MedWire News: Study results show patients with schizophrenia have a reduced gray matter (GM) volume early in their illness compared with healthy individuals, although this difference diminishes with age.
It is known that total brain volume and, in particular GM volume is reduced in patients with schizophrenia. However, previous studies have not included life-long follow-up, making it unclear if this reduction occurs across the lifespan or only in the early phase of the illness.
To investigate, Subrata Bose (Imperial College London, UK) and co-authors studied the effects of age on brain tissue volumes in 34 male patients with schizophrenia and 33 gender-matched healthy controls.
The researchers found that compared with controls, patients with schizophrenia had a significant reduction in total brain volume (1596 vs 1509 mm3), GM volume (822 vs 755 mm3), and white matter (WM) volume (565 vs 525 mm3).
More specifically, areas of significant regional GM volume decrease included the inferior frontal gyri bilaterally, right precentral gyrus, right insula, left orbital gyrus, and left medial frontal gyrus. Regression slope analysis of relative GM volumes showed a slower relative GM loss with age in patients compared with healthy controls.
However, the 0.67% WM loss per year (0.11% reduction per years as a proportion of the total brain volume) increased with age in schizophrenia but not in controls (0.002% increase per year).
“It remains to be determined if this is a regional or global process – future studies using diffusion tensor imaging would provide sensitivity to address this,” write the study authors in the journal Schizophrenia Research.
The authors also found an increase in cerebrospinal fluid in areas adjacent to the regional reduction of regional GM volume (sylvian fissure and infero-medial frontal regions bilaterally).
Taken together, “the study results suggest that there may be two pathologic effects – one occurring prior to illness onset, or during the early course of illness, affecting GM, and another acting later to affect WM,” say Bose et al.
“Longitudinal studies from illness onset with repeated scanning over many years will be needed to further explore the relationship between gray and white matter changes,” concludes the team.
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