Patterns of Regional Cerebral Blood Flow as a Function of Age Throughout the Lifespan

Background: Understanding the influence of aging on the brain remains a challenge in determining its role as a risk factor for Alzheimer's disease. Objective: To identify patterns of aging in a large neuroimaging cohort. Methods: A large psychiatric cohort of 31,227 individuals received brain SPECT at rest and during a concentration task for a total of 62,454 scans. ANOVA was done to identify the mean age trends over the course of the age range in this group, 0-105 years. A regression model in which brain SPECT regions of interest was used to predict chronological age (CA) was then utilized to derive brain estimated age (BEA). The difference between CA and BEA was calculated to determine increased brain aging in common disorders in our sample such as depression, dementia, substance use, and anxiety. Results: Throughout the lifespan, variations in perfusion were observed in childhood, adolescence, and late life. Increased brain aging was seen in alcohol use, cannabis use, anxiety, bipolar, schizophrenia, attention-deficit/hyperactivity disorder, and in men. Conclusion: Brain SPECT can predict chronological age and this feature varies as a function of common psychiatric disorders.