He has suffered from poor health, however, and has been transferred to hospital several times. His recent applications for bail on the basis of his health have been denied.
Amnesty International said the sentence was "absolutely outrageous" .
"This sentence demonstrates the authorities' ruthless determination to crush all forms of dissent and leaves no room for doubt about the extreme lengths to which they are willing to go to in order to silence peaceful critics," regional director Heba Morayef said.
The rights group also pointed to similar pending charges against the activist.
He has been charged in connection with an open letter published in the New York Times, and over an Instagram post featuring an image of Bahrain's king with an excerpt from the Koran, Amnesty said.