Dissociation of neurocognitive deficits in a monozygotic twin pair concordant for schizophrenia.

Cognitive impairment varies markedly among schizophrenic individuals, although the reason for this is unknown. A monozygotic twin pair concordant for schizophrenia was evaluated using electrophysiological and neurobehavioral measures. Each twin showed a distinctive pattern of deficits; furthermore, clinical course and electrophysiological activity were not consonant with social and neurobehavioral functioning. Results suggest complex interrelationships between neurocognitive functioning and clinical presentation in schizophrenia.