Two studies were conducted to explore the cognitive effects of combination ethinyl estradiol and levonorgestrel contraceptive use during late adolescence and young adulthood. Three groups of females, naturally cycling, active pill phase, and hormone-free interval phase, were tested on a battery of estrogen-sensitive, i.e., place learning and word generation, and estrogen-insensitive, i.e., map drawing, mental rotation, digit span, story recall, and object recall, tasks. Study 2 was conducted as a means to replicate the findings observed in Study 1 and to manipulate task difficulty and sensitivity. Two measures of mood were administered, and salivary estradiol levels at time of testing were assayed. Findings from both studies do not suggest mood or endogenous estrogen effects on cognition. Additionally, findings from both studies suggest no cognitive effects of combination ethinyl estradiol and levonorgestrel conceptive use. The large sample size of Study 2, n = 65, indicates sufficient power to detect statistical differences. These studies do not provide evidence of either cognitive detrimental or beneficial effects of combined oral contraceptive use during either late adolescence or young adulthood. Post-hoc analyses with a nondepressed subsample, however, suggest potential sparing of estrogen-sensitive place learning by active pill phase females relative to hormone-free interval and naturally cycling females during periods of low endogenous estrogens
