Some of the core cognitive problems that affect people with schizophrenia, such as reduced information processing speed and impaired working memory, are associated with alterations in the brain’s connective “white matter” tissues, according to a study published September 2017 in JAMA Psychiatry.

The research team, led by 2016 Distinguished Investigator Grantee Elliot Hong, M.D., of the University of Maryland School of Medicine, concluded that these white matter impairments are found specifically in tracts of the brain that control the speed of information processing. They also suggest that the link between white matter impairment and deficits in working memory in people with schizophrenia are related to white matter’s effect on processing speed. Working memory refers to the ability to keep information “in mind” over short periods in order to accomplish immediate tasks.

The study tested processing speed and working memory, and calibrated these results with sophisticated imaging of the microstructures found in white matter in 166 patients with schizophrenia and 213 healthy individuals.

The patients had significantly slower information processing speed and problems with working memory, as well as significant white matter abnormalities, compared to the healthy participants. The abnormal white matter regions observed in the brains of those with schizophrenia were those regions with strong connections to information processing speed.

Dr. Hong, with University of Maryland School of Medicine first author Peter Kochunov, Ph.D., and their colleagues conclude that the impairments in white matter that affect processing speed are not caused by antipsychotic medications or the wear and tear of the chronic disease, but may underlie these cognitive deficits from the start of an individual’s schizophrenia.

“Our hope is that these findings may elevate research interest in white matter–directed pharmacological interventions to enhance cognition for patients with schizophrenia,” they write.

Other grantees who contributed to this research include two Scientific Council members: Patricio O'Donnell, M.D., Ph.D., a 2010 Distinguished Investigator, 2003 and 2001 Independent Investigator, and 1995 Young Investigator; and Laura M. Rowland,  Ph.D. , a 2017 Independent Investigator and 2006 Young Investigator; as well as Joshua J. Chiappelli, M.D., a 2014 Young Investigator.