Complex sentence: Nixon helmed the writing team for over a decade, until 1983, and again introduced many social issues into storylines, including the Vietnam War, the anti-war movement, homosexuality, the AIDS epidemic, and American television's first onscreen abortion.
Split into simpler sentences: Nixon helmed the writing team for over a decade, until 1983. She again introduced many social issues into storylines, including the Vietnam War, the anti-war movement, homosexuality, the AIDS epidemic, and American television's first onscreen abortion.