It is more than that, he clearly has a version of schizophrenia and maybe DID syndrome with Mr. Robot being a personality in his head that takes control of his body. He isn't always aware that Mr. Robot takes control. That one time in the cafe Mr. Robot showed that he could control Elliot's body and mess with one of the guys to get punched out. What Eliot sees isn't always reality.

There are also those three days Elliot lost that Mr. Robot took over to do the Evil Corp hack.