Kathleen McKenna

An Open Trial of Clozapine in 11 Adolescents with Childhood-Onset Schizophrenia

OBJECTIVE To review the response of 11 adolescents with childhood-onset schizophrenia to a 6-week open clozapine trial. METHOD Eleven children meeting DSM-III-R criteria for schizophrenia had a 6-week open trial of clozapine (mean sixth week daily dose 370 mg). Behavioral ratings included the Brief Psychiatric Rating Scale and Childrens Global Assessment Scale. RESULTS More than half showed marked improvement in Brief Psychiatric Rating Scale ratings by 6 weeks of clozapine therapy compared to admission drug rating and compared to a systematic 6-week trial of haloperidol. CONCLUSIONS This open trial indicates that clozapine may be a promising treatment for children and adolescents with schizophrenia who do not respond well to typical neuroleptics. A double-blind placebo-controlled study is ongoing.

Neuropsychological deficits in pediatric patients with childhood-onset schizophrenia and psychotic disorder not otherwise specified

OBJECTIVE Children with transient psychotic symptoms and serious emotional disturbances who do not meet current criteria for schizophrenia or other presently recognized diagnostic categories commonly present diagnostic and treatment problems. Clarifying the connections between children with narrowly defined schizophrenia and children with a more broadly defined phenotype (i.e., Psychotic Disorder Not Otherwise Specified, PD-NOS) has implications for understanding the pathophysiology of schizophrenia. In this study, the neuropsychological test performance of a subgroup of children with atypical psychosis was compared with that of patients with childhood-onset schizophrenia (COS). METHOD Cognitive function was assessed with neuropsychological test battery regimens in 51 neuroleptic-nonresponsive patients within the first 270 at NIMH testing (24 PD-NOS, 27 COS) were included in this analysis. Seventeen (39%) of 44 COS subjects were unavailable for this study as their IQ tested <70. The PD-NOS patients were younger than the COS patients at the time of testing (12.0+/-2.8 vs 14.4+/-1.8years, respectively, p<0.004). The test levels of these groups were compared with each other. RESULTS The neuropsychological test results for the PD-NOS and COS patients were 1-2standard deviations below normative data across a broad array of cognitive functions. There were no overall differences in the test levels for the six summary scales (F=2.82, df=1, 36, p=0.10) or in the profile shape (F=1.70, df=5, 180, p=0.14) between the PD-NOS and COS groups. For the COS patients, there was a significant difference between their mean full-scale WISC IQ (84.7+/-16.2) and their average standard scores for both the spelling (97.7+/-16.1, n=23, t=4.0, p=0.001) and reading decoding subtests (97.7+/-13.7, n=23, t=3.7, p=0.001) of the Kaufman Test of Educational Achievement. CONCLUSIONS Treatment-refractory PD-NOS and COS patients share a similar pattern of generalized cognitive deficits, including deficits in attention, learning and abstraction which are commonly observed in adult patients with schizophrenia. These data support a hypothesis that at least some of the PD-NOS cases belong within the schizophrenic spectrum, which is of importance for future genetic studies planned for this cohort.

Smooth pursuit eye movements in childhood-onset schizophrenia: Comparison with attention-deficit hyperactivity disorder and normal controls

Abnormalities of the smooth pursuit eye movements of adults with schizophrenia have been well described. We examined smooth pursuit eye movements in schizophrenic children, contrasting them with normal and attention-deficit hyperactivity disorder (ADHD) subjects, to determine whether there is continuity of eye movement dysfunction between childhood- and adult-onset forms of schizophrenia. Seventeen schizophrenic children with onset of illness by age 12, 18 ADHD children, and 22 normal children were studied while engaged in a smooth pursuit eye tracking task. Eye tracking variables were compared across the three groups. Schizophrenic children exhibited significantly greater smooth pursuit impairments than either normal or ADHD subjects. Within the schizophrenic group, there were no significant relationships between eye tracking variables and clinical variables, or ventricular/brain ratio. Childhood-onset schizophrenia is associated with a similar pattern of smooth pursuit abnormalities to that seen in later-onset schizophrenia.

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.

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.

Childhood-onset schizophrenia: The severity of premorbid course

OBJECTIVE To review the premorbid histories of 23 children meeting DSM-III-R criteria for schizophrenia with onset before age 12 years and to compare these with childhood data of later-onset schizophrenics. METHOD Premorbid features up to 1 year before onset of first psychotic symptoms were rated from hospital and clinic records, clinical interviews, rating scales, and tests. RESULTS In keeping with previous studies, specific developmental disabilities and transient early symptoms of autism, particularly motor stereotypies, were common. Comparison with the childhood of later-onset schizophrenics showed greater delay in language development, and more premorbid speech and language disorders, learning disorders, and disruptive behavior disorders. (Sixty percent had received or were estimated to meet criteria for one or more clinical diagnoses.) CONCLUSIONS Childhood-onset schizophrenia may represent a more malignant form of the disorder, although selection and ascertainment bias cannot be ruled out. The presence of prepsychotic language difficulties focuses attention on the importance of early temporal and frontal lobe development; early transient motor stereotypies suggest developmental basal ganglia abnormalities and extend previous findings seen in the childhood of later-onset patients.