10 and diagnostic scales are used to establish a diagnosis. The most commonly used biomarkers in psychotic illnesses are those regarding the neuroimmune system, metabolic abnormalities, neurotrophins and neurotransmitter systems and proteomics. A current issue faced by clinicians is the lack of biomarkers to help develop a more accurate diagnosis, with the possibility of initiating the most effective treatment. The detection of biological markers for psychosis has the potential to contribute to improvements in its diagnosis, prognosis and treatment effectiveness. The mixture of multiple biomarkers may improve the ability to differentiate and classify these patients. In this sense, the aim of this study was to analyze the literature concerning the potential biomarkers that could be used in medical practice and to review the newest developments in electrochemical sensors used for dopamine detection, one of the most important exploited biomarkers.

Candidate metabolic biomarkers for schizophrenia in CNS and periphery: Do any possible associations exist?

Due to the limitations of analytical techniques and the complicity of schizophrenia, nowadays it is still a challenge to diagnose and stratify schizophrenia patients accurately. Many attempts have been made to identify and validate available biomarkers for schizophrenia from CSF and/or peripheral blood in clinical studies with consideration to disease stages, antipsychotic effects and even gender differences. However, conflicting results handicap the validation and application of biomarkers for schizophrenia. In view of availability and feasibility, peripheral biomarkers have superior advantages over biomarkers in CNS. Meanwhile, schizophrenia is considered to be a devastating neuropsychiatric disease mainly taking place in CNS featured by widespread defects in multiple metabolic pathways whose dynamic interactions, until recently, have been difficult to difficult to investigate. Evidence for these alterations has been collected piecemeal, limiting the potential to inform our understanding of the interactions among relevant biochemical pathways. Taken these points together, it will be interesting to investigate possible associations of biomarkers between CNS and periphery. Numerous studies have suggested putative correlations within peripheral and CNS systems especially for dopaminergic and glutamatergic metabolic biomarkers. In addition, it has been demonstrated that blood concentrations of BDNF protein can also reflect its changes in the nervous system. In turn, BDNF also interacts with glutamatergic, dopaminergic and serotonergic systems. Therefore, this review will summarize metabolic biomarkers identified both in the CNS (brain tissues and CSF) and peripheral blood. Further, more attentions will be paid to discussing possible physical and functional associations between CNS and periphery, especially with respect to BDNF.

Effects of interactions between variation in dopaminergic genes, traumatic life events, and anomalous self-experiences on psychosis proneness: Results from a cross-sectional study in a nonclinical sample

Background

There is a growing number of studies showing interactions between genetic polymorphisms associated with dopaminergic neurotransmission and traumatic life events (TLEs) on a risk of psychotic-like experiences (PLEs). Anomalous self-experiences (ASEs) have been associated both with TLEs as well as with PLEs. However, it remains unknown what is the role of ASEs in the complexity of gene–environment interactions on the emergence of PLEs.

Patients and methods

We included 445 young adults—university students from three big cities in Poland. We used the Traumatic Events Checklist to assess TLEs, the Inventory of Psychotic-Like anomalous self-experiences in order to measure ASEs, and the Prodromal Questionnaire (PQ16) to record the level of PLEs. The following gene polymorphisms, related to dopaminergic neurotransmission, were determined: the catechol-O-methyltransferase (COMT) rs4680 polymorphism, the dopamine D2 receptor (DRD2) rs6277 polymorphism, and the dopamine transporter 1 (DAT1) rs28363170 polymorphism.

Results

There was a significant effect of the interaction between the DAT1 polymorphism, a severity of ASEs, and a history of TLEs on the level of PLEs. Among the DAT1 10R/10R homozygotes with low level of ASEs, a severity of PLEs was significantly higher in individuals with a history of any TLEs. Higher scores of the PQ16 were associated with a greater severity of ASEs both in the DAT1 9R allele carriers and the DAT1 10R/10R homozygotes.

Conclusion

Our findings imply that genetic liability related to aberrant dopamine transport might impact the association between TLEs and PLEs in subjects with high levels of ASEs.

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.

Theranostic Biomarkers for Schizophrenia

Schizophrenia is a highly heritable, chronic, severe, disabling neurodevelopmental brain disorder with a heterogeneous genetic and neurobiological background, which is still poorly understood. To allow better diagnostic procedures and therapeutic strategies in schizophrenia patients, use of easy accessible biomarkers is suggested. The most frequently used biomarkers in schizophrenia are those associated with the neuroimmune and neuroendocrine system, metabolism, different neurotransmitter systems and neurotrophic factors. However, there are still no validated and reliable biomarkers in clinical use for schizophrenia. This review will address potential biomarkers in schizophrenia. It will discuss biomarkers in schizophrenia and propose the use of specific blood-based panels that will include a set of markers associated with immune processes, metabolic disorders, and neuroendocrine/neurotrophin/neurotransmitter alterations. The combination of different markers, or complex multi-marker panels, might help in the discrimination of patients with different underlying pathologies and in the better classification of the more homogenous groups. Therefore, the development of the diagnostic, prognostic and theranostic biomarkers is an urgent and an unmet need in psychiatry, with the aim of improving diagnosis, therapy monitoring, prediction of treatment outcome and focus on the personal medicine approach in order to improve the quality of life in patients with schizophrenia and decrease health costs worldwide.

The Role of Genes, Stress, and Dopamine in the Development of Schizophrenia

The dopamine hypothesis is the longest standing pathoetiologic theory of schizophrenia. Because it was initially based on indirect evidence and findings in patients with established schizophrenia, it was unclear what role dopamine played in the onset of the disorder. However, recent studies in people at risk of schizophrenia have found elevated striatal dopamine synthesis capacity and increased dopamine release to stress. Furthermore, striatal dopamine changes have been linked to altered cortical function during cognitive tasks, in line with preclinical evidence that a circuit involving cortical projections to the striatum and midbrain may underlie the striatal dopamine changes. Other studies have shown that a number of environmental risk factors for schizophrenia, such as social isolation and childhood trauma, also affect presynaptic dopaminergic function. Advances in preclinical work and genetics have begun to unravel the molecular architecture linking dopamine, psychosis, and psychosocial stress. Included among the many genes associated with risk of schizophrenia are the gene encoding the dopamine D2 receptor and those involved in the upstream regulation of dopaminergic synthesis, through glutamatergic and gamma-aminobutyric acidergic pathways. A number of these pathways are also linked to the stress response. We review these new lines of evidence and present a model of how genes and environmental factors may sensitize the dopamine system so that it is vulnerable to acute stress, leading to progressive dysregulation and the onset of psychosis. Finally, we consider the implications for rational drug development, in particular regionally selective dopaminergic modulation, and the potential of genetic factors to stratify patients.

Neuropsychological Profile in Patients with Schizotypal Personality Disorder or Schizophrenia

Neuropsychological impairments have been consistently reported in patients with schizophrenia. As little is known whether subjects with schizotypal personality disorder exhibit neurocognitive dysfunction similar to that in schizophrenia, we assessed the neuropsychological profile of 15 subjects with schizotypal personality disorder and compared it with that for 15 patients with schizophrenia and for 15 psychiatrically normal volunteers. All participants were administered a standard neuropsychological battery assessing language ability, spatial ability, visuomotor function, verbal memory, visual memory, auditory attention, visual attention, and executive function. Performance on most of the cognitive domains was impaired in patients with schizotypal personality disorder but less than patients with schizophrenia. Specifically, impairment in verbal memory and visuomotor ability in patients with schizotypal personality disorder and patients with schizophrenia were comparable, while patients with schizophrenia performed worse on the test of executive function than did patients with schizotypal personality disorder. As a whole, cognitive deficits in patients with schizotypal personality disorder were qualitatively similar to, but quantitatively milder than, those for patients with schizophrenia. The results suggest that cognitive abilities related to frontotemporal lobe function are disturbed across these schizophrenia-spectrum disorders.

Relationship between plasma homovanillic acid and outcome in patients with psychosis spectrum disorders

BACKGROUND

Psychosis spectrum disorders, especially schizophrenia, have been linked to disturbed dopaminergic activity in the brain. Plasma homovanillic acid (pHVA) levels partly represent dopaminergic metabolism in the central nervous system. In the present study associations between (changes in) pHVA levels, symptom severity and symptomatic improvement in patients with psychoses were investigated.

METHODS

From a total of 80 patients, 58 fulfilled all inclusion criteria and their symptom profile and severity were assessed by means of the Comprehensive Assessment of Symptoms and History (CASH), the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression Scale for Severity and Improvement (CGI-S/CGI-I) at baseline and after 6 weeks of antipsychotic treatment. After inclusion, all patients were prescribed first- or second-generation antipsychotics by their treating psychiatrist. A total of 12 patients had first-episode psychosis (FEP). At both time points, pHVA levels were measured. Subsequently, pHVA levels were compared with an age-matched control sample and changes in pHVA levels (ΔpHVA) after treatment were associated with clinical parameters.

RESULTS

Before analyses, data were scrutinized for possible confounders, particularly gender, smoking, medication status (including antipsychotic class), and recent drug use. The pHVA levels in patients were not different from those in controls. Treatment resulted in a significant decrease of all parameters. Symptomatic improvement as well as ΔpHVA was most pronounced in FEP patients.

CONCLUSION

These findings show that patients with FEP have a more favourable outcome than non-FEP patients and that greater ΔpHVA also suggests that FEP patients still have the capacity to adjust dopaminergic neurotransmission.

Biomarkers in schizophrenia: A focus on blood based diagnostics and theranostics

Identifying biomarkers that can be used as diagnostics or predictors of treatment response (theranostics) in people with schizophrenia (Sz) will be an important step towards being able to provide personalized treatment. Findings from the studies in brain tissue have not yet been translated into biomarkers that are practical in clinical use because brain biopsies are not acceptable and neuroimaging techniques are expensive and the results are inconclusive. Thus, in recent years, there has been search for blood-based biomarkers for Sz as a valid alternative. Although there are some encouraging preliminary data to support the notion of peripheral biomarkers for Sz, it must be acknowledged that Sz is a complex and heterogeneous disorder which needs to be further dissected into subtype using biological based and clinical markers. The scope of this review is to critically examine published blood-based biomarker of Sz, focusing on possible uses for diagnosis, treatment response, or their relationship with schizophrenia-associated phenotype. We sorted the studies into six categories which include: (1) brain-derived neurotrophic factor; (2) inflammation and immune function; (3) neurochemistry; (4) oxidative stress response and metabolism; (5) epigenetics and microRNA; and (6) transcriptome and proteome studies. This review also summarized the molecules which have been conclusively reported as potential blood-based biomarkers for Sz in different blood cell types. Finally, we further discusses the pitfall of current blood-based studies and suggest that a prediction model-based, Sz specific, blood oriented study design as well as standardize blood collection conditions would be useful for Sz biomarker development.

Adverse childhood experiences (ACEs), genetic polymorphisms and neurochemical correlates in experimentation with psychotropic drugs among adolescents

Epidemiological and clinical data show frequent associations between adverse childhood experiences (ACEs) and substance abuse susceptibility particularly in adolescents. A large body of evidences suggests that the possible dysregulation of neuroendocrine responses as well as neurotransmitters function induced by childhood traumatic experiences and emotional neglect could constitute one of the essential biological changes implementing substance abuse vulnerability. Moreover, genotype variables and its environment interactions have been associated with an increased risk for early onset substance abuse. In this paper we present several data that support the hypothesis of the involvement of hypothalamus-pituitary-adrenal (HPA) axis in mediating the combined effect of early adverse experiences and gene variants affecting neurotransmission. The presented data also confirm the relationship between basal plasma levels of cortisol and ACTH, on the one hand, and retrospective measures of neglect during childhood on the other hand: the higher the mother and father neglect (CECA-Q) scores are, the higher the plasma levels of the two HPA hormones are. Furthermore, such positive relationship has been proved to be particularly effective and important when associated with the "S" promoter polymorphism of the gene encoding the 5-HTT transporter, both in homozygote and heterozygote individuals.

Psychopathological and nutritional correlates of plasma homovanillic acid in adolescents with anorexia nervosa

Dopaminergic abnormalities have been described in anorexia nervosa but studies about plasma level of homovanillic acid (pHVA) have yielded conflicting results probably due to the small number and the heterogeneity of patients. Plasma HVA, nutritional and hormonal parameters and several scales - the Eating Attitudes Test (EAT), the Beck Depression Inventory (BDI), the Leyton Obsessional Inventory-child version (LOI-C) and the State and Trait Anxiety Inventory (STAI) - were assessed in 44 adolescent anorexia nervosa patients (mean age 14.7 years, SD 1.7) consecutively admitted to an Eating Disorder Unit. They were evaluated at admission, at discharge and, in 34 cases, after 9 months of follow-up. pHVA was also assessed in 16 control adolescents. Patients had significantly higher pHVA than controls (p = .002). About 31% of patients had a very high level of pHVA, a significantly higher (p = .006) mean score in the BDI and a non significantly higher mean score in the EAT. After weight recovery some laboratory parameters improved as well as the EAT (p = .019), the BDI (p = 001) and the Interference score of the LOI-C (p = .004). Moreover, pHVA decreased significantly (p=.036). At follow-up, patients with normal weight had lower (p = .037) pHVA than patients with low weight. The conclusion would be that there is a dopaminergic dysfunction in anorexic patients, specially in a subgroup with high depressive and anorexic symptomatology. With weight recovery and psychopathological improvement, pHVA tends to normalization.

Homovanillic acid (HVA) plasma levels inversely correlate with attention deficit-hyperactivity and childhood neglect measures in addicted patients

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) seems to be a risk condition for substance use disorders, possibly in relationship to common neurobiological changes, underlying both addictive and externalising behaviour susceptibility. Although this vulnerability has been primarily attributed to gene variants, previous studies suggest that also adverse childhood experiences may influence neurotransmission, affecting in particular brain dopamine (DA) system and possibly concurring to the development of behavioural disorders. Therefore, we decided to investigate ADHD symptoms and plasma concentrations of the DA metabolite homovanillic acid (HVA) in abstinent addicted patients, in comparison with healthy control subjects, evaluating whether ADHD scores were related with HVA levels, as expression of DA turnover, and whether HVA values, in turn, were associated with childhood emotional neglect.

METHODS

Eighty-two abstinent drug dependent patients, and 44 normal controls, matched for age and sex, completed the Wender Utah Rating Scale (WURS), measuring ADHD symptoms, and the Childhood Experience of Care and Abuse Questionnaire (CECA-Q). Blood samples were collected to determine HVA plasma levels.

RESULTS

Addicted individuals showed significantly higher ADHD scores and lower HVA levels respect to control subjects. ADHD scores at WURS in addicted patients negatively correlated with plasma HVA values. In turn, plasma HVA levels were inversely associated with childhood neglect measures, reaching statistical significance with "mother-antipathy" and "mother neglect" scores.

CONCLUSIONS

These findings suggest the possibility that childhood experience of neglect and poor mother-child attachment may have an effect on central dopamine function as an adult, in turn contributing to both ADHD and substance abuse neurobiological vulnerability.

Differential effects of haloperidol, clozapine and olanzapine on learning and memory functions in mice

Many schizophrenic patients exhibit impairments in neurocognitive functions. Typical antipsychotic drugs such as haloperidol, have limited or even detrimental influence on cognitive functions. In contrast, atypical antipsychotic drugs, such as clozapine and olanzapine, may improve memory function in schizophrenics. However, only a few studies have been conducted to directly compare the effects of olanzapine, clozapine and haloperidol on memory functions in animal models. Thus, their effects on this issue were investigated in the present studies by using one-way step-through passive avoidance task and Morris water maze as models of learning and memory. The results showed that olanzapine did not affect acquisition, consolidation or retrieval process in step-through test. Moreover, it improved spatial learning function in mice in Morris water maze task. Clozapine and haloperidol appeared to impair acquisition process and consolidation process, respectively, in step-through test. Both drugs impaired spatial learning function in mice in Morris water maze task. The results suggested a positive implication for the clinical medication of olanzapine in schizophrenic treatment.

On feeling in control: A biological theory for individual differences in control perception

This review aims to create a cross-disciplinary framework for understanding the perception of control. Although, the personality trait locus of control, the most common measure of control perception, has traditionally been regarded as a product of social learning, it may have biological antecedents as well. It is suggested that control perception follows from the brain's capacity for self regulation, leading to flexible and goal directed behaviours. To this account, a model is presented which spans several levels of analyses. On a behavioural level, control perception may be a corollary of emotion regulation, executive functions, and social cognition. On a neural level, these self-regulatory functions are substantiated in part by the dorsolateral and ventral prefrontal cortex and the anterior cingulate cortex. In addition, a possible role of subcortical-cortical dopamine pathways underlying control perception is discussed.

Disorganization of semantic memory underlies alogia in schizophrenia: an analysis of verbal fluency performance in Japanese subjects

Patients with schizophrenia exhibit impaired semantic memory as well as deficits in a wide range of language-related functions, such as verbal fluency, comprehension and production of complex sentences. Since language and memory disturbances may underlie some of the psychotic symptoms of schizophrenia, the present study investigated the specific association between alogia (i.e. poverty of speech, poverty of content of speech, blocking, and increased latency of response) and semantic memory organization using the category fluency task (CFT) as a measure of verbal fluency. Thirty-eight patients with schizophrenia and an equal number of normal controls entered the study. Semantic structure was derived from multidimensional scaling analysis using sequential word outputs from the CFT. Patients with schizophrenia revealed disorganized semantic structure (e.g. irregular association of category members) compared with controls, consistent with previous reports. The patients were then divided into two groups, i.e. alogia- and non-alogia subjects, based on the Alogia scores from the Scale for the Assessment of Negative Symptoms (SANS). The symptom-based analysis showed that the semantic structure for the alogia group (Alogia score < or =2) was more disorganized than that for the non-alogia group (Alogia score <1) although the number of words produced did not differ between the two groups. The results of cluster analysis revealed the presence of bizarre coherence specifically in the alogia group. These results indicate that semantic memory disorganization may contribute to the symptom of alogia in schizophrenia. In addition, this is one of the few studies that examined verbal fluency in Japanese patients with schizophrenia and suggest that the language abnormalities in schizophrenia are universal.

Prediction of changes in memory performance by plasma homovanillic acid levels in clozapine-treated patients with schizophrenia

RATIONALE

Cognitive dysfunction in schizophrenia has been demonstrated to be dependent, in part, on dopaminergic activity. Clozapine has been found to improve some domains of cognition, including verbal memory, in patients with schizophrenia.

OBJECTIVES

This study tested the hypothesis that plasma homovanillic acid (pHVA) levels, a peripheral measure of central dopaminergic activity, would predict the change in memory performance in patients with schizophrenia treated with clozapine.

METHODS

Twenty-seven male patients with schizophrenia received clozapine treatment for 6 weeks. Verbal list learning (VLL)-Delayed Recall (VLL-DR), a test of secondary verbal memory, was administered before and after clozapine treatment. Blood samples to measure pHVA levels were collected at baseline.

RESULTS

Baseline pHVA levels were negatively correlated with change in performance on VLL-DR; the lower baseline pHVA level was associated with greater improvement in performance on VLL-DR during treatment with clozapine. Baseline pHVA levels in subjects who showed improvement in verbal memory during clozapine treatment ( n=13) were significantly lower than those in subjects whose memory performance did not improve ( n=14).

CONCLUSIONS

The results of this study indicate that baseline pHVA levels predict the ability of clozapine to improve memory performance in patients with schizophrenia.

Gray matter features of schizotypal disorder patients exhibiting the schizophrenia-related code types of the Minnesota Multiphasic Personality Inventory

OBJECTIVE

Previous studies have suggested that several code types of the Minnesota Multiphasic Personality Inventory (MMPI) are useful markers for identifying schizophrenia. We hypothesized that schizotypal disorder (STD) patients with such schizophrenia-related code types have the morphological brain abnormalities associated with schizophrenia.

METHOD

Voxel-based morphometric analysis with statistical parametric mapping (SPM) 99 software was used to investigate the differences in brain morphology between 14 STD patients with the schizophrenia-related code types of the MMPI and 28 normal individuals.

RESULTS

The STD patients showed significantly decreased gray matter volume in the insular regions bilaterally and in the left entorhinal cortex, compared with the controls.

CONCLUSION

Our findings suggest that STD patients with the schizophrenia-related code types have volume reductions in these regions as an endophenotype that overlaps with schizophrenia.

Rat organic anion transporter 3 (rOAT3) is responsible for brain-to-blood efflux of homovanillic acid at the abluminal membrane of brain capillary endothelial cells

The mechanism that removes homovanillic acid (HVA), an end metabolite of dopamine, from the brain is still poorly understood. The purpose of this study is to identify and characterize the brain-to-blood HVA efflux transporter at the rat blood-brain barrier (BBB). Using the Brain Efflux Index method, the apparent in vivo efflux rate constant of [3H]HVA from the brain, k(eff), was determined to be 1.69 x 10(-2) minute(-1). This elimination was significantly inhibited by para-aminohippuric acid (PAH), benzylpenicillin, indoxyl sulfate, and cimetidine, suggesting the involvement of rat organic anion transporter 3 (rOAT3). rOAT3-expressing oocytes exhibited [3H]HVA uptake (K(m) = 274 micromol/L), which was inhibited by several organic anions, such as PAH, indoxyl sulfate, octanoic acid, and metabolites of monoamine neurotransmitters. Neurotransmitters themselves did not affect the uptake. Furthermore, immunohistochemical analysis suggested that rOAT3 is localized at the abluminal membrane of brain capillary endothelial cells. These results provide the first evidence that rOAT3 is expressed at the abluminal membrane of the rat BBB and is involved in the brain-to-blood transport of HVA. This HVA efflux transport system is likely to play an important role in controlling the level of HVA in the CNS.

The effect of melperone, an atypical antipsychotic drug, on cognitive function in schizophrenia

Melperone, a butyrophenone, has been shown to possess atypical antipsychotic properties, i.e. ability to produce an antipsychotic effect in man at doses that cause minimal extrapyramidal side effects. In addition, melperone shares the following with other atypical antipsychotic drugs: (1) effectiveness for ameliorating negative symptoms; (2) no prolactin elevation; and (3) effectiveness in the treatment of some patients with neuroleptic-resistant schizophrenia. Other atypical antipsychotic drugs have been reported to improve cognitive function. This study was performed to investigate the effect of melperone on cognitive function. Nineteen patients with schizophrenia or schizoaffective disorder, including 11 neuroleptic-resistant patients, were treated with melperone for 6 weeks. A comprehensive neurocognitive test battery and psychopathological ratings (Brief Psychiatric Rating Scale, BPRS) were administered at baseline and after 6 weeks of melperone treatment. Treatment with melperone was associated with improvement in executive function, as measured by the Wisconsin Card Sorting Test (WCST)-Categories and WCST-Percent Perseveration. On the other hand, visuospatial manipulation, as measured by the Wechsler Intelligent Scale for Children-Revised (WISC-R) Maze, worsened during melperone treatment. There were no significant changes in other domains of cognition, i.e. verbal learning and memory, verbal working memory, verbal fluency and sustained attention. Scores of WCST-Categories and Perseveration at 6 weeks were predicted from the relevant cognitive test scores at baseline and the change in BPRS Total and Positive scores. These results suggest the usefulness of melperone for facilitating work and social function in patients with schizophrenia. The differences in the cognition-enhancing abilities between melperone and clozapine are discussed.

Semantic structure in schizophrenia as assessed by the category fluency test: effect of verbal intelligence and age of onset

It has been reported that long-term memory function, including the semantic structure of category, is impaired in patients with schizophrenia. The present study was performed to determine: (1) whether the deficit in semantic structure in schizophrenia is independent of cultural backgrounds, and (2) the effect of age of onset and verbal intelligence on the degradation of semantic structure in these patients. Fifty-seven Japanese patients with schizophrenia and 33 normal control subjects entered the study. The semantic structure was derived by Multidimensional Scaling (MDS) analysis based on data from the ANIMAL category fluency test. The semantic structure was compared between: (1) schizophrenic patients as a whole vs. normal control subjects; (2) earlier onset (age of onset <20 years) vs. later-onset groups of patients; and (3) high Vocabulary score (score of the Vocabulary subtest from the WAIS-R>7) vs. low Vocabulary score patient groups. Normal control subjects demonstrated the domestic/size dimension in semantic structure, while no such dimension was obtained in patients with schizophrenia. The subgroup comparisons revealed that the later onset or the high Vocabulary score group maintained a relatively intact semantic structure compared with the earlier onset or the low Vocabulary score group, respectively. These findings suggest that the deficit in semantic structure in patients with schizophrenia is commonly observed irrespective of cultural backgrounds, and that age of onset and the level of verbal intelligence are closely related to severity of degradation of the semantic structure in schizophrenia.

Ventricular enlargement in schizophrenia spectrum patients with prodromal symptoms of obsessive-compulsive disorder

We hypothesized that male patients with schizophrenia spectrum disorders who have prodromal symptoms of obsessive-compulsive disorder (OCD) have ventricular enlargement compared with non-psychotic OCD patients, and that the difference in the ventricular size would offer a clue to the early detection of schizophrenia spectrum disorders. The ventricle-brain ratios (VBRs) in eight male patients with schizophrenia or schizotypal personality disorder (SPD) who had prodromal symptoms of OCD were compared with eight male patients with non-psychotic OCD and 14 normal male comparison subjects using three-dimensional magnetic resonance imaging (MRI). The VBR of the schizophrenia spectrum group was significantly larger than those of the OCD group or comparison subjects. Even the minimum VBR in the schizophrenia spectrum group was larger than the maximum VBR in the OCD group. These results may suggest the usefulness of three-dimensional MRI for early detection of patients with schizophrenia spectrum disorders who manifest OCD symptoms early in the course of the illness.