We analyzed serial prolactin findings (Figure 1, plotting unadjusted means and SEs) using a 2-way repeated-measures analysis of covariance (RANCOVA), with covariates for contraceptive and seasonal effects. The RANCOVA yielded a significant time × contraceptive interaction (F8,400 = 2.83, P<.01), indicative of earlier "peaking" in contraceptive users, which remained significant after Greenhouse-Geisser correction (F2,77 = 2.83, P<.05). Examination of resulting curves and proportions of contraceptive users across groups indicated that the interaction could not have confounded group and time effects of main interest. There was no main effect of contraceptives or main or interaction effects implicating season of testing. A main effect of time of sampling (F8,400 = 5.17, P<.005), showing expected stimulation of prolactin after m-CPP administration, remained significant after Greenhouse-Geisser correction (F2.77,138.63 = 5.17, P<.005). More important, after removal of covariates, a significant group × time interaction effect was obtained (F24,400 = 2.10, P<.005), which remained after Greenhouse-Geisser correction (F8.32,138.63 = 2.10, P<.04). Simple effects of group were indicated at 180 (F3,50 = 4.50, P<.01) and 210 (F3,50 = 3.52, P<.025), and, as a trend, at 240 minutes (F3,50 = 2.74, P<.055). The pattern of results on covariate-adjusted pairwise comparisons, conducted with and without Bonferroni corrections (Figure 1), indicates "blunted" prolactin response in both bulimic and abused participants. An adjunctive analysis, conducted using 1-way ANCOVA (with covariates controlling for seasonal effects) testing group differences on an index of change (Δ-peak) on prolactin (ie, peak minus baseline at each time point for each subject), indicated no seasonal effects, but a significant overall group effect (F3,55 = 3.15, P<.04). Covariate-adjusted contrasts showed mean Δ-peak prolactin for bulimic women (5.62 ± 3.95), abused bulimic women (7.26 ± 7.06), and abused women who were normal eaters (5.73 ± 5.19) to always be lower than the score obtained in the group of nonabused women who were normal eaters (13.57 ± 9.94).