Complex sentence: Most Soviet citizens had no power to change the existing system, therefore, most of them tried to make the best of a bad situation; rates of alcoholism, mental illness, divorce and suicide rose inexorably during the Brezhnev era.
Split into simpler sentences: Most Soviet citizens had no power to change the existing system, so most of them tried to make the best of a bad situation. Rates of alcoholism, mental illness, divorce and suicide rose inexorably during the Brezhnev era.