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11-03-2014 | Mental health | Article

Researchers unite psychosis theories


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medwireNews: A marker of neurodevelopment predicts decline in cognitive function in patients with schizophrenia, say researchers.

The team reports that the age at which infants first learned to stand without support was associated with abstraction with memory in adult life.

“These findings suggest that neurodevelopmental and neurodegenerative processes in schizophrenia may be mechanistically related,” write Graham Murray (University of Cambridge, UK) and co-workers in Schizophrenia Bulletin.

The 36 schizophrenia patients in the study, who were drawn from the Northern Finland 1966 Birth Cohort, learned to stand unaided at an average age of 11.2 months, compared with 10.3 months in 76 mentally healthy controls. The team previously found this measure to be a “sensitive predictor of adolescent or adult cognitive, academic, and psychiatric outcomes.”

All study participants underwent cognitive assessment at the age of 33 years and again 9 years later, during which time verbal learning, visual learning and abstraction (without memory) remained stable or declined by a similar amount, in line with normal ageing, in schizophrenia patients and controls.

By contrast, abstraction with memory, assessed with the Abstraction, Inhibition, and Working Memory task, declined by an average of 2.2 points in patients, compared with a 0.8-point improvement in controls, and this difference was independent of educational level.

Among 27 of the schizophrenia patients with a known age at which they first stood unaided, there was a significant correlation between this measure and change in abstraction with memory, with older age associated with a larger deterioration. The association persisted after accounting for gender, use of antipsychotic medication, level of function and level of education, and was not present in the control group.

Murray et al therefore say that this finding “argues for the relevance of neurodevelopmental processes in changes that occur much later in life.”

They believe that, rather than neurodevelopmental dysfunction contributing to some aspects of schizophrenia, while neurodegeneration accounts for other changes, their findings “suggest that developmental and degenerative aspects of schizophrenia may be 2 manifestations of a common underlying process.”

medwireNews ( is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2014

By Eleanor McDermid, Senior medwireNews Reporter