Neurologic signs and symptom dimensions in children of schizophrenics

Abstract

The relationship between neurological functioning and the positive and negative symptom dimensions of positive formal thought disorder, poverty of speech, and affective flattening was assessed longitudinally in the children of schizophrenic, affectively disordered, and normal control adults. Two measures of childhood neurological functioning and ratings of childhood, early adolescent, and adolescent positive and negative symptom dimensions were all conducted by examiner's who were blind to the children's group membership.;The major finding from the series of correlational analyses and multiple linear regressions that were conducted between each of the two childhood neurologic measures and each of the three symptom dimensions that was longitudinally assessed was that childhood neurologic dysfunction was significantly related to the presence of affective flattening by adolescence, and this relationship was specific to the offspring of schizophrenics. In contrast, multiple linear regression revealed that childhood neurological measures did not contribute to the presence of positive thought disorder that was found during adolescence for the offspring of affectively disordered adults. Childhood intellectual functioning was found to be significantly associated with childhood neurological functioning and adolescent affective flattening for the offspring of schizophrenic and affectively disordered adults, but not for the normal control children. No significant relationships were found between childhood neurologic or intellectual functioning and poverty of speech by adolescence for any of the groups.;These results are interpreted to suggest that neurologic and intellectual factors are overlapping domains of functioning that may reflect liability factors to the development of psychiatric disorders in children at genetic risk for psychopathology and that disturbances in thinking and affect reflect at least partially independent symptom dimensions in the developmental course of psychopathology. An integral association between neurologic impairment and affective flattening is suggested, and it is proposed that neurologic deficits precede and underlie the presence of sub-clinical levels of affective flattening in the offspring of schizophrenics. It is further suggested that neurologic and affective deficits may configurally reflect a biological marker of schizophrenic psychopathology and/or that they may be a phenotypic expression of the underlying schizophrenic genotype in the first degree relatives of schizophrenics.