Women with pre-existing mental health problems and those who start using oral contraceptives (OCs) at a young age are at increased risk of developing self-reported mood disorder while taking the contraceptive pill, a study shows.

The data comes from two Swedish studies involving a total of 302 women (mostly younger than 30) with past or current OC use, of whom 145 had experienced adverse mood symptoms while on OCs.

All participants underwent the Mini-International Neuropsychiatric Interview that assessed for mental illnesses, the authors wrote in BMJ Sexual & Reproductive Health.

Among women who reported adverse mood effects while taking OCs, 83% reported symptoms of depression, 72% complained of mood swings and 64% reported irritability, with nearly two thirds saying they had three or more of these and other mood symptoms.