Robert Royko, 45, could have been sentenced to more than five years. The minimum under federal sentencing guidelines was more than four years, but U.S. District Judge Wayne R. Andersen said there was reason to be lenient.
Andersen said pharmaceutical drugs Royko had been taking in large quantities to cope with emotional problems contributed to the bizarre April 2005 incident in which Royko entered a bank with a ski mask and a fake bomb and demanded money.
A police officer knocked the fake bomb out of Royko's hand and arrested him.
He pleaded guilty to the crime last March.
Andersen said bank robbery is a serious crime but expressed doubt that Royko would have tried to rob the bank if not for the pharmaceutical drugs that were prescribed by a doctor to help Royko deal with an emotional problem.
"People ought to go to jail for a meaningful period if they rob a bank," Andersen said.
Royko said he was taking 600 pills a month at the time of his arrest.
Since his arrest, Royko has spent a total of nine months in federal custody. That amount will be subtracted from the 30-month sentence. With time off for good behavior he must serve 85 percent of the remaining 21 months on the term.
Royko said he has has made progress in dealing with the emotional problem but still needs treatment.
His father, a Pulitzer Prize-winning columnist who worked for three Chicago newspapers, died in 1997.