Background: Negative mood symptoms remain one of the major reasons for discontinuation of oral contraceptive pills. The aim of this study was to compare acoustic startle response and prepulse inhibition (PPI) in women with different experience of oral contraceptive pills.
Methods: Thirty women currently on combined oral contraceptives (COCs) with no reports of adverse mood symptoms, 28 women currently on COCs and experiencing mood-related side effects from treatment, 27 women who had discontinued COC use for reasons other than adverse mood symptoms and 32 women who had discontinued COC use due to adverse mood effects were included. The eyeblink component of the acoustic startle reflex was assessed using electromyographic measurements of musculus Orbicularis Oculi. Twenty pulse-alone trials (115dB 40ms broad-band white noise) and 40 prepulse-pulse trials were presented. The prepulse stimuli consisted of a 115dB 40ms noise burst preceded at a 100ms interval by 20ms prepulses that were 72, 74, 78, or 86dB.
Results: Patients with adverse mood effects of COCs exhibited lower levels of PPI with 86dB prepulse compared to COC users with no adverse effects of COCs (p<0.05). There was no difference in PPI between the two groups of prior COC users. No significant difference was found between the groups regarding acoustic startle response.
Conclusion: Relative to COC users with no reports of adverse mood symptoms, subjects suffering from COC-induced negative mood displayed deficits in PPI of acoustic startle. The fact that there was no difference in PPI between the two groups of prior COC users indicates that deficient PPI is related to adverse mood effects caused by COCs.