<psychiatry> A delusion of self-depreciation, or that one's own body is of minute size. ... Origin: micro-+ G. Mania, frenzy ... (05 Mar 2000) ... 
micromania 1. A form of mania in which the patient thinks him/herself, or some bodily part, to be reduced in size; an insane habit of belittling oneself. 2. A delusion that one's own body is of minute size.
[video game retailer] Micromania is a major video game retail company in France. In 2008 it was purchased by GameStop for approximately US$700 million (€480 million) in cash. ...
self-deprecation
pathological self-deprecation or belief that one is very small