A former Brooklyn federal prosecutor has been missing from his Upper West Side home since Thursday, authorities said.

Richard Appleby, 66, former chief of narcotics prosecution for the Brooklyn US Attorney’s Office was last seen at his home on West 86th Street, police said.

Appleby suffers from Parkinson’s disease, which can cause dementia.

Appleby stands about 5-feet-9 and weighs about 160 pounds.

He was last seen wearing a denim shirt and black jogging pants.