Pubertal development and onset of psychosis in childhood onset schizophrenia

Clinical features and comorbidity in very early-onset schizophrenia: a systematic review

Background

Very early-onset schizophrenia (VEOS) is a form of schizophrenia that manifests before the age of 13 years and is characterized by the presence of positive, negative, and disorganized symptoms. The condition is exceptionally rare and, to date, limited studies have been conducted, resulting in incomplete information about its clinical features.

Methods

The present study involves a systematic review of the existing literature regarding the clinical features and comorbidities of VEOS.

Results

The first search retrieved 384 studies. Of these, 366 were removed following the application of exclusion criteria, resulting in 18 studies for the final set.

Conclusion

The results highlight that VEOS shares similarities with early-onset and adult-onset schizophrenia but also exhibits distinct and recognizable characteristics, including a more severe clinical profile (particularly in females), increased visual hallucinations, and high comorbidities with neurodevelopmental disorders. These findings may support clinicians in formulating early diagnoses and developing effective treatment strategies for pediatric and adolescent patients with psychosis.

Shared and distinct white matter abnormalities in adolescent-onset schizophrenia and adolescent-onset psychotic bipolar disorder

BACKGROUND

While adolescent-onset schizophrenia (ADO-SCZ) and adolescent-onset bipolar disorder with psychosis (psychotic ADO-BPD) present a more severe clinical course than their adult forms, their pathophysiology is poorly understood. Here, we study potentially state- and trait-related white matter diffusion-weighted magnetic resonance imaging (dMRI) abnormalities along the adolescent-onset psychosis continuum to address this need.

METHODS

Forty-eight individuals with ADO-SCZ (20 female/28 male), 15 individuals with psychotic ADO-BPD (7 female/8 male), and 35 healthy controls (HCs, 18 female/17 male) underwent dMRI and clinical assessments. Maps of extracellular free-water (FW) and fractional anisotropy of cellular tissue (FAT) were compared between individuals with psychosis and HCs using tract-based spatial statistics and FSL's Randomise. FAT and FW values were extracted, averaged across all voxels that demonstrated group differences, and then utilized to test for the influence of age, medication, age of onset, duration of illness, symptom severity, and intelligence.

RESULTS

Individuals with adolescent-onset psychosis exhibited pronounced FW and FAT abnormalities compared to HCs. FAT reductions were spatially more widespread in ADO-SCZ. FW increases, however, were only present in psychotic ADO-BPD. In HCs, but not in individuals with adolescent-onset psychosis, FAT was positively related to age.

CONCLUSIONS

We observe evidence for cellular (FAT) and extracellular (FW) white matter abnormalities in adolescent-onset psychosis. Although cellular white matter abnormalities were more prominent in ADO-SCZ, such alterations may reflect a shared trait, i.e. neurodevelopmental pathology, present across the psychosis spectrum. Extracellular abnormalities were evident in psychotic ADO-BPD, potentially indicating a more dynamic, state-dependent brain reaction to psychosis.

Association between the 2D:4D ratio and schizophrenia

OBJECTIVE

To investigate the potential association between the ratio of the second digit length to the fourth digit length (2D:4D) and schizophrenia, to provide evidence regarding the pathogenesis of schizophrenia.

METHODS

In this study, we enrolled 843 patients with schizophrenia (387 men and 456 women), all of whom met the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), and 1050 normal healthy controls (477 men and 573 women). The digit lengths of both hands were measured in all subjects and the 2D:4D ratio was analyzed.

RESULTS

In the healthy controls, the 2D:4D ratio was sexually dimorphic, with a larger value in women than in men. In addition, the 2D:4D ratio in the schizophrenia patients was significantly larger than in the healthy controls. The 2D:4D ratio of the right hand was more sexually dimorphic than the left hand. Furthermore, the difference in 2D:4D ratios between the male patients and male controls was significantly larger than in their female counterparts.

CONCLUSIONS

By analyzing the 2D:4D ratio and considering alternative factors related to schizophrenia, our findings support the hypothesis that there are abnormal cerebral conditions in schizophrenia patients.

Interactome analysis reveals ZNF804A, a schizophrenia risk gene, as a novel component of protein translational machinery critical for embryonic neurodevelopment

Recent genome-wide association studies identified over 100 genetic loci that significantly associate with schizophrenia (SZ). A top candidate gene, ZNF804A, was robustly replicated in different populations. However, its neural functions are largely unknown. Here we show in mouse that ZFP804A, the homolog of ZNF804A, is required for normal progenitor proliferation and neuronal migration. Using a yeast two-hybrid genome-wide screen, we identified novel interacting proteins of ZNF804A. Rather than transcriptional factors, genes involved in mRNA translation are highly represented in our interactome result. ZNF804A co-fractionates with translational machinery and modulates the translational efficiency as well as the mTOR pathway. The ribosomal protein RPSA interacts with ZNF804A and rescues the migration and translational defects caused by ZNF804A knockdown. RNA immunoprecipitation-RNAseq (RIP-Seq) identified transcripts bound to ZFP804A. Consistently, ZFP804A associates with many short transcripts involved in translational and mitochondrial regulation. Moreover, among the transcripts associated with ZFP804A, a SZ risk gene, neurogranin (NRGN), is one of ZFP804A targets. Interestingly, downregulation of ZFP804A decreases NRGN expression and overexpression of NRGN can ameliorate ZFP804A-mediated migration defect. To verify the downstream targets of ZNF804A, a Duolink in situ interaction assay confirmed genes from our RIP-Seq data as the ZNF804A targets. Thus, our work uncovered a novel mechanistic link of a SZ risk gene to neurodevelopment and translational control. The interactome-driven approach here is an effective way for translating genome-wide association findings into novel biological insights of human diseases.

Focusing on the Differences of Resting-State Brain Networks, Using a Data-Driven Approach to Explore the Functional Neuroimaging Characteristics of Extraversion Trait

In recent years, functional magnetic resonance imaging (fMRI) has been widely used in studies that explored the personality-brain association. Researches on personality neuroscience have the potential to provide personality psychology with explanatory models—that is, why people differ from each other rather than how they differ from each other (DeYoung and Gray, 2009). As one of the most important dimensions of personality traits, extraversion is the most stable core and a universal component in personality theory. The aim of the present study was to employ a fully data-driven approach to study the brain mechanism of extraversion in a sample of 111 healthy adults. The Eysenck Personality Questionnaire (EPQ) was used to measure the personality characteristics of all the subjects. We investigated whether the subjects can be grouped into highly homogeneous communities according to the characteristics of their intrinsic connectivity networks (ICNs). The resultant subjects communities and the representative characteristics of ICNs were then associated to personality concepts. Finally, we found one ICN (salience network) whose subject community profiles exhibited significant associations with Extraversion trait.

A prenatal interruption of DISC1 function in the brain exhibits a lasting impact on adult behaviors, brain metabolism, and interneuron development

Mental illnesses like schizophrenia (SCZ) and major depression disorder (MDD) are devastating brain disorders. The SCZ risk gene, disrupted in schizophrenia 1 (DISC1), has been associated with neuropsychiatric conditions. However, little is known regarding the long-lasting impacts on brain metabolism and behavioral outcomes from genetic insults on fetal NPCs during early life. We have established a new mouse model that specifically interrupts DISC1 functions in NPCs in vivo by a dominant-negative DISC1 (DN-DISC1) with a precise temporal and spatial regulation. Interestingly, prenatal interruption of mouse Disc1 function in NPCs leads to abnormal depression-like deficit in adult mice. Here we took a novel unbiased metabonomics approach to identify brain-specific metabolites that are significantly changed in DN-DISC1 mice. Surprisingly, the inhibitory neurotransmitter, GABA, is augmented. Consistently, parvalbumin (PV) interneurons are increased in the cingulate cortex, retrosplenial granular cortex, and motor cortex. Interestingly, somatostatin (SST) positive and neuropeptide Y (NPY) interneurons are decreased in some brain regions, suggesting that DN-DISC1 expression affects the localization of interneuron subtypes. To further explore the cellular mechanisms that cause this change, DN-DISC1 suppresses proliferation and promotes the cell cycle exit of progenitors in the medial ganglionic eminence (MGE), whereas it stimulates ectopic proliferation of neighboring cells through cell non-autonomous effect. Mechanistically, it modulates GSK3 activity and interrupts Dlx2 activity in the Wnt activation. In sum, our results provide evidence that specific genetic insults on NSCs at a short period of time could lead to prolonged changes of brain metabolism and development, eventually behavioral defects.

Relationship between menarche and psychosis onset in women with first episode of psychosis

AIM

The aim of this study was to explore the relationship between age at menarche and age at first episode of psychosis, as well as clinical severity and outcome, in a population of women with first-episode psychosis.

METHODS

Clinical and socio-demographical data, age at menarche and at first-episode psychosis, parental history of psychosis and cannabis-use habits were obtained from 42 subjects with a first episode of psychosis. Positive and Negative Syndrome Scale, Clinical Global Impression, Global Assessment Function, Disability Assessment Schedule, Wechsler Adult Intelligence Scale and Wechsler Intelligence Scale for Children, European Quality of Life, and Lewis and Murray Obstetric Complication Scales were administered. Statistical analysis was performed by means of zero-order correlations and Mann-Whitney U and Kruskal-Wallis tests using SPSS version 17.0.

RESULTS

We found no significant correlation between age at menarche and age at first-episode psychosis, or with the clinical scores performed. We observed that subjects with earlier age at menarche had more parental history of psychosis.

CONCLUSIONS

Our negative results do not support the theory of a possible protective role of oestrogen, which seems to be more complex than previously thought. We would suggest that further research is needed to investigate developmental influences of sex steroids on the onset of psychosis and potentially therapeutic benefits based upon oestrogen.

The Clinical Presentation of Childhood-Onset Schizophrenia: A Literature Review

This literature review explores the research on the clinical presentation of childhood-onset schizophrenia (COS) that was conducted in the period 1994–2004. A literature search was done using Internet search engines and psychological databases to collect English-language journal articles from 1994 onwards. Research indicates that COS is a stable diagnosis. Generally, there is a clear history of premorbid abnormalities, an insidious onset and a deteriorating course. For the majority of cases there seems to be a poor outcome. Despite the limitations in the research conducted thus far, findings provide important insights into COS and several possibilities for future research.

Brain network informed subject community detection in early-onset schizophrenia

Early-onset schizophrenia (EOS) offers a unique opportunity to study pathophysiological mechanisms and development of schizophrenia. Using 26 drug-naïve, first-episode EOS patients and 25 age- and gender-matched control subjects, we examined intrinsic connectivity network (ICN) deficits underlying EOS. Due to the emerging inconsistency between behavior-based psychiatric disease classification system and the underlying brain dysfunctions, we applied a fully data-driven approach to investigate whether the subjects can be grouped into highly homogeneous communities according to the characteristics of their ICNs. The resultant subject communities and the representative characteristics of ICNs were then associated with the clinical diagnosis and multivariate symptom patterns. A default mode ICN was statistically absent in EOS patients. Another frontotemporal ICN further distinguished EOS patients with predominantly negative symptoms. Connectivity patterns of this second network for the EOS patients with predominantly positive symptom were highly similar to typically developing controls. Our post-hoc functional connectivity modeling confirmed that connectivity strength in this frontotemporal circuit was significantly modulated by relative severity of positive and negative syndromes in EOS. This study presents a novel subtype discovery approach based on brain networks and proposes complex links between brain networks and symptom patterns in EOS.

Empirical evidence for psychopharmacologic treatment in early-onset psychosis and schizophrenia

Psychotic symptoms presenting in youth can be clinically complex and require that a child and adolescent psychiatrist use significant skill in making a diagnosis and initiating treatment. There are a number of illnesses to rule out before making a diagnosis of early-onset schizophrenia in particular. Psychosis in youth has significant associated morbidity and places high demands not only on families but also on the medical and educational systems. More effective pharmacologic and nonpharmacologic treatments for psychosis are needed. Nonpharmacologic therapies targeting relatively treatment-resistant domains of dysfunction such as neurocognition are also necessary as adjunctive treatments to our extant pharmacologic agents.

Neurobiology and phenotypic expression in early onset schizophrenia

AIM

Early-onset schizophrenia (onset before adulthood) is a rare and severe form of the disorder that shows phenotypic and neurobiological continuity with adult-onset schizophrenia. Here, we provide a synthesis of keynote findings in this enriched population to understand better the neurobiology and pathophysiology of early-onset schizophrenia.

METHODS

A synthetic and integrative approach is applied to review studies stemming from epidemiology, phenomenology, cognition, genetics and neuroimaging data. We provide conclusions and future directions of research on early-onset schizophrenia.

RESULTS

Childhood and adolescent-onset schizophrenia is associated with severe clinical course, greater rates of premorbid abnormalities, poor psychosocial functioning and increased severity of brain abnormalities. Early-onset cases show similar neurobiological correlates and phenotypic deficits to adult-onset schizophrenia, but show worse long-term psychopathological outcome. Emerging technological advances have provided important insights into the genomic architecture of early-onset schizophrenia, suggesting that some genetic variations may occur more frequently and at a higher rate in young-onset than adult-onset cases.

CONCLUSIONS

Clinical, cognitive, genetic and imaging data suggest increased severity in early-onset schizophrenia. Studying younger-onset cases can provide useful insights into the neurobiological mechanisms of schizophrenia and the complexity of gene-environment interactions leading to the emergence of this debilitating disorder.

Increased ratio of 2nd to 4th digit (2D:4D) in schizophrenia

Sex differences in the onset, epidemiology, clinical presentation and neuropathology of schizophrenia suggest that sexual dimorphism in brain development may be relevant to pathogenesis. Sex hormones, in particular testosterone, are considered to be crucial in brain development, but few investigations have examined the potential role of prenatal testosterone in schizophrenia. In this study, we examined a retrospective marker of prenatal testosterone release - 2D:4D finger length ratio (2D:4D), the relative length of 2nd to 4th digit, in 64 Asian patients with schizophrenia and 64 sex-matched controls. No significant difference in mean finger lengths was present, however 2D:4D ratio was significantly different between patients and controls. The effect was primarily seen in males consistent with a 'less masculinised' pattern and hypotheses suggesting that schizophrenia may be associated with an abnormality in prenatal circulating testosterone.

The relationship between symptoms and stress in adolescents with schizophrenia

Stress predicts outcomes in adults with schizophrenia, but its effect in adolescents is unknown. We used exploratory data analysis to examine changes in symptoms and to correlate symptoms with stress at 0, 6, 30, and 54 weeks in 40 adolescents with schizophrenia. Symptoms were measured with the Early Signs and Symptoms Scale; stress was measured with the Hassles Scale. From baseline to 54 weeks, symptom severity decreased significantly. Symptom severity and stress correlated significantly at baseline, 30 weeks, and 54 weeks, after controlling for the number of hospitalizations and baseline symptom severity. These results implicate stress in schizophrenia symptoms in adolescents and justify examining stress management for these patients.

Olanzapine versus placebo in adolescents with schizophrenia: a 6-week, randomized, double-blind, placebo-controlled trial

OBJECTIVE

To assess olanzapine's efficacy and tolerability in adolescents with schizophrenia.

METHOD

One hundred seven inpatient and outpatient adolescents (olanzapine, n = 72, mean age 16.1 years; placebo, n = 35, mean age 16.3 years) with schizophrenia participated in this randomized (2:1), international, multisite, industry-sponsored trial. All patients met DSM-IV-TR criteria for schizophrenia, and they were treated for up to 6 weeks with flexible doses of olanzapine (2.5-20.0 mg/day) or placebo. Last-observation-carried-forward mean changes from baseline to endpoint on the anchored version of the Brief Psychiatric Rating Scale for Children, Clinical Global Impression Scale-Severity of Illness, and Positive and Negative Syndrome Scale (PANSS) were assessed.

RESULTS

More olanzapine-treated versus placebo-treated patients completed the trial (68.1% versus 42.9%, p =.020). Compared with placebo-treated patients, olanzapine-treated adolescents had significantly greater improvement in Brief Psychiatric Rating Scale for Children total (p =.003), Clinical Global Impressions Scale-Severity of Illness (p =.004), PANSS total (p =.005), and PANSS positive scores (p =.002). Olanzapine-treated patients gained significantly more baseline-to-endpoint weight (4.3 kg versus 0.1 kg, p <.001). Significantly more olanzapine-treated versus placebo-treated patients gained 7% or greater of their body weight at any time during treatment (45.8% versus 14.7%, p =.002). Prolactin and triglyceride mean baseline-to-endpoint changes were significantly higher in olanzapine-treated versus placebo-treated adolescents. The incidence of treatment-emergent significant changes in fasting glucose, cholesterol, or triglycerides did not differ between the groups at endpoint, but significantly more olanzapine-treated patients had high triglycerides at any time during treatment.

CONCLUSIONS

Olanzapine-treated adolescents with schizophrenia experienced significant symptom improvement. Significant increases in weight, triglycerides, uric acid, most liver function tests, and prolactin were observed during olanzapine treatment.Clinical trial registration information-Olanzapine Versus Placebo in the Treatment of Adolescents With Schizophrenia. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00051298.

Child and adolescent schizophrenia: pharmacological approaches

BACKGROUND

Childhood-onset schizophrenia is a serious, chronic and disabling illness that can significantly affect the quality of life of the affected individuals and their families. The affected children commonly show significant premorbid developmental impairment and social abnormalities that may provide an early clinical clue to pursue treatment. Until recent times, treatment approaches for childhood schizophrenia were derived from the adult population. However, given the unique developmental challenges in the pediatric population, this extrapolation may not hold true.

OBJECTIVE

This review encompasses and elaborates on the efficacy, safety and tolerability data available at present for both typical and atypical antipsychotics for treatment of childhood schizophrenia.

METHOD

A literature search was conducted on PUBMED with special emphasis on double-blind placebo-controlled studies in childhood schizophrenia. Data from similar studies presented in recent meetings were also added to the review.

CONCLUSIONS

Recent research in pediatric psychopharmacology has led to the Food and Drug Administration's approval of two atypical antipsychotics for the treatment of schizophrenia. Although data in this age group are still sparse, research in this unique population has grown over the years.

Public health implications of altered puberty timing

Changes in puberty timing have implications for the treatment of individual children, for the risk of later adult disease, and for chemical testing and risk assessment for the population. Children with early puberty are at a risk for accelerated skeletal maturation and short adult height, early sexual debut, potential sexual abuse, and psychosocial difficulties. Altered puberty timing is also of concern for the development of reproductive tract cancers later in life. For example, an early age of menarche is a risk factor for breast cancer. A low age at male puberty is associated with an increased risk for testicular cancer according to several, but not all, epidemiologic studies. Girls and, possibly, boys who exhibit premature adrenarche are at a higher risk for developing features of metabolic syndrome, including obesity, type 2 diabetes, and cardiovascular disease later in adulthood. Altered timing of puberty also has implications for behavioral disorders. For example, an early maturation is associated with a greater incidence of conduct and behavior disorders during adolescence. Finally, altered puberty timing is considered an adverse effect in reproductive toxicity risk assessment for chemicals. Recent US legislation has mandated improved chemical testing approaches for protecting children's health and screening for endocrine-disrupting agents, which has led to changes in the US Environmental Protection Agency's risk assessment and toxicity testing guidelines to include puberty-related assessments and to the validation of pubertal male and female rat assays for endocrine screening.

Diagnostic and sex effects on limbic volumes in early-onset bipolar disorder and schizophrenia

OBJECTIVE

The limbic structures in early-onset schizophrenia-spectrum illness (SZ) and bipolar disorder (BPD) were studied to discern patterns associated with diagnosis and sex.

METHODS

Thirty-five youths with DSM-IV BPD without psychosis, 19 with BPD with psychosis, 20 with SZ, and 29 healthy controls (HC), similar in age (6-17 years) and sex, underwent structured and clinical interviews, neurological examination, and cognitive testing. Structural magnetic resonance images (MRIs) were acquired on a 1.5 Tesla, General Electric Signa Scanner. Differences in subcortical brain volumes, including the amygdala and hippocampus, were evaluated using two-way (diagnosis, sex) univariate analyses covarying for total cerebral volume and age.

RESULTS

Youth with SZ and BPD showed no differences in amygdala and hippocampal volumes. However, boys with SZ had smallest left amygdala and girls with BPD had the smallest left hippocampal volumes. In exploratory analyses, SZ showed reduced thalamic volumes bilaterally and both BPD groups had larger right nucleus accumbens (NA) volumes relative to HC.

CONCLUSION

There were no limbic volumetric differences between BPD and SZ. However, there were diagnosis-by-sex interactions in the amygdala and hippocampus, structures that are rich in sex hormone receptors. In addition, smaller thalamus was associated with SZ while larger right NA volumes were most related to BPD. This study underscores the importance of assessing diagnostic effects and sex effects on the brain in future studies and provides evidence that boys and girls with SZ and BPD may have differential patterns of neuropathology associated with disease expression.

Pathophysiology of early onset schizophrenia

Early onset schizophrenia (with onset before adulthood) represents a rarer and possibly more severe form of the disorder which has received particular attention in the last two decades. Current evidence strongly suggest continuity with adult onset schizophrenia, with phenomenological, cognitive, genetic and neuroimaging data pointing towards similar neurobiological correlates and clinical deficits but worse long term outcome. Future research in early onset cases is likely to increase further our insight into the neurodevelopmental origins of schizophrenia and the complex gene-environment interactions affecting its emergence.

Comparative study of neurological soft signs in schizophrenia with onset in childhood, adolescence and adulthood

OBJECTIVE

To compare neurological soft signs (NSS) in patients of schizophrenia with onset in childhood (COS), adolescence (AdOS) and adulthood (AOS).

METHOD

Assessment of NSS in 15 patients of COS and 20 patients each of AdOS and AOS was made using condensed neuropsychiatric examination for NSS.

RESULTS

NSS were significantly more frequent in COS (100%) and AdOS (90%) when compared with AOS (55%) patients. COS patients showed significantly higher scores on temporal and frontal lobe NSS, of which differences between the three groups in temporal lobe NSS disappeared on ancova. Parietal lobe dependent NSS were seen in a few COS patients. The NSS were more in those with lesser IQ, lower education and higher Positive and Negative Syndrome Scale scores.

CONCLUSION

Findings indicate that earlier onset types may be more strongly associated with a generalized disruption of brain function. Non-suppression of primitive reflexes with cortical maturation in COS point towards disordered neurodevelopment. Preponderance of fronto-temporal and a relative lack of parietal lobe NSS point towards differential lobar involvement. Neurodevelopmental abnormalities leading to NSS also lead to lower IQ and lower educational level.

The schizophrenia prodrome: a developmentally informed review and update for psychopharmacologic treatment

In recent years substantial strides have been made in recognizing the prodrome for schizophrenia as a prospective entity in adolescents and young adults. Preliminary data suggest that atypical antipsychotic medications may improve symptoms and delay or prevent progression to schizophrenia, but substantial additional research is needed before the balance of long-term risks and benefits can be confidently assessed. Other medications or psychotherapies might benefit these patients as well. Some centers are beginning to examine if and how currently used prodromal diagnostic strategies and intervention studies might inform recognition and treatment of younger patients possibly prodromal for childhood-onset schizophrenia.

Practice parameter for the assessment and treatment of children and adolescents with schizophrenia. American Academy of Child and Adolescent Psychiatry

This practice parameter reviews the literature on the assessment and treatment of children and adolescents with schizophrenia. Recommendations are based on the limited research available, the adult literature, and clinical experience. Early-onset schizophrenia is diagnosed using the same criteria as in adults, and it appears to be continuous with the adult form of the disorder. Noted characteristics of youth with schizophrenia include predominance in males, high rates of premorbid abnormalities, and often poor outcome. Differential diagnosis includes psychotic mood disorders, developmental disorders, organic conditions, and nonpsychotic emotional/behavioral disorders. Treatment strategies incorporate antipsychotic medications with psychoeducational, psychotherapeutic, and social and educational support programs. The advent of atypical antipsychotic agents has enhanced the potential for effective treatment.

A review of MRI findings in schizophrenia

After more than 100 years of research, the neuropathology of schizophrenia remains unknown and this is despite the fact that both Kraepelin (1919/1971: Kraepelin, E., 1919/1971. Dementia praecox. Churchill Livingston Inc., New York) and Bleuler (1911/1950: Bleuler, E., 1911/1950. Dementia praecox or the group of schizophrenias. International Universities Press, New York), who first described 'dementia praecox' and the 'schizophrenias', were convinced that schizophrenia would ultimately be linked to an organic brain disorder. Alzheimer (1897: Alzheimer, A., 1897. Beitrage zur pathologischen anatomie der hirnrinde und zur anatomischen grundlage einiger psychosen. Monatsschrift fur Psychiarie und Neurologie. 2, 82-120) was the first to investigate the neuropathology of schizophrenia, though he went on to study more tractable brain diseases. The results of subsequent neuropathological studies were disappointing because of conflicting findings. Research interest thus waned and did not flourish again until 1976, following the pivotal computer assisted tomography (CT) finding of lateral ventricular enlargement in schizophrenia by Johnstone and colleagues. Since that time significant progress has been made in brain imaging, particularly with the advent of magnetic resonance imaging (MRI), beginning with the first MRI study of schizophrenia by Smith and coworkers in 1984 (Smith, R.C., Calderon, M., Ravichandran, G.K., et al. (1984). Nuclear magnetic resonance in schizophrenia: A preliminary study. Psychiatry Res. 12, 137-147). MR in vivo imaging of the brain now confirms brain abnormalities in schizophrenia. The 193 peer reviewed MRI studies reported in the current review span the period from 1988 to August, 2000. This 12 year period has witnessed a burgeoning of MRI studies and has led to more definitive findings of brain abnormalities in schizophrenia than any other time period in the history of schizophrenia research. Such progress in defining the neuropathology of schizophrenia is largely due to advances in in vivo MRI techniques. These advances have now led to the identification of a number of brain abnormalities in schizophrenia. Some of these abnormalities confirm earlier post-mortem findings, and most are small and subtle, rather than large, thus necessitating more advanced and accurate measurement tools. These findings include ventricular enlargement (80% of studies reviewed) and third ventricle enlargement (73% of studies reviewed). There is also preferential involvement of medial temporal lobe structures (74% of studies reviewed), which include the amygdala, hippocampus, and parahippocampal gyrus, and neocortical temporal lobe regions (superior temporal gyrus) (100% of studies reviewed). When gray and white matter of superior temporal gyrus was combined, 67% of studies reported abnormalities. There was also moderate evidence for frontal lobe abnormalities (59% of studies reviewed), particularly prefrontal gray matter and orbitofrontal regions. Similarly, there was moderate evidence for parietal lobe abnormalities (60% of studies reviewed), particularly of the inferior parietal lobule which includes both supramarginal and angular gyri. Additionally, there was strong to moderate evidence for subcortical abnormalities (i.e. cavum septi pellucidi-92% of studies reviewed, basal ganglia-68% of studies reviewed, corpus callosum-63% of studies reviewed, and thalamus-42% of studies reviewed), but more equivocal evidence for cerebellar abnormalities (31% of studies reviewed). The timing of such abnormalities has not yet been determined, although many are evident when a patient first becomes symptomatic. There is, however, also evidence that a subset of brain abnormalities may change over the course of the illness. The most parsimonious explanation is that some brain abnormalities are neurodevelopmental in origin but unfold later in development, thus setting the stage for the development of the symptoms of schizophrenia. Or there may be additional factors, such as stress or neurotoxicity, that occur during adolescence or early adulthood and are necessary for the development of schizophrenia, and may be associated with neurodegenerative changes. Importantly, as several different brain regions are involved in the neuropathology of schizophrenia, new models need to be developed and tested that explain neural circuitry abnormalities effecting brain regions not necessarily structurally proximal to each other but nonetheless functionally interrelated. (ABSTRACT TRUNCATED)

Update on childhood-onset schizophrenia

Updated findings from the ongoing National Institute of Mental Health Child Psychiatry Branch longitudinal study of childhood-onset schizophrenia (COS) are presented, along with replications from collaborators at other sites. Clinical and neurobiologic continuities of COS with poor-outcome adult-onset schizophrenia suggests that their underlying pathophysiology is the same. However, these early-onset cases appear to have more striking genetic contributions to their etiology. Updated findings involve risk factors (birth complications, cytogenic abnormalities, early language and motor problems, and familial psychopathology), treatment trials, and brain magnetic resonance imaging studies.

Relationship between sex differences in onset of schizophrenia and puberty

Some neurodevelopmental hypotheses of schizophrenia have postulated that sex differences in onset of illness could be explained by sexual dimorphism in onset of puberty, suggesting that early maturation accounts for the later onset of illness in women. The objective of this study was to analyse the relationship between age of menarche and age of onset of schizophrenia in a sample of Chilean patients. The medical records of 105 schizophrenic women diagnosed according to DSM-III-R criteria were studied. In all cases age of onset (first psychotic symptoms) and age of menarche were obtained. Pearson's correlation and student's t-test were used to analyse the data. The mean age of menarche in the sample of female patients (12. 98 years, S.D.=1.49) was significantly different from that of the general population of Santiago, Chile (12.53 years, S.D.=1.32) (t=2. 38; P<0.05). The mean age of onset of schizophrenia in female patients (19.92 years, S.D.=5.13) was significantly earlier in the Chilean sample than that reported in European and North American samples (P<0.05). No differences were observed when comparing the mean age at menarche. The subtypes with the earliest onset presented the earliest age of menarche and the subtypes with the latest onsets showed the latest ages at menarche. However, no correlation was observed between the age at onset of illness and the age at menarche, both in the total sample and in the analysis by subtype. The results of this study do not support a correlation between puberty and age of onset of illness.

Childhood-onset schizophrenia: rare but worth studying

Childhood-onset schizophrenia (defined by an onset of psychosis by age 12) is a rare and severe form of the disorder that is clinically and neurobiologically continuous with the adult-onset disorder. There is growing evidence for more salient risk or etiologic factors, particularly familial, in this possibly more homogeneous patient population. For the 49 patients with very early onset schizophrenia studied to date at the National Institute of Mental Health, there were more severe premorbid neuro-developmental abnormalities, a higher rate of cytogenetic anomalies, and a seemingly higher rate of familial schizophrenia and spectrum disorders than later onset cases. There was no evidence for increased obstetric complications or environmental stress. These data, while preliminary, suggest that a very early age of onset of schizophrenia may be secondary to greater familial vulnerability. Consequently, genetic studies of these patients may be particularly informative and may provide important etiologic information.