WASHINGTON — Drugmaker Abbott Laboratories has been fined $1.6 billion for marketing its anti-seizure medication Depakote for other unauthorized uses, US authorities and the company announced Monday.

The Department of Justice said Abbott pleaded guilty and would pay a criminal fine and forfeiture of $700 million, and pay another $800 million to settle civil suits with authorities in the case.

Abbott said it also will pay states authorities another $100 million "to resolve consumer protection matters."

Abbott pleaded guilty to one charge of marketing Depakote, or valproic acid, for other health problems than its approved uses: epileptic seizures, bipolar mania and preventing migraine headaches.

The company had promoted it for use in controlling agitation and aggression in elderly dementia patients, and to treat schizophrenia. Neither use was approved by the US regulator, the Food and Drug Authority, the Justice Department said.

"Not only did Abbott engage in off-label promotion, but it targeted elderly dementia patients and downplayed the risks apparent from its own clinical studies," acting associate attorney general Tony West said in a statement.

"As this criminal and civil resolution demonstrates, those who put profits ahead of patients will pay a hefty price."

Abbott said it had already set aside funds to settle the four-year-old case.

Abbott shares were up 0.5 percent to $62.69 in early afternoon trade.