Defining the course of brain structural change and plasticity in schizophrenia

Mendelian randomization studies of brain MRI yield insights into the pathogenesis of neuropsychiatric disorders

BACKGROUND

Observational studies have identified various associations between neuroimaging alterations and neuropsychiatric disorders. However, whether such associations could truly reflect causal relations remains still unknown.

RESULTS

Here, we leveraged genome-wide association studies (GWAS) summary statistics for (1) 11 psychiatric disorders (sample sizes varied from n = 9,725 to 1,331,010); (2) 110 diffusion tensor imaging (DTI) measurement (sample size n = 17,706); (3) 101 region-of-interest (ROI) volumes, and investigate the causal relationship between brain structures and neuropsychiatric disorders by two-sample Mendelian randomization. Among all DTI-Disorder combinations, we observed a significant causal association between the superior longitudinal fasciculus (SLF) and the risk of Anorexia nervosa (AN) (Odds Ratio [OR] = 0.62, 95 % confidence interval: 0.50 ~ 0.76, P = 6.4 × 10- 6). Similar significant associations were also observed between the body of the corpus callosum (fractional anisotropy) and Alzheimer's disease (OR = 1.07, 95 % CI: 1.03 ~ 1.11, P = 4.1 × 10- 5). By combining all observations, we found that the overall p-value for DTI - Disorder associations was significantly elevated compared to the null distribution (Kolmogorov-Smirnov P = 0.009, inflation factor λ = 1.37), especially for DTI - Bipolar disorder (BP) (λ = 2.64) and DTI - AN (λ = 1.82). In contrast, for ROI-Disorder combinations, we only found a significant association between the brain region of pars triangularis and Schizophrenia (OR = 0.48, 95 % CI: 0.34 ~ 0.69, P = 5.9 × 10- 5) and no overall p-value elevation for ROI-Disorder analysis compared to the null expectation.

CONCLUSIONS

As a whole, we show that SLF degeneration may be a risk factor for AN, while DTI variations could be causally related to some neuropsychiatric disorders, such as BP and AN. Also, the white matter structure might have a larger impact on neuropsychiatric disorders than subregion volumes.

What a Clinician Should Know About the Neurobiology of Schizophrenia: A Historical Perspective to Current Understanding

The brain is no doubt the "organ" of psychiatry; yet, over the years, few evidence-based classifications of psychiatric disorders have been based on brain mechanisms. The National Institute of Mental Health notably proposed one such system, known as Research Domain Criteria, although it has not yet influenced any changes in the DSM. Of all the major psychiatric disorders, the brain has been studied most extensively in schizophrenia, with its speculative pathology first documented by Emil Kraepelin as early as the beginning of the 20th century. Subsequently, the revolution in technology over the past 50 years has changed how investigators are able to view the brain before death without performing biopsies. Schizophrenia is thus found to have both structural and functional widespread brain anomalies that likely lead to its clinical deterioration. At the onset of illness, acquiring an MRI scan could be part of the routine evaluation to determine how progressive the disease has so far been. However, this practice is not yet recognized by the American Psychiatric Association in any of its guidelines on the treatment of schizophrenia.

Schizophrenia as a progressive brain disease

There is convincing evidence that schizophrenia is characterized by abnormalities in brain volume. At the Department of Psychiatry of the University Medical Centre Utrecht, Netherlands, we have been carrying out neuroimaging studies in schizophrenia since 1995. We focused our research on three main questions. First, are brain volume abnormalities static or progressive in nature? Secondly, can brain volume abnormalities in schizophrenia be explained (in part) by genetic influences? Finally, what environmental factors are associated with the brain volume abnormalities in schizophrenia?

Based on our findings we suggest that schizophrenia is a progressive brain disease. We showed different age-related trajectories of brain tissue loss suggesting that brain maturation that occurs in the third and fourth decade of life is abnormal in schizophrenia. Moreover, brain volume has been shown to be a useful phenotype for studying schizophrenia. Brain volume is highly heritable and twin and family studies show that unaffected relatives show abnormalities that are similar, but usually present to a lesser extent, to those found in the patients. However, also environmental factors play a role. Medication intake is indeed a confounding factor when interpreting brain volume (change) abnormalities, while independent of antipsychotic medication intake brain volume abnormalities appear influenced by the outcome of the illness.

In conclusion, schizophrenia can be considered as a progressive brain disease with brain volume abnormalities that are for a large part influenced by genetic factors. Whether the progressive volume change is also mediated by genes awaits the results of longitudinal twin analyses. One of the main challenges for the coming years, however, will be the search for gene-by-environment interactions on the progressive brain changes in schizophrenia.

Palate size and shape in schizophrenia

The palate is considered typical of the structures in which schizophrenia-related minor physical anomalies may occur. In this study, we aimed to compare the dimensions and form of palate in patients with schizophrenia with nonpsychiatric controls in a blinded manner. Dental stone casts of 127 patients with schizophrenia and 127 controls were prepared from impressions of the maxillary dental arch. Palate dimensions were measured on the stone casts using a digital caliper and palatometer. Palate length did not differ significantly between the groups, but there was a significant difference in palate width and depth, which were significantly higher in the schizophrenia group. As a result of using multivariate analysis for assessing independent risk factors affecting patients with schizophrenia, furrowed palate shape, palate width, and ellipsoid maxillary dental arch shape were found to be significant. This study also revealed that patients with schizophrenia demonstrate certain gender-related predilections in the differences of palate parameters compared to same-sex controls. As the palate develops in conjunction with both the face and brain, our study findings can significantly contribute to the assumption that there might be structural abnormalities of the palate that could represent specific markers of embryological dysmorphogenesis underlying schizophrenia.

Cognitive Remediation for the Treatment of Cognitive Dysfunction in the Early Course of Psychosis

The development of cognitive remediation programs has been a key step toward the creation of a treatment approach to address the cognitive-symptom domain in psychosis. Studies support the efficacy of cognitive remediation in producing moderate effects on cognition at the group level in patients with schizophrenia. Cognitive remediation may harness neuroplasticity in relevant systems that underpin the cognitive functions being addressed. Since neuroplasticity may be greater in people who (1) are younger and (2) have not yet experienced the consequences of long-term psychosis, cognitive remediation may be particularly effective in people in the early course of illness or in the prodrome, prior to the onset of frank symptoms. The present article reviews the evidence for implementing cognitive remediation in patients with recent-onset psychosis and people identified as being at high risk for developing schizophrenia, and also the evidence for cognitive remediation to modify neural targets. Promising findings suggest that cognitive remediation may be useful in addressing cognitive deficits in early-course and prodromal participants. Additionally, a growing literature using neuroimaging techniques demonstrates the ability of cognitive remediation paradigms to engage neural targets.

Treatment resistance and other complicating factors in the management of schizophrenia

Treatment resistance, along with its sibling partial response, remains a common phenomenon in schizophrenia, complicating the disability burden inherent in the disease. Antipsychotic medications are the mainstay of treatment, and treatment resistance has mainly been defined in terms of poor response to antipsychotic medication. At the same time, clozapine, the most effective antipsychotic, remains underutilized at the expense of exposing patients to polypharmacy. We review known causes of disability in schizophrenia, how they impact various areas of everyday functioning, and discuss potential treatment options including but not limited to pharmacological approaches aimed at maximizing treatment response and reducing treatment resistance.

Decreased axial diffusivity within language connections: a possible biomarker of schizophrenia risk

Siblings of patients diagnosed with schizophrenia are at elevated risk for developing this disorder. The nature of such risk associated with brain abnormalities, and whether such abnormalities are similar to those observed in schizophrenia, remain unclear. Deficits in language processing are frequently reported in increased risk populations. Interestingly, white matter pathology involving fronto-temporal language pathways, including arcuate fasciculus (AF), uncinate fasciculus (UF), and inferior occipitofrontal fasciculus (IOFF), are frequently reported in schizophrenia. In this study, high spatial and directional resolution diffusion MRI data was obtained on a 3T magnet from 33 subjects with increased familial risk for developing schizophrenia, and 28 control subjects. Diffusion tractography was performed to measure white matter integrity within AF, UF, and IOFF. To understand these abnormalities, Fractional Anisotropy (FA, a measure of tract integrity) and Trace (a measure of overall diffusion), were combined with more specific measures of axial diffusivity (AX, a putative measure of axonal integrity) and radial diffusivity (RD, a putative measure of myelin integrity). Results revealed a significant decrease in Trace within IOFF, and a significant decrease in AX in all tracts. FA and RD anomalies, frequently reported in schizophrenia, were not observed. Moreover, AX group effect was modulated by age, with increased risk subjects demonstrating a deviation from normal maturation trajectory. Findings suggest that familial risk for schizophrenia may be associated with abnormalities in axonal rather than myelin integrity, and possibly associated with disruptions in normal brain maturation. AX should be considered a possible biomarker of risk for developing schizophrenia.

Hospitalization and psychosis: influences on the course of cognition and everyday functioning in people with schizophrenia

Long term institutional stay has decreased markedly in people with schizophrenia, although there are still many individuals with a history of long-term institutional stay residing in the community. In addition, although the average duration of acute admissions for schizophrenia is also decreasing, there are indications that psychotic episodes leading to acute admissions are associated with risk for cognitive and functional declines and changes in brain structure. In this paper we review the literature on cognitive changes with aging and institutionalization in schizophrenia, reaching to the conclusion that the reasons for current chronic institutionalization largely include severe psychosis and aggressive behavior. Thus, these factors may be the operative factor in the age-related declines in cognition and functioning reported in this population. We also present evidence to suggest that these changes may be similar to those seen in younger patients who experience repeated psychotic episodes leading to hospitalization. Our conclusion is that there is minimal evidence that hospitalization, long or short, leads to cognitive and functional changes, but rather that the reason for these hospitalizations may underlie cognitive and functional declines. Prevention of relapse and discovering treatments to assist patients with resistant symptoms may reduce the risk of cognitive and functional declines across the lifespan in people with schizophrenia.

A plausible model of schizophrenia must incorporate psychological and social, as well as neuro developmental, risk factors

Subtle alterations in brain development caused by genes or early environmental hazards, such as obstetric complications, play a role in projecting some individuals on a trajectory toward schizophrenia. High-risk and cohort studies demonstrate that children destined to develop schizophrenia tend to have delayed milestones and subtle neuromotor and cognitive impairments (particularly in coordination and language). These neurocognitive problems lead to difficulties in interpersonal relations, and their progressive alienation makes these at-risk children more likely to harbor odd or paranoid ideas. This cascade of increasingly deviant development may then be compounded by brain maturational changes during adolescence with a resultant lability of the dopaminergic response to stress. As a result, the individual is more susceptible to the effects of the abuse of dopamine-releasing drugs, and to other risk factors such as migration or stressful life events; social isolation may be a common pathway underlying several of the social risk factors.

Cigarette smoking and white matter microstructure in schizophrenia

The majority of patients with schizophrenia smoke cigarettes. Both nicotine use and schizophrenia have been associated with alterations in brain white matter microstructure as measured by diffusion tensor imaging (DTI). The purpose of this study was to examine fractional anisotropy (FA) in smoking and non-smoking patients with schizophrenia and in healthy volunteers. A total of 43 patients (28 smoking and 15 non-smoking) with schizophrenia and 40 healthy, non-smoking participants underwent DTI. Mean FA was calculated in four global regions of interest (ROIs) (whole brain, cerebellum, brainstem, and total cortical) as well as in four regional ROIs (frontal, temporal, parietal and occipital lobes). The non-smoking patient group had a significantly higher intellectual quotient (IQ) compared with the patients who smoked, and our results varied according to whether IQ was included as a covariate. Without IQ correction, significant between-group effects for FA were found in four ROIs: total brain, total cortical, frontal lobe and the occipital lobe. In all cases the FA was lower among the smoking patient group, and highest in the control group. Smoking patients differed significantly from non-smoking patients in the frontal lobe ROI. However, these differences were no longer significant after IQ correction. FA differences between non-smoking patients and controls were not significant. Among smoking and non-smoking patients with schizophrenia but not healthy controls, FA was correlated with IQ. In conclusion, group effects of smoking on FA in schizophrenia might be mediated by IQ. Further, low FA in specific brain areas may be a neural marker for complex pathophysiology and risk for diverse problems such as schizophrenia, low IQ, and nicotine addiction.

Workshop on defining the significance of progressive brain change in schizophrenia: December 12, 2008 American College of Neuropsychopharmacology (ACNP) all-day satellite, Scottsdale, Arizona. The rapporteurs' report

In 1990 a satellite session of the American College of Neuropsychopharmacology (ACNP) Annual Meeting was held that focused on the question of whether progressive changes in brain structure occur in schizophrenia and this session raised considerable controversy. Eighteen years later, on December 12, 2008, after much data have since accumulated on this topic, a group of approximately 45 researchers gathered after the annual ACNP meeting to participate in a similar workshop on several unresolved questions still remaining: (1) How strong and consistent is the evidence? (2) Is there anatomic specificity to changes and is it disease specific or subject specific? (3) What is the time course? (4) What is the underlying pathophysiology (i.e. is it central to the disease process or is it due to neuroleptic treatment or other epiphenomena? (5) What is its clinical significance? and (6) Are there treatment implications? The day was chaired by Lynn E. DeLisi and co-chaired by Stephen J. Wood. Christos Pantelis and Jeffrey A. Lieberman extensively helped with its planning. The ACNP assisted in its organization as an official satellite of its annual meeting and several pharmaceutical companies provided support with unrestricted educational grants. The following is a summary of the sessions as recounted by rapporteurs whose job was to record as closely as possible the outcome of discussions on the above outlined questions.

Superior temporal gyrus volume change in schizophrenia: a review on region of interest volumetric studies

Imaging studies of schizophrenia (SCZ) have repeatedly demonstrated volume differences in superior temporal gyrus (STG) and its subregions. Among them, some studies employed the Region of Interest (ROI) method. We carried out a systematic review of the published literature on STG volumetry MRI studies to examine the potential of ROI method for identifying specific structural differences and correlations with clinical variables including hallucinations and thought disorder symptoms in SCZ. Forty-six studies were identified as suitable for review and analysis including 1444 patients with SCZ and 1327 controls. Female and left-handed subjects are under-represented in the literature and insight from sex and handedness differences may be lost. Thirty-five studies reported significant differences in STG or subregional volumes including bilateral or unilateral ROI, and volume reduction was the most common change in SCZ. Thirty studies reported correlations between volume changes and clinical symptoms or syndromes and 18 found positive results. Among them, left STG or subregions appear to be more involved in the generation of hallucinations and thought disorder than right side. The majority of five follow-up studies found evidence of progressive changes in volumes. Clinical heterogeneity, MRI acquisition parameters, anatomical landmarks for ROI, and sample characteristics, are likely to be the main factors leading to heterogeneous results. Clearly this research links pathophysiological changes in the STG with the development of hallucinations and thought disorder in patients with SCZ, especially in the left side. There is a suggestion that these changes may be progressive but this requires more thorough and comprehensive assessment.

Auditory hallucinations in schizophrenia: the role of cognitive, brain structural and genetic disturbances in the left temporal lobe

In this article we review research in our laboratory on auditory hallucinations using behavioral and MRI measure. The review consists of both previously published and new data that for the first time is presented together in a cohesive way. Auditory hallucinations are among the most common symptoms in schizophrenia, affecting more than 70% of the patients. We here advance the hypothesis that auditory hallucinations are internally generated speech perceptions that are lateralized to the left temporal lobe, in the peri-Sylvian region. From this we predict that hallucinating patients should have problems identifying a simultaneously presented external speech sound, as measured through performance on the dichotic listening (DL) paradigm with consonant-vowel syllables, since this technique lateralizes the stimulus input. Across a series of behavioral experiments, we have shown that patients with schizophrenia who experience frequent auditory hallucinations fail to demonstrate an expected right ear advantage on the dichotic listening test. Absence of a right ear advantage is indicative of a functional deficit in the left peri-Sylvian region. The results also revealed that patients with ongoing auditory hallucinations were more impaired than patients with previous hallucinations, and that a higher score on the hallucination item in a standard symptom rating scale (BPRS) correlated negatively with number of correct reports for the right ear stimulus. Moreover, we have found that schizophrenia patients fail to shift attention to the left ear stimulus, when explicitly instructed to focus on the right or left ear stimulus only, thus showing a deficit in inhibition of attention and response-inhibition. The behavioral DL data are substantiated in two MR morphometry studies that revealed significant reductions in grey matter density in the left peri-Sylvian region in hallucinating patients, and patients with reduced left temporal lobe grey matter density. Hallucinating patients also failed to show a right ear advantage in the dichotic listening test. Ongoing fMRI studies are focused on the underlying synaptic and molecular mechanisms by investigating the effects of the glutamate antagonist drug memantine on auditory perception and speech lateralization, and examination of temporal cortex-specific gene expression in the left peri-Sylvian region.

The effect of cannabis on the brain: can it cause brain anomalies that lead to increased risk for schizophrenia?

PURPOSE OF REVIEW

This review explores what is known about the association of cannabis with schizophrenia, its effects on the brain, and whether the brain changes known to be present in schizophrenia could be caused by cannabis and thus lead to a psychosis.

RECENT FINDINGS

The heavy use of cannabis is known to be associated with some adverse consequences, such as the occurrence of acute psychotic episodes and the development of chronic schizophrenia in some people even after its use has terminated. Recent studies have produced controversy about whether cannabis in heavy use can cause irreversible brain damage, particularly to adolescents, and thus whether a chronic psychosis could be a result of brain changes caused by cannabis.

SUMMARY

From the evidence that exists, it appears that the above view is unlikely and that cannabis may even have benign effects on brain structure, not producing deleterious damage. Its neurochemical interactions with the dopaminergic pathway, however, may, particularly in genetically vulnerable individuals, have adverse consequences.

Schizophrenia, "Just the Facts": what we know in 2008 part 1: overview

For every disorder, there is a set of established findings and accepted constructs upon which further understanding is built. The concept of schizophrenia as a disease entity has been with us for a little more than a century, although descriptions resembling this condition predate this conceptualization. In 1988, for the inaugural issue of Schizophrenia Research, at the invitation of the founding editors, a senior researcher, since deceased (RJ Wyatt) published a summary of generally accepted ideas about the disorder, which he termed "the facts" of schizophrenia. Ten years later, in conjunction with two of the authors (MSK, RT), he compiled a more extensive set of "facts" for the purpose of evaluating conceptual models or theoretical constructs developed to understand the nature of schizophrenia. On the 20th anniversary of this journal, we update and substantially expand our effort to periodically summarize the current body of information about schizophrenia. We compile a body of seventy-seven representative major findings and group them in terms of their specific relevance to schizophrenia -- etiologies, pathophysiology, clinical manifestations, and treatments. We rate each such "fact" on a 0-3 scale for measures of reproducibility, whether primary to schizophrenia, and durability over time. We also pose one or more critical questions with reference to each "fact", answers to which might help better elucidate the meaning of that finding for our understanding of schizophrenia. We intend to follow this paper with the submission to the journal of a series of topic-specific articles, critically reviewing the evidence.

What happens after the first episode? A review of progressive brain changes in chronically ill patients with schizophrenia

Numerous imaging studies have revealed structural brain changes in schizophrenia. Decreases in brain tissue are accompanied by increases in ventricle volumes and cerebrospinal fluid. Whether or not these brain changes are progressive beyond the first episode is subject to debate. To assess if progressive brain changes occur in chronically ill patients, 11 longitudinal magnetic resonance imaging and computed tomography studies were reviewed. Patients were ill for on average 10 years at their initial scan. Follow-up intervals varied between 1 and 10 years. Overall, the findings suggest continuous progressive brain tissue decreases and lateral ventricle volume increases in chronically ill patients, up to at least 20 years after their first symptoms. The extent of progressive brain tissue decrease in patients (-0.5% per year) is twice that of healthy controls (-0.2% per year). These findings are consistent with the extent of postmortem brain tissue loss in schizophrenia. Progressive volume loss seems most pronounced in the frontal and temporal (gray matter) areas. Progressive lateral ventricle volume increases are also found. More pronounced progressive brain changes in patients is associated with poor outcome, more negative symptoms, and a decline in neuropsychological performance in one or some of the studies, but not consistently so. Higher daily cumulative dose of antipsychotic medication intake is either not associated with brain volume changes or with less prominent brain volume changes. The progressive brain changes present in chronic schizophrenia may represent a continuous pathophysiological process taking place in the brains of these patients that warrants further study.

The concept of progressive brain change in schizophrenia: implications for understanding schizophrenia

Kraepelin originally defined dementia praecox as a progressive brain disease, although this concept has received various degrees of acceptance and rejection over the years since his famous published textbooks appeared. This article places an historical perspective on the current renewal of Kraepelin's concept in brain imaging literature that supports progressive brain change in schizophrenia from its earliest stages through its chronic course. It is concluded that a great deal of future research is needed focusing on the longitudinal course of change, the extent to the regions of change within each individual and the underlying mechanism and implications of brain change through functional and neurochemical imaging, combined with structural studies in the same individuals.

Impaired facial emotion recognition and reduced amygdalar volume in schizophrenia

Structural abnormalities of the amygdala and impaired facial emotion recognition have been reported in schizophrenia. Most studies demonstrated reduced amygdalar volumes in schizophrenia patients, and difficulty in recognizing negative facial emotions has also been reported. However, findings on the deficit in facial emotion recognition have been inconsistent, and the relationships between this impairment and amygdalar volume reduction remain unclear. In this study, we investigated these relationships by performing volumetric analysis of the amygdala and evaluation of facial emotion recognition performance in the same subjects with schizophrenia. The sample group comprised 20 schizophrenia patients and 20 matched healthy controls. We measured the volumes of the amygdalae with high-resolution magnetic resonance imaging (MRI) at 3.0 Tesla. Additionally, we included a task that evaluated the subjects' ability to recognize the intensity of basic facial emotions. We found that impaired facial emotion recognition in schizophrenia patients is emotion-specific (sadness, surprise, disgust, and anger). Moreover, the volume of each amygdala on either side of the brain was reduced. Finally, we found a correlation between left amygdalar volume and the recognition of sadness in facial expressions. This study demonstrated that amygdala dysfunction may contribute to impaired facial emotion recognition in schizophrenia.

Early detection of schizophrenia by diffusion weighted imaging

A novel magnetic resonance imaging method was used to determine whether it is feasible to detect early signs of cortical atrophy among individuals who are at high risk for developing schizophrenia. Fifteen individuals at high-risk for schizophrenia and 15 of their first degree relatives diagnosed with schizophrenia were compared with controls (n=25) who did not have a family history of psychiatric illness or psychiatric hospitalizations. On the basis of a voxelwise analysis of apparent diffusion coefficient (ADC) maps derived from diffusion weighted magnetic resonance imaging, these individuals showed evidence of deficits in four separate regions of the brain, all on the left side only: parahippocampal gyrus, lingual gyrus, superior frontal gyrus, and middle frontal gyrus. However, conventional volumetric quantification of ventricular space to detect atrophy failed to reveal differences between high-risk subjects and controls. It is concluded that ADC may be a more sensitive measure than ventricular volume assessments for use in future studies of early prediction of schizophrenia.

Understanding structural brain changes in schizophrenia

Schizophrenia is a chronic progressive disorder that has at its origin structural brain changes in both white and gray matter. It is likely that these changes begin prior to the onset of clinical symptoms in cortical regions, particularly those concerned with language processing. Later, they can be detected by progressive ventricular enlargement. Current magnetic resonance imaging (MRI) technology can provide a valuable tool for detecting early changes in cortical atrophy and anomalous language processing, which may be predictive of who will develop schizophrenia.

Mr morphometry analysis of grey matter volume reduction in schizophrenia: association with hallucinations

The authors used voxel-based morphometry (VBM) to study GM volume differences in the whole brain volume between a group of patients with schizophrenia and a healthy control group. There were 12 patients and 12 control subjects. The subjects were scanned in a 1.5 T MR scanner. The patients had all been evaluated by a senior psychiatrist on the brief psychiatric rating scale (BPRS). The VBM data was correlated with reports of rate and frequency of hallucinations based on their scores on the BPRS hallucination item. There were significant grey matter volume reductions in the schizophrenia patient group in the left superior (transverse) temporal gyrus, the left middle frontal gyrus, and in the right cuneus. Areas of grey matter volume reduction that correlated negatively with hallucinations were found in the left superior (transverse) temporal gyrus, left thalamus, and left and right cerebellum. This article proposes that significant reductions in grey matter volume may be instrumental in generating spontaneous neuronal activity that is associated with speech perception experiences in the absence of an external acoustic stimulus that may cause hallucinations.

Neuroprotective effects of olanzapine in a rat model of neurodevelopmental injury

Recent clinical studies have suggested that treatment with atypical antipsychotic drugs, such as olanzapine, may slow progressive changes in brain structure in patients with schizophrenia. To investigate the possible neural basis of this effect, we sought to determine whether treatment with olanzapine would inhibit the loss of hippocampal neurons associated with the administration of the excitotoxin, kainic acid, in neonatal rats. At post-natal day 7 (P7), rats were exposed to kainic acid via intracerebroventricular administration. Neuronal loss within the CA2 and CA3 subfields of the hippocampus and neurogenesis within the dentate gyrus of the hippocampus were then assessed at P14 by Fluoro-Jade B and BrdU labeling, respectively. Daily doses of olanzapine (2, 6, or 12 mg/day), haloperidol (1.2 mg/kg), melatonin (10 mg/kg), or saline were administered between P7 and P14. Melatonin is an anti-oxidant drug and was included in this study as a positive control, since it has been observed to have neuroprotective effects in a variety of animal models. The highest dose of olanzapine and melatonin, but not haloperidol, ameliorated the hippocampal neuronal loss triggered by kainic acid administration. However, drug administration did not have a significant effect on the rate of neurogenesis. These results suggest that olanzapine has neuroprotective effects in a rat model of neurodevelopmental insult, and may be relevant to the observed effects of atypical antipsychotic drugs on brain structure in patients with schizophrenia.

Regional specificity of cerebrospinal fluid abnormalities in first episode schizophrenia

The timing and regional specificity of cerebrospinal fluid (CSF) enlargements have not been well described in schizophrenia. High-resolution magnetic resonance images and computational image analysis methods were used to localize cross-sectional changes in lateral ventricle and sulcal and subarachnoid CSF in first episode schizophrenia patients (51 males/21 females) and healthy subjects (37 males/41 females). Volumes were obtained for each lateral ventricle horn and regional differences identified by comparing the distances from the ventricular surfaces to the central core at anatomically matched locations. Extra-cortical CSF differences were compared by measuring the proportion of CSF voxels sampled from spatially homologous cortical surface points. Significant extra-cortical CSF enlargements were observed in first episode patients, where regional differences surrounded the temporal, anterior frontal and parietal cortices. Volume and ventricular surface analyses failed to show significant effects of diagnosis. However, interactions indicated dorsal superior horn expansions in female patients compared with same-sex controls. Since ventricular enlargements are widely reported in chronic patients, our observations at first episode suggest ventricular enlargement may progress after disease onset with early changes occurring around the dorsal superior horn. In contrast, sulcal and subarachnoid CSF increases may be manifest near or before the first episode but after brain development is complete, reflecting pronounced reductions in proximal brain tissue.

Magnetic resonance imaging study of the ventricle-brain ratio in parents of schizophrenia subjects

Structural abnormalities found in probands with schizophrenia have been reported to occur to some degree in their unaffected relatives. However, there has yet to be a study that has focused on brain changes of parents of schizophrenics who are not the presumed obligate carriers. Using MRI, the authors studied the ventricle-brain ratio (VBR) of 9 pairs of parents of schizophrenics and 18 age- and sex-matched healthy controls. VBRs of the unaffected parents of schizophrenics were significantly larger than those of the controls. Our results suggest that large VBRs aggregate in the parents of schizophrenics and may serve as an indicator of vulnerability to the disorder.

Review of longitudinal functional neuroimaging studies of drug treatments in patients with schizophrenia

We systematically reviewed twenty-one functional neuroimaging studies that used longitudinal designs to investigate the effects of medication treatments on brain functioning among patients with schizophrenia. The studies reviewed were comprised of functional magnetic resonance imaging and positron emission tomography research using a baseline and at least one follow-up. The present review summarizes the different effects of medication and disease status on brain function, with attention to functional normalization, specific drug effects, and comparisons of typical versus atypical antipsychotics. Particular emphasis is given to methodological limitations in the existing literature, including lack of reliability data, clinical heterogeneity among studies, and inadequate study designs and statistics. Suggestions are made for improving future longitudinal neuroimaging studies of treatment effects in schizophrenia.

Schizophrenia: update on genetics, cognitive behavioural therapy and early intervention

There have been considerable advances in the understanding of schizophrenia in recent years. This educational review paper focuses on three areas of interest and relevance to trainees preparing for the membership examination of the Royal College of Psychiatrists (MRCPsych): (a) recent advances in the genetics of schizophrenia; (b) advances in cognitive behavioural therapy in schizophrenia; and (c) advances in early intervention strategies for schizophrenia. Relevant papers and systematic reviews are discussed, and recommendations for further reading are provided.

Failure to find progressive temporal lobe volume decreases 10 years subsequent to a first episode of schizophrenia

The present study used magnetic resonance imaging to examine the volumes of the temporal lobe and the superior temporal gyrus in a 10-year follow-up study of 27 patients with schizophrenia and 10 controls. No change over time was observed in these structures when patients were compared with controls. These results do not support the notion that progressive temporal lobe deterioration occurs in schizophrenia.

N-acetyl-aspartate levels in the dorsolateral prefrontal cortex in the early years of schizophrenia are inversely related to disease duration

Magnetic resonance spectroscopy studies in schizophrenia have revealed consistently reduced N-acetyl aspartate (NAA) levels in chronic patients, but not in recent-onset patients. Studies on the relationship between this marker and disease duration have commonly been negative, although it is also true that they have been conducted in patients with long-standing disease. We compared NAA levels in the dorsolateral prefrontal cortex in 16 recent-onset patients (duration: 1.8+/-0.6 years), 19 chronic patients (duration: 9.7+/-6.1 years), and 20 healthy controls. We studied the NAA/creatine and choline/creatine ratios in the dorsolateral prefrontal cortex in both hemispheres, controlling for the effect of age. Chronic patients had significantly lower NAA/Cr ratios in the left hemisphere compared to recent-onset patients and healthy controls, with no difference in Cho/Cr ratio. There were no differences between controls and recent-onset patients. There was a significant inverse relationship between left-side NAA/Cr and disease duration, suggesting that prefrontal NAA levels may progressively decrease in schizophrenia. Taken within the context of the existing literature, these results indicate that this process may be limited to the early years following the onset of the disease. Therefore, reduced prefrontal levels of NAA may be limited to chronic schizophrenia patients.

Schizophrenia genes, gene expression, and neuropathology: on the matter of their convergence

This review critically summarizes the neuropathology and genetics of schizophrenia, the relationship between them, and speculates on their functional convergence. The morphological correlates of schizophrenia are subtle, and range from a slight reduction in brain size to localized alterations in the morphology and molecular composition of specific neuronal, synaptic, and glial populations in the hippocampus, dorsolateral prefrontal cortex, and dorsal thalamus. These findings have fostered the view of schizophrenia as a disorder of connectivity and of the synapse. Although attractive, such concepts are vague, and differentiating primary events from epiphenomena has been difficult. A way forward is provided by the recent identification of several putative susceptibility genes (including neuregulin, dysbindin, COMT, DISC1, RGS4, GRM3, and G72). We discuss the evidence for these and other genes, along with what is known of their expression profiles and biological roles in brain and how these may be altered in schizophrenia. The evidence for several of the genes is now strong. However, for none, with the likely exception of COMT, has a causative allele or the mechanism by which it predisposes to schizophrenia been identified. Nevertheless, we speculate that the genes may all converge functionally upon schizophrenia risk via an influence upon synaptic plasticity and the development and stabilization of cortical microcircuitry. NMDA receptor-mediated glutamate transmission may be especially implicated, though there are also direct and indirect links to dopamine and GABA signalling. Hence, there is a correspondence between the putative roles of the genes at the molecular and synaptic levels and the existing understanding of the disorder at the neural systems level. Characterization of a core molecular pathway and a 'genetic cytoarchitecture' would be a profound advance in understanding schizophrenia, and may have equally significant therapeutic implications.

The NMDA receptor glycine modulatory site: a therapeutic target for improving cognition and reducing negative symptoms in schizophrenia

Numerous clinical studies demonstrate that subanaesthetic doses of dissociative anaesthetics, which are non-competitive antagonists at the NMDA receptor, replicate in normal subjects the cognitive impairments, negative symptoms and brain functional abnormalities of schizophrenia. Post-mortem and genetic studies have identified several abnormalities associated with schizophrenia that would interfere with the activation of the glycine modulatory site on the NMDA receptor. Placebo controlled clinical trials with agents that directly or indirectly activate the glycine modulatory site consistently reduce negative symptoms and frequently improve cognition in patients with chronic schizophrenia, who are receiving concurrent typical antipsychotics. Thus, there is convincing evidence that the glycine modulatory site on the NMDA receptor is a valid therapeutic target for improving cognition and associated negative symptoms in schizophrenia.

Longitudinal assessment of psychopathological domains over late-stage schizophrenia in relation to duration of initially untreated psychosis: 3-year prospective study in a long-term inpatient population

There remains uncertainty regarding any progressive nature of psychopathology and cognitive dysfunction in late-stage schizophrenia, and whether duration of initially untreated psychosis (DUP) might be associated with such 'progression'. This study examines longitudinally, over 3 years, the psychopathology and neuropsychology in 82 inpatients with DSM-IV schizophrenia, many of whom were admitted in the pre-neuroleptic era. Increase in executive dysfunction exceeded that in general cognitive impairment. Positive but not negative symptom severity decreased modestly; the primary predictor of negative symptom severity was DUP. On index assessment, psychopathology evidenced a three-factor structure; at follow-up, psychomotor poverty evidenced greater prominence and cohesion, and was on both occasions predicted primarily by DUP, while reality distortion was altered and disorganisation disassembled into alternative elements. It would appear that as years of chronic, refractory illness accrue, psychomotor poverty becomes more sharply delineated and dominant within the overall structure of psychopathology, and its prominence is predicted enduringly by DUP.

S100B serum levels and long-term improvement of negative symptoms in patients with schizophrenia

S100B, a calcium-binding protein produced by astroglial cells, mediates paracrine and autocrine effects on neurons and glial cells. It regulates the balance between proliferation and differentiation in neurons and glial cells by affecting protective and apoptotic mechanisms. Post-mortem studies have demonstrated a deficit in synapses and dendrites in brains of schizophrenics. Recent studies have shown increased S100B levels in medicated acutely psychotic schizophrenic patients as well as unmedicated or drug naive schizophrenics. One study reported a positive correlation between negative symptoms and S100B. S100B serum levels (quantitative immunoassay) and psychopathology (Positive and Negative Syndrome Scale, PANSS) were examined upon study admission and after 12 and 24 weeks of standardized treatment in 98 chronic schizophrenic patients with primarily negative symptoms. Compared to age- and sex-matched healthy controls, the schizophrenic patients showed significantly increased S100B concentrations upon admission and after 12 and 24 weeks of treatment. High PANSS negative scores were correlated with high S100B levels. Regression analysis comparing psychopathology subscales and S100B identified negative symptomatology as the predicting factor for S100B. S100B is not just elevated during acute stages of disease since it remains elevated for at least 6 months following an acute exacerbation. With regard to psychopathology, negative symptomatology appears to be the predicting factor for the absolute S100B concentration. This might indicate that S100B in schizophrenic patients either promotes apoptotic mechanisms by itself or is released from astrocytes as part of an attempt to repair a degenerative or destructive process.

3D morphometrics of craniofacial dysmorphology reveals sex-specific asymmetries in schizophrenia

Over early fetal life cerebral and craniofacial morphogenesis proceed in embryological intimacy. Therefore, craniofacial shape differences between schizophrenia patients and controls are informative of developmental disturbance(s) in cerebral-craniofacial morphogenesis. 3D craniofacial coordinates were calculated from interlandmark distances for 169 patients with DSM-III-R schizophrenia and 78 matched normal controls. These were analysed using geometric morphometrics with visualisation of the resultant statistical models. Patients of both sexes were characterised by an intricate topography of 3D shape change involving lengthened lower mid-facial height, shortened upper mid-facial height, nasion located posteriorly and a wider face posteriorly; there was sex-specific rotation of the midface such that the base of the nose is more anterior in female patients but more posterior in male patients. Importantly, there were sex-specific asymmetries: in males, controls evidenced marked directional asymmetry while patients showed reduced directional asymmetry; conversely, in females controls evidenced little directional asymmetry while patients showed marked directional asymmetry. In schizophrenia, the topography of craniofacial dysmorphology appears to reflect subtle disruption to a critical 3D trajectory of embryonic-fetal craniofacial growth, particularly along the midline, with disturbance to the establishment of normal asymmetries in a sex-related manner.

Cerebral ventricular change over the first 10 years after the onset of schizophrenia

Whether the brain structural abnormalities seen in schizophrenia are progressive is controversial. We previously reported on a longitudinal study of 50 first-episode patients with schizophrenia and 20 controls who had serial MRI scans during the first 5 years of illness. Greater enlargement of lateral ventricles and reduction of hemispheric volume was observed over time in the patients compared with controls. The present study obtained MRI scans from 26 of these patients and 10 controls at a follow-up 10 years subsequent to their first evaluations. The initial, 4-5th and 10th year scans were examined for the degree of change in ventricular and hemispheric volume. Significantly greater ventricular enlargement during the second 5 years was detected in the patient cohort compared with controls (P<0.05) with nine of the patients having ventricular enlargement (as measured by percent change) occurring at a rate exceeding that of any of the controls from years 1 through 10. The rate of ventricular change during the first 5 years was significantly correlated with age at first hospitalization, and ventricular enlargement in years 5-10 was correlated with the amount of time spent in hospital. Paradoxically, greater change in ventricles over time was correlated with better, not worse, outcome at the 10th year of follow-up with regard to the presence of symptoms. These data suggest heterogeneity in the course of brain change whereby some patients may exhibit active structural brain change only early in their illness or not at all after their first episode, while others continue to exhibit ventricular change spanning the decade subsequent to their first episode. Despite these differences among patients, the present study fails to detect any relationship of ventricular enlargement to poorer outcome as has been reported by other investigators.

Meta-analysis of brain weight in schizophrenia

Brain weight is often said to be decreased in schizophrenia, but a reduction has only been found in a minority of studies. We have therefore carried out a meta-analysis to answer this basic neuropathological question. Data were identified from literature searches and from contacting researchers in the field who were invited to submit unpublished data. Inclusion criteria were: an operational diagnosis of schizophrenia, or comparison subjects with no neurological or psychiatric history, aged 18 or over, for whom brain weight, age and sex were known. Exclusion criteria were: a history of head injury, epilepsy, substance dependence or leucotomy; neuropathological evidence of neurodegenerative disorder or focal brain lesion. Results were analysed by multilevel modelling. Brain weight was, as expected, related to age and sex (both p<0.0001). After control for these factors, there was an effect of diagnosis, with brains from the 540 schizophrenia subjects being 2% lighter than from the 794 controls (weighted mean difference=24 g [95% confidence interval, 1-47 g]; p=0.04). The difference was similar in male and female patients. There was no correlation with duration of illness. In conclusion, brain weight is slightly but significantly reduced in schizophrenia, consistent in direction and magnitude with MRI volumetric findings. The result encourages a continuing search for the histological and molecular correlates of schizophrenia.

Early and late neurodevelopmental disturbances in schizophrenia and their functional consequences

OBJECTIVE

The evidence from structural imaging studies supports the notion that schizophrenia arises from an early abnormality in brain development. In this paper we review the timing of structural changes in schizophrenia and argue that schizophrenia is a neuro-developmental disorder with limited progressive brain changes occurring during the evolution and early phase of psychosis.

METHOD

The available cross-sectional and longitudinal studies are reviewed, along with data from our own research.

RESULTS

The current literature, including our own data, suggests that structural brain changes are apparent premorbidly, consistent with a neurodevelopmental lesion. These are prominent in frontal and cingulate regions, and appear related to premorbid neuropsychological deficits in executive function. However, there appear to be additional brain changes over the transition to illness and beyond.

CONCLUSIONS

We propose first, that an early neurodevelopmental insult interacts with either normal or abnormal postpubertal brain maturation to produce further (late neurodevelopmental) brain structural and functional changes; and second, that the effect of such neurodevelopmental lesions will have different consequences for functions that normally develop early in life, such as memory, compared with functions developing later, such as executive functions. A model is presented suggesting that the structural and functional abnormalities in schizophrenia can be understood as a consequence of the neurodevelopmental stage at which brain changes occur.

Does schizophrenia result from developmental or degenerative processes?

The debate as to whether schizophrenia is a neurodevelopmental or a neurodegenerative disorder has its roots in the latter part of the 19th century when authorities such as Clouston (1891) posited that at least some insanities were "developmental" in origin. These views were soon eclipsed by Kraepelin's (1896) concept of dementia praecox as a degenerative disease, and the latter view carried not only the day but also much of the 20th century. Then, in the 1980s several research groups again began to speculate that schizophrenia might have a significant developmental component (Feinberg, 1982-1983; Schulsinger et al., 1984; Murray et al., 1985; Murray and Lewis, 1987; Weinberger et al., 1987). What became known as the "neurodevelopmental hypothesis" received support from neuropathological studies implicating anomalies in early brain development such as aberrant migration of neurons. Unfortunately, these studies proved difficult, if not impossible, to replicate (Harrison, 1999). The pendulum, therefore, began to swing again, and in the latter part of the 1990s came renewed claims that the clinical progression of the illness was accompanied by continued cerebral ventricular enlargement and reduction in the volumes of certain brain structures. Nevertheless, since few doubt that there is a developmental component to schizophrenia, the question which we will address in this paper is whether schizophrenia is a) simply the final consequence of a cascade of increasing developmental deviance (Bramon et al., 2001), or b) whether there is an additional brain degeneration following onset of psychosis which is superimposed on the developmental impairment (Lieberman, 1999).

S100B in brain damage and neurodegeneration

S100B is a calcium-binding peptide produced mainly by astrocytes that exert paracrine and autocrine effects on neurons and glia. Some knowledge has been acquired from in vitro and in vivo animal experiments to understand S100B's roles in cellular energy metabolism, cytoskeleton modification, cell proliferation, and differentiation. Also, insights have been gained regarding the interaction between S100B and the cerebral immune system, and the regulation of S100B activity through serotonergic transmission. Secreted glial S100B exerts trophic or toxic effects depending on its concentration. At nanomolar concentrations, S100B stimulates neurite outgrowth and enhances survival of neurons during development. In contrast, micromolar levels of extracellular S100B in vitro stimulate the expression of proinflammatory cytokines and induce apoptosis. In animal studies, changes in the cerebral concentration of S100B cause behavioral disturbances and cognitive deficits. In humans, increased S100B has been detected with various clinical conditions. Brain trauma and ischemia is associated with increased S100B concentrations, probably due to the destruction of astrocytes. In neurodegenerative, inflammatory and psychiatric diseases, increased S100B levels may be caused by secreted S100B or release from damaged astrocytes. This review summarizes published findings on S100B regarding human brain damage and neurodegeneration. Findings from in vitro and in vivo animal experiments relevant for human neurodegenerative diseases and brain damage are reviewed together with the results of studies on traumatic, ischemic, and inflammatory brain damage as well as neurodegenerative and psychiatric disorders. Methodological problems are discussed and perspectives for future research are outlined.

Altered hemispheric asymmetry and positive symptoms in schizophrenia: equivalent current dipole of auditory mismatch negativity

The abnormality of mismatch negativity (MMN) in schizophrenia is thought to be associated with perceptional disturbance and cognitive dysfunction. The purpose of the present study was to investigate the change of the normal functional hemispheric lateralization in schizophrenia by employing the equivalent current dipole (ECD) model of auditory MMN with individual MRI and high-density electroencephalography (EEG). The MMNs resulting from auditory stimuli with passive oddball paradigm in a group of schizophrenics (n = 15), and also a group of age-, sex-, and handedness-matched normal controls, were recorded by 128 channel EEG. The location and power of ECD sources at the peak point were calculated. Individual 3-D brain magnetic resonance images (MRI) were used for realistic head modeling and for source localization. For both groups, the MMN source was determined to be located in the superior temporal gyrus (STG). However, the normal functional hemispheric asymmetry of ECD power was significantly altered in the schizophrenics (chi(2) test = 16.13, p < 0.001). Left MMN ECD power and the asymmetry coefficient (AC) were negatively correlated with the positive scores from Positive and Negative Syndrome Scale (PANSS) (r = -0.673, p = 0.008), especially with the hallucinatory behavior subscale (r = -0.677, p = 0.008). These findings support the deficits in preattentive automatic processing of auditory stimuli, especially in the left hemisphere, and indicate the correlation between positive symptoms, especially auditory hallucination, and left temporal lobe dysfunction in schizophrenia.

Schizophrenia: solving the puzzle

BACKGROUND

Schizophrenia is a common mental illness with an incidence of 15 new cases per 100,000 population per year.

AIM

To review evidence for current neurodevelopmental models of the aetiology of schizophrenia.

METHODS

We performed a literature search using Medline and PsychINFO. We evaluated the relevance of each article and tracked other relevant articles through references.

RESULTS

There is considerable evidence to support neurodevelopmental models of the aetiology of schizophrenia. One or more aetiological events occur between conception and birth that disturb central nervous system (CNS) development, leading to persisting alterations in brain structure and function. These early events, acting in concert with genetic loading and later influences or insults, predispose to the development of schizophrenia in early adulthood.

CONCLUSIONS

There have been considerable advances in schizophrenia research over the past 20 years. Future study of Indices of neural development will help advance our understanding of this common, disabling mental illness.

Increased duration of illness is associated with reduced volume in right medial temporal/anterior cingulate grey matter in patients with chronic schizophrenia

It is unclear whether the neuroanatomical abnormalities associated with schizophrenia change over the course of the disorder. We addressed this issue by examining whether the magnitude of structural brain abnormalities in patients with chronic schizophrenia was related to their duration of illness. Thirty-nine subjects with schizophrenia (34 male, 5 female, range of illness duration 2-31 years) were scanned using magnetic resonance imaging. Images were segmented into grey and white matter, cerebrospinal fluid and dura/blood vessels using the Structural Magnetic Resonance Toolkit (SMaRT). Voxel-based analysis identified brain areas whose volume varied significantly with time since the first onset of psychosis. Right medial temporal, medial cerebellar and bilateral anterior cingulate grey matter volume, and white matter volume in the right posterior limb of the internal capsule, were all negatively correlated with illness duration (p < 0.002). Conversely, illness duration was positively correlated with the volume of the right globus pallidus (p < 0.002). These correlations were not a function of chronological age or age at illness onset. The inverse correlation between right frontal, temporal and cerebellar volumes and the time since the onset of schizophrenia could reflect progressive tissue loss following the first episode of the disorder.

Brain volumes in familial and non-familial schizophrenic probands and their unaffected relatives

Structural brain abnormalities are consistently reported in schizophrenic subjects but the etiology of these abnormalities remains unclear. We tested the contribution of genetic predisposition and obstetric complications to the structural brain abnormalities found in schizophrenic probands and their relatives. MRI scans were carried out on 35 schizophrenic probands from families multiply affected with the disorder, and 63 of their unaffected relatives, including 10 parents who appeared to transmit genetic risk to their children; as well as 31 schizophrenic probands from families with no other affected members, 33 of their unaffected relatives; and finally 68 controls. Volumetric measurements of whole brain, lateral ventricles, third ventricle, cerebellum, and temporal lobes were completed for each subject. The impact of obstetric complications on brain structure was assessed across the gradient of presumed genetic predisposition. Both groups of schizophrenic probands displayed enlargement of the lateral and third ventricles, and there was a gradient of ventricular enlargement amongst the unaffected relatives in proportion to their likelihood of carrying schizophrenic genes. Ventricular enlargement was largely confined to males in both probands and unaffected relatives. Obstetric complications were associated with ventricular enlargement only in the familial probands. Non-familial probands displayed reduced volume of the temporal lobes bilaterally. In families with several schizophrenic members, ventricular enlargement is a marker for genetic liability, particularly in males. Individuals inheriting the susceptibility to schizophrenia appear particularly prone to develop ventricular enlargement in response to obstetric complications.

Reduction of the synaptophysin level but normal levels of glycerophospholipids in the gyrus cinguli in schizophrenia

The 'membrane hypothesis' of schizophrenia postulates a disturbance in the metabolism and structure of membrane phospholipids resulting in a disturbance in the function of neuronal membrane proteins. Most studies exploring this hypothesis have examined components of peripheral blood. Since it may be questioned if these peripheral measurements reflect changes in the brain, we studied the fatty acid composition of glycerophospholipids in brain tissue. As a marker for synaptic density, we also measured the synaptic vesicle protein synaptophysin. Brain tissue (gyrus cinguli) from 11 schizophrenic patients (mean age 80 +/- 10 years) and 13 controls (mean age 75 +/- 14 years) was examined. The glycerophospholipid fatty acids were determined by gas chromatography. Synaptophysin protein level was determined using quantitative immunoblotting followed by Western blotting. There were no significant differences between the groups in the total or in any individual level of fatty acids, either in the n - 6 or n - 3 series. The level of synaptophysin was significantly p = (0.002) decreased in the schizophrenic group(0.73 + 0.18) as compared with the control group (1.02 + 0.21). The normal pattern and concentration of glycerophospholipids fatty acids found in the present study do not support the membrane hypothesis of schizophrenia. The possibility of a type II error should, however. be considered. On the other hand, the reduced synaptophysin' levels in the gyrus cinguli demonstrate that biological differences can be revealed in this relatively small sample. This also lends further support to the notion that a synaptic disturbance or loss is of importance in the pathogenesis of schizophrenia.

A longitudinal study of hippocampal volume in first episode psychosis and chronic schizophrenia

Brain abnormalities have been identified in patients with schizophrenia, but what is unclear is whether these changes are progressive over the course of the disorder. In this longitudinal study, hippocampal and temporal lobe volumes were measured at two time points in 30 patients with first episode psychosis (mean follow-up interval=1.9 years, range 0.54-4.18 years) and 12 with chronic schizophrenia (mean follow-up interval=2.3 years, range 1.03-4.12 years) and compared to 26 comparison subjects (mean follow-up interval 2.2 years, range 0.86-4.18 years). Hippocampal, temporal lobe, whole-brain and intracranial volumes (ICV) were estimated from high-resolution magnetic resonance images. Only whole-brain volume showed significant loss over the follow-up interval in both patient groups. The rate of this volume loss was not different in the first episode group compared to the chronic group. There were no changes in either hippocampal or temporal lobe volumes. The negative findings for the hippocampus and temporal lobes may mean that the abnormalities in these regions are stable features of schizophrenia. Alternatively, the period before the onset of frank psychotic symptoms may be the point of greatest risk for progressive change.

Increased S100B blood levels in unmedicated and treated schizophrenic patients are correlated with negative symptomatology

S100B, a calcium-binding protein produced by astroglial cells, is a marker of astroglial cellular integrity. It has been shown to be increased in acute brain damage and neurodegeneration. A recent study showed increased S100B levels in medicated acutely psychotic patients with schizophrenia. The study presented here included 26 drug-free patients with acute schizophrenia and 26 matched healthy controls. S100B blood concentrations were determined using a quantitative immunoassay upon admission and after 6 weeks of neuroleptic treatment. The PANSS was used to investigate psychopathology. Unmedicated schizophrenic patients showed significantly increased S100B levels compared to matched healthy controls. After 6 weeks of treatment, 11 patients showed normal S100B levels while in 15 patients the levels remained increased. These patients showed significantly higher PANSS negative scores upon admission and after 6 weeks of treatment. Schizophrenic patients display a loss of astroglial integrity which is not caused by neuroleptic medication. Continuously increased S100B levels are associated with negative symptomatology.