Progressive ventricular enlargement in schizophrenia: comparison to bipolar affective disorder and correlation with clinical course

Biomarkers of neuroprogression and late staging in bipolar disorder: A systematic review

BACKGROUND

Bipolar disorder may undertake a progressive course in a subset of patients, and research efforts have been made to understand the biological basis underlying this process. This systematic review examined the literature available on biological markers associated with illness progression in bipolar disorder.

METHODS

Peer-reviewed articles were assessed using Embase, PsycINFO and PubMed, as well as from external sources. After initial screening, a total of 871 citations from databases and other sources were identified. Participants with a diagnosis of bipolar disorder were included in our systematic review; however, studies with participants younger than 15 or older than 65 were excluded. All studies were assessed using the Newcastle-Ottawa Scale assessment tool, and data pertaining to the results were extracted into tabular form using Google Sheets and Google Documents. The systematic review was registered on PROSPERO international prospective register of systematic reviews (ID Number: CRD42020154305).

RESULTS

A total of 35 studies were included in the systematic review. Increased ventricular size and reduction of grey matter volume were the most common brain changes associated with illness progression in bipolar disorder. Among the several biomarkers evaluated in this systematic review, findings also indicate a role of peripheral inflammatory markers in this process.

DISCUSSION

The studies evaluating the biological basis of the illness progression in bipolar disorder are still scarce and heterogeneous. However, current evidence supports the notion of neuroprogression, the pathophysiological process related to progressive brain changes associated with clinical progression in patients with bipolar disorder. The increase in peripheral inflammatory biomarkers and the neuroanatomical changes in bipolar disorder suggest progressive systemic and structural brain alterations, respectively.

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.

Transdiagnostic neuroimaging in psychiatry: A review

Transdiagnostic approach has a long history in neuroimaging, predating its recent ascendance as a paradigm for new psychiatric nosology. Various psychiatric disorders have been compared for commonalities and differences in neuroanatomical features and activation patterns, with different aims and rationales. This review covers both structural and functional neuroimaging publications with direct comparison of different psychiatric disorders, including schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorder, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, conduct disorder, anorexia nervosa, and bulimia nervosa. Major findings are systematically presented along with specific rationales for each comparison.

Volumetric brain magnetic resonance imaging predicts functioning in bipolar disorder: A machine learning approach

Neuroimaging studies have been steadily explored in Bipolar Disorder (BD) in the last decades. Neuroanatomical changes tend to be more pronounced in patients with repeated episodes. Although the role of such changes in cognition and memory is well established, daily-life functioning impairments bulge among the consequences of the proposed progression. The objective of this study was to analyze MRI volumetric modifications in BD and healthy controls (HC) as possible predictors of daily-life functioning through a machine learning approach. Ninety-four participants (35 DSM-IV BD type I and 59 HC) underwent clinical and functioning assessments, and structural MRI. Functioning was assessed using the Functioning Assessment Short Test (FAST). The machine learning analysis was used to identify possible candidates of regional brain volumes that could predict functioning status, through a support vector regression algorithm. Patients with BD and HC did not differ in age, education and marital status. There were significant differences between groups in gender, BMI, FAST score, and employment status. There was significant correlation between observed and predicted FAST score for patients with BD, but not for controls. According to the model, the brain structures volumes that could predict FAST scores were: left superior frontal cortex, left rostral medial frontal cortex, right white matter total volume and right lateral ventricle volume. The machine learning approach demonstrated that brain volume changes in MRI were predictors of FAST score in patients with BD and could identify specific brain areas related to functioning impairment.

Are there progressive brain changes in schizophrenia? A meta-analysis of structural magnetic resonance imaging studies

BACKGROUND

It is well established that schizophrenia is associated with structural brain abnormalities, but whether these are static or progress over time remains controversial.

METHODS

A systematic review of longitudinal volumetric studies using region-of-interest structural magnetic resonance imaging in patients with schizophrenia and healthy control subjects. The percentage change in volume between scans for each brain region of interest was obtained, and data were combined using random effects meta-analysis.

RESULTS

Twenty-seven studies were included in the meta-analysis, with 928 patients and 867 control subjects, and 32 different brain regions of interest. Subjects with schizophrenia showed significantly greater decreases over time in whole brain volume, whole brain gray matter, frontal gray and white matter, parietal white matter, and temporal white matter volume, as well as larger increases in lateral ventricular volume, than healthy control subjects. The time between baseline and follow-up magnetic resonance imaging scans ranged from 1 to 10 years. The differences between patients and control subjects in annualized percentage volume change were -.07% for whole brain volume, -.59% for whole brain gray matter, -.32% for frontal white matter, -.32% for parietal white matter, -.39% for temporal white matter, and +.36% for bilateral lateral ventricles.

CONCLUSIONS

These findings suggest that schizophrenia is associated with progressive structural brain abnormalities, affecting both gray and white matter. We found no evidence to suggest progressive medial temporal lobe involvement but did find evidence that this may be partly explained by heterogeneity between studies in patient age and illness duration. The causes and clinical correlates of these progressive brain changes should now be the focus of investigation.

Morphometrical and morphological analysis of lateral ventricles in schizophrenia patients versus healthy controls

The goal of this report was to highlight lateral ventricle morphology and volume differences between schizophrenia patients and matched controls. Subjects identified as suitable for analysis comprised 15 schizophrenia patients and 15 healthy subjects. The method applied is three-dimensional (3D) volume rendering starting from structural magnetic resonance imaging (MRI) studies of selected ventricular regions. Differences between groups relative to the global ventricular system and its subdivisions were found. Total lateral ventricle volume, right ventricle volume and left ventricle volume were all higher in schizophrenia patients than in controls; unilateral differences between the two groups were also outlined (right ventricle volume>left ventricle volume in schizophrenia patients vs. healthy subjects). Furthermore, occipital and frontal horn enlargement was found in schizophrenia patients compared with normal controls, but the difference in the temporal horn was not statistically significant. A substantial difference was noted in lateral ventricle morphology between the two groups. Our findings were consistent with the literature and may shed light on some of the discrepancies in previous reports on differences in lateral ventricle volume enlargement.

A prospective longitudinal volumetric MRI study of superior temporal gyrus gray matter and amygdala-hippocampal complex in chronic schizophrenia

A progressive post-onset decrease in gray matter volume 1.5 years after first hospitalization in schizophrenia has been shown in superior temporal gyrus (STG). However, it is still controversial whether progressive volume reduction occurs in chronic schizophrenia in the STG and amygdala-hippocampal complex (AHC), structures found to be abnormal in chronic schizophrenia. These structures were measured at two time points in 16 chronic schizophrenia patients and 20 normal comparison subjects using manual tracing with high spatial resolution magnetic resonance imaging (MRI). Average interscan interval was 3.1 years for schizophrenia patients and 1.4 years for healthy comparison subjects. Cross-sectional comparisons showed smaller relative volumes in schizophrenia compared with controls in posterior STG and AHC. An ANCOVA with interscan interval as a covariate showed there was no statistically significant progression of volume reduction in either the STG or AHC in the schizophrenia group compared with normal subjects. In the schizophrenia group, volume change in the left anterior AHC significantly correlated with PANSS negative symptoms. These data, and separately reported first episode data from our laboratory, suggest marked progression at the initial stage of schizophrenia, but less in chronic schizophrenia.

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.

The effect of ageing on grey and white matter reductions in schizophrenia

Total brain volume and, in particular gray matter (GM) volume is reduced in patients with schizophrenia and recent studies suggest there is greater progressive loss of brain volume in the patients with schizophrenia than in normal controls. However, as the longitudinal studies do not include life-long follow-up, it is not clear if this occurs across the lifespan or only in the early phase of the illness. In this study we investigated this by studying the effects of age on brain tissue volumes in schizophrenia (n=34, age range=27-65 years)to test the prediction that there is a progressive loss in grey matter volume with increasing age in patients compared to healthy controls (n=33, age range=18-73 years). The results showed there was diminished relative GM volume loss with age in patients with schizophrenia compared to controls--in contrast to our prediction. However, there was increased relative white matter (WM) loss with age in schizophrenia. The results also replicated previous findings that patients with schizophrenia have significantly lower total (1509 versus 1596 mm(3)) and regional GM volume (755 versus 822 mm(3)) and increased cerebrospinal fluid (CSF) volume when compared to matched healthy volunteers. Overall these findings indicate that the proportion of grey matter in schizophrenia is reduced compared to controls early in the illness, and this difference diminishes with age; the corresponding effect in the proportion of WM is an increase with age compared to controls. This suggests that illness related factors may differentially affect grey and white matter, with implications for understanding the pathophysiology of schizophrenia and related psychotic disorders.

Neuroprotective effect of atypical antipsychotics in cognitive and non-cognitive behavioral impairment in animal models

Antipsychotic drugs are divided into two groups: typical and atypical. Recent clinical studies show atypical antipsychotics have advantages over typical antipsychotics in a wide variety of neuropsychiatric conditions, in terms of greater efficacy for positive and negative symptoms, beneficial effects on cognitive functioning, and fewer extra pyramidal side effects in treating schizophrenia. As such, atypical antipsychotics may be effective in the treatment of depressive symptoms associated with psychotic and mood disorders, posttraumatic stress disorder and psychosis in Alzheimer disease. In this paper, we describe the effects and potential neurochemical mechanisms of action of atypical antipsychotics in several animal models showing memory impairments and/or non-cognitive behavioral changes. The data provide new insights into the mechanisms of action of atypical antipsychotics that may broaden their clinical applications.

Neurodevelopmental basis of bipolar disorder: a critical appraisal

Neurodevelopmental factors have been implicated in the pathophysiology of mental disorders. However, the evidence regarding their role in bipolar disorder is controversial. We reviewed the pertinent literature searching for evidence regarding a neurodevelopmental origin of bipolar disorder. Findings from clinical, epidemiological, neuroimaging, and post-mortem studies are discussed, as well as the implications of the available data for a better understanding of the mechanisms involved in the genesis of bipolar disorder. While some evidence exists for developmental risk factors in bipolar disorder, further research is needed to determine the precise extent of their contribution to pathogenesis. The timing and course of such developmentally mediated neurobiological alterations also need to be determined. Of particular importance for further study is the possibility that bipolar disorder may be mediated by an abnormal maturation of brain structures involved in affect regulation.

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.

Prolongation of P300 latency is associated with the duration of illness in male schizophrenia patients

The association of P300 components with age, illness duration and gender were examined in schizophrenia patients and whether such variables indicate a progressive course. A total of 60 patients with schizophrenia and 70 healthy controls were studied utilizing standard auditory oddball tasks. Both healthy and schizophrenia groups had a significant positive correlation between age and P300 latency. There was also a significant positive correlation between illness duration and P300 latency in the schizophrenia group. The prolonged latency of P300, associated with age or illness duration, was more prominent in male than female schizophrenia subjects. These findings suggest gender differences in disease progression in schizophrenia.

Neuropsychological functioning in MRI-derived subgroups of schizophrenia

This study examined neuropsychological functioning in two subgroups of patients with familial schizophrenia. Those who showed evidence of progressive ventricular enlargement observed across serial MRI scans (n=6) were compared with subjects whose ventricular volume remained static (n=10) over an average of 28 months. No differences were found in terms of age, education, ethnicity, level of psychotic symptomatology, DSM-IV subtype, age of onset, or duration of illness. Neurocognitively, the static ventricle group was impaired across more cognitive domains and had a larger percentage of subjects falling into the impaired range on a majority of measures, with the greatest differences on measures of attention (p<0.02) and nonverbal memory (p<0.07). These results suggest that clinically meaningful differences between these two MRI-derived subgroups of patients with schizophrenia may exist, and further underscore the heterogeneity of the illness.

A volumetric MRI and magnetization transfer imaging follow-up study of patients with first-episode schizophrenia

Conventional MRI studies have not provided definitive evidence of progressive loss of brain volume in the early stages of schizophrenia, although more subtle changes may have gone undetected. We have looked for such subtle changes using volumetric MRI and magnetization transfer imaging (MTI), an advanced MRI technique sensitive to subtle neuropathological abnormalities. Magnetization transfer images and high-resolution volumetric T1-weighted images were acquired from 16 patients with first-episode schizophrenia at the start of the study and 3.7 years later. A group of 12 healthy controls were also scanned on two occasions. Images were processed using a voxel-based approach that allows whole-brain analysis. There was a group difference with a significant volume loss in the patients' white matter adjacent to the lateral ventricles in the right and left temporal lobes, in medial temporal gyrus, and in the white matter in and around the right middle frontal gyrus. No cortical differences were detected between the groups using MTI or volumetric MRI. The absence of any time-by-group interaction suggests that these abnormalities do not progress in the early stages of the disease. The results of the study need to be interpreted in the light of the small sample size and of the limitations of current image analysis methods.

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.

Brain morphology in first-episode schizophrenia: a meta-analysis of quantitative magnetic resonance imaging studies

BACKGROUND

A number of meta-analytic reviews of structural brain imaging studies have shown that multiple subtle brain abnormalities are consistently found in schizophrenia. However, quantitative reviews till now published have included mainly studies performed on chronic schizophrenic patients but have failed to provide clear information on specific, possibly different, findings in first-episode schizophrenia.

METHODS

We performed a systematic search for MRI studies that reported quantitative measurements of volumes of brain regions in first-episode schizophrenic patients and in healthy controls. Twelve meta-analyses were performed for 6 cerebral regions.

RESULTS

Twenty-one studies were identified as suitable for analysis. Significant overall effect sizes were demonstrated for lateral and third ventricular volume increase, and for volume reduction of whole brain and hippocampus, but not for temporal lobe, amygdala and total intracranial volumes.

CONCLUSIONS

The available literature data strongly indicate that some brain abnormalities are already present in first-episode schizophrenic patients. However, unlike the results of published meta-analyses conducted primarily on samples of chronic schizophrenic patients, the present study did not confirm a significant reduction of temporal lobe or amygdala volumes in first-episode schizophrenia. These findings support the hypothesis of different patterns of involvement of various cerebral areas over the time course of schizophrenia.

Differential effects of long-term treatment with typical and atypical antipsychotics on NGF and BDNF levels in rat striatum and hippocampus

The results of mostly short-term treatment studies in human patients and animals suggest that second-generation antipsychotics (SGAs) such as risperidone (RISP) and olanzapine (OLZ) compared to first-generation antipsychotics (FGAs) such as haloperidol (HAL) and chlorpromazine (CPZ) have neuroprotective effects. The animal studies indicate that these effects are probably mediated through increased expression of neurotrophic factors such as nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF). However, since antipsychotics are commonly used for very long-term treatment periods, particularly in schizophrenic patients, it is important to measure the effects of chronic administration of antipsychotic drugs on the aforementioned growth factors. This study determined the effects of 90- and 180-day treatments with two FGAs, HAL and CPZ, and two SGAs, RISP and OLZ, on the levels of NGF and BDNF protein in hippocampus and striatum of rat. Furthermore, since a preliminary study showed that 90-day treatment of HAL caused significant reductions in the expression of both NGF and BDNF the HAL-treated animals were then switched to SGAs for the next 90 days to assess the potential for restoration of trophic factor levels. After the 90-day treatment, NGF levels in the hippocampus were reduced by 60-70% with HAL or CPZ, and by only 25-30% with RISP or OLZ compared to levels with vehicle only. After the 180-day treatment, NGF levels were further reduced with HAL, RISP, and OLZ, but not with CPZ. The magnitude of the NGF decreases in the striatum was larger (70-90%) with all the antipsychotics compared to the hippocampus. However, the pattern of BDNF changes in the hippocampus differed significantly from the striatum after 90- or 180-day treatment with the antipsychotics. In hippocampus, compared to controls, BDNF levels remained unchanged with OLZ both after 90 and 180 days of treatment. Whereas, larger decreases in BDNF levels were observed with HAL or CPZ and intermediate decreases were observed with RISP after 90 days of treatment that continued to decline up to 180 days. Furthermore, switching HAL animals after 90 days of treatment to either RISP or OLZ for the next 90 days significantly restored levels of both NGF and BDNF in both the brain regions. These data indicate that SGAs compared to FGAs induce less deleterious effects on neurotrophic factor levels in the brain and may also offer ability to reverse the more pronounced negative effects of FGAs as well. These data may have significant clinical implications for long-term antipsychotic selection as well as the common practice of antipsychotic switchover.

Longitudinal volumetric MRI study in first- and multiple-episode male schizophrenia patients

In this longitudinal study we compared brain volume changes in first- and multiple-episode patients with schizophrenia to normal aging changes observed in healthy control subjects scanned at comparable times. Two to four years after an initial examination including MRI volumetry, we followed up 21 first episode patients, 17 patients after multiple episodes of schizophrenia, and 20 healthy controls. Volumetric measurements of left and right hemispheres, total brain volume, lateral ventricles, hippocampus and amygdala as well as a clinical evaluation were performed. Patients with schizophrenia showed significant ventricular enlargement and volume reduction of the hippocampus-amygdala complex compared with healthy control subjects both at baseline and follow-up. While there were no differences between patients and controls with respect to mean annual volume changes in the measured regions, patients with schizophrenia showed higher between-subject variability in ventricular volume change. These data are consistent with cross-sectional studies demonstrating ventricular enlargement and hippocampal volume deficits in schizophrenia. However, we were not able to demonstrate a difference in the rate of volume changes over time that distinguished patients with schizophrenia from healthy controls for any of the brain structures measured. Drawbacks of the study are that the follow-up was done after a relatively short interval and that there was a difference in time to follow-up and age between patients and controls. Our results do not support the hypothesis that schizophrenia leads to progressive volume reduction in these areas, although there may be a subset of patients with morphologically visible disease progression.

Regional structural characterization of the brain of schizophrenia patients

RATIONALE AND OBJECTIVES

We study morphologic characteristics and age-related changes in patients with schizophrenia to investigate whether abnormal neurodevelopment and brain structure have a role in the pathophysiological course of this disease.

MATERIALS AND METHODS

Our data consist of a set of cranial magnetic resonance images of 46 patients with schizophrenia and age- and sex-matched healthy controls. We deformed a template brain image to our set of subject images. Jacobian fields of these deformations were reduced to sets of 52 normalized region volumes for each subject by using a neuroanatomic atlas. Normalized regional volumes of the control and patient groups were compared by using Student t-test, and age correlation of each region volume was calculated for the two groups. All results were corrected for multiple comparisons by using permutation testing. We used a classifier based on support vector machines and a feature selection method to determine our ability to discriminate brains of controls from those of patients.

RESULTS

Analysis of normalized region volumes shows enlargement of the third ventricle in patients. The age-correlation study showed a significant positive correlation in the third ventricle and right thalamus of controls, but not patients. Using an average of 6.5 features, our classifier was able to correctly identify 72% of patients and 70% of controls.

CONCLUSION

In addition to enlargement of the third ventricle, brains of patients with schizophrenia show a different pattern of age-related changes.

Olanzapine attenuates the okadaic acid-induced spatial memory impairment and hippocampal cell death in rats

It is hypothesized that olanzapine, an atypical antipsychotic drug, has beneficial effects on cognitive impairment and neuropathological changes in treating neurodegenerative diseases. In the present study, we investigated the effects of chronic administration of olanzapine on the spatial memory impairment and hippocampal cell death induced by the direct injection of okadaic acid (OA), a potent neurotoxin, into the rat hippocampus. After being pretreated with olanzapine (0.5 or 2 mg/kg/day, i.p.) for 2 weeks, the rats were unilaterally microinjected with OA (100 ng) into the hippocampus, and then were continuously administrated with olanzapine for an additional week The rats were trained on a spatial memory task in an eight-arm radial maze before OA administration, and tested on the same task 18 h after the last olanzapine injection. After the behavioral test, the rats were killed for Nissl staining and terminal deoxynucleutidyl transferase-mediated biotinylated UTP nick end labeling staining. OA significantly induced spatial memory impairment, and caused pyramidal cell loss in the CAI and apoptotic cell death in the hippocampus. Olanzapine significantly attenuated OA-induced spatial memory impairment and the OA-induced neuropathological changes in the hippocampus. These findings suggest that olanzapine may have therapeutic effects in treatment of cognitive impairment and neuropathological changes of schizophrenia and other neurodegenerative diseases.

Schizophrenia syndromes associated with changes in ventricle-to-brain ratios: a serial high-resolution three-dimensional magnetic resonance imaging study in first-episode schizophrenia patients using subvoxel registration and semiautomated quantification

A cohort of patients with first-episode schizophrenia was dichotomised into two age- and sex-matched groups of clinical syndromes, the active and withdrawn, and underwent high-resolution three-dimensional magnetic resonance imaging at baseline and 8 months later. A cohort of age- and sex-matched normal controls was also imaged at the same time intervals. The application of subvoxel registration and semiautomated quantification techniques demonstrated a significantly different outcome in ventricular changes between the two groups of patients. Compared with the controls, the withdrawn patients showed progressive ventricular enlargement, with an increase in ventricle-to-brain volume ratio, whereas the active group showed a reduction in ventricle-to-brain volume ratio, with a change opposite in sign and smaller in magnitude. These findings lend further support for the aetiological validity of this syndromal model of schizophrenia and are likely to be of importance in furthering our understanding of its pathogenesis and in the development of suitable therapeutic strategies.

Meta-analysis of the time-course of brain volume reduction in schizophrenia: implications for pathogenesis and early treatment

BACKGROUND

Whole brain volume (BV) is significantly reduced in groups of schizophrenic patients, but there is disagreement as to when in relation to onset of illness these losses occur. Given what is known about the normal development and lifetime course of BV, intraventricular volume (IVV), extracerebral volume (ECV), and intracranial volume (ICV) changes, it is possible to allocate (within a narrow range of uncertainty) excessive brain volume loss (EBVL) to either the time before or the time after attainment of maximum brain volume (BVmax).

METHOD

Decreases in patient ICV relative to control ICV reflect early reductions in brain growth, while increases in ECV reflect later BV losses. There is however uncertainty as whether any relative increases in patient IVV occur early, later, or both. IVV differences were first assumed to be of early origin, so that early EBVL was measured by ICV-IVV differences and later EBVL by ECV differences alone. The IVV differences were then assumed to be of later origin, so that early EBVL was measured by ICV differences alone, and later EBVL by ECV+IVV differences. The results taken together delineate the maximum and minimum values for early and later losses.

RESULTS

Patient-control volume differences in BV and ICV for 20 published magnetic resonance imaging (MRI) studies of schizophrenic patients (n=982) and controls (n=1049), and differences in ECV for 17 of the same 20 studies, comprising 889 patients and 942 controls, showed a significant patient BV decrease of 34 cc's (t=-4.94, df=19, p<0.0001), ICV decrease of 20.1 cc's (t=-2.64, df=19, p<0.02) and ECV Increase of 14.1 cc's (t=3.65, df=16, p<0.001). In the 17 studies which included ECV and IVV, as well as ICV differences, the patient ICV-IVV decrease was 20.2 cc's (t=-2.56, df=16, p<0.05) and the ECV+IVV increase was 17.1 cc's (t=-4.11, df=16, p<0.001).

CONCLUSION

There is a small but significant whole brain EBVL in schizophrenia patients both before and after BV(max), regardless of when excessive IVV enlargement is assumed to occur.

The NR1 subunit of the glutamate/NMDA receptor in the superior temporal cortex in schizophrenia and affective disorders

The NMDA receptor has been implicated in the pathophysiology of several diseases including schizophrenia and affective disorders. We have investigated the NR1 subunit of the NMDA receptor in a well-defined series of psychiatric cases using radioligand binding and quantitative immunoblotting techniques. Saturable radioligand binding of [(3)H]L-689,560 to the glycine site on this subunit of the NMDA receptor was undertaken in superior temporal cortex of patients with schizophrenia, bipolar disorder, depression and matched control subjects. A tendency towards an increased receptor density was found in schizophrenia. A significant decrease in NMDA receptor density below control value was found in both bipolar and depressive disorders. The immunoblotting technique was used to identify NR1 protein in the same series of cases of which two bands were identified consistent with NR1 splice variants. A tendency to a decrease in the density of the NR1 upper band below control values was found in bipolar and depressed patients, but not schizophrenics. Consistent with this observation, the ratio between the upper and lower NR1-immunoreactive bands showed a significant decrease in bipolar disorder, although the ratio in depression did not reach significance. No significant difference was found in the NR1 lower band in any patient group compared with control. The finding of an increase NMDA receptor density in schizophrenia is consistent with the previous reports, with a possible compensatory response to glutamatergic deficits in superior temporal cortex in schizophrenia. The findings in affective disorders are interesting in respect of reports of cortical NMDA receptor deficits in suicide victims, although antidepressant drug treatment may contribute to these changes.

Characterization of brain plasticity in schizophrenia using template deformation

RATIONALE AND OBJECTIVE

Abnormal neurodevelopment may play a role in the pathophysiology of schizophrenia. We used deformation-based morphometry to examine voxel-wise age-related changes in patients with schizophrenia compared with healthy brains.

MATERIALS AND METHODS

We used a set of skull-stripped brains from an image database of cranial magnetic resonance images. We then deformed a template brain to the rest of the brains creating a set of deformation fields. Using the Jacobian values of these deformation fields, we calculated the voxel-wise t-score for comparison of controls with patients. We also calculated the voxel-wise Pearson correlation of Jacobian with age for both controls and patients.

RESULTS

By examining the volume renderings of these statistical fields, we found that healthy people undergo age-related expansion of the ventricles, the surrounding periventricular white matter, and a corresponding decline in the frontal lobes and cingulate gyrus. In contrast, patients show much less of this age-related expansion of the ventricles and less atrophy in the cerebral cortex. In addition, patients have larger ventricles and reduced volume in the frontal/parietal lobes.

CONCLUSION

These constellations of findings suggest that otherwise normal age-related ventricular enlargement and cortical loss occurs in schizophrenia patients, albeit at an earlier age.

New insights help define the pathophysiology of bipolar affective disorder: neuroimaging and neuropathology findings

Bipolar affective disorder (BD) is a severe mental illness, characterized by episodes of mania and depression. With the development of Magnetic Resonance Imaging (MRI), neuroimaging methods are now allowing investigation of the neurocircuitry involved in this disorder. This in turn has aided further neuropathological exploration of the brain. Structural MRI and Magnetic Resonance Spectroscopy studies suggest that brain abnormalities in BD are mostly regional, as global measures (cerebral, white and gray matter and ventricular volumes) do not seem to be affected in the majority of patients. The prefrontal and anterior cingulate cortices, and amygdalae are consistently implicated in BD, whilst the evidence for hippocampal involvement is less convincing. Functional studies have found that the activity of the dorsal prefrontal cortex and the anterior cingulate are closely associated with mood symptoms. Activity in the ventral and orbital prefrontal cortex appears reduced both during episodes and in remission. In contrast, amygdala activity shows a persistent increase. We suggest that abnormal interaction between the amygdala and the ventral/orbitofrontal cortex may be a central feature of the pathophysiology of BD.

Neuroprotective effects of olanzapine on methamphetamine-induced neurotoxicity are associated with an inhibition of hyperthermia and prevention of Bcl-2 decrease in rats

It is hypothesized that atypical antipsychotic drugs have neuroprotective effects which may be one of the mechanisms in treatment of schizophrenia. We investigated the neuroprotective effects of olanzapine (OLA), an atypical antipsychotic drug, on methamphetamine (METH)-induced neurotoxicity in rats. After pretreatment with OLA (2 mg/kg/day) by intraperitoneal injection for 2 weeks, rats were administered METH (7.5 mg/kg, four times at 2-h intervals) by subcutaneous injection while their body temperature was monitored. The rats were sacrificed 24 h after the last injection of METH for immunohistochemistry. METH-induced 24 h mortality was effectively reduced and METH-induced decrease of tyrosine hydroxylase immunoreactivity in caudate putamen (CPu) was significantly attenuated by OLA chronic pretreatment. Furthermore, we showed that the above neuroprotective potential of OLA might be associated with its attenuating effects on METH-induced hyperthermia and with its preventative actions on METH-induced decrease of Bcl-2, an anti-apoptotic gene product, in the CPu. Our results suggest that OLA may be a neuroprotective agent and that its neuroprotective potential may contribute to its therapeutic effects in treatment of schizophrenia.

Schizophrenia: from phenomenology to neurobiology

Schizophrenia is a common and debilitating illness, characterized by chronic psychotic symptoms and psychosocial impairment that exact considerable human and economic costs. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, treatment, genetics and neurobiology of schizophrenia. Although studied extensively from a clinical, psychological, biological and genetic perspective, our expanding knowledge of schizophrenia provides only an incomplete understanding of this complex disorder. Recent advances in neuroscience have allowed the confirmation or refutation of earlier findings in schizophrenia, and permit useful comparisons between the different levels of organization from which the illness has been studied. Schizophrenia is defined as a clinical syndrome that may include a collection of diseases that share a common presentation. Genetic factors are the most important in the etiology of the disease, with unknown environmental factors potentially modulating the expression of symptoms. Schizophrenia is a complex genetic disorder in which many genes may be implicated, with the possibility of gene-gene interactions and a diversity of genetic causes in different families or populations. A neurodevelopmental rather than degenerative process has received more empirical support as a general explanation of the pathophysiology, although simple dichotomies are not particularly helpful in such a complicated disease. Structural brain changes are present in vivo and post-mortem, with both histopathological and imaging studies in overall agreement that the temporal and frontal lobes of the cerebral cortex are the most affected. Functional imaging, neuropsychological testing and clinical observation are also generally consistent in demonstrating deficits in cognitive ability that correlate with abnormalities in the areas of the brain with structural abnormalities. The dopamine and other neurotransmitter systems are certainly involved in the treatment or modulation of psychotic symptoms. These broad findings represent the distillation of a large body of disparate data, but firm and specific findings are sparse, and much about schizophrenia remains unknown.

Volumetric brain imaging findings in mood disorders

Volumetric neuroimaging is increasingly being used by researchers of affective disorders to assess potential involvement of different brain structures in mood regulation and to test neuroanatomic models of mood disorders. In unipolar depression, findings suggest abnormalities in the frontal lobe (particularly the subgenual prefrontal cortex), basal ganglia (particularly the caudate and putamen), cerebellum, and hippocampus/amygdala complex. In bipolar disorder, abnormalities in the third ventricle, frontal lobe, cerebellum, and possibly the temporal lobe are noted. We review the findings for the various regions of the brain, and discuss the implications on the understanding of mood disorders. Directions for future research in volumetric imaging is then discussed.

Schizophrenia and viral infection during neurodevelopment: a focus on mechanisms

The task of defining schizophrenia pathogenesis has fascinated and frustrated researchers for nearly a century. In recent years, unprecedented advances from diverse fields of study have given credence to both viral and developmental theories. This review considers possible mechanisms by which viral and developmental processes may interact to engender schizophrenia. Many of the current controversies in schizophrenia pathogenesis are reviewed in light of the viral hypothesis, including: epidemiological findings and the role of a genetic diathesis, phenotype heterogeneity, abnormalities in excitatory and inhibitory neurotransmitter systems, anomalous cerebral latereralization, and static vs progressive disease. The importance of animal models in elucidating the impact of viral infections on developing neurons is illustrated by recent studies in which neonatal rats are infected with lymphocytic choriomeningitis virus in order to examine alterations in hippocampal circuitry. Finally, consideration is given to a new hypothesis that some cases of schizophrenia could be instigated by a viral infection that disrupts developing inhibitory circuits, consequently unleashing glutamatergic neurotransmission leading to selective excitotoxicity, and a degenerative disease course.

The neuropsychology and neuroanatomy of bipolar affective disorder: a critical review

Bearden CE, Hoffman KM, Cannon TD. The neuropsychology and neuroanatomy of bipolar affective disorder: a critical review. Bipolar Disord 2001: 3: 106 150. C Munksgaard, 2001

OBJECTIVES

To present a comprehensive review of the existing neuropsychological and neuroimaging literature on bipolar affective disorder. This review critically evaluates two common conceptions regarding the neuropsychology of bipolar disorder: 1) that, in contrast to schizophrenia, bipolar affective disorder is not associated with general cognitive impairment independent of illness episodes, and 2) relative right hemisphere (RH) dysfunction is implicated in bipolar illness patients, supported by reports of relatively greater impairment in visuospatial functioning, lateralization abnormalities, and mania secondary to RH lesions.

METHODS

The major computerized databases (Medline and PSYCInfo) were consulted in order to conduct a comprehensive, integrated review of the literature on the neuropsychology and neuroanatomy of bipolar disorder. Articles meeting specified criteria were included in this review.

RESULTS

In a critical evaluation of the above notions, this paper determines that: 1) while there is little evidence for selective RH dysfunction, significant cognitive impairment may be present in bipolar illness, particularly in a subgroup of chronic, elderly or multiple-episode patients, suggesting a possible toxic disease process, and 2) the underlying functional correlate of these cognitive deficits may be white matter lesions ('signal hyperintensities') in the frontal lobes and basal ganglia, regions critical for executive function, attention, speeded information processing, learning and memory, and affect regulation. While this hypothesized neural correlate of cognitive impairment in bipolar disorder is speculative, preliminary functional neuroimaging evidence supports the notion of frontal and subcortical hypometabolism in bipolar illness.

CONCLUSIONS

The etiology of the structural brain abnormalities commonly seen in bipolar illness, and their corresponding functional deficits, remains unknown. It is possible that neurodevelopmental anomalies may play a role, and it remains to be determined whether there is also some pathophysiological progression that occurs with repeated illness episodes. More research is needed on first-episode patients, relatives of bipolar probands, and within prospective longitudinal paradigms in order to isolate disease-specific impairments and genetic markers of neurocognitive function in bipolar disorder.

A serial longitudinal quantitative MRI study of cerebral changes in first-episode schizophrenia using image segmentation and subvoxel registration

Lateral ventricular enlargement is the most consistently replicated brain abnormality found in schizophrenia. This article reports a first episode, longitudinal study of ventricular volume using high-resolution serial magnetic resonance imaging (MRI) and recently developed techniques for image registration and quantitation. Baseline and follow-up (on average 8 months later) MRI scans were carried out on 24 patients and 12 controls. Accurate subvoxel registration was performed and subtraction images were produced to reveal areas of regional brain change. Whereas there were no differences between patients and controls with respect to the mean change in ventricular volume, the patients were much more variable in this respect and showed larger increases and decreases. The percentage increase in ventricular size was greater than one standard deviation of control values for 14 patients and the percentage decrease exceeded one standard deviation in eight patients. Although the finding of progressive ventricular enlargement in a proportion of patients supports other studies indicating an ongoing neuropathological process in the early stages of schizophrenia, the reduction of ventricular size in the remaining patients is more difficult to explain. It is suggested that this may reflect improvement in nutrition and hydration following treatment.

Oxidative stress and role of antioxidant and omega-3 essential fatty acid supplementation in schizophrenia

1. Schizophrenia is a major mental disorder that has a lifetime risk of 1% and affects at young age (average age at the onset 24 +/- 4.6 years) in many cultures around the world. The etiology is unknown, the pathophysiology is complex, and most of the patients need treatment and care for the rest of their lives. 2. Cellular oxidative stress is inferred from higher tissue levels of reactive oxygen species (ROS, e.g., O2*-, OH*, OH-, NO* and ONOO--) than its antioxidant defense that cause peroxidative cell injury, i.e., peroxidation of membrane phospholipids, particularly esterified essential polyunsaturated fatty acids (EPUFAS), proteins and DNA. 3. Oxidative stress can lead to global cellular with predominantly neuronal peroxidation, since neurons are enriched in highly susceptible EPUFAs and proteins, and damages DNA is not repaired effectively. 4. Such neuronal peroxidation may affect its function (i.e., membrane transport, loss of mitochondrial energy production, gene expression and therefore receptor-mediated phospholipid-dependent signal transduction) that may explain the altered information processing in schizophrenia. 5. It is possible that the oxidative neuronal injury can be prevented by dietary supplementation of antioxidants (e.g., vitamins E, C and A; beta-carotene, Q-enzyme, flavons, etc.) and that membrane phospholipids can be corrected by dietary supplementation of EPUFAs. 6. It may be that the oxidative stress is lower in populations consuming a low caloric diet rich in antioxidants and EPUFAs, and minimizing smoking and drinking. 7. Oxidative stress exists in schizophrenia based on altered antioxidant enzyme defense, increased lipid peroxidation and reduced levels of EPUFAs. The life style of schizophrenic patients is also prooxidative stress, i.e., heavy smoking, drinking, high caloric intake with no physical activity and treatment with pro-oxidant drugs. 8. The patients in developed countries show higher levels of lipid peroxidation and lower levels of membrane phospholipids as compared to patients in the developing countries. 9. Initial observations on the improved outcome of schizophrenia in patients supplemented with EPUFAs and antioxidants suggest the possible beneficial effects of dietary supplementation. 10. Since the oxidative stress exists at or before the onset of psychosis the use of antioxidants from the very onset of psychosis may reduce the oxidative injury and dramatically improve the outcome of illness.

Cerebral white matter lesions in bipolar affective disorder: relationship to outcome

BACKGROUND

Twenty per cent of patients with bipolar affective disorder suffer an illness that responds inadequately to treatment and has a poor outcome. Many patients, but not all, with bipolar disorder show white matter abnormalities on T(2)-weighted magnetic resonance imaging (MRI).

AIMS

To explore the hypothesis that white matter abnormalities on MRI are seen more frequently in subjects whose illness has a poor outcome compared with those with a good outcome or controls.

METHOD

Two groups of age- and gender-matched patients with bipolar disorder (14 with a good outcome and 15 with a poor outcome) and 15 controls, aged 20-65 years, were studied. Axial T(2)-weighted MRI scans were examined for the presence and severity of white matter abnormalities.

RESULTS

Significantly more poor outcome group members had deep subcortical punctate, but not periventricular, white matter hyperintensities than the good outcome group (P:=0.035) or controls (P:=0.003) and these abnormalities were of greater severity (P:=0.030 and P:<0.014, respectively).

CONCLUSIONS

Subcortical white matter lesions are associated with poor outcome bipolar disorder.

Evidence for progression of brain structural abnormalities in schizophrenia: beyond the neurodevelopmental model

OBJECTIVE

Clinical, neuroimaging, neuropathological and neuropsychological evidence suggests that, in schizophrenia, there is structural and functional disturbance of the hippocampus. The purpose of this paper is to present published findings concerning the nature, timing and course of these putative disturbances of hippocampal function and the pathophysiological mechanisms involved, and to explore whether schizophrenia is a disorder of neurodevelopment, neurodegeneration or a combination of both processes.

METHOD

The available cross-sectional and longitudinal evidence for hippocampal involvement in schizophrenia is reviewed and a model of hippocampal involvement in this disorder, which derives from our own cross-sectional and longitudinal hippocampal imaging data, is described.

RESULTS

We propose a three-hit model in which an early neurodevelopmental lesion renders the hippocampus vulnerable to further insult later in life during the transition phase to active illness. The available evidence suggests that the left hippocampus is particularly vulnerable during these early stages, while further insult involving the hippocampus bilaterally occurs in those who develop a chronic form of the illness.

CONCLUSIONS

Intervention strategies should target the most vulnerable stages of the illness, in particular the transition phase to psychosis, when novel treatments may prevent the illness or ameliorate its effects.

Brain and ventricle instability during psychotic episodes of the schizophrenias

Recent reports from serial brain scans suggest that the rate of ventricular expansion and/or brain atrophy may be accelerated in at least some schizophrenics. The authors assessed the effect of state changes upon such findings.Within-subject 3D MRIs were assessed for ventricular and brain volumes during periods of [partial] remission and of exacerbation of psychosis. Additional scans at comparable within-subject SAPS were used to assess rates of change in volumes that were independent of SAPS changes. Correlations of changes of ventricle and brain volumes vs. change of SAPS cores between scans revealed that ventricle volumes decreased during a period of psychotic exacerbation and increased at a time of [partial] remission (r(p)=-0.666; P<0.0005); conversely, brain volumes increased during psychotic exacerbation and decreased at [partial] remission (r(p)=+0.448; P=0.032). Scans at comparable SAPS scores suggested that the majority of patients had rates of ventricular expansion comparable to controls (0.9+/-0.6 cc/year), though two patients appeared to have rates of ventricular increase of 4.5+/-2. 1 cc/year (Lilliefores P=0.036; K-means clustering F=17.75). Exacerbation of psychosis in schizophrenia is accompanied by evidence of brain swelling, especially of periventricular brain, with encroachment of brain substance upon ventricular volumes. Controlled for state changes, the majority of schizophrenics show rates of ventricular expansion or brain atrophy indistinguishable from controls.

Defining the course of brain structural change and plasticity in schizophrenia

Recent evidence from controlled CT and MRI longitudinal studies suggests that some cerebral ventricular enlargement and hemispheric volumetric reductions (e.g. cerebral atrophy) may have a progressive component in patients with schizophrenia. These studies vary in cohort composition, stage of illness examined, duration of follow-up interval, imaging techniques used, and specific brain regions with findings. They also conflict with earlier evidence suggesting that schizophrenia is a neurodevelopmental disorder with brain pathological deviance occurring prior to the illness onset. The newer brain imaging reports may be detecting subtle brain plasticity that results from a continuing cortical disruptive process, may be epi-phenomena caused by scanning and image analysis artifacts or may possibly reflect systemic physiological fluctuations. Future longitudinal studies of subjects at all stages of illness using a variety of new technologies are needed to clarify these findings.

Regional brain volume change over the life-time course of schizophrenia

The concept that schizophrenia has its antecedents in neurodevelopment has long been debated and has been at the forefront of research on this disorder over the last decade. However new recent evidence from controlled longitudinal studies indicates that some of the structural brain anomalies observed in schizophrenia may continue to progress sporadically after the onset of clinical illness. The studies vary in cohort composition, stage of illness studied, duration of follow-up interval, and specific brain regions with findings. Nevertheless, the findings as a whole suggest that the brain changes in size throughout the lifespan of an individual and to a greater extent in schizophrenia. While the detected abnormalities could be explained by various technical artifacts, or physiological epi-phenomena, that they result from an ongoing neurochemical, physiological or morphological process characteristic of the underlying basis for the disorder is an intriguing possibility that lends itself to possible future intervention.

Progressive atrophy of the frontal lobes in first-episode schizophrenia: interaction with clinical course and neuroleptic treatment

OBJECTIVE

This prospective study examined the interaction of clinical course of disease and brain structure with time in schizophrenic patients.

METHOD

A total of 21 first-episode schizophrenic patients, 10 patients with other psychiatric disorders and a control group of 9 healthy volunteers had CT at first admission and at reinvestigation 5 years later.

RESULTS

At first admission all of the patients had enlarged cortical fissures and sulci compared to controls, and the duration of untreated psychosis was significantly correlated with sulcal enlargement. At reinvestigation, frontal and central brain atrophy had progressed in schizophrenic patients.

CONCLUSION

The study indicated that ongoing psychosis and lifetime dose of classical antipsychotics were the main candidates accounting for the finding of progressively disturbed brain structure during the first 5 years of schizophrenia.

Is schizophrenia a neurodegenerative disorder? A clinical and neurobiological perspective

The history of psychiatric research is filled with widely accepted etiologic and pathophysiologic theories that eventually were proven wrong. The prevailing pathophysiologic theories of schizophrenia have emphasized the role of abnormal neurodevelopment in determining the onset and course of the illness. Relatively little attention has been paid to the role of neurodegenerative processes despite the clinical course of the illness and the fact that most patients experience varying degrees of behavioral and cognitive deterioration. This is partially due to the absence of clear histologic evidence of neurodegeneration, but may also be due to the narrow traditional conception of neurodegeneration that is generally employed. This article suggests that the rejection of a role for neurodegeneration in the pathophysiology of schizophrenia is unproven and may be premature. A wholly neurodevelopmental perspective of the illness imbues the illness with a pessimistic inevitability and therapeutic nihilism that may be unwarranted. This article reviews selectively a diverse body of evidence that is consistent with the hypothesis that schizophrenia involves a limited neurodegenerative process reflected by the psychotic symptoms and that is most active in the early stages of the illness. The evidence for this hypothesis comes from studies of premorbid status, illness course, symptomatology and treatment effects as well as neuroimaging and postmortem findings. Recent results from the latter interpreted in the context of molecular neurobiology suggest new pathophysiologic models.

Structural brain imaging in schizophrenia: a selective review

Structural neuroimaging studies have provided some of the most consistent evidence for brain abnormalities in schizophrenia. Since the initial computed tomography study by Johnstone and co-workers, which reported lateral ventricular enlargement in schizophrenia, advances in brain imaging technology have enabled further and more refined characterization of abnormal brain structure in schizophrenia in vivo. This selective review discusses the major issues and findings in structural neuroimaging studies of schizophrenia. Among these are evidence for generalized and regional brain volume abnormalities, the specificity of anatomic findings to schizophrenia and to men versus women with schizophrenia, the contribution of genetic influences, and the timing of neuroanatomic pathology in schizophrenia. The second section reviews new approaches for examining brain structure in schizophrenia and their applications to studies on the pathophysiology of schizophrenia.

Differential effects of olanzapine on the gene expression of superoxide dismutase and the low affinity nerve growth factor receptor

Neuroanatomical studies of schizophrenia suggest that progressive neuropathological changes (such as neuronal atrophy and/or cell death) occur over the lifetime course of the disease. Early intervention with atypical neuroleptics has been shown to prevent progression of at least some symptoms, although the mechanisms by which neuroleptics may do this remain unknown. In this study, PC12 cells were used to determine the effects of the new atypical antipsychotic olanzapine on the gene expression of superoxide dismutase (SOD1) and the low affinity nerve growth factor receptor (p75). The results show that olanzapine increases SOD1 at concentrations of 10 and 100 microM after 48 hr of incubation in PC12 cultures. The treatment decreases p75 gene expression at concentrations 100 microM after 48 hr of incubation. Since both the upregulation of SOD1 mRNA and the antisense blockade of p75 mRNA have been associated with reduced cell death, our results suggest that olanzapine has neuroprotective potential and thus may be useful in preventing further neurodegeneration accompanying schizophrenia.

CSF N-CAM in neuroleptic-naïve first-episode patients with schizophrenia

An increased concentration of neural cell adhesion molecule (N-CAM) 105-115 kDa has been reported in patients with schizophrenia in both CSF and in post-mortem brain samples. To determine whether increased N-CAM is integral to the disease process or, alternatively, results from early treatment, CSF N-CAM was measured in a blind study of first episode (FE) patients, who were either neuroleptic-naïve (NN) or neuroleptic-treated (NT, < 100 mg Haldol equivalents), multi-episode (ME) patients, and controls. Overall, the FE patients displayed lower N-CAM concentrations as compared to controls (p = 0.043). This decrease in N-CAM in FE patients was seen only in the FE-NT group as compared to both controls (p = 0.0006). The FE-NT group also showed a lower CSF N-CAM compared to that in the FE-NN (p = 0.025) group. No difference in CSF N-CAM between the FE-NN and control group was found. ME patients showed an increased N-CAM as compared with FE patients (p = 0.018), but not as compared to controls (p = 0.93). Neuroleptic-naïve first-episode patients do not display a phenotypic increase in N-CAM. Thus, N-CAM is altered in first-episode patients following acute neuroleptic treatment and withdrawal, as compared to neuroleptic-naïve first-episode patients.

Inositol levels are decreased in postmortem brain of schizophrenic patients

BACKGROUND

A previous study reported decreased levels of inositol in frontal cortex of postmortem brain from bipolar patients and suicide victims. The aim of the present study was to test the specificity of this finding.

METHODS

Inositol and the enzyme that synthesizes it, inositol monophosphatase, were measured in postmortem brain tissue from frontal and occipital cortex and cerebellum from 10 schizophrenic patients and the previously reported controls. Inositol levels were assayed gas-chromatographically as trimethylsilyl derivatives with mannitol as an internal standard. Inositol monophosphatase activity in brain homogenates was measured as the difference between phosphate release from inositol-l-phosphate in the absence and in the presence of Li+.

RESULTS

Inositol was significantly reduced in all three areas in the schizophrenic patient' brains: inositol monophosphatase was unchanged. Postmortem interval did not correlate with inositol levels and did not differ between control group and schizophrenic patients.

CONCLUSIONS

These results suggest an abnormality of second messenger precursor availability in common with schizophrenia and affective psychopathology.

Ventricular enlargement in poor-outcome schizophrenia

BACKGROUND

A subset of patients with schizophrenia, defined on the basis of longitudinal deficits in self-care, may show a classic ("Kraepelinian") degenerative course. An independent validator of the phenomenologically defined Kraepelinian subtype might be provided by a structural indicator of possible brain degeneration: ventricular size as measured by computed tomography (CT).

METHODS

To examine whether Kraepelinian patients would show a differential increase in ventricular size over time, two CT scans were conducted at intervals separated by > 4 years, an average of 5 years. Fifty-three male patients with DSM-III-R diagnoses of chronic schizophrenia were subdivided into Kraepelinian (n = 22; mean age = 42 +/- 6 years) and non-Kraepelinian (n = 31; mean age = 38 +/- 12.2 years) subgroups. Kraepelinian patients were defined on the basis of longitudinal criteria: > 5 years of complete dependence on others for life necessities and care, lack of employment, and sustained symptomatology. Thirteen normal elderly volunteers (mean age = 60 +/- 17.8) were also scanned at 4-year intervals. CT measurements were made by raters without knowledge of subgroup membership. A semiautomated computer program was used to trace the anterior horn, lateral ventricles, and temporal horns for each slice level on which they were clearly seen.

RESULTS

The ventricles showed a bilateral increase in size over the 4-year interval in the Kraepelinian subgroup, more marked in the left hemisphere than the right. By contrast, neither the non-Kraepelinian subgroup nor the normal volunteers showed significant CT changes from scan 1 to scan 2.

CONCLUSIONS

Thus, the longitudinal dysfunctions in self-care that characterize the Kraepelinian patients were associated with an independent indicator of brain abnormality.

Which characteristics of schizophrenia predate psychosis?

Neuropsychological and brain structural abnormalities are present in first onset schizophrenia; the balance of evidence is that in the majority of cases these are developmental in origin. A proportion of first degree relatives also show lateral ventricular enlargement, cortical volume decrease and possibly loss of the normal cerebral asymmetry; these findings suggest that certain families transmit a genetic defect in the control of neurodevelopment. On the contrary, decrement in left hippocampal volume appears to be secondary to perinatal hypoxia. High risk, follow-back and cohort studies all demonstrate that preschizophrenics as a group show deviant development; delayed milestones, lower IQ, solitary play, excessive anxiety, and minor neurological problems are all common. It seems likely, but not proven, that these are a manifestation of underlying neurodevelopmental disorder.