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Brain loss in schizophrenia reflects accelerated brain aging

Progressive brain loss in schizophrenia reflects accelerated aging of the brain and potentially individual variation and medication use, according to recent findings.

“Cross-sectional MRI studies have convincingly shown that brain volumes in schizophrenia patients are smaller than those in healthy subjects. Some of these abnormalities, such as changes in white matter volume and structure, are present before illness onset and are most likely of a developmental, possibly genetic, nature and appear to be stable over time,” Hugo G. Schnack, PhD, of Brain Center Rudolf Magnus, University Medical Centre Utrecht, the Netherlands, and colleagues wrote. “Although several studies suggest that gray matter volume reductions are related to outcome, psychosis, relapses, medication, cannabis use and genetic liability, the cause and nature of the progressive loss of gray matter are still unclear.”

To assess associations between progressive brain loss in schizophrenia and aging of the brain, researchers evaluated 341 individuals with schizophrenia and 386 healthy controls. MRI scans and machine learning algorithms predicted brain age and the presence of schizophrenia, based on gray matter density maps. Baseline age ranged from 16 to 67 years.

Brain age was significantly greater than chronological age at baseline (+ 3.36 years) among individuals with schizophrenia, and progressively increased during follow-up by an additional 1.24 years.

Acceleration in brain aging was not constant, decreasing from 2.5 years per year shortly after illness onset to a normal rate of 1 year per year approximately 5 years after illness onset.

“Our data suggest that the widely reported progressive gray matter loss in schizophrenia reflects in part an accelerated aging of the brain that is quantitatively, but not qualitatively, different from that observed in healthy aging. While we also find brain abnormalities that are qualitatively different from those observed in healthy subjects, their evolution over time is highly variable. Thus, the progressive brain loss in schizophrenia appears to reflect two different processes: one relatively homogeneous, reflecting accelerated aging of the brain and related to outcome, the other more variable and specific, possibly reflecting individual variation related to the illness and to medication use,” the researchers wrote. “Differentiating between these two processes may not only elucidate the various factors influencing brain loss in schizophrenia, but also assist in individualizing treatment.” – by Amanda Oldt

Disclosure: Schnack reports no relevant financial disclosures. Please see the full study for a list of all authors’ relevant financial disclosures.