LOUISVILLE, Ky.—The Presbyterian Church (U.S.A.) suffered its worst annual membership decline in decades last year.

The Louisville-based denomination reported 2.2 million active and confirmed members in 2007, a loss of 57,572 members and a 2.5 percent decrease from 2006. It’s the denomination’s largest membership loss in terms of numbers since 1981 and the steepest percentage loss since 1974, when it fell 2.7 percent.

The church has steadily been losing members since peaking at 4.25 million in the mid-1960s.

Opinions differ about the cause for the decline, including controversies over homosexuality, low birth rates, an aging white population and a societal move away from institutions in general. Some congregations also have left for a more conservative Presbyterian denomination.