Period of emotional turmoil in one’s forties (7,6)
(Other definitions for midlife crisis that I've seen before include "(Male?) menopause" , "Loss of confidence in one's 40s or 50s, perhaps?" , "Period of panic (when one may not exactly act one's age!)" , "An ageing concern?" , "Period of panic experienced by persons of a certain age" .)
(Other definitions for mid-life crisis that I've seen before include "Loss of confidence in one's 40s or 50s, perhaps?" , "(Male?) menopause" , "An ageing concern?" , "Loss of confidence with age" , "In which someone might lose self-confidence" .)