Variation in fourteen brain structure volumes in schizophrenia: A comprehensive meta-analysis of 246 studies

Area of Science:

• Neuroimaging
• Psychiatry
• Radiology

Background:

• Structural MRI studies consistently show reduced average brain volumes in schizophrenia.
• Group differences in brain volume variability remain under-explored in schizophrenia research.
• Understanding variability may clarify schizophrenia heterogeneity and pathophysiology.

Purpose of the Study:

• To meta-analyze brain volume variability across multiple structures in schizophrenia.
• To compare variability in intracranial, total brain, ventricular, gray matter, and specific regional volumes between schizophrenia patients and controls.
• To investigate if variability differences contribute to understanding schizophrenia.

Main Methods:

• Meta-analysis of 246 MRI studies focusing on brain volume variability.
• Inclusion of 13 brain structures with medium to large mean effect sizes (Cohen's d≥0.4).
• Comparison of variability in intracranial volume, total brain volume, lateral ventricles, third ventricle, total gray matter, frontal gray matter, prefrontal gray matter, temporal gray matter, superior temporal gyrus gray matter, planum temporale, hippocampus, fusiform gyrus, insula, and caudate nucleus.

Main Results:

• No significant differences in variability were found for cortical and subcortical gray matter volumes.
• Increased variability in intracranial volume was observed in schizophrenia.
• Significantly increased variability was detected in lateral and third ventricle volumes in schizophrenia patients compared to controls.

Conclusions:

• Schizophrenia is characterized by increased variability in ventricular and intracranial volumes, not cortical/subcortical structures.
• These findings emphasize the importance of analyzing brain volume distributions, particularly ventricles, in schizophrenia.
• Further research into brain volume variability is crucial for elucidating schizophrenia pathophysiology and heterogeneity.