Dysbindin (DTNBP1, 6p22.3) is associated with childhood-onset psychosis and endophenotypes measured by the Premorbid Adjustment Scale (PAS).

Straub et al. (2002) recently identified the 6p22.3 gene dysbindin (DTNBP1) through positional cloning as a schizophrenia susceptibility gene. We studied a rare cohort of 102 children with onset of psychosis before age 13. Standardized ratings of early development, medication response, neuropsychological and cognitive performance, premorbid dysfunction and clinical follow-up were obtained. Fourteen SNPs were genotyped in the gene DTNBP1. Family-based pairwise and haplotype transmission disequilibrium test (TDT) analysis with the clinical phenotype, and quantitative transmission disequilibrium test (QTDT) explored endophenotype relationships. One SNP was associated with diagnosis (TDT p=.01). The QTDT analyses showed several significant relationships. Four adjacent SNPs were associated (p values=.0009-.003) with poor premorbid functioning. These findings support the hypothesis that this and other schizophrenia susceptibility genes contribute to early neurodevelopmental impairment.

GAD1 (2q31.1), which encodes glutamic acid decarboxylase (GAD67), is associated with childhood-onset schizophrenia and cortical gray matter volume loss.

Postmortem brain studies have shown deficits in the cortical gamma-aminobutyric acid (GABA) system in schizophrenic individuals. Expression studies have shown a decrease in the major GABA-synthesizing enzyme (glutamic acid decarboxylase (GAD67) mRNA levels in neurons in dorsolateral prefrontal cortex in schizophrenics relative to controls. In the present study, SNPs in and around the GAD1 gene, which encodes the protein GAD67, were tested on a rare, severely ill group of children and adolescents with childhood-onset schizophrenia (COS) (n=72), in a family-based association analysis. Compared to adult-onset samples, the COS sample has evidence for more salient familial, and perhaps genetic, risk factors for schizophrenia, as well as evidence for frontal cortical hypofunction, and greater decline in cortical gray matter volume on anatomic brain MRI scans during adolescence. We performed family-based TDT and haplotype association analyses of the clinical phenotype, as well as association analyses with endophenotypes using the QTDT program. Three adjacent SNPs in the 5' upstream region of GAD1 showed a positive pairwise association with illness in these families (P=0.022-0.057). Significant transmission distortion of 4-SNP haplotypes was also observed (P=0.003-0.008). Quantitative trait TDT analyses showed an intriguing association between several SNPs and increased rate of frontal gray matter loss. These observations, when taken together with the positive results reported recently in two independent adult-onset schizophrenia pedigree samples, suggest that the gene encoding GAD67 may be a common risk factor for schizophrenia.

Differentiating childhood-onset schizophrenia from psychotic mood disorders.

OBJECTIVE: The authors systematically examined a sample of patients who were referred to an ongoing National Institute of Mental Health (NIMH) study of childhood-onset schizophrenia (COS), but who received diagnoses of mood disorders at the NIMH, to analyze the reliability of these research-setting diagnoses and to characterize the patients clinically. Pilot data regarding the clinical course of these patients over a 2- to 7-year follow-up period were also obtained. METHOD: Thirty-three cases were selected from the 215 pediatric patients who had been screened in person from 1991 to 1999 for admission to the COS study. These 33 patients had been excluded from the COS study on the basis of a day-long evaluation, including a structured diagnostic interview, which yielded a diagnosis of a mood disorder rather than schizophrenia. This subgroup, together with six COS subjects (for a total N= 39), were included in a diagnostic reliability study in which they were reevaluated by three psychiatrists who were blind to the initial research diagnosis. In addition, pilot follow-up data regarding current function and treatment status were obtained for 25 of the 33 patients with mood disorders. RESULTS: Overall, the interrater reliability of the three raters was excellent (kappa = 0.90). Global reliability between these raters and the NIMH research diagnoses was good (average kappa across diagnoses = 0.61), and agreement for those patients who had mood disorders was good (86% agreement; kappa = 0.60). Pilot follow-up data indicate that none of the subjects with a diagnosed mood disorder developed a clinical course resembling schizophrenia. CONCLUSIONS: Many of the patients referred to the NIMH COS study with clinical diagnoses of schizophrenia had psychotic mood disorders diagnosed on the basis of a comprehensive research evaluation including structured diagnostic interviews, and these research diagnoses were reliable. The diagnosis of COS is difficult and requires a time-consuming evaluation process.

Smooth pursuit eye-tracking impairment in childhood-onset psychotic disorders.

OBJECTIVE: Although childhood-onset schizophrenia is relatively rare, a sizable group of children with severe emotional disturbances have transient psychotic symptoms that fall outside of current syndrome boundaries. The relationship of this group of children to those with childhood-onset schizophrenia and other childhood psychiatric disorders is unclear. In this study, the authors compared smooth pursuit eye tracking, a biological trait marker associated with schizophrenia, of children and adolescents with psychotic disorder not otherwise specified to that of children with childhood-onset schizophrenia and healthy comparison subjects. METHOD: By means of infrared oculography, smooth pursuit eye movements during a 17 degrees /second visual pursuit task were quantitatively and qualitatively compared in 55 young adolescents (29 with childhood-onset schizophrenia and 26 with psychotic disorder not otherwise specified) and their respective independent healthy comparison groups (a total of 38 healthy subjects). RESULTS: Subjects with childhood-onset schizophrenia had qualitatively poorer eye tracking, higher root mean square error, lower gain, and a greater frequency of catch-up saccades than healthy children. Subjects with psychotic disorder not otherwise specified also had qualitatively poorer eye tracking, higher root mean square error, and lower gain than healthy children, but saccade frequency did not differ significantly. CONCLUSIONS: Children with childhood-onset schizophrenia exhibit a pattern of eye-tracking dysfunction similar to that reported for adult patients. Similar abnormalities were seen in the subjects with psychotic disorder not otherwise specified except that they did not exhibit a greater frequency of catch-up saccades. Prospective longitudinal neurobiological and clinical follow-up studies of both groups are currently underway to further validate the distinction between these two disorders. Also, family studies are planned to establish whether eye-tracking dysfunction represents a trait- or state-related phenomenon in subjects with psychotic disorder not otherwise specified.

Children and adolescents with psychotic disorder not otherwise specified: a 2- to 8-year follow-up study.

Although psychotic phenomena in children with disruptive behavior disorders are more common than expected, their prognostic significance is unknown. To examine the outcome of pediatric patients with atypical psychoses, a group of 26 patients with transient psychotic symptoms were evaluated with clinical and structured interviews at the time of initial contact (mean age, 11.6 +/- 2.7 years) and at follow-up 2 to 8 years later. Measures of functioning and psychopathology were also completed at their initial assessment. Risk factors associated with adult psychotic disorders (familial psychopathology, eyetracking dysfunction in patients and their relatives, obstetrical complications, and premorbid developmental course in the proband) had been obtained at study entry. On follow-up examination (mean age, 15.7 +/- 3.4 years), 13 patients (50%) met diagnostic criteria for a major axis I disorder: three for schizoaffective disorder, four for bipolar disorder, and six for major depressive disorder. The remaining 13 patients again received a diagnosis of psychotic disorder not otherwise specified (NOS), with most being in remission from their psychotic symptoms. Among this group who had not developed a mood or psychotic disorder, disruptive behavior disorders were exceedingly common at follow-up and were the focus of their treatment. Higher initial levels of psychopathology, lower cognitive abilities, and more developmental motor abnormalities were found in patients with a poor outcome. Obstetrical, educational, and family histories did not differ significantly between the groups. Through systematic diagnostic evaluation, children and adolescents with atypical psychotic disorders can be distinguished from those with schizophrenia, a difference with important treatment and prognostic implications. Further research is needed to delineate the course and outcome of childhood-onset atypical psychoses, but preliminary data indicate improvement in psychotic symptoms in the majority of patients and the development of chronic mood disorders in a substantial subgroup.

Childhood-onset schizophrenia/autistic disorder and t(1;7) reciprocal translocation: identification of a BAC contig spanning the translocation breakpoint at 7q21.

Childhood-onset schizophrenia (COS) is defined by the development of first psychotic symptoms by age 12. While recruiting patients with COS refractory to conventional treatments for a trial of atypical antipsychotic drugs, we discovered a unique case who has a familial t(1;7)(p22;q21) reciprocal translocation and onset of psychosis at age 9. The patient also has symptoms of autistic disorder, which are usually transient before the first psychotic episode among 40-50% of the childhood schizophrenics but has persisted in him even after the remission of psychosis. Cosegregating with the translocation, among the carriers in the family available for the study, are other significant psychopathologies, including alcohol/drug abuse, severe impulsivity, and paranoid personality and language delay. This case may provide a model for understanding the genetic basis of schizophrenia or autism. Here we report the progress toward characterization of genomic organization across the translocation breakpoint at 7q21. The polymorphic markers, D7S630/D7S492 and D7S2410/D7S646, immediately flanking the breakpoint, may be useful for further confirming the genetic linkage for schizophrenia or autism in this region. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:749-753, 2000. Published 2000 Wiley-Liss, Inc.

An open trial of plasma exchange in childhood-onset obsessive-compulsive disorder without poststreptococcal exacerbations.

Patients with childhood-onset obsessive-compulsive disorder (OCD) with symptom exacerbations following streptococcal infections benefit from treatment with plasma exchange. In this study, 5 patients with treatment-refractory OCD without a history of streptococcus-related exacerbations underwent an open 2-week course of therapeutic plasma exchange. Behavioral ratings, completed at baseline and 4 weeks after the initial treatment, included the Clinical Global Impressions Scale and the Yale-Brown Obsessive Compulsive Scale. All 5 patients completed the trial with few side effects, but none showed significant improvement. Plasma exchange does not benefit children and adolescents with OCD who do not have streptococcus-related exacerbations.

Childhood-onset psychotic disorders: magnetic resonance imaging of volumetric differences in brain structure.

OBJECTIVE: Although childhood-onset schizophrenia is rare, children with brief psychotic symptoms and prominent emotional disturbances commonly present diagnostic and treatment problems. Quantitative anatomic brain magnetic resonance images (MRIs) of a subgroup of children with psychotic disorder not otherwise specified were compared with those of children with childhood-onset schizophrenia and healthy comparison subjects. METHOD: Anatomic MRIs were obtained for 71 patients (44 with childhood-onset schizophrenia and 27 with psychotic disorder not otherwise specified) and 106 healthy volunteers. Most patients had been treated with neuroleptics. Volumetric measurements for the cerebrum, anterior frontal region, lateral ventricles, corpus callosum, caudate, putamen, globus pallidus, and midsagittal thalamic area were obtained. RESULTS: Patients had a smaller total cerebral volume than healthy comparison subjects. Analysis of covariance for total cerebral volume and age found that lateral ventricles were larger in both patient groups than in healthy comparison subjects and that schizophrenia patients had a smaller midsagittal thalamic area than both subjects with psychotic disorder not otherwise specified and healthy comparison subjects. CONCLUSIONS: Pediatric patients with psychotic disorder not otherwise specified showed a pattern of brain volumes similar to those found in childhood-onset schizophrenia. Neither group showed a decrease in volumes of temporal lobe structures. Prospective longitudinal magnetic resonance imaging and clinical follow-up studies of both groups are currently underway to further validate the distinction between these two disorders.

Premorbid speech and language impairments in childhood-onset schizophrenia: association with risk factors.

OBJECTIVE: As both premorbid neurodevelopmental impairments and familial risk factors for schizophrenia are prominent in childhood-onset cases (with onset of psychosis by age 12), their relationship was examined. METHOD: Premorbid language, motor, and social impairments were assessed in a cohort of 49 patients with childhood-onset schizophrenia. Familial loading for schizophrenia spectrum disorders, familial eye-tracking dysfunction, and obstetrical complications were assessed without knowledge of premorbid abnormalities and were compared in the patients with and without developmental impairments. RESULTS: Over one-half of the patients in this group had developmental dysfunction in each domain assessed. The patients with premorbid speech and language impairments had higher familial loading scores for schizophrenia spectrum disorders and more obstetrical complications, and their relatives had worse smooth-pursuit eye movements. The boys had more premorbid motor abnormalities, but early language and social impairments did not differ significantly between genders. There were no other significant relationships between premorbid social or motor abnormalities and the risk factors assessed here. CONCLUSIONS: Premorbid developmental impairments are common in childhood-onset schizophrenia. The rates of three risk factors for schizophrenia (familial loading for schizophrenia spectrum disorders, familial eye-tracking dysfunction, and obstetrical complications) were increased for the probands with premorbid speech and language impairments, suggesting that the pathophysiology of schizophrenia involves the abnormal development of language-related brain regions.

Lessons from childhood-onset schizophrenia.

Childhood-onset schizophrenia (with an onset of psychosis by age 12) is a rare and severe form of the disorder which is clinically and neurobiologically continuous with the adult-onset disorder. Very early onset diseases provide an opportunity to look for more salient or striking risk or etiologic factors in a possibly more homogenous patient population. For the 47 patients with very early onset schizophrenia studied to date, there were more severe premorbid neurodevelopmental abnormalities, more cytogenetic anomalies, and potentially greater family histories of schizophrenia and associated spectrum disorders than later onset cases. There was no evidence for relatively increased obstetrical complications or environmental stress. These data, while preliminary, suggest a very early age of onset of schizophrenia may be secondary to greater genetic vulnerability. It is anticipated that future genetic studies of these patients may provide important etiologic information.

Velocardiofacial syndrome in childhood-onset schizophrenia.

OBJECTIVES: Deletion of chromosome 22q11 (velocardiofacial syndrome) is associated with early neurodevelopmental abnormalities and with schizophrenia in adults. The rate of 22q11 deletions was examined in a series of patients with childhood-onset schizophrenia (COS), in whom early premorbid developmental and cognitive impairments are more pronounced than in adult-onset cases. METHOD: Through extensive recruiting and screening, a cohort of 47 patients was enrolled in a comprehensive study of very-early-onset schizophrenia. All were tested with fluorescence in situ hybridization for deletions on chromosome 22q11. RESULTS: Three (6.4%) of 47 patients were found to have a 22q11 deletion. All 3 COS patients with 22q11 deletions had premorbid impairments of language, motor, and social development, although their physical characteristics varied. Brain magnetic resonance imaging revealed increased midbody corpus callosum area and ventricular volume in relation both to healthy controls and to other COS patients. CONCLUSIONS: The rate of 22q11 deletions in COS is higher than in the general population (0.025%, p < .001) and may be higher than reported for adult-onset schizophrenia (2.0%, p = .09). These results suggest that 22q11 deletions may be associated with an earlier age of onset of schizophrenia, possibly mediated by a more salient neurodevelopmental disruption.

Childhood-onset schizophrenia: progressive brain changes during adolescence.

BACKGROUND: Previous NIMH childhood onset schizophrenia (COS) anatomic brain MRI studies found progression of ventricular volume and other structural brain anomalies at 2-year follow up across mean ages 14 to 16 years. However, studies in adult patients generally do not show progression of ventricular volume or correlation of ventricular volume with duration of illness. To address issues of progression of brain anomalies in schizophrenia, this report extends previous studies to include a third longitudinal scan, uses a larger sample size, and includes measures of the amygdala and hippocampus. METHODS: Volumes of the total cerebrum, lateral ventricles, hippocampus, and amygdala were quantified on 208 brain magnetic resonance imaging scans from 42 adolescents with COS (23 with one or more repeat scan) and 74 age- and gender-matched controls (36 with one or more repeat scan). A statistical technique permitting combined use of cross-sectional and longitudinal data was used to assess age-related changes, linearity, and diagnostic group differences. RESULTS: Differential nonlinear progression of brain anomalies was seen during adolescence with the total cerebrum and hippocampus decreasing and lateral ventricles increasing in the COS group. The developmental curves for these structures reached an asymptote by early adulthood for the COS group and did not significantly change with age in the control group. CONCLUSIONS: These findings reconcile less striking progression of anatomic brain images usually seen for adult schizophrenia and complement other data consistent with time-limited, diagnostic-specific decreases in brain tissue. Adolescence appears to be a unique period of differential brain development in schizophrenia.

Clinical and neurobiological correlates of cytogenetic abnormalities in childhood-onset schizophrenia.

OBJECTIVE: Cytogenetic abnormalities are increased in schizophrenia, suggesting a possible etiologic contribution. However, their clinical and pathophysiologic roles in the disorder are unknown. To investigate this, a group of children and adolescents participating in a comprehensive study of childhood-onset schizophrenia were screened for chromosomal abnormalities, and their clinical and neurobiological correlates were examined. METHOD: Cytogenetic screening with the use of high-resolution banding, fluorescent in situ hybridization for chromosome 22q11 deletions, and molecular fragile X testing was undertaken in a group of 47 children and adolescents with very early onset of schizophrenia. Clinical, neurobiological (including brain morphometry), and risk factor measures of the subjects with cytogenetic abnormalities were compared with those of the remaining patients without cytogenetic anomalies. RESULTS: Five patients had previously undiagnosed cytogenetic abnormalities. Lower performance IQ and more pronounced premorbid developmental impairments were seen in this subgroup. Rates of obstetric complications, familial schizophrenia spectrum disorders, and familial eye tracking dysfunction were similar for the patients with and without cytogenetic abnormalities. CONCLUSIONS: Cytogenetic abnormalities appear to be increased in childhood-onset schizophrenia, suggesting an association with a very early age at onset. The data from the subgroup of patients with cytogenetic anomalies are consistent with a model in which a childhood onset of schizophrenia is due to a greater impairment of neurodevelopment secondary to the interaction of a number of factors, particularly genetic ones.

Obstetrical complications and childhood-onset schizophrenia.

OBJECTIVE: Increased obstetrical complications have been reported in individuals with adult-onset schizophrenia, with several studies finding an association between such complications and an earlier age at onset. Consequently, obstetrical records were examined for individuals with childhood-onset schizophrenia to determine if birth complications were more prevalent. METHOD: The birth records of 36 patients with childhood-onset schizophrenia and 35 sibling comparison subjects were rated for birth complications by two psychiatrists who were unaware of group membership. RESULTS: There were no significant differences between the groups in rates of obstetrical complications. Patients with such complications did not have a relatively earlier age at onset of schizophrenia. CONCLUSIONS: A very early age at onset of schizophrenia is probably not due to birth complications.

Including children and adolescents with schizophrenia in medication-free research.

OBJECTIVE: There has been an increasing focus on the ethical issues raised by studies requiring the withdrawal of effective medication in schizophrenic adults. This article examines the risks and benefits of a medication-free period for pediatric patients with treatment-refractory schizophrenia who are participating in an ongoing study. METHOD: Between April 1993 and March 1998, 31 children and adolescents were admitted with a diagnosis of treatment-resistant, childhood-onset schizophrenia. Parental consent was obtained so that patients could participate in a medication-free research period. Patients were evaluated at screening, at the end of a 4-week washout, at the completion of a 6- to 8-week atypical neuroleptic trial, and at a 2- to 4-year follow-up. RESULTS: At the completion of a 4-week drug-free period, seven patients (23%) were diagnosed with another disorder on the basis of data gained from the drug-free period and their lack of schizophrenic symptoms. Their revised diagnoses were posttraumatic stress disorder (N = 1), an atypical psychosis labeled "multidimensionally impaired" (N = 4), and personality disorder (N = 2). At follow-up, three of these patients remained free of neuroleptic therapy. For eight patients (26%), the washout was curtailed because of rapid and severe deterioration of their schizophrenic symptoms. CONCLUSIONS: For children and adolescents with treatment-refractory schizophrenia, a medication-free period can be conducted safely for at least 4 weeks for inpatients. Such trials are useful on clinical grounds and for providing homogeneous patient groups for research. This study also highlights the necessity of having access to hospitalization to observe children and adolescents with psychotic symptoms while medication free.

Progressive cortical change during adolescence in childhood-onset schizophrenia. A longitudinal magnetic resonance imaging study.

BACKGROUND: Adolescence provides a window to examine regional and disease-specific late abnormal brain development in schizophrenia. Because previous data showed progressive brain ventricular enlargement for a group of adolescents with childhood-onset schizophrenia at 2-year follow-up, with no significant changes for healthy controls, we hypothesized that there would be a progressive decrease in volume in other brain tissue in these patients during adolescence. METHODS: To examine cortical change, we used anatomical brain magnetic resonance imaging scans for 15 patients with childhood-onset schizophrenia (defined as onset of psychosis by age 12 years) and 34 temporally yoked, healthy adolescents at a mean (SD) age of 13.17 (2.73) years at initial baseline scan and 17.46 (2.96) years at follow-up scan. Cortical gray and white matter volumes were obtained with an automated analysis system that classifies brain tissue into gray matter, white matter, and cerebrospinal fluid and separates the cortex into anatomically defined lobar regions. RESULTS: A significant decrease in cortical gray matter volume was seen for healthy controls in the frontal (2.6%) and parietal (4.1%) regions. For the childhood-onset schizophrenia group, there was a decrease in volume in these regions (10.9% and 8.5%, respectively) as well as a 7% decrease in volume in the temporal gray matter. Thus, the childhood-onset schizophrenia group showed a distinctive disease-specific pattern (multivariate analysis of variance for change X region X diagnosis: F, 3.68; P = .004), with the frontal and temporal regions showing the greatest between-group differences. Changes in white matter volume did not differ significantly between the 2 groups. CONCLUSIONS: Patients with very early-onset schizophrenia had both a 4-fold greater decrease in cortical gray matter volume during adolescence and a disease-specific pattern of change. Etiologic models for these patients' illness, which seem clinically and neurobiologically continuous with later-onset schizophrenia, must take into account both early and late disruptions of brain development.