Psychiatric diagnostic dilemmas among people with intellectual and developmental disabilities.

BACKGROUND: Research regarding the accuracy of co-morbid psychiatric diagnoses in individuals with intellectual and developmental disabilities (IDD) is sparse. Yet correct diagnostic assignment is vital so that effective and appropriate treatment can be implemented, especially for the large numbers of individuals requiring expensive and restrictive behavioural health crisis services. METHOD: A retrospective review of de-identified data from multidisciplinary specialty team assessments completed for 50 individuals with ID (IntellectualDisability) with and without ASD and unresolved behavioural health challenges was conducted. The accuracy and reliability of the psychiatric diagnoses upon referral were compared with the diagnoses after the comprehensive team evaluation, and within-individual diagnostic agreement was calculated. The agreement between the Mood and Anxiety Semi-Structured interview tool (MASS) and the full team evaluation was also calculated. The influence of demographic and clinical characteristics on diagnostic agreement was explored. RESULTS: The most common chief complaints upon referral were aggression to others and self-injurious behaviour. Individuals were taking a median of six medications (interquartile range: 5 to 7); 80% were taking an antipsychotic medication. The most common medical conditions were constipation (70%) and gastroesophageal reflux disease (52%). Measures of interrater reliability of the referral diagnoses with the team assessment were below 0.5 (kappa range: -0.04 to 0.39), with the exception of ruling out dementia (kappa = 0.85). The interrater reliability estimates for the MASS evaluations for depression and anxiety were higher (kappa = 0.69 and 0.64) and reflected higher sensitivity and PPV. The odds of any referral diagnosis being confirmed by team evaluation were low: 0.25 (range: 0 to 0.67). The level of diagnostic agreement for each patient was not significantly attributable to demographic or clinical characteristics, although effect sizes indicate a possible positive relationship to age and the number of prescribed psychotropic medications at referral. CONCLUSION: Individuals in the current study had serious psychiatric and behavioural problems despite psychiatric care in their communities. The majority of psychiatric diagnoses provided upon referral were not supported by the multidisciplinary specialty team's assessment. In addition to possible diagnostic inaccuracy, the group in the study suffered from multiple medical co-morbidities and were exposed to polypharmacy. Results emphasise the importance of multidisciplinary evaluation by clinicians with expertise in neurodevelopmental disabilities when people with ID with and without ASD have complex behavioural health needs that are unresponsive to usual care. In addition, based on agreement with the full team evaluation, the MASS shows promise as an assessment tool, especially with regards to identifying anxiety and depression.

Prenatal tobacco smoke exposure and neurological impairment at 10 years of age among children born extremely preterm: a prospective cohort.

OBJECTIVE: To determine the association between prenatal tobacco smoke exposure and neurological impairment at 10 years of age among children born extremely preterm (<28 weeks of gestation). DESIGN: The Extremely Low Gestational Age Newborn (ELGAN) Study, a prospective cohort. SETTING: Ten-year follow-up of extremely preterm infants born at 14 US hospitals between 2002 and 2004. METHODS: Prenatal tobacco smoke exposure was defined as a mother's report at enrolment of active (i.e. maternal) and passive smoking during pregnancy. Poisson regression with generalized estimating equations was used. Models adjusted for mother's age, race/ethnicity, education, insurance, pre-pregnancy body mass index, US region, multiple gestation and infant's sex; and in sensitivity analysis, gestational age at delivery and clinical subtype of preterm birth, given their classification as intermediate and non-confounding variables. MAIN OUTCOMES: Neurological impairment at 10 years, epilepsy, cerebral palsy and cognitive impairment. RESULTS: Of 1200 ELGAN study survivors, 856 were assessed at 10 years of age with neurological outcomes, of whom 14% (118/856) had active tobacco exposure during pregnancy and 24% (207/852) had passive tobacco exposure. Compared with children who were not exposed prenatally to tobacco, children exposed to active tobacco use during pregnancy had a higher risk of epilepsy (14% versus 5%; adjusted relative risk: 1.68, 95% CI 1.45-1.92). This risk remained after adjustment for gestational age at delivery and clinical subtype of preterm birth. Prenatal tobacco smoke exposure was not associated with other assessed neurological outcomes, including cerebral palsy and multiple measures of cognitive impairment. CONCLUSIONS: Among children born extremely preterm, prenatal active tobacco smoke exposure was associated with an increased risk of epilepsy at 10 years of life. TWEETABLE ABSTRACT: Among infants born before 28 weeks of gestation, prenatal active tobacco smoke exposure was associated with an increased risk of epilepsy at 10 years of life.

Enhanced local processing of dynamic visual information in autism: evidence from speed discrimination.

An important issue for understanding visual perception in autism concerns whether individuals with this neurodevelopmental disorder possess an advantage in processing local visual information, and if so, what is the nature of this advantage. Perception of movement speed is a visual process that relies on computation of local spatiotemporal signals but requires the comparison of information from more than a single spatial location or temporal point. This study examined speed discrimination in adolescents (ages 13-18 years old) with autism spectrum disorders (ASD). Compared to healthy controls (n=17), individuals with ASD (n=19) showed similarly precise speed discrimination when two comparison motion stimuli (random dot patterns) were presented closely in time (0.5s). With a longer temporal interval (3s) between the motion stimuli, individuals with ASD outperformed healthy controls on speed discrimination. On a second task--global motion perception--in which individuals were asked to detect coherent motion, individuals with ASD exhibited slightly degraded performance levels. The observed temporally selective enhancement in speed discrimination indicates that a local processing advantage in autism develops over a longer temporal range and is not limited to the spatial domain. These results suggest a dynamic perceptual mechanism for understanding, and therapeutically addressing, atypical visual processing in this neurodevelopmental disorder.

A prospective open-label treatment trial of olanzapine monotherapy in children and adolescents with bipolar disorder.

OBJECTIVE: The goal of this study was to assess the effectiveness and tolerability of olanzapine in the treatment of acute mania in children and adolescents. METHODS: This was an 8-week, open-label, prospective study of olanzapine monotherapy (dose range 2.5-20 mg/day) involving 23 bipolar youths (manic, mixed, or hypomanic; 5-14 years old). Weekly assessments were made using the Young Mania Rating Scale (YMRS), Clinical Global Impressions Severity Scale (CGI-S), Brief Psychiatric Rating Scale, and Children's Depression Rating Scale. Adverse events were assessed through self-reports, vital sign and weight monitoring, laboratory analytes, and extrapyramidal symptom rating scales (Barnes Akathisia Scale, Simpson-Angus Scale, and Abnormal Involuntary Movement Scale). RESULTS: Twenty-two of the 23 youths (96%) completed the study. Olanzapine treatment was associated with significant improvement in mean YMRS score (-19.0 +/- 9.2, p < 0.001). Using predefined criteria for improvement of > or = 30% decline in the YMRS and a CGI-S Mania score of < or = 3 at endpoint, the overall response rate was 61%. Overall, olanzapine was well tolerated, and extrapyramidal symptom measures were not significantly different from baseline. Body weight increased significantly over the study (5.0 +/- 2.3 kg, p < 0.001). CONCLUSIONS: Open-label olanzapine treatment was efficacious and well tolerated in the treatment of acute mania in youths with bipolar disorder. Future placebo-controlled, double-blind studies are warranted.

Abnormal neurologic maturation in adolescents with early-onset schizophrenia.

OBJECTIVE: This study evaluated neurologic functioning in adolescents with schizophrenia with onset of psychosis before age 13. METHOD: The authors administered a structured neurologic examination to 21 adolescents with early-onset schizophrenia and 27 healthy age- and sex-matched comparison subjects. RESULTS: The adolescents with schizophrenia had a high frequency of neurologic abnormalities. Neurologic signs decreased with age in the healthy comparison subjects but not in the subjects with schizophrenia. CONCLUSIONS: The adolescents with schizophrenia had a high burden of neurologic impairment and a pattern of abnormalities similar to that of adults with schizophrenia. The persistence of neurologic signs in the adolescents with schizophrenia, which faded with age in the healthy comparison adolescents, supports earlier evidence of a delay in or failure of normal brain development during adolescence.

Distinguishing illness severity from tic severity in children and adolescents with Tourette's disorder.

OBJECTIVE: To examine whether tic severity, comorbid disorders, or both are associated with illness morbidity in youths with Tourette's disorder (TD). METHOD: Subjects were 156 consecutively referred youths (aged 5-20 years) who met DSM-III-R criteria for Tourette's disorder at a major academic medical center. All subjects were evaluated with a clinical interview by a child and adolescent psychiatrist and an assessment battery that included the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Epidemiologic version. Statistical analysis used chi 2 and multivariate logistic regression. RESULTS: Nineteen (12%) of the 156 youths with TD required psychiatric hospitalization. Current age, TD severity, TD duration, obsessive-compulsive disorder, psychosis, major depression, bipolar disorder, panic disorder, and overanxious disorder were significant univariate predictors of psychiatric hospitalization (p < .01). While tic severity was marginally significant as a predictor of psychiatric hospitalization (p < .05), major depression (p < .016) and bipolar disorder (p < .001) were robust predictors of psychiatric hospitalization, even after statistical adjustment for collinearity and correction for all other variables assessed. CONCLUSION: The findings indicate that comorbid mood disorders are strongly associated with illness morbidity in youths with TD, highlighting the importance of attention to comorbidity in patients with TD.

Risperidone treatment for juvenile bipolar disorder: a retrospective chart review.

OBJECTIVE: To investigate the effectiveness and tolerability of the atypical neuroleptic risperidone in the treatment of juvenile mania. METHOD: This is a retrospective chart review of outpatients with the diagnosis of bipolar disorder (DSM-IV) treated with risperidone at a university center. Response to treatment was evaluated using the Clinical Global Impression Scale (CGI) with separate assessments of mania, psychosis, aggression, and attention-deficit/hyperactivity disorder (ADHD). RESULTS: Twenty-eight youths (mean +/- SD age, 10.4 +/- 3.8 years) with bipolar disorder (25 mixed and 3 hypomanic) who had been treated with risperidone were identified. These children received a mean dose of 1.7 +/- 1.3 mg over an average period of 6.1 +/- 8.5 months. Using a CGI Improvement score of < or = 2 (very much/much improved) to define robust improvement, 82% showed improvement in both their manic and aggressive symptoms, 69% in psychotic symptoms, but only 8% in ADHD symptoms. CONCLUSIONS: Although limited by its retrospective nature, this study suggests that risperidone may be effective in the treatment of manic young people and indicates the need for controlled clinical trials of risperidone and other atypical neuroleptics in juvenile mania.

Anterior cingulate cortex dysfunction in attention-deficit/hyperactivity disorder revealed by fMRI and the Counting Stroop.

BACKGROUND: The anterior cingulate cognitive division (ACcd) plays a central role in attentional processing by: 1) modulating stimulus selection (i.e., focusing attention) and/or 2) mediating response selection. We hypothesized that ACcd dysfunction might therefore contribute to producing core features of attention-deficit/hyperactivity disorder (ADHD), namely inattention and impulsivity. ADHD subjects have indeed shown performance deficits on the Color Stroop, an attentional/cognitive interference task known to recruit the ACcd. Recently, the Counting Stroop, a Stroop-variant specialized for functional magnetic resonance imaging (fMRI), produced ACcd activation in healthy adults. In the present fMRI study, the Counting Stroop was used to examine the functional integrity of the ACcd in ADHD. METHODS: Sixteen unmedicated adults from two groups (8 with ADHD and 8 matched control subjects) performed the Counting Stroop during fMRI. RESULTS: While both groups showed an interference effect, the ADHD group, in contrast to control subjects, failed to activate the ACcd during the Counting Stroop. Direct comparisons showed ACcd activity was significantly higher in the control group. ADHD subjects did activate a frontostriatal-insular network, indicating ACcd hypoactivity was not caused by globally poor neuronal responsiveness. CONCLUSIONS: The data support a hypothesized dysfunction of the ACcd in ADHD.

Polymerization of purified yeast septins: evidence that organized filament arrays may not be required for septin function.

The septins are a family of proteins required for cytokinesis in a number of eukaryotic cell types. In budding yeast, these proteins are thought to be the structural components of a filament system present at the mother-bud neck, called the neck filaments. In this study, we report the isolation of a protein complex containing the yeast septins Cdc3p, Cdc10p, Cdc11p, and Cdc12p that is capable of forming long filaments in vitro. To investigate the relationship between these filaments and the neck filaments, we purified septin complexes from cells deleted for CDC10 or CDC11. These complexes were not capable of the polymerization exhibited by wild-type preparations, and analysis of the neck region by electron microscopy revealed that the cdc10Delta and cdc11Delta cells did not contain detectable neck filaments. These results strengthen the hypothesis that the septins are the major structural components of the neck filaments. Surprisingly, we found that septin dependent processes like cytokinesis and the localization of Bud4p to the neck still occurred in cdc10Delta cells. This suggests that the septins may be able to function in the absence of normal polymerization and the formation of a higher order filament structure.

The influence of extended-year schooling on growth of achievement and perceived competence in early elementary school.

The influence of additional school days on academic and psychosocial skills was examined through comparison of an extended-year program (210 days) with a traditional program (180 days). Kindergartners matched on background characteristics and magnet school attendance received tests of mathematics, reading, general knowledge, vocabulary, and perceived competence at the beginning (Fall K) and end (Spring K) of the traditional kindergarten year and at the beginning of the next traditional year (Fall 1). Although groups performed equivalently at Fall K, extended-year students outperformed traditional students at Fall 1 in mathematics, reading, and general knowledge and had higher levels of cognitive competence. Mathematics and reading achievement differences at Fall 1 were not associated with differences in the quality or intensity of educational efforts made during the traditional school year (i.e., Fall K to Spring K) or to differences between teachers in the traditional and extended-year programs. Results indicated that providing students with additional instruction time by lengthening the school year could be a promising educational reform.

Childhood-onset schizophrenia: an open-label study of olanzapine in adolescents.

OBJECTIVE: Olanzapine, a potent 5-HT2a/2c, dopamine D1D2D4 antagonist with anticholinergic activity, has a profile of known receptor affinity similar to that of clozapine. This pilot study examined the efficacy of olanzapine for treatment-refractory childhood-onset schizophrenia in eight patients who had received 8-week open-label trials. For comparison, data are included from 15 patients who had received 6-week open-label clozapine trials using identical rating instruments (largely by the same raters) in the same treatment setting. METHOD: Twenty-three children and adolescents with an onset of DSM-III-R schizophrenia by age 12 for whom at least two different typical neuroleptics had been ineffective participated in the two separate studies. Some of the patients were intolerant of clozapine, although it had been effective (n = 4). Patients receiving olanzapine were evaluated over 8 weeks with the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Positive Symptoms, the Scale for the Assessment of Negative Symptoms, and the Clinical Global Impressions Scale for Improvement. RESULTS: For the eight patients who received olanzapine trials, at week 8 there was a 17% improvement in the BPRS total score, a 27% improvement in the Scale for the Assessment of Negative Symptoms, and a 1% improvement in the Scale for the Assessment of Positive Symptoms, relative to "ideal" admission status on typical neuroleptics. In contrast, the magnitude of the effect sizes for each of the clinical ratings was larger at week 6 of the previous clozapine trial than for an 8-week olanzapine trial, relative to admission status on typical neuroleptics. For the four children who had received both clozapine and olanzapine, BPRS total scores were significantly lower at week 6 of clozapine treatment compared with week 6 of olanzapine treatment (p = .03). CONCLUSION: These data provide preliminary evidence for the efficacy of olanzapine for some children and adolescents with treatment-refractory schizophrenia, but they also suggest the need for a more rigorous double-blind comparison of these two atypical antipsychotics.

Attention deficits in childhood-onset schizophrenia: reaction time studies.

The hypothesis of continuity between childhood-onset and adult schizophrenia was tested by comparing the performance of 15 patients with childhood-onset schizophrenia and 52 age-matched controls on 2 reaction time paradigms that have been used to study adult schizophrenia. On simple reaction time to tones with regular and irregular preparatory intervals of 2, 4, and 8 s, patients showed greater effects of the length of the preparatory interval in the regular condition and greater effects of the preparatory interval (girls only) and the preceding preparatory interval in the irregular series. On simple reaction time to random lights and tones, patients were faster on ipsimodal sequences than cross-modal sequences compared with controls. Overall, patients were much slower than controls in both paradigms. The results suggest similar attention dysfunction as is found in adult schizophrenia and thus are consistent with the continuity hypothesis.

"Multidimensionally impaired disorder": is it a variant of very early-onset schizophrenia?

OBJECTIVE: To examine the validity of diagnostic criteria for a subgroup of children with atypical psychosis (n = 19), designated here as "multidimensionally impaired." These children are characterized by poor attention and impulse control, psychotic symptoms, and poor affective control. METHOD: Children and adolescents (n = 19) meeting our criteria for multidimensionally impaired syndrome with onset of psychotic symptoms at or before age 12 years were identified from a total of 150 in-person screenings for very early-onset schizophrenia between 1990 and 1996. We compared the premorbid adjustment, family history, follow-up status, and laboratory measures for a subgroup of these children with those of (1) a rigorously defined group of 29 children with DSM-III-R schizophrenia and (2) 19 children with attention-deficit hyperactivity disorder. RESULTS: Patients with multidimensionally impaired syndrome and patients with very early-onset schizophrenia shared a similar pattern of early transient autistic features, postpsychotic cognitive decline, and an elevated risk of schizophrenic-spectrum disorders among their first-degree relatives. This pattern was not seen in the attention-deficit hyperactivity disorder group. In contrast to very early-onset schizophrenia, the multidimensionally impaired group had significantly poorer scores on the Freedom From Distractibility factor on the WISC-R, a less deviant pattern of autonomic reactivity, and no progression to schizophrenia. CONCLUSIONS: The findings support the distinction of the multidimensionally impaired cases as separate from those with other psychiatric disorders, and there is somewhat greater evidence to suggest that this disorder belongs in the schizophrenia spectrum.

Autonomic nervous system markers of psychopathology in childhood-onset schizophrenia.

BACKGROUND: Consistent abnormalities in peripheral indicators of autonomic activity, ie, skin conductance (SC) and heart rate (HR), have been reported in adult-onset schizophrenia. Herein, we use these markers to test the hypothesis of continuity between childhood-onset schizophrenia and adult-onset schizophrenia. METHODS: Skin conductance and HR were recorded from 21 severely ill children and adolescents (mean age, 14.1 years) with childhood-onset (< or = 12 years) schizophrenia (patient group) and from 54 age-matched controls (control group) during a rest period, a series of innocuous tones, reaction time instructions, and a simple warned reaction time task. RESULTS: During rest, patients had higher rates of spontaneous SC responses (SCRs) and HRs than controls, but their SC level was marginally lower and declined more slowly over time. Half of the patients, compared with 4% of the controls, failed to give SC-orienting responses to the first 2 tones. Patients who responded had impaired SCR magnitudes, and their habituation was more erratic than that of controls. The increase in SC level and SCR frequency at the onset of the task period was greatly attenuated in the patients, so that both variables were higher in controls. Patients had smaller SCRs and anticipatory HR responses to the reaction time stimuli. Skin conductance nonresponding was associated with negative and total symptoms, and spontaneous SCR frequency was associated with positive symptoms. CONCLUSIONS: The findings show similar abnormalities in autonomic nervous system activity in childhood-onset schizophrenia to those found in adult chronic schizophrenia, thus supporting the hypothesis of continuity of the childhood and adult forms of the illness. Comparisons with data from other childhood disorders suggest that the combination of low-elicited SC activity with high levels of spontaneous SC activity may be specific to schizophrenia.

Actin cytoskeleton: are FH proteins local organizers?

The FH proteins, defined by the presence of 'formin homology' regions, are important for a number of actin-dependent processes, including polarized cell growth and cytokinesis. They are large, probably multi-domain, proteins and their function may be in part mediated by an interaction with profilin.

Pubertal development and onset of psychosis in childhood onset schizophrenia.

In this study, pubertal development was examined for a sample of children and adolescents with childhood onset schizophrenia (COS) defined as psychosis by age 12. Developmental and psychiatric histories were obtained for 28 adolescents (mean age 14.5 +/- 2.3 years) with severe, treatment refractory COS (14 males, 14 females). Age of onset of psychosis was also examined in relation to menarche and development of secondary sex characteristics. Girls had a trend towards developing secondary sex characteristics earlier than boys (P = 0.06), consistent with North American norms. Males (N = 14) and females (N = 14) had similar age of onset of psychosis. The age of development of secondary sex characteristics was associated with onset of psychosis for girls, but this finding was driven by one outlier. There was no significant correlation between development of psychosis and menarche. Neither male nor female probands differed significantly from their well siblings or from North American norms in their age of onset of pubertal development. There was no evidence of early onset of secondary sex characteristics for this sample. Finally, there was an absence of a clear relationship between onset of psychosis and indices of sexual development for these very early onset cases.

Quantitative magnetic resonance imaging of the corpus callosum in childhood onset schizophrenia.

Corpus callosum size has been found to be abnormal in adult schizophrenia, and other studies have implicated abnormal interhemispheric communication in this disorder. To assess continuity with brain abnormalities in the later onset disorder and to further localize brain maldevelopment, this structure was examined in a unique sample of childhood onset schizophrenics. Anatomic brain magnetic resonance imaging scans were acquired for 25 patients (mean age 13.9 +/- 2.1) who had onset of schizophrenia by age 12 (mean age at onset 9.9 +/- 1.9) and 55 normal children. The midsagittal area of the corpus callosum was divided into seven sections. With no adjustment for brain volume, no diagnostic differences were observed. After adjustment for the smaller cerebral volume of the schizophrenics, larger total, anterior and posterior corpus callosum areas emerged for the schizophrenics. These findings provide further evidence for continuity between childhood onset and later onset schizophrenia and support other studies showing white matter sparing in the context of decreased cortical volume.

Childhood-onset schizophrenia: biological markers in relation to clinical characteristics.

OBJECTIVE: The purpose of this study was to examine the relationships between clinical and neurobiological measures of childhood-onset schizophrenia. It was hypothesized that there would be a more striking pattern in the rare cases with very early onset than is seen in subjects with later onset. METHOD: Premorbid, clinical, prenatal, perinatal, and magnetic resonance imaging brain measures were examined in 29 children and adolescents who met the DSM-III-R criteria for schizophrenia with onset before age 12. Specifically, gender, premorbid adjustment, and clinical symptoms were examined in relation to cerebral volume, ventricular volume, and maternal obstetrical complications. RESULTS: Males were more likely to have had an insidious onset than females. There was a significant negative correlation between score on the Scale for the Assessment of Negative Symptoms and total cerebral volume. CONCLUSIONS: These neurobiological associations support the continuity of early-onset schizophrenia with the later-onset disorder; the striking association between smaller cerebral volume and negative symptoms suggests a more homogeneous or more potent neurobiological basis for very early-onset schizophrenia.

Cerebrospinal fluid monoamine metabolites in childhood-onset schizophrenia.

OBJECTIVE: Pediatric studies of cerebrospinal fluid (CSF) monoamine metabolites in childhood-onset schizophrenia may help to elucidate both pathophysiology and treatment response in early-onset psychosis. METHOD: CSF homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) and serum prolactin were measured during drug-free and antipsychotic medication conditions in 18 patients (mean age = 14.2 years, SD = 1.7) who had onset of schizophrenia by age 12 (mean age at onset = 9.9 years, SD = 1.8). Relationships between changes in CSF monoamines and serum prolactin and clinical outcome were examined, and the degree of change in CSF monoamines in response to clozapine treatment was compared with that for 16 patients with later-onset schizophrenia. RESULTS: Despite patients' significant clinical improvement with treatment, CSF monoamine concentrations and ratios of HVA/5-HIAA and HVA/MHPG did not significantly change with 6 weeks of either haloperidol or clozapine treatment. Serum prolactin levels increased during haloperidol treatment. Clozapine had similar effects on CSF monoamines in patients with childhood- and later-onset schizophrenia. CONCLUSIONS: While these data are compatible with continuity between childhood- and later-onset schizophrenia, they also highlight the complexity of the biochemical events mediating clinical changes in schizophrenia.

Cerebral glucose metabolism in childhood onset schizophrenia.

Decreased frontal cortical glucose metabolism has been demonstrated in adult schizophrenics both at rest and while engaging in tasks that normally increase frontal metabolism, such as the Continuous Performance Test (CPT). The authors tested the hypothesis that adolescents with childhood onset schizophrenia would also demonstrate hypofrontality while performing the CPT. Cerebral glucose metabolism was examined in 16 adolescents (mean age 14.1 +/- 1.7) with onset of schizophrenia by age 12 (mean age at onset 9.9 +/- 1.8) and 26 healthy adolescents selected to be similar in age, sex and handedness using positron emission tomography and 18F-fluorodeoxyglucose. Patients with childhood onset schizophrenia made fewer correct and more incorrect identifications on the CPT. Region of interest analysis revealed no significant group differences in global cerebral glucose metabolism, but increased metabolic rate in supramarginal gyrus (F = 6.74, P < 0.05) and inferior frontal gyrus/insula (F = 7.09, P < 0.05) and decreased metabolic rate in middle frontal gyrus (F = 6.72, P < 0.05) and superior frontal gyrus (t = 2.04, P < 0.05) in schizophrenics. Comparison of effect sizes with an identically designed study of adult schizophrenics did not indicate more severe hypofrontality in childhood onset schizophrenia. Pixel-based analyses indicated a more complex pattern of group differences in cerebral metabolism with bilaterally increased cerebellar metabolic rate in childhood onset schizophrenics. These findings suggest that childhood onset schizophrenia may be associated with a similar, but not more severe, degree of hypofrontality relative to that seen in adult onset schizophrenia.