The Baltimore Longitudinal Study of Aging suggests that cognitive decline in middle age follows diverse and non-linear patterns, particularly affecting memory, reasoning, and reaction time.

A non-linear pattern, potentially linked to aerosols, which are tiny particles — like dust or smoke — suspended in the atmosphere; and A cyclical pattern related to the Interdecadal Pacific ...

While a graded increase in mortality risk was observed with more CircS components, the linear trend was borderline significant (p = 0.06), and no non-linear pattern was detected.