Estas loco/loca? 'Are you crazy?' I was often called that because I was not willing to conform to our social norms. The words loco/loca were used to put people down.
People used their index finder to make a gesture around their ear. This meant whomever they were referring to was mentally ill. This gesture was also used to put people down. While I was growing up in Puerto Rico mentally ill people were looked down upon.