μανία/mania (=combining form meaning passion, forse, mania, enthusiasm, frenzy) > μένος/menos(=life, vigor)
In Psychology mania is defined as the state of abnormally elevated or irritable mood in a period of time of seven or more days, where the mood is not causedby drugs or a medical illness.
Sourse: American Psychiatric Association's diagnostic manual.
In Greek Mythology Mania was the personification of insanity.
In Roman and Etruscan mythology Mania was the goddess of death and mother of ghosts, undead and spirits of the night.