This is somewhat old news, but I just discovered for myself that patients in an Armenian mental institution were forced to vote for the ruling Republican party during the parliamentarian elections earlier in 2007.  Source: 168 Hours

According to Lragir.am the patients of the psychic institution of salt mine were made to vote for the 15th number of the proportional ballot, that is the Republican Party.

The citizen who provided this information is one of the relatives of the patients. The patient called him and said that the ballot-box was brought in, however the patients were not allowed to vote on their own and cast ballots in the boxes.

The nurse threatened the patients to give a shot if they vote on their own. Only after the alert call the patient, who made noise was allowed to vote alone.

But 15 others were made to vote for the 15th number in the ballot. After the alert several other patients were able to vote on their own.