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 p resently recognized diagnostic categories commonly present diagnostic and t reatment problems. Clarifying the connections between children with narrowl y 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 atypica l psychosis was compared with that of patients with childhood-onset schizop hrenia (COS). Method: Cognitive function was assessed with neuropsychologic al test battery regimens in 51 neuroleptic-nonresponsive patients within th e first 2 weeks after admission while receiving stable medication. Only tho se patients who had an IQ > 70 at NIMH testing (24 PD-NOS, 27 COS) were inc luded 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 t han the COS patients at the time of testing (12.0 +/- 2.8 vs 14.4 +/- 1.8 y ears, respectively, p < 0.004). The test levels of these groups were compar ed with each other. Results: The neuropsychological test results for the PD -NOS and COS patients were 1-2 standard deviations below normative data acr oss 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 differ ence between their mean full-scale WISC IQ (84.7 +/- 16.2) and their averag e 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: Treatm ent-refractory PD-NOS and COS patients share a similar pattern of generaliz ed cognitive deficits, including deficits in attention, learning and abstra ction which are commonly observed in adult patients with schizophrenia. The se data support a hypothesis that at: least some of the PD-NOS cases belong within the schizophrenic spectrum, which is of importance for future genet ic studies planned for this cohort. (C) 2000 Elsevier Science B.V. All righ ts reserved.