A new international study has determined that parts of the cerebral cortex develop differently in people with schizophrenia.
The discovery stems from an assessment of brain development during childhood and adolescence in people with and without schizophrenia.
Schizophrenia is generally considered to be a disorder of brain development; it shares many risk factors, both genetic and environmental, with other neurodevelopmental disorders such as autism and intellectual disability.
The normal path for brain development is determined by the combined effects of a complex network of genes and a wide range of environmental factors. Determining the path of schizophrenia is difficult even with advanced brain imaging studies.
In the current study, researchers reviewed both healthy and patient populations in order to map the disturbances in brain structures as they emerge, i.e., the disturbed trajectories of brain development.
With access to new statistical approaches and long-term follow-up with participants, in some cases over more than a decade, the researchers were able to describe brain development patterns associated with schizophrenia.
“Specifically, this paper shows that parts of the brain’s cortex develop differently in people with schizophrenia,” said first author Aaron F. Alexander-Bloch, Ph.D., a neuroscientist with the National Institute of Mental Health. The cortex is the outermost layer of neural tissue in the brain.
“The mapping of the path that the brain follows in deviating from normal development provides important clues to the underlying causes of the disorder,” said Dr. John Krystal, editor of Biological Psychiatry.
The findings were derived by investigating the trajectory of cortical thickness growth curves in 106 patients with childhood-onset schizophrenia and a comparison group of 102 healthy volunteers.
Each participant, ranging from seven years of age, had repeated imaging scans over the course of several years. Then, using over 80,000 vertices across the cortex, the researchers modeled the effect of schizophrenia on the growth curve of cortical thickness.
This revealed differences that occur within a specific group of highly-connected brain regions that mature in synchrony during typical development, but follow altered trajectories of growth in schizophrenia.
“These findings show a relationship between the hypothesis that schizophrenia is a neurodevelopmental disorder and the longstanding hypothesis — first articulated by the German anatomist Karl Wernicke in the late 19th century — that it is a disease of altered connectivity between regions of the brain,” added Alexander-Bloch.