Some psychiatric studies indicate that among distinguished artists the rates of manic depression and major depression are ten to thirteen times as prevalent as in the population at large.
Option elimination -
Take an example. Say a population of distinguished artists, 10,000 out of which 500 have manic depression and major depression. So the rate is = 5%
(A) the rates of manic depression and major depression are ten to thirteen times as prevalent as in - Does it make sense to say "the rates (5%) are ...as prevalent as in population? The disease can be more prevalent in artists than the prevalence of disease in the population at large. But the rate can't be as prevalent as the rate in the population large. The rate can be higher or lower but not prevalent. "prevalent" means widespread. The rate can't be widespread, but a disease can.
(B) the rates of manic depression and major depression are ten to thirteen times more prevalent than in - the same issue. The rates are more prevalent than the rates in...
(C) the rates of manic depression and major depression are ten to thirteen times more prevalent when compared to - "more than" is right and not "more when." Otherwise, there is a meaning issue as well.
(D) manic depression and major depression are ten to thirteen times as prevalent when compared to - "as prevalent as" and not "as prevalent when."
(E) manic depression and major depression are ten to thirteen times more prevalent than in - OK. These types of depression are more prevalent amongst distinguished artists than in the population at large.