Heterogeneity of the psychoses: is there a neurodegenerative psychosis?

Distinguishing schizophrenia spectrum from non-spectrum disorders among young patients with first episode psychosis and at high clinical risk: The role of basic self-disturbance and neurocognition

INTRODUCTION

The distinction between the schizophrenia spectrum and other types of disorders may be clinically relevant in terms of its predictive validity as suggested by studies showing schizophrenia spectrum patients have more unfavourable outcomes compared to other psychotic disorders. The present study aimed to investigate whether basic self-disturbances and neurocognitive processes that have been linked to psychosis risk have discriminative power for schizophrenia spectrum disorders in patients presenting with first episode psychosis (FEP) and at ultra-high risk for psychosis (UHR).

METHODS

38 FEP patients, 48 UHR patients, and 33 healthy controls were assessed for basic self-disturbances (using the Examination of Anomalous Self-Experience, EASE, interview), source monitoring and aberrant salience (behavioural tasks to measure neurocognitive constructs). Clinical groups were divided into patients with schizophrenia spectrum disorders and those with other non-spectrum disorders and were further compared on measures controlling for symptom severity and age.

RESULTS

Basic self-disturbances distinguished schizophrenia spectrum from non-spectrum disorders in the 'FEP only' sample, F = 19.76, p < 0.001, η²_partial = 0.37, and also in the combined UHR/FEP sample, F = 23.56, p < 0.001, η²_partial = 0.22. Additionally, some processes related to source monitoring deficits were elevated in schizophrenia spectrum disorders. In contrast, the two groups (schizophrenia spectrum vs other diagnoses) performed similarly in aberrant salience tasks. Comparable results were obtained for analyses performed with an FEP/UHR combined sample and the 'FEP only' sample.

DISCUSSION

Basic self-disturbances at the phenomenological level and source monitoring deficits on the neurocognitive level may be useful in identifying risk of schizophrenia spectrum disorders at the earliest clinical presentation.

A White Matter Connection of Schizophrenia and Alzheimer's Disease

Schizophrenia (SZ) is a severe psychiatric illness associated with an elevated risk for developing Alzheimer's disease (AD). Both SZ and AD have white matter abnormalities and cognitive deficits as core disease features. We hypothesized that aging in SZ patients may be associated with the development of cerebral white matter deficit patterns similar to those observed in AD. We identified and replicated aging-related increases in the similarity between white matter deficit patterns in patients with SZ and AD. The white matter "regional vulnerability index" (RVI) for AD was significantly higher in SZ patients compared with healthy controls in both the independent discovery (Cohen's d = 0.44, P = 1·10-5, N = 173 patients/230 control) and replication (Cohen's d = 0.78, P = 9·10-7, N = 122 patients/64 controls) samples. The degree of overlap with the AD deficit pattern was significantly correlated with age in patients (r = .21 and .29, P < .01 in discovery and replication cohorts, respectively) but not in controls. Elevated RVI-AD was significantly associated with cognitive measures in both SZ and AD. Disease and cognitive specificities were also tested in patients with mild cognitive impairment and showed intermediate overlap. SZ and AD have diverse etiologies and clinical courses; our findings suggest that white matter deficits may represent a key intersecting point for these 2 otherwise distinct diseases. Identifying mechanisms underlying this white matter deficit pattern may yield preventative and treatment targets for cognitive deficits in both SZ and AD patients.

Nonverbal communication remains untouched: No beneficial effect of symptomatic improvement on poor gesture performance in schizophrenia

BACKGROUND

Gestures are an important part of communication. Patients with schizophrenia present gesture deficits that tend to deteriorate in the course of the disease and hamper functional outcome. This gesture deficit has been associated with motor abnormalities, cognitive impairment, and psychotic symptoms. Unaffected, first-degree relatives of schizophrenia patients share some subclinical motor and cognitive abnormalities. We aimed to investigate, whether gesture performance changes with symptomatic improvement in patients, and to test the longitudinal performance in unaffected, first-degree relatives.

METHODS

In this study, we measured gesture performance using a validated test in 33 patients, 29 first-degree relatives and 38 healthy controls. Measurements were completed shortly after admission and before discharge in patients. Performance was rated blindly by experts using video recordings of the gesture task. Additionally, we evaluated cognitive function and psychotic symptoms at both visits.

RESULTS

Gesture performance was poorer in relatives compared to controls and poorer in patients compared to both relatives and controls. Patients showed an improvement in psychopathology but a significant decrease in gesture performance at follow-up, while performance in the other groups remained stable. Proportional change of gesture performance correlated with change of cognitive function in patients, whereas there were no correlations with change of cognitive function in the other groups.

CONCLUSION

While symptom severity was reduced, the gesture deficit further deteriorated in schizophrenia. The finding argues for distinct processes contributing to poor nonverbal communication skills in patients, requiring novel alternative treatment efforts.

Translating ENIGMA schizophrenia findings using the regional vulnerability index: Association with cognition, symptoms, and disease trajectory

Patients with schizophrenia have patterns of brain deficits including reduced cortical thickness, subcortical gray matter volumes, and cerebral white matter integrity. We proposed the regional vulnerability index (RVI) to translate the results of Enhancing Neuro Imaging Genetics Meta-Analysis studies to the individual level. We calculated RVIs for cortical, subcortical, and white matter measurements and a multimodality RVI. We evaluated RVI as a measure sensitive to schizophrenia-specific neuroanatomical deficits and symptoms and studied the timeline of deficit formations in: early (≤5 years since diagnosis, N = 45, age = 28.8 ± 8.5); intermediate (6-20 years, N = 30, age 43.3 ± 8.6); and chronic (21+ years, N = 44, age = 52.5 ± 5.2) patients and healthy controls (N = 76, age = 38.6 ± 12.4). All RVIs were significantly elevated in patients compared to controls, with the multimodal RVI showing the largest effect size, followed by cortical, white matter and subcortical RVIs (d = 1.57, 1.23, 1.09, and 0.61, all p < 10^-6 ). Multimodal RVI was significantly correlated with multiple cognitive variables including measures of visual learning, working memory and the total score of the MATRICS consensus cognitive battery, and with negative symptoms. The multimodality and white matter RVIs were significantly elevated in the intermediate and chronic versus early diagnosis group, consistent with ongoing progression. Cortical RVI was stable in the three disease-duration groups, suggesting neurodevelopmental origins of cortical deficits. In summary, neuroanatomical deficits in schizophrenia affect the entire brain; the heterochronicity of their appearance indicates both the neurodevelopmental and progressive nature of this illness. These deficit patterns may be useful for early diagnosis and as quantitative targets for more effective treatment strategies aiming to alter these neuroanatomical deficit patterns.

Potential mechanisms for phencyclidine/ketamine-induced brain structural alterations and behavioral consequences

Evidence of structural abnormalities in the nervous system of recreational drug [e.g., phencyclidine (PCP) or ketamine] users and/or preclinical animal research models suggests interference with the activity of multiple neurotransmitters, particularly glutamate neurotransmission. The damage to the central nervous system (CNS) may include neuronal loss, synaptic changes, disturbed neural network formation and reduced projections to subcortical fields. Notably, the reduced projections may considerably compromise the establishment of the subcortical areas, such as the nucleus accumbens located in the basal forebrain. With its abundant dopaminergic innervation, the nucleus accumbens is believed to be directly associated with addictive behaviors and mental disorders. This review seeks to delineate the relationship between PCP/ketamine-induced loss of cortical neurons and the reduced level of polysialic acid neural cell adhesion molecule (PSA-NCAM) in the striatum, and the likely changes in striatal synaptogenesis during development. The basic mechanism of how PSA-NCAM cell surface expression may be regulated will also be discussed, as well as the hypothesis that PSA-NCAM activity is critical to the regulation of synaptic protein expression. Overall, the present review will address the general hypothesis that damage/interruption of cortico-striatal communication and subcortical synaptogenesis could underlie the erratic/sensitization or addictive states produced by chronic or prolonged PCP/ketamine usage.

Electrophysiological correlates of visual backward masking in patients with first episode psychosis

Visual backward masking is strongly impaired in patients with schizophrenia. Masking deficits have been proposed as potential endophenotypes of schizophrenia. Masking performance deficits manifest as strongly reduced amplitudes in the electroencephalogram (EEG). In order to fulfill the criteria of an endophenotype, masking deficits should not vary substantially across time and should be present at the first psychotic event. To verify whether these conditions are met for visual backward masking, we tested patients with first episode psychosis (n = 21) in a longitudinal study. Patients were tested with visual backward masking and EEG three times every six months over a period of one year. We found that the EEG amplitudes of patients with first episode psychosis were higher as compared to those of patients with schizophrenia but lower as compared to those of unaffected controls. More interestingly, we found that the EEG amplitudes of patients with first episode psychosis remained stable over the course of one year. Since chronic schizophrenia patients have strongly reduced amplitudes, we speculate that the neural correlates of masking deficits (EEG amplitudes) continue to decrease as the disease progresses.

Cerebellar volume and cerebellocerebral structural covariance in schizophrenia: a multisite mega-analysis of 983 patients and 1349 healthy controls

Although cerebellar involvement across a wide range of cognitive and neuropsychiatric phenotypes is increasingly being recognized, previous large-scale studies in schizophrenia (SZ) have primarily focused on supratentorial structures. Hence, the across-sample reproducibility, regional distribution, associations with cerebrocortical morphology and effect sizes of cerebellar relative to cerebral morphological differences in SZ are unknown. We addressed these questions in 983 patients with SZ spectrum disorders and 1349 healthy controls (HCs) from 14 international samples, using state-of-the-art image analysis pipelines optimized for both the cerebellum and the cerebrum. Results showed that total cerebellar grey matter volume was robustly reduced in SZ relative to HCs (Cohens's d=-0.35), with the strongest effects in cerebellar regions showing functional connectivity with frontoparietal cortices (d=-0.40). Effect sizes for cerebellar volumes were similar to the most consistently reported cerebral structural changes in SZ (e.g., hippocampus volume and frontotemporal cortical thickness), and were highly consistent across samples. Within groups, we further observed positive correlations between cerebellar volume and cerebral cortical thickness in frontotemporal regions (i.e., overlapping with areas that also showed reductions in SZ). This cerebellocerebral structural covariance was strongest in SZ, suggesting common underlying disease processes jointly affecting the cerebellum and the cerebrum. Finally, cerebellar volume reduction in SZ was highly consistent across the included age span (16-66 years) and present already in the youngest patients, a finding that is more consistent with neurodevelopmental than neurodegenerative etiology. Taken together, these novel findings establish the cerebellum as a key node in the distributed brain networks underlying SZ.

From the psychosis prodrome to the first-episode of psychosis: No evidence of a cognitive decline

Cognitive deficits have an important role in the neurodevelopment of schizophrenia and other psychotic disorders. However, there is a continuing debate as to whether cognitive impairments in the psychosis prodrome are stable predictors of eventual psychosis or undergo a decline due to the onset of psychosis. In the present study, to determine how cognition changes as illness emerges, we examined baseline neurocognitive performance in a large sample of helping-seeking youth ranging in clinical state from low-risk for psychosis through individuals at clinical high-risk (CHR) for illness to early first-episode patients (EFEP). At baseline, the MATRICS Cognitive Consensus battery was administered to 322 individuals (205 CHRs, 28 EFEPs, and 89 help-seeking controls, HSC) that were part of the larger Early Detection, Intervention and Prevention of Psychosis Program study. CHR individuals were further divided into those who did (CHR-T; n = 12, 6.8%) and did not (CHR-NT, n = 163) convert to psychosis over follow-up (Mean = 99.20 weeks, SD = 21.54). ANCOVAs revealed that there were significant overall group differences (CHR, EFEP, HSC) in processing speed, verbal learning, and overall neurocognition, relative to healthy controls (CNTL). In addition, the CHR-NTs performed similarly to the HSC group, with mild to moderate cognitive deficits relative to the CTRL group. The CHR-Ts mirrored the EFEP group, with large deficits in processing speed, working memory, attention/vigilance, and verbal learning (>1 SD below CNTLs). Interestingly, only verbal learning impairments predicted transition to psychosis, when adjusting for age, education, symptoms, antipsychotic medication, and neurocognitive performance in the other domains. Our findings suggest that large neurocognitive deficits are present prior to illness onset and represent vulnerability markers for psychosis. The results of this study further reinforce that verbal learning should be specifically targeted for preventive intervention for psychosis.

Total Tau and Phosphorylated Tau Protein Serum Levels in Patients with Schizophrenia Compared with Controls

Tau protein is located in the axons of neurons and in Alzheimer Disease, is abnormally phosphorylated and aggregates into paired helical filaments (neurofibrillary tangles) reflecting the degree of neurofibrillary pathology and neurodegeneration. Although tau and phosphorylated tau (p-Tau) pathology is a hallmark for dementia, few studies were performed in patients of schizophrenia. This preliminary serum study was designed to compare serum total tau and p-Tau levels of schizophrenia patients with healthy controls. The study was included 42 patients diagnosed with schizophrenia and 42 healthy control subjects. Sociodemographic form was applied to both groups and PANSS was applied to patient group. Serum total tau and p-Tau levels were measured by ELISA method. Total tau and p-Tau levels of patients were significantly lower than healthy controls. There was a positive correlation between amount of past electroconvulsive therapies and total tau level. However total tau and p-Tau levels were positively correlated. Our study results showed that serum total tau and p-Tau levels of patients with schizophrenia were significantly lower than healthy controls.

Is schizophrenia a neurodegenerative disease? Evidence from age-related decline of brain-derived neurotrophic factor in the brains of schizophrenia patients and matched nonpsychiatric controls

BACKGROUND

Brain-derived neurotrophic factor (BDNF) protein levels decline in the brain during senescence and are also shown to be reduced in schizophrenia patients. BDNF is present in both the gray and white matters of the brain. It is unclear whether BDNF abnormalities in schizophrenia are specific to gray and/or white matter.

OBJECTIVE

We hypothesized that the age-related BDNF decline is abnormal and contributes to the reduced BDNF in schizophrenia.

METHODS

We tested this hypothesis by measuring BDNF protein levels in postmortem gray and white matter, using the prefrontal cortex (PFC) and the genu of the corpus callosum as regions of interests, from 20 schizophrenia patients and 20 matched nonpsychiatric controls. Samples were selected across the adult lifespan--from 20 to 80 years of age.

RESULTS

PFC gray matter BDNF protein levels were significantly lower in older age in both nonpsychiatric comparisons and patients, while BDNF in white matter did not decrease significantly with age in either group. PFC BDNF was linearly lower from 20 to 80 years of age in nonpsychiatric comparisons. In schizophrenia, the age effect was similarly linear in younger patients but a decline did not occur in older patients.

CONCLUSION

PFC BDNF does not follow a normative linear age effect in schizophrenia patients as they grow older, which may represent a 'floor effect' due to earlier decline or a survivor cohort of older patient donors who are less susceptible to a schizophrenia-related pathological aging process.

Patients with poor response to antipsychotics have a more severe pattern of frontal atrophy: a voxel-based morphometry study of treatment resistance in schizophrenia

Approximately 30% of schizophrenia patients do not respond adequately to the therapy. Previous MRI studies have suggested that drug treatment resistance is associated with brain morphological abnormalities, although region-of-interest analysis of MR studies from nonresponder and responder patients failed to demonstrate a statistically significant difference between these two schizophrenia subgroups. We have used a voxel-based analysis of segmented MR studies to assess structural cerebral differences in 20 nonresponder and 15 responder patients and 16 age-matched normal volunteers. Differences between the three groups emerged bilaterally mainly at the level of the superior and middle frontal gyri, primarily due to reduced grey matter volumes in nonresponders, as compared to both normal volunteers and responder patients. Post hoc direct comparison between the two schizophrenia subgroups demonstrated significantly reduced grey matter volumes in middle frontal gyrus bilaterally, in the dorsolateral aspects of left superior frontal gyrus extending into postcentral gyrus and in the right medial temporal cortex. Our results extend and integrate previous findings suggesting a more severe atrophy in nonresponder schizophrenia patients, compared to responder patients, mainly at the level of the superior and middle frontal gyri. Longitudinal studies in drug-naïve patients are needed to assess the role of these associations.

Neurodevelopmental and neurodegenerative models of schizophrenia: white matter at the center stage

Schizophrenia is a disorder of cerebral disconnectivity whose lifetime course is modeled as both neurodevelopmental and neurodegenerative. The neurodevelopmental models attribute schizophrenia to alterations in the prenatal-to-early adolescent development. The neurodegenerative models identify progressive neurodegeneration as its core attribute. Historically, the physiology, pharmacology, and treatment targets in schizophrenia were conceptualized in terms of neurons, neurotransmitter levels, and synaptic receptors. Much of the evidence for both models was derived from studies of cortical and subcortical gray matter. We argue that the dynamics of the lifetime trajectory of white matter, and the consistency of connectivity deficits in schizophrenia, support white matter integrity as a promising phenotype to evaluate the competing evidence for and against neurodevelopmental and neurodegenerative heuristics. We develop this perspective by reviewing normal lifetime trajectories of white and gray matter changes. We highlighted the overlap between the age of peak of white matter development and the age of onset of schizophrenia and reviewed findings of white matter abnormalities prior to, at the onset, and at chronic stages of schizophrenia. We emphasized the findings of reduced white matter integrity at the onset and findings of accelerated decline in chronic stages, but the developmental trajectory that precedes the onset is largely unknown. We propose 4 probable lifetime white matter trajectory models that can be used as the basis for separation between the neurodevelopmental and neurodegenerative etiologies. We argue that a combination of the cross-sectional and longitudinal studies of white matter integrity in patients may be used to bridge the neurodevelopment and degeneration heuristics to advance schizophrenia research.

Ten year neurocognitive trajectories in first-episode psychosis

Objective: Neurocognitive impairment is commonly reported at onset of psychotic disorders. However, the long-term neurocognitive course remains largely uninvestigated in first episode psychosis (FEP) and the relationship to clinically significant subgroups even more so. We report 10 year longitudinal neurocognitive development in a sample of FEP patients, and explore whether the trajectories of cognitive course are related to presence of relapse to psychosis, especially within the first year, with a focus on the course of verbal memory.

Method: Forty-three FEP subjects (51% male, 28 ± 9 years) were followed-up neurocognitively over five assessments spanning 10 years. The test battery was divided into four neurocognitive indices; Executive Function, Verbal Learning, Motor Speed, and Verbal Fluency. The sample was grouped into those relapsing or not within the first, second and fifth year.

Results: The four neurocognitive indices showed overall stability over the 10 year period. Significant relapse by index interactions were found for all indices except Executive Function. Follow-up analyses identified a larger significant decrease over time for the encoding measure within Verbal Memory for patients with psychotic relapse in the first year [F_{(4, 38)} = 5.8, p = 0.001, η² = 0.40].

Conclusions: Main findings are long-term stability in neurocognitive functioning in FEP patients, with the exception of verbal memory in patients with psychotic relapse or non-remission early in the course of illness. We conclude that worsening of specific parts of cognitive function may be expected for patients with on-going psychosis, but that the majority of patients do not show significant change in cognitive performance during the first 10 years after being diagnosed.

Drug safety and efficacy evaluation of sertindole for schizophrenia

INTRODUCTION

Despite the progress in antipsychotic treatment, modern antipsychotic medication is still associated with side effects, reduced compliance, drug discontinuation and insufficient effects on negative and cognitive symptoms. Sertindole is an antipsychotic compound, with high affinity for dopamine D(2), serotonin 5-HT(2A), 5-HT(2C) and α(1)-adrenergic receptors, which has been reintroduced in the market after extended re-evaluation of its safety and risk-benefit profile.

AREAS COVERED

Sertindole's pharmacological profile, pharmacokinetics, neuophysiological properties, efficacy on positive, negative and cognitive symptoms and safety issues are covered in this article, based on a literature review from 1990 to 2012.

EXPERT OPINION

Based on five double-blind, randomized, placebo-, haloperidol- or risperidone-controlled studies in patients with schizophrenia, sertindole shows a comparable efficacy with haloperidol and risperidone on positive symptoms, while the effect on negative symptoms seems to be superior. Sertindole is generally well tolerated, but is associated with a dose-related QTc interval prolongation (+22 ms). Risk factors for drug-induced arrhythmia, such as cardiac diseases, congenital long QT syndrome, prolongated QTc at baseline, etc. and drug interactions should be considered before prescribing sertindole. To minimize cardiovascular risk, regular ECG recording is required. Sertindole can be an important second-line option for the treatment of schizophrenia for patients intolerant to at least one other antipsychotic. Further comparison with other SGAs and investigations on subgroups (e.g., children, elderly, first-episode, treatment-refractory patients, etc.) are still needed for a precise understanding of the therapeutic benefits and its role in schizophrenia therapy.

Conceptualization of the liability for schizophrenia: clinical implications

Historically, the Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnostic criteria for schizophrenia have emphasized several features, including symptoms of psychosis, a dissociation of symptoms from their etiology, a reliance on clinical symptoms, and a categorical approach to classifying the disorder. Although these emphases are quite useful, they have limitations. We review these here, and stress the importance of incorporating recent data on the genetic /biological and neurodevelopmental origins of schizophrenia into current conceptions of the disorder. We also review “schizotaxia, ” which is a concept thai embodies this point of view, occurs before the onset of psychosis, and is hypothesized to represent the liability for schizophrenia. If our hypothesis on this point is correct, the identification of schizotaxic individuals will eventually facilitate the development of prevention strategies by identifying a premorbid (but clinically significant) condition for schizophrenia. Moreover, the identification of biological or neuropsychological components of schizotaxia will provide more specific bases for developing novel treatment interventions. Our initial attempts to develop protocols for the assessment and treatment of schizotaxia are encouraging, and will be reviewed.

Clozapine for the treatment of schizophrenia

INTRODUCTION

Despite considerable progress in the pharmacological treatment of schizophrenia, about 30% of patients are minimally responsive to antipsychotics and there is still an excessively high rate of mortality in schizophrenia patients. Clozapine , a D(2)-5HT(2) antagonist, was the first antipsychotic to demonstrate efficacy in treatment-resistant patients, and to be associated with the lowest risk of death.

AREAS COVERED

The pharmacodynamics, pharmacokinetics, clinical efficacy, safety and cost-effectiveness of clozapine are covered in this article, based on a literature review (PubMed) from 1975 to 2012. Pivotal, as well as supporting, randomized controlled trials are reviewed, along with observational and/or naturalistic safety studies. This review of clozapine will allow the reader to determine the place for clozapine in the schizophrenia treatment landscape.

EXPERT OPINION

Studies conducted so far suggest that clozapine is the treatment of choice for schizophrenic patients who are refractory to treatment, display violent behaviors, or who are at high risk of suicide. However, it is also the antipsychotic with the worst side effect profile, the highest risk of complications, and the most difficult to prescribe. Experience with clozapine should therefore be included in the education of future physicians.

Optimized voxel brain morphometry: association between brain volumes and the response to atypical antipsychotics

To date, few studies have addressed the relationship between brain structure alterations and responses to atypical antipsychotics in schizophrenia. To this end, in this study, magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) were used to assess the relationship between the brain volumes of gray (GM) and white (WM) matters and the clinical response to risperidone or olanzapine in 30 schizophrenia patients. In comparison with healthy controls, the patients in this study showed a bilateral decrease in the anteromedial cerebellar hemispheres, the rectal gyrus and the insula, together with bilateral increases in GM in the basal ganglia. Both patient groups had a significantly smaller volume of WM in a region encompassing the internal and external capsules as compared to the controls. We found an inverse association between striatal size and the degree of clinical improvement, and a direct association between the degree of insular volume deficit and its improvement. The non-responder patient group showed a significant decrease in their left rectal gyrus as compared with the responder group. This study reveals a pattern of structural alterations in schizophrenia associated with the response to risperidone or olanzapine.

Patient subgroups of schizophrenia based on the Positive and Negative Syndrome Scale: composition and transition between acute and subsided disease states

The present study focuses on schizophrenia patient subgroups with specific symptom pattern using the Positive and Negative Syndrome Scale (PANSS). In this report, we intend to (1) provide a more appropriate analytic method for exploring the subgroups based on PANSS data, (2) validate identified subgroups with external variables, and (3) estimate probabilities of subgroup changes between 2 disease states. The analyzed data include 219 acute-state patients who had completed the PANSS within 1 week of index admission and 225 subsided-state patients who were living in the community and under family care. Regression extension of latent class analysis was performed. We found that acute schizophrenia can be classified into 4 subgroups--whole syndrome, whole syndrome without hostility, partial syndrome with negative symptoms, and partial syndrome with pure reality distortion--and that subsided schizophrenia can be classified into 3 subgroups--florid symptom, marked negative, and remitted. Patients of the whole syndrome, whole syndrome without hostility, partial syndrome with negative symptoms, and partial syndrome with pure reality distortion subgroups at the acute state were most likely to transit to the florid symptom (61%), florid symptom (48%), marked negative (42%), and remitted (56%) subgroups at the subsided state, respectively. Significant relationships of obtained subgroups with sociodemographic variables and neurocognitive variables were identified. These results of different subgroups will provide the background for facilitating current molecular, genetic, and neurobiological studies of schizophrenia.

Hippocampal volume reduction in first-episode and chronic schizophrenia: a review and meta-analysis

Several magnetic resonance imaging studies have reported hippocampal volume reduction in patients with schizophrenia, but other studies have reported contrasting results. In this review and meta-analysis, the authors aim to clarify whether a reduction in hippocampal volume characterizes patients with schizophrenia by considering illness phase (chronic and first episode) and hippocampus side separately. They made a detailed literature search for studies reporting physical volumetric hippocampal measures of patients with schizophrenia and healthy control (HC) participants and found 44 studies that were eligible for meta-analysis. Individual meta-analyses were also performed on 13 studies of first-episode patients and on 22 studies of chronic patients. The authors also detected any different findings when only males or both males and females were considered. Finally, additional meta-analyses and analyses of variance investigated the role of the factors "illness phase" and "side" on hippocampal volume reduction. Overall, the patient group showed significant bilateral hippocampal volume reduction compared with HC. Interestingly, first-episode and chronic patients showed same-size hippocampal volume reduction. Moreover, the left hippocampus was smaller than the right hippocampus in patients and HC. This review and meta-analysis raises the question about whether hippocampal volume reduction in schizophrenia is of neurodevelopmental origin. Future studies should specifically investigate this issue.

Absence and size of massa intermedia in patients with schizophrenia and bipolar disorder

OBJECTIVE

To evaluate the absence and size of massa intermedia (MI), a midline thalamic structure, and its gender-specific alteration in patients with schizophrenia and bipolar disorder.

METHODS

Thirty-five patients with schizophrenia (17 females and 18 males), 21 patients with bipolar disorder (15 females and 6 males) and 89 healthy controls (50 females and 39 males) were evaluated by magnetic resonance imaging. Thin-slice magnetic resonance images of the brain were evaluated. MI was determined in coronal and sagittal images, and area of the MI was measured on the sagittal plane.

RESULTS

Females had a significantly lower incidence of absent MI compared with males in the healthy control group. The absence of MI in schizophrenia and bipolar patients was not higher than the incidence in healthy controls. The size of MI showed a gender difference. The mean MI area size was smaller in female schizophrenia patients than in female controls, while no significant difference was observed between male schizophrenia patients and their controls.

CONCLUSIONS

The size of MI, a gender difference midline structure, is smaller in females with schizophrenia, and the results of this study support other studies of structural aberration of the thalamus and other midline structures in the brains of patients with 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.

Investigating the neurodevelopmental hypothesis of schizophrenia

1. An optimal intra-uterine environment is critical for normal development of the brain. It is now thought that abnormal development in a compromised prenatal and/or early postnatal environment may be a risk factor for several neurological disorders that manifest postnatally, such as cerebral palsy, schizophrenia and epilepsy. 2. The present review examines some of the effects of abnormal prenatal brain development and focuses on one disorder that has been hypothesized to have, at least in part, an early neurodevelopmental aetiology: schizophrenia. 3. The key neuropathological alterations and changes in some of the neurotransmitter systems observed in patients with schizophrenia are reviewed. Evidence in support of a neurodevelopmental hypothesis for schizophrenia is examined. 4. A summary of the animal models that have been used by researchers in an attempt to elucidate the origins of this disorder is presented. Although no animal model of a complex human disorder is ever likely to emulate deficits in all aspects of structure and function observed in patients with a neuropsychiatric illness, our findings and those of others give support to the early neurodevelopmental hypothesis. 5. Thus, it is possible that an adverse event in utero disrupts normal brain development and creates a vulnerability of the brain that predisposes an already at-risk individual (e.g. genetic inheritance) to develop the disorder later in life.

Pharmacoeconomic evaluation of schizophrenia in Taiwan: model comparison of long-acting risperidone versus olanzapine versus depot haloperidol based on estimated costs

Antipsychotics are the keystone in schizophrenia treatment. Although the benefits of the new generation of antipsychotics has been demonstrated over the last decade, the issues of patient compliance and higher purchasing price of atypical antipsychotics remain unresolved. Risperidone is the only atypical antipsychotic agent with long-acting formulation. Long-acting risperidone is a water-based injection and it has been associated with a low level of pain. The aim of the present study was to test whether an improvement in compliance with the use of a long-acting risperidone, compared with olanzapine and depot haloperidol, can increase the effectiveness and the cost-effectiveness indexes. An economic comparison model with decision tree, rather than a prospective design with real clinical drug trial, was applied. The unit cost for each medical procedure was obtained from the claimed-database of the Bureau of National Health Insurance in Taiwan. An executive committee simulated the incidence of extrapyramidal side-effects and proposed a therapeutic model for each strategy based on a literature review. The probabilities of treatment response of different agents and those of different mental health states were estimated by the executive committee and 10 senior psychiatrists who were randomly selected. Sensitivity analysis was performed for drug cost-effectiveness and compliance improvement for using long-acting risperidone. The results showed that long-acting risperidone is more cost-effective than either olanzapine or depot haloperidol for treating schizophrenia patients whose conditions are stable and whose illness duration ranges from 1 to 5 years. The comparison model with the Kaplan-Meier decision tree may serve as an alternative to prospectively designed studies for cost-effectiveness of atypical antipsychotics.

Change in the relationship between anhedonia and functional deficits over a 20-year period in individuals with schizophrenia

Although early theorists suggested that deficits in emotional experience be considered a hallmark characteristic of schizophrenia, there has been limited research, and inconsistent findings, on the relationship between anhedonia and functional capacity in individuals after the onset of schizophrenia. Stronger relationships have typically been reported for chronic samples in contrast to first episode samples, although it is not clear whether this is due to selection biases that influence recruitment in these different groups, or whether results reflect a change over the course of illness. The current longitudinal study examined the relationship between physical anhedonia and functional status in a sample of 61 individuals with schizophrenia at regular intervals over a 20-year period. Subjects were recruited into the study during an index hospitalization and completed assessments at 2-, 4.5-, 7.5-, 10-, 15-, and 20-year follow-ups. Analyses indicate that the relationship between anhedonia and impairments increases over time, although mean performance on these measures is stable across this same time period. These results suggest increasing convergence of impairments in emotional, adaptive, and cognitive capacities over time, with physical anhedonia associated with poorer outcome.

Effect of age and global function score on schizophrenic p300 characteristics

The relationship between function level and P300 has long been ignored and awaits clarification. Further, previous Western studies have discussed the trait/state markers of schizophrenic P300; this has not been assessed for an analogous Chinese population. P300 was recorded and compared in 153 schizophrenic patients and 101 normal controls. Reduced and delayed P300 was demonstrated for the schizophrenic group. Regression analysis was performed to determine the factors contributing to P300 amplitude and latency variation. Global Assessment of Functioning score and age had a significant influence on P300 latency prolongation. Amplitude decrement was not affected by age, duration of illness, education, psychotic status, antipsychotic dosage, or function level. Our results were grossly concordant with analogous Western reports and provided evidence that function level is an important variable contributing to P300 latency change in Chinese schizophrenics. Besides, the effect of gender on P300 amplitude was noted in normal population.

Imaging frontostriatal function in ultra-high-risk, early, and chronic schizophrenia during executive processing

CONTEXT

Individuals experiencing prodromal symptoms of schizophrenia (ultra-high-risk group) demonstrate impaired performance on tasks of executive function, attention, and working memory. The neurobiological underpinnings of such executive deficits in ultra-high-risk individuals remains unclear.

OBJECTIVE

We assessed frontal and striatal functions during a visual oddball continuous performance task, in ultra-high-risk, early, and chronic schizophrenic patients with the use of functional magnetic resonance imaging.

DESIGN

Cross-sectional case-control design.

SETTING

Community; outpatient clinic. Patients Fifty-two individuals (control, n = 16; ultra-high risk, n = 10; early, n = 15; chronic, n = 11) from a referred clinical sample and age- and sex-matched control volunteers underwent scanning.

MAIN OUTCOME MEASURES

Percentage of active voxels and percentage signal change calculated for the anterior cingulate gyrus (ACG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), basal ganglia, and thalamus. Performance on the visual oddball task was measured with percentage of hits and d' (a measure based on the hit rate and the false-alarm rate).

RESULTS

The ultra-high-risk group showed significantly smaller differential activation between task-relevant and task-irrelevant stimuli in the frontal regions (ACG, IFG, MFG) than the control group. Frontostriatal activation associated with target stimuli in the early and chronic groups was significantly lower than the control group, while the ultra-high-risk group showed a trend toward the early group.

CONCLUSIONS

Our findings suggest that prefrontal function begins to decline before the onset of syndromally defined illness and hence may represent a vulnerability marker in assessing the risk of developing psychotic disorders among ultra-high-risk individuals.

Serum prolactin levels in unmedicated first-episode and recurrent schizophrenia patients: a possible marker for the disease's subtypes

Various studies indicate that we must consider schizophrenia not as a single disease but as several distinct etiological processes that give rise to characteristic symptoms. In the current study, we aimed to examine prolactin serum levels in unmedicated first-episode and recurrent schizophrenic patients. The prolactin levels were compared among the different schizophrenia subtypes, i.e. paranoid, schizoaffective and disorganized. Prolactin serum samples were assessed on the morning after the admission in 48 first-episode and 38 recurrent unmedicated hospitalized schizophrenia patients. Two psychiatrists made the diagnosis without knowledge of laboratory results and completed the rating scales. Despite all prolactin levels being within or close to the normal range, we found significant differences in prolactin serum levels among schizophrenia subtype patients: the lowest values were for the paranoid type, intermediate for the schizoaffective and the highest for the disorganized patients. The results seem to indicate a pronounced hyperdopaminergic activity in paranoid schizophrenia, suggesting differences in dopaminergic tone between the schizophrenia subtypes, and support the clinical and the neuropsychological individuality of disease subtypes. There were no significant differences in prolactin serum levels of the schizophrenia subtypes between the first-episode and the recurrent patients. It appears that there are constant patterns of dopamine bioactivity in acutely psychotic unmedicated schizophrenia patients, whether the patients are first admitted or recurrent.

Anticipation and CAG*CTG repeat expansion in schizophrenia and bipolar affective disorder

The genetic contribution to the etiologies of schizophrenia and bipolar affective disorder (BPAD) has been considered for many decades, with twin, family, and adoption studies indicating consistently that the familial clustering of affected individuals is accounted for mainly by genetic factors. Despite the strong evidence for a genetic component, very little is understood about the underlying genetic and molecular mechanisms for schizophrenia and BPAD. In the early 1990s, after the discovery of "dynamic mutation" or "unstable DNA" as a molecular basis for the genetic anticipation observed in Huntington's disease, myotonic dystrophy, and many others, and the recently rediscovered, albeit still controversial, evidence for genetic anticipation in major psychoses, the genetic epidemiology of schizophrenia and BPAD was re-evaluated to demonstrate strong endorsement for the unstable DNA model. Many of the non-Mendelian genetic features of schizophrenia and BPAD could be explained by the behaviour of unstable DNA, and several molecular genetic approaches became available for testing the unstable DNA hypothesis. However, despite promising findings in the mid-1990s, no trinucleotide repeat expansion has yet been identified as a cause of idiopathic schizophrenia or BPAD.

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.

Neuroanatomy and neurophysiology in schizophrenia

Schizophrenia is a major mental disorder, characterized by their set of symptoms, including hallucinatory-delusional symptoms, thought disorder, emotional flattening, and social withdrawal. Since 1980s, advances in neuroimaging and neurophysiological techniques have provided tremendous merits for investigations into schizophrenia as a brain disorder. In this article, we first overviewed neuroanatomical studies using structural magnetic resonance imaging (s-MRI), MR spectroscopy (MRS), and postmortem brains, followed by neurophysiological studies using event-related potentials (ERPs) and magnetoencephalography (MEG), in patients with schizophrenia. Evidences from these studies suggest that schizophrenia is a chronic brain disorder, structurally and functionally affecting various cortical and subcortical regions involved in cognitive, emotional, and motivational aspects of human behavior. Second, we reviewed recent investigations into neurobiological basis for schizophrenic symptoms (auditory hallucinations and thought disorder) using these indices as well as hemodynamic assessments such as positron emission tomography (PET) and functional MRI (f-MRI). Finally, we addressed the issue of the heterogeneity of schizophrenia from the neurobiological perspective, in relation to the neuroanatomical and neurophysiological measures.

Review of immunological and immunopathological findings in schizophrenia

The involvement of immunological and immunopathological mechanisms in the etiopathogenesis of schizophrenia has been a matter of research, with recently increasing effort. This article reviews the findings focusing on postmortem neuropathology, the blood-brain barrier, antibodies, acute phase proteins, immunocompetent cells, and activation markers of immunocompetent cells. Evidence for the two primarily postulated hypotheses (the infectious hypothesis and the autoimmune hypothesis) is critically discussed. On the basis of the findings, perspectives for future research are outlined aiming at a precise and consequent strategy to elucidate a potential involvement of immune mechanisms in the etiopathogenesis of schizophrenia.

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.

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.

The Th2-hypothesis of schizophrenia: a strategy to identify a subgroup of schizophrenia caused by immune mechanisms

Immunologic findings in schizophrenia have been described for decades, but it was not possible to identify a pathogen until now. Most of these studies report immune abnormalities in a group of the investigated patients, but a distinct subgroup of schizophrenia with immune-related pathology has still not been characterized. In this paper we have integrated the most important immunologic data in schizophrenia research and hypothesize a shift to Th2-like immune reactivity in a subgroup of schizophrenic patients. Besides the immunological abnormalities, this subgroup is further characterized by more pronounced negative symptoms and poor therapy outcome. There is evidence that this subgroup might be caused by a prenatal viral infection.

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.

Longitudinal study of brain morphology in first episode schizophrenia

BACKGROUND

Beginning with Kraepelin, schizophrenia has been viewed as a progressive disorder. Although numerous studies of the longitudinal course of schizophrenia have demonstrated the clinical deterioration that occurs predominantly in the early stages of the illness, the pathophysiology of this clinical phenomenon has not been established. This aspect of the illness may be of critical importance to understanding the pathogenesis of schizophrenia and determining preventive therapeutic strategies. Abnormalities in brain morphology have been consistently described in schizophrenia, but it is not known when in the natural history of the illness they arise and whether they are progressive. Previous studies of brain morphology have been inconclusive, in part because of the variability of methods for image acquisition and analysis, assessment of patients already at chronic stages of their illness with extensive prior treatment exposure, and inadequate periods of follow-up.

METHODS

To address these questions we examined 107 patients in their first episode of schizophrenia or schizoaffective disorder and 20 healthy volunteers using high resolution magnetic resonance imaging (MRI) and clinical assessments of psychopathology and treatment outcome for periods of up to 6 years. Fifty-one patients and 13 control subjects had MRIs after at least 12 months of follow-up.

RESULTS

Results confirm the findings of ventricular enlargement and anterior hippocampal volume reductions in first episode schizophrenia patients that have been previously reported. In addition, we found changes in selected structures over time in relation to treatment outcome, including increases in ventricular volume that were associated with poor outcome patients. Contrary to our hypothesis, there were no significant reductions in cortical and hippocampal volumes over time.

CONCLUSIONS

The finding of progressive ventricular enlargement in patients with poor outcome schizophrenia is consistent with the hypothesis that persistent positive and negative symptoms result in progressive brain changes in the form of ventricular enlargement, possibly due to neurodegeneration rather than the confounding effects of treatment. Future studies of first episodes of schizophrenia should utilize higher resolution imaging techniques that compare clinically well characterized patients with and without poor outcome and recurrent symptoms to control subjects who are well matched to patients for age and gender. There is also a need to control for treatment effects of typical antipsychotic medication on brain structure.

The timing of neurodevelopmental abnormality in schizophrenia: an integrative review of the neuroimaging literature

In this paper we will review recent neuroimaging research in schizophrenia, with an aim to critically evaluate several recent proposals concerning the nature and the timing of the neuroanatomic abnormalities underlying the disorder. Specifically, enlargement of cerebrospinal fluid spaces, deficits in cortical gray matter, and reduced volume of mesiotemporal structures have all been reported in patients in the first episode of schizophrenia, their first-degree relatives, and individuals with schizotypal personality disorder, supporting the possibility that these abnormalities reflect a genetically mediated neurodevelopmental disorder. These findings from the empirical literature will be synthesized from the perspective of dual cytoarchitectonic trends theory of neurodevelopment, as well as in relation to current conceptions of the schizophrenia prodrome. We believe that the evidence shows that sufficient groundwork has been laid to begin longitudinal neuroimaging studies of adolescents at clinical risk for schizophrenia, in order to more definitively determine the pathophysiology of the disorder. Such information could have significant implications in terms of understanding the prediction, treatment, and ultimately the prevention of schizophrenia.

Biological markers and schizophrenia

OBJECTIVE

The delivery of biological markers for schizophrenia would greatly assist preventative strategies by identifying at-risk individuals who could then be monitored and treated in a manner with a view to minimising subsequent morbidity. This paper aims to present a selection of biological measures that may indicate risk of schizophrenia.

METHOD

A selective and brief review is provided of intensively studied putative markers, including enlarged cerebral ventricles, dopamine D2 receptor density, amphetamine-stimulated central nervous system dopamine release, plasma homovanillic acid and smooth pursuit eye tracking dysfunction.

RESULTS

A number of biological measures have been reported to be correlated with schizophrenia.

CONCLUSIONS

Presently, none of these measures has satisfactory performance characteristics in terms of predictive validity, noninvasiveness, ease of testing and low cost that would enable their widespread use. However, a few have potential for further investigation and development.

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.

Cortical bcl-2 protein expression and apoptotic regulation in schizophrenia

BACKGROUND

The etiology of schizophrenia remains unknown; however, a role for apoptosis has been hypothesized. Bcl-2 is a potent inhibitor of apoptosis and also exerts neurotrophic activity in the central nervous system (CNS). Bcl-2 expression is increased in the CNS of several neurodegenerative disorders. Given that schizophrenia has certain features of a limited neurodegenerative disorder, it was hypothesized that cortical Bcl-2 expression is increased in schizophrenia.

METHODS

Postmortem temporal cortex was obtained from the Stanley Foundation Neuropathology Consortium with matched control, schizophrenic, bipolar, and depressed subjects. Bcl-2 protein was measured by enzyme-linked immunoassay (ELISA) and Western blot. Primary analysis was limited to schizophrenia versus control subjects.

RESULTS

The ELISA demonstrated 25% less Bcl-2 protein in schizophrenia (p =.046), supported by Western blot results. A secondary analysis of schizophrenic and bipolar subjects revealed twofold higher mean Bcl-2 in antipsychotic-treated versus neuroleptic-naive subjects.

CONCLUSIONS

Contrary to our hypothesis, cortical Bcl-2 was reduced in schizophrenia. This supports the notion that schizophrenia is not a classic neurodegenerative disorder; however, less Bcl-2 protein may signal neuronal vulnerability to proapoptotic stimuli and to neuronal atrophy. Also, the association between neuroleptic exposure and higher Bcl-2 levels could underlie the favorable long-term outcomes of patients who receive maintenance antipsychotic treatment.

Towards the prevention of schizophrenia

There is a growing emphasis on attempts to identify the early signs and symptoms of schizophrenia, largely because early detection and treatment of psychosis (i.e., secondary prevention) are associated with relatively favorable clinical outcomes. This raises the issue of whether prevention of psychosis itself is possible. The achievement of this goal will require the identification of a premorbid state that could serve as the foundation for treatment strategies aimed ultimately at the prevention of schizophrenia. Fortunately, evidence for such a state is emerging, in part because schizophrenia may result from a neurodevelopmental disorder that is associated with a variety of clinical, neurobiological, and neuropsychologic features occurring well before the onset of psychosis. These features may serve as both indicators of risk for subsequent deterioration and the foundation of treatment efforts. We reformulated Meehl's term schizotaxia to describe this liability and discuss here how its study could form the basis for future strategies of prevention. We also include a description of our initial attempts to devise treatment protocols for schizotaxia. It is concluded that schizotaxia is a feasible concept on which to base prevention efforts, and that treatment of adult schizotaxia may be among the next steps in the process.