If I want to determine the difference between two correlated measurements (i.e., pre-post scores), is a one-sample t-test on the difference scores compared to 0 an identical test to a paired sample t-test?
Yes. We can test this easily enough in R or whatever you like e.g. (R code):
set.seed(123) x1 <- rnorm(100) x2 <- rnorm(100) diff <- x1-x2 t.test(x1,x2, paired = TRUE) t.test(diff)
but it also follows from the definition of a paired t-test.